####018006702#### FXUS62 KILM 161735 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 135 PM EDT Fri May 16 2025 .SYNOPSIS... Above normal temperatures near record highs are expected through Saturday. A weak cold front accompanied with isolated showers and storms will track across the area Saturday night. Mainly dry weather with above normal temps are then expected until a storm system likely affects the area toward the middle of next week bringing cooler temps and better rain chances. && .UPDATE... No significant changes to the forecast with the early afternoon update. Still not expecting much in the way of shower/storm activity later today but some high-res models do show a bit of convection, mainly north of a Lumberton to Elizabethtown to Burgaw line, so can't completely rule out an isolated damaging wind gust through early evening given plenty of shear, instability and downdraft CAPE. Record highs still look to be in play as well although high clouds could hamper heating a tad. && .NEAR TERM /THROUGH TONIGHT/... Somewhat deep west to northwest (early) flow will remain in place across the area today. Near record to record highs are expected for afternoon highs with only Florence (95 forecast...record 93) at least at this point explicitly in record territory. The next candidate to break a record is Lumberton (94 forecast...record 96) as the coastal areas may see a race between the resultant sea breeze which will be decent as the westerly flow isn't the strongest I have seen and the warmth. For tonight into Saturday morning expect warm and dry conditions to continue with lows in the lower to perhaps only middle 70s. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Breezy conditions slated for Sat as a sfc trof across the central Carolinas gets displaced by a sfc cold front driving ESE. This aided by an upper low over the Great Lakes and associated upper trof axis extending south of it, all pushing to the East. By Sun daybreak the upper low will be over the NE States with its trof axis extending south across the area. This will help drive a cold front across the FA likely sat aftn and night. It'll likely stall just south of the FA as it becomes aligned parallel with the flow aloft. Models do scour a good chunk of moisture after crossing the Appalachians leaving mainly clouds associated with its passage. Eventhough POPS will be 20% at best, the isolated convection that does develop will immediately have the potential to go severe given the avbl instability and shear. Max temps in the 90s Sat will have the potential to reach record levels across a few of our climatic sites. Later Sun thru Sun night, building upper ridge axis along the MIssissippi River Valley and the upper trof axis off the SE STates Coast will result in NW flow aloft. Could see an embedded vort within this NW flow push across the FA Sun aftn resulting in a possibility of raising POPs across the FA. Not entirely bought on this given previous model runs kept it south of the FA. Sun max temps a few degrees cooler than Sat maxes. && .LONG TERM /MONDAY THROUGH THURSDAY/... The FA will be more under the influence of the upper ridging across the Central U.S. with the upper trof axis remaining well offshore from the FA. NW flow aloft will continue Mon thru Tue with yet another embedded vort s/w trof that possibly drops across the FA within NW flow. Once again, confidence remains low given the back and forth progged movement/strength of this feature. Nevertheless, a reflection of it will be the cloudiness being invoked into the fcst. Late Tue into Wed the upper ridge axis pushes off the SE States Coast followed by a sharpening/amplifying upper trof across the Eastern 1/3rd of the U.S. This has been advertised by models, however the remain wishy-washy with any Pop threat. At this point will cap Pops in the low to possibly modest chance during the mid-week period. Temps this period will start above normal then drop back to near or below normal depending how much of that Canadian airmass infiltrates the FA. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... High confidence in VFR conditions through 18Z Sat. There is a very low risk of MVFR cigs at KLBT/KFLO late tonight and Sat morning as a shortwave approaches. Extended Outlook...Mainly VFR conditions are expected through the period. && .MARINE... Through Tonight...Southwest winds which have probably reached their peak just north of 15 knots will continue today in a range of 10-15 knots. Speeds will diminish slightly tonight before the low level jetting once again sees an uptick. Significant seas will see a narrow range of 3-4 feet today dropping in a subtle nature to 2-4 feet later tonight into Saturday AM. Saturday through Tuesday Night...Tightened sfc pg will be ongoing to start Sat off. Inland sfc trof will be replaced by a SE-ward dropping cold front Sat aftn. This front should push off the mainland and thru the local waters mainly Sat night. Could see tstorm activity spring up after pushing off the coasts, as it interacts with the Gulf Stream. Winds Sat into Sat night will flirt with SCA 25+ kt wind gusts. The sfc pg will relax after FROPA and remain-so thru Mon night, resulting in reduced wind speeds to aob 10 kt. Wind directions will be the problem child during this period. By Tue, some organization of the pressure field as well as some tightening of the gradient. Seas start at 2-4 ft with 5 footers possible. Mainly looking at wind driven waves at 5 or less second periods becoming dominant with an underlying small but identifiable SE swell at 8+ second periods. && .CLIMATE... High temperature records may be challenged Friday and Saturday as anomalously warm air overspreads the region ahead of a cold front. Record highs for our four climate sites are as follows: For Friday, May 16th... Wilmington, NC: 94F (1915) Lumberton, NC: 96F (1962, 1941) Florence, SC: 93F (2022) N. Myrtle Beach, SC: 91F (1941) Saturday, May 17th... Wilmington, NC: 92F (1960, 1990) Lumberton, NC: 96F (1941) Florence, SC: 93F (1977) N. Myrtle Beach, SC: 92F (1941) && .ILM WATCHES/WARNINGS/ADVISORIES... NC...None. SC...None. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...RJB NEAR TERM...SHK SHORT TERM...DCH LONG TERM...DCH AVIATION...RJB MARINE...DCH/SHK CLIMATE... ####018008766#### FXUS63 KILX 161735 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 1235 PM CDT Fri May 16 2025 .KEY MESSAGES... - There is a slight risk of severe storms east of the IL river from mid afternoon into mid evening. There is a level 3 of 5 (enhanced) risk for severe storms south of I-72, and a level 4 of 5 (moderate) risk south of I-70. All severe hazards are in play. - Southwest winds gusting 35-45 mph this afternoon will combine with relative humidity values below 30% north of I-72 to result in increased fire danger. These winds will also result in a risk for localized blowing dust, which could briefly diminish visibility for motorists. && .UPDATE... Issued at 938 AM CDT Fri May 16 2025 WPC surface analysis depicts an unseasonably strong (981mb) surface low centered across west-central MN, beneath an expansive upper level trough apparent on water vapor satellite. As that upper low meanders towards the east-southeast today, it will phase with a southern stream shortwave lifting out of the Plains. The arrival of this southern stream energy across a dryline this afternoon should foster convective development across a portion of central/southeast IL, though the northward extent of storms remains unclear due to uncertainty in moisture return with surface dewpoints in the mid 40s to mid 50s north of I-72 this morning. Nonetheless, giving the seasonably strong forcing and weak capping, the CAMs' depiction of intense convection capable of all severe hazards remains on track; in addition, the past several hourly iterations of the HRRR advertise pockets of hurricane force (74+ mph) wind gusts which seems like a distinct possibility given all the dry air in place (the entrainment of dry air results in evaporational cooling and strong negative bouyancy in thunderstorms). We'll continue to keep our peepers on model trends, and especially the suite of surface observations and mesoanalysis data to assess the potential going into early afternoon. As it stands, the timeframe of greatest concern remains 2-9pm, with areas near I-55 and east at the highest risk (though areas as far west as the IL River could be impacted). Bumgardner && .DISCUSSION... Issued at 345 AM CDT Fri May 16 2025 SPC Day1 outlook continues an enhanced to moderate risk risk of severe storms south of I-72 from mid afternoon to mid evening, with the moderate risk south of I-70. This area has a 30-45% chance of damaging wind gusts within 25 miles of a point, with 10% or greater probability of wind gusts 75 mph (hurricane force) or higher within 25 miles of a point. Areas south of I-70 have a 10-15% chance of tornadoes within 25 miles of a point with a 10% or greater probability of EF2 or stronger tornadoes within 25 miles of a point. The slight risk of severe storms extends as far nw as just east of the IL river, and areas east of the IL river had a 10% or greater probability of 2 inch or larger hail within 25 miles of a point. SPC issued a Public Severe Weather Outlook (PWO) to address the moderate risk area over southern parts of IL/IN into east central and southeast MO and central and western KY. ILX will be doing a special 18Z sounding today in support of this severe wx risk. Please stay weather aware today especially if you are east of the IL river. Convection had shifted into far southern IL/IN and into southeast MO tied to a more active frontal boundary early this morning while nearly clear skies prevailed over central IL CWA. A strong 981 mb low pressure was over far west central MN and weaker 1000 mb low in central KS. Temps at 330 am were in the low to mid 60s over central IL and upper 60s to near 70F in southeast IL. Much drier air had moved into central IL with dewpoints ranging from the 45-50F nw of the IL river, to the mid 60s from Paris, to Mattoon to Effingham southeast. A negative tilted mid level trough to move into the mid/upper MS river valley late today with strong surface low tracking eastward across central MN and pressure gradient to tighten over central IL. This will increase SSW winds back to breezy levels during mid/late morning with wind gusts of 35-45 mph north of I-70 this afternoon and winds turn WSW to SW. DESI HREF had 20-40% chance of wind gusts of 45 mph or higher from I-72 north this afternoon. Strong instability lifts back north into portions of central and southeast IL during this afternoon with MLCAPES rising to 2000-3700 j/kg east of the IL river by 21Z/4 pm, highest in southeast IL where 0-6km bulk shear values are 50-70 kts. The 0-3 km helicity is forecast to reach 200-250 m2/s2 by late afternoon and supports supercells and tornadoes especially in southeast IL. Convection to start develop along and east of the IL river during mid afternoon and become more widespread and strong as it shifts into eastern/se IL during late afternoon and early evening with passage of cold front. Most of convection should be east of CWA by sunset. Warm highs today in the mid to upper 80s though should be a bit shy of record highs in the lower 90s. Breezy westerly winds prevail tonight and Saturday with gusts 25-30 mph as large low pressure system moves east of Lake Huron. Mostly sunny Saturday with cooler highs in the low to mid 70s. Light wind on Sunday with increasing clouds from the sw by Sunday afternoon and have slight chance of showers sw CWA later Sunday. Seasonable highs Sunday in the mid to upper 70s. More active weather pattern returns during next week, with chances of showers and some thunderstorms Sunday night and Monday, and higher chances of convection and heavier rainfall Monday night through Tue evening per blended forecast. Though models still differ with evolution of storm systems translating eastward through the MO, mid MS and Ohio river valleys during Mon through Wed frame. Highs in the low to mid 70s Monday to cool into the low to mid 60s Wed and mid to upper 60s Thu. Seasonably cool lows Wed and Thu nights in the mid to upper 40s. 07 && .AVIATION... (For the 18z TAFs through 18z Saturday Afternoon) Issued at 1232 PM CDT Fri May 16 2025 Between an unseasonably deep low pressure system across the Upper Midwest and a surface high to our east, the pressure gradient has tightened across central IL favoring stiff south to southwest winds which will gust 25 to 35 kt (sporadically higher) through the evening. Meanwhile, a shortwave disturbance lifting out of the Central Plains will spark storms somewhere across the area, with the highest confidence in storms at DEC and CMI and less certainly further northwest. These storms will be capable of generating localized large hail and wind gusts over 50 kt, as well as briefly diminished visibility. Behind a cold front, winds will shift to westerly this evening and remain gusty through the early portion of the overnight period. Lower ceilings will filter in from the north towards sunrise/11z, with HREF giving a 40-60% for MVFR at PIA and BMI for several hours during the early to mid morning. Winds pick back up a bit around 15-16z as diurnal heating deepens mixing. Bumgardner && .FIRE WEATHER... Issued at 315 AM CDT Fri May 16 2025 The latest RAP and HRRR models continue to show dewpoints dropping sufficiently to bring RH values into the 20-30% range north of I-72 late morning and afternoon. Combining this with south to southwest winds gusting 35-45 mph this afternoon and shifting west to southwest will increase the risk for erratic fire behavior, so we recommend limiting or at least using extra precautions with any burning activities during the late morning into early evening. A special weather statement was issued for areas from I-72 northward to address the enhanced fire danger today. Bumgardner/Huettl && .CLIMATE... Issued at 300 AM CDT FRI May 16 2025 Peoria IL tied a record high of 93F on May 15th which was 1st set in 1894. The normal high temperature on this day is 74. Record temperatures for today May 16: && .CLIMATE... Issued at 300 AM CDT FRI May 16 2025 Peoria IL tied a record high of 93F on May 15th which was 1st set in 1894. The normal high temperature on this day is 74. Record temperatures for today May 16: && .ILX WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 11 PM CDT this evening for ILZ027>031-037- 038. && $$ ####018004625#### FXUS65 KFGZ 161733 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 1033 AM MST Fri May 16 2025 .SYNOPSIS...Seasonable temperatures and light winds forecast for today, before cooler and windier conditions return over the weekend. Slight chances for precipitation also expected Sunday and Monday. Warm and dry conditions look to return by the middle of next week. && .UPDATE...A nice quiet morning across northern and central Arizona with clear skies and warming temperatures. Expect generally light winds around 5-15 mph with gusts around 20-25 mph in spots. Only minor updates needed as the forecast looks right on track. && .PREV DISCUSSION /416 AM MST/...Today will look and feel very similar to yesterday, with daytime highs near average for this time of year and winds 5-15 mph out of the southwest. Are you tired of the windy weekends? Well...bad news...more gusty conditions are expected this weekend as a deep trough begins to descend from the Great Basin region. There has been some mixed opinions with model guidance on how this low pressure system will ultimately shake out, but there has been a clear and consistent signal that winds will increase out of the southwest Saturday and Sunday. Look for winds this weekend to be 15-25 mph, gusting 30-40 mph. The element where models are differing in their solutions is mostly the trajectory of this trough, which is impacting the potential for precipitation this weekend and early next week. Recent model runs are showing a slower on-set of the core of this low pressure system reaching Arizona, so showers now look to enter our CWA by late Saturday night/early Sunday morning, primarily across far northern AZ. We could see a second closed low push into the state on Monday, bringing showers as far south as the White Mountains. But there is still wavering confidence on how Monday will turn out in terms of precipitation. Taking into account the elevated winds and drier conditions for our southern/eastern zones, a Fire Weather Watch has been issued for the Little Colorado River Valley and White Mountains for Saturday afternoon. For Sunday afternoon, this Fire Weather Watch becomes limited to the Little Colorado River Valley in Apache County. Tuesday Onward...As the previously mentioned trough heads east, we'll start to see a quick return of warm/dry May weather. Daytime highs are forecast to reach 5-15 degrees above normal by the end of next week, with typical spring-like breezes each afternoon. && .AVIATION...Friday 16/18Z through Saturday 17/18Z...VFR conditions, though smoke could reduce visibility locally near and downwind of Greer (in eastern Arizona) and Blind fire (SE of KLFG). Winds becoming SW 5-15 kts with gusts to 20 kts through 02Z then becoming light and variable. Southwest winds begin to increase after 16Z. OUTLOOK...Saturday 17/18Z through Monday 19/18Z...VFR conditions prevailing, though smoke could reduce visibility near and downwind of wildfires. Isolated to scattered -SHRA and a slight chance of -TSRA after 06Z Sunday mainly north of I-40. Winds Saturday and Sunday afternoons SW 15-25 kts with gusts to 30-35 kts. Patchy blowing dust in northeast Arizona. Northwest winds 10-20kts developing after 16Z Monday. && .FIRE WEATHER...Today through Saturday...Dry conditions will continue with minimum RH values mostly below 15%. Southwest to west afternoon winds 10 to 20 mph today. Southwest winds increase on Saturday to 15-25 mph gusting 30-40 mph. Critical fire weather possible Saturday in the Little Colorado River Valley and White Mountains where a Fire Weather Watch is in effect. Sunday through Tuesday...Windy and cooler Sunday and Monday. A 20- 40% chance of showers north of I-40 Sunday and over most of northern Arizona Monday. Southwest winds 15-25 mph gusting 30-40 mph on Sunday, then west-northwest 10-20 mph on Monday. Critical fire weather possible Sunday in the eastern Little Colorado River Valley where a Fire Weather Watch is in effect. Warmer, less wind, and drier on Tuesday. && .FGZ WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Saturday morning through Saturday evening for AZZ112>114-117-140. Fire Weather Watch from Sunday morning through Sunday evening for AZZ114. && $$ PUBLIC...Meola/Konieczny AVIATION...MAS FIRE WEATHER...JJ For Northern Arizona weather information visit weather.gov/flagstaff ####018004864#### FXUS63 KLBF 161735 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 1235 PM CDT Fri May 16 2025 .KEY MESSAGES... - Very strong northwest wind gusts up to 60 mph are possible across north central Nebraska today allowing for a High Wind Warning to be put in place. - Cooler temperatures continue through early next week before returning to near normals. - Rain showers and thunderstorms return on Saturday night lasting through Tuesday with an increasing risk of severe storms especially on Sunday where there is a Slight Risk (level 2 of 5). && .SHORT TERM /THROUGH SATURDAY/... Issued at 358 AM CDT Fri May 16 2025 The main weather concern in the short term in the potential for very strong winds today as a cut-off low will continues to spin over the northern Plains. As the pressure gradient tightens around the western and southwestern edge today, surface winds will increase significantly. Latest models and soundings suggest northwest wind gusts in excess of 60 mph in some locations. Latest probabilities also hint at the the potential of seeing over 55 mph wind gusts over 50 percent. While some locations may not actually reach high wind criteria (gusts over 58 mph), there is still enough support to favor these stronger winds. Plus, with the continued favorability of these stronger winds over the past few days, could see them rising even a little bit from what is currently forecasted. After collaboration with surrounding offices, have opted to raise a High Wind Warning for much of north central Nebraska (basically northeast of a line from Merriman to Oconto). At this time there's no plans to extend the warning further to the southwest, but if winds continue to trend up, an extension further to the southwest may be needed. In addition to strong winds, this low will bring some light rain to areas north of Highway 2. Rain will move in from the north by 8am CT and spread southward through the morning and afternoon. Precipitation will exit the region by Friday evening giving way to clearing skies and dry conditions lasting through Saturday. Temperatures will remain cooler especially across the north through today as 850 mb temperatures in the 2 to 5 C range result in surface temperatures in the low to mid 50s. Further to the south forecasted temperatures will be slightly warmer in the 60s and low 70s where rain and clouds won't hinder temperatures. Clearing skies and some sun on Saturday will allow temperatures to range from the mid 60s in the north to the mid 70s south of I-80. Low temperatures will be quite chilly tonight as temperatures plummet into the mid to upper 30s for most locations. At this time, no frost/freeze headlines are anticipated, but this will be something to watch today. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Issued at 358 AM CDT Fri May 16 2025 Active weather returns on Saturday night lasting through next Tuesday as several rounds of disturbances impact the region. At this time the severe potential remains low for Saturday night, but is increasing for both Sunday and Monday evenings. A developing low and strong upper level trough will bring some better instability and forcing across the High Plains both Sunday and Monday. Hazards with these systems will mainly be large hail and strong winds, however, a tornado threat is also possible. Stay tuned to the latest forecasts for the most up to date information including timing details, updated threats, and locations of greatest impact. Weak upper level ridging returns by mid-week with dry conditions for most locations through next Thursday. Temperatures begin to drop through the first half of the extended as plenty of clouds and precipitation are expected through at least Tuesday. Expect highs to struggle to only rise into the 50s on Tuesday. Temperatures begin to rise once again to near normals (low to mid 70s) for the second half of the week as clouds mix out and more favorable weather conditions return. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1235 PM CDT Fri May 16 2025 MVFR ceilings continue across north central Nebraska including the KVTN terminal. Expecting an improvment to a VFR celing by 23Z. Very strong northwest winds 25 to 35 knots with gusts to around 45 knots can be expected at the KLBF and KVTN terminals this afternoon, with winds diminishing by 00Z/17th and during the evening. && .LBF WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 8 PM CDT /7 PM MDT/ this evening for NEZ005>010-025>029-038-094. && $$ SHORT TERM...Kulik LONG TERM...Kulik AVIATION...Roberg ####018005206#### FXUS63 KTOP 161736 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1236 PM CDT Fri May 16 2025 .KEY MESSAGES... - Warm temperatures through Monday, windy today across the area. - Severe storm chances focused on Sunday afternoon/evening and possibly Monday as well. All hazards possible at this time with a medium to high level of variability regarding exact areas for each day. - Cooler after the storm system rolls through beginning Tuesday with temperatures closer to normal. && .DISCUSSION... Issued at 337 AM CDT Fri May 16 2025 Currently, a strong area of low pressure is focused north of the area and slowly moving east across the northern Plains into the Upper MS Valley region. Pacific moisture is streaming into the Pacific Northwest region, while subtropical moisture plume is still evident from the central Pacific Ocean streaming across the Baja region into the southern Plains and across the deep south. The primary frontal system across the CONUS is situated southeast of the region into the southern MS Valley region into the eastern portions of the Mid MS Valley where it has become mostly stalled trailing further south into the southern Plains. Today, warm temperatures remain across the area with a secondary push of dry air moving into the region as the surface ridge expands southeast behind the primary low pressure regime north of the area. Have held off mention of a wind advisory across northern areas, but some could see a brief gust this afternoon that is near advisory limits. Not expecting long- lasting or widespread winds to justify a wind advisory at this time for northern areas. Just note that it will be windy this afternoon but then begin to calm into the evening hours. There are some returns west of the area on composite radar but would anticipate anything to be virga moving across the area mainly this morning which could also provide a brief strong wind gust to areas that see any virga move overhead. Warm and mostly sunny through Saturday. Any rain should hold off into Sunday morning time frame. The questions begin around this time as well. First, how much rain develops ahead of the primary trough deepening across the western CONUS and when does the lead shortwave come into play across the area. If the isentropic ascent is strong enough, expecting that Sunday morning will have periods of showers and embedded storms that wouldn't likely be severe. How long these linger into the day will ultimately be a primary factor in how far north the warm front advances and how quickly the atmosphere recovers for severe weather potential into the afternoon Sunday. There still appears to be a medium to high degree of variability amongst the various models on how far north and how fast the warm sector surges into the afternoon and evening. Nonetheless, it does appear that right now, much of the area should eventually see potential for severe storm development off the dryline over central Kansas areas and then also possibly along the warm front as it lifts north. GFS and SREF still showing a surge north through the afternoon of the warm sector with the NAM, ECMWF and Canadian more slowly lifting deeper instability north. Most favored areas for severe potential on Sunday at this time appear to be generally along I-70 and south with a gradual spread north into the early evening for severe potential. Sufficient instability and orthogonal shear vectors off the dryline should allow for all hazards to remain possible with mostly discrete supercells favored as it would appear right now. So, those with Sunday plans will need to remain weather aware for sure and be ready to adjust indoor vs outdoor plans. Into Monday, the main trough is still looking slow to move east out of the central Rockies. This could keep the area under the gun once again through Monday for severe potential. At least eastern areas may see a more favorable setup depending on how far east the dryline will advance into the afternoon. But, some models still indicating that much of the area could still see storm potential with the warm sector still across the bulk of the area. Showers and storms could linger into Tuesday until the main trough finally moves across the area and exits the region. Not anticipating that Tuesday would see severe storms at this time. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1234 PM CDT Fri May 16 2025 Main aviation hazard over the course of the TAF will be gusty winds this afternoon. Expect northwest winds gusting upwards of 30-35 mph this afternoon with sustained winds around 20 mph. Winds should begin to fall below 10 mph after sunset this evening with some mid and high clouds filtering over the area. Winds should not shift too much through the remainder of the period, staying around or below 10 mph. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Drake AVIATION...Griesemer ####018004718#### FXUS63 KIWX 161736 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 136 PM EDT Fri May 16 2025 .KEY MESSAGES... - Severe thunderstorms are possible from 6-11pm EDT this evening. The greatest risk will be in the southern half of our area. - Damaging straight-line winds will be the primary threat but hail and tornadoes cannot be ruled out. - Dry weather returns for the weekend with highs in the 60s to low 70s. && .DISCUSSION... Issued at 352 AM EDT Fri May 16 2025 Round 1 of severe wx has ended and we now prepare for a potential round 2 later today. Deep upper low will continue to pinwheel over the Upper Midwest with a second embedded shortwave swinging through our area later today, pulling the upper low further ESE and pushing a surface occluded/cold front through the area. This front passes during the favorable time for severe weather (early evening) but the instability picture is much more muddled today. Cold midlevel temps will support decent midlevel lapse rates but surface dewpoints will only be around 60F at best. This keeps SBCAPE values generally at or below 2000 J/kg. There will be a stout capping inversion for much of the day but that does look to break with the passing front roughly 23-03Z. Wind/shear profiles are obviously highly favorable for organized storms if sustained updrafts manage to develop. With the passing front and at least moderate instability there seems like a decent chance for that to happen. Multicell lines/clusters will likely be the primary mode given linear forcing with damaging straight-line winds the primary hazard given 50+ kts of flow not too far from the surface. There is also a secondary hail and tornado risk though. Hail will be somewhat limited by more modest instability but there is likely enough for some 1"+ hail given cold midlevel temps. And while surface winds are not as backed as one would like to see for a tornado risk, the degree of 0-1km shear can't be ignored. 0-3km line-normal shear vectors should also easily exceed 30 kts and will present a QLCS tornado risk (if other storm- scale criteria are met). Our entire CWA will have some chance of severe weather this evening but the best chances appear in our southern half. Potential failure points include more limited instability and later/weaker forcing which would likely lead to a more isolated threat given the lack of a solid/organized convective line. More organized activity south of our area may also limit the threat this far north. Given highly active short-term and relatively quiet weather over the weekend into early next week, did not make any changes to the NBM initialization. Upper low continues to pinwheel east on Sat with just a low chance of a few sprinkles in our N/NE zones. Sunday will be dry and pleasant with cool temps, mostly sunny skies, and low humidity. Precip chances do return to the area late Mon into Wed as another upper low approaches the region. Still some uncertainty with the track of this low but most guidance keeps us on the cooler/more stable side with decent rain chances but a low severe risk at this time. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 127 PM EDT Fri May 16 2025 An upper level speed max lifting across downstream portion of upper trough and an accompanying upper level short wave will help to advect some increased low level moisture northward late this afternoon/early this evening. Sfc dew points have mixed out nicely early this afternoon into the upper 40s to lower 50s. The challenging part of this convective forecast is trying to assess extent of moisture return in advance of this short wave tonight and how much destabilization can occur. Strengthening low/mid level wind fields and initial dry profiles do suggest potential of some strong winds with any storms (or showers). Have not made substantial changes to previous timing of main potential threat in the 00Z-03Z window for thunder. Otherwise, southerly gusts to 20 to 25 knots will be maintained in advance of the associated cold front this evening, with post-frontal west winds gusting to 30 to 35 knots by Saturday afternoon. Conditions should remain primarily VFR this period with the exception of any stronger showers and storms. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...Small Craft Advisory from 5 PM this afternoon to 5 PM EDT Saturday for LMZ043-046. && $$ DISCUSSION...AGD AVIATION...Marsili ####018006550#### FXUS63 KAPX 161736 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 136 PM EDT Fri May 16 2025 .KEY MESSAGES... - Warm, dry, and somewhat windy conditions results in elevated wildfire danger today. - Another round of showers and embedded thunderstorms tonight. - Cool weather and cloudy skies return this weekend. High pressure continues quiet weather through the midweek. && .UPDATE... Issued at 933 AM EDT Fri May 16 2025 Inherited forecast remains on track at this juncture. Cyclonic dry slotting firmly in place, with just a few lingering low clouds over the Sault and Kinross courtesy of last night's line of convection. Expecting sunny skies to be the rule throughout much of the day with breezy southwest winds (a few 25+ mph gusts seem a fair bet, especially near Lake Michigan) promoting excellent mixing throughout the day. Dewpoints will lower, and with highs topping out in the 70s and 80s (perhaps upper 80s in those downsloping locales such as TVC, APN, PZQ), that will lead to low RHs that will contribute to elevated fire danger, with last night's rainfall being the only thing that really stands in the way of a full blown Red Flag Warning across the region. Looking upstream, convection is materializing across southeast Nebraska and southwest Iowa as a wave riding the secondary cold front attached to the main surface low over Minnesota marches eastward. Clouds set to increase from the southwest later today as this feature approaches, with perhaps a shower building on the immediate Lake Michigan shoreline late this afternoon, with better shower and thunder potential increasing through the evening into early tonight. For more details, please see the attached short term forecast. && .SHORT TERM /THROUGH TONIGHT/... Issued at 321 AM EDT Fri May 16 2025 Pattern Synopsis/Forecast: Occluded front, tied to deep low pressure spinning across the northern Plains, sweeping rapidly east across the area early this morning. Band of decaying showers and embedded thunderstorms along and just ahead of this front, with aggressive dry slot punching in just behind it. Front will exit stage right early this morning as dry slot overspreads the entirety of northern Michigan today. Upstream low pressure and secondary cold front make a run at our area tonight, drumming up another round of showers and perhaps some embedded thunderstorms in the process. Primary Forecast Concerns: Temperature/wind/relative humidity trends today (focus on fire weather concerns) and showers and thunderstorm evolution tonight. Details: Dry slot today is impressive, resulting in mostly sunny skies...with just some increasing clouds later this afternoon into the evening. Good vertical mixing with those clear skies, helping drive some decent southwest winds and warm temperatures across the region. Expecting highs well up into the 80s across interior northern lower Michigan, with reading just a smidge cooler for areas north of the big bridge and near those big waters. That mixing will also help plummet relative humidity rather aggressively by this afternoon. Combine that with those warm temperatures and gusty southwest winds and the stage is set for elevated wildfire concerns this afternoon. Will address that issues in our hazardous weather products/graphics and fire weather products. Slug of deeper moisture arrives tonight ahead of that secondary cold front and vort max wrapping around parent upstream low pressure. Expect scattered to numerous showers to spread back overhead quickly this evening. A few embedded thunderstorms also expected. Cannot completely rule out an isolated severe storm or two given relatively steep mid level lapse rates and modest shear through the convective column. Marginally severe wind gusts and hail would be the primary concerns with any more organized updraft. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 321 AM EDT Fri May 16 2025 Pattern Synopsis/Forecast: Midlevel closed low pressure at the base of a shortwave trough will be centered over the Upper Great Lakes at the start of the long term. Chances of precipitation begin to dissipate as midlevel heights rise and push subsidence across the northwoods through Tuesday. A few scattered showers will linger across parts of Michigan through Saturday as the surface level low begins to dissipate and slowly move towards the northeast. Besides the on and off showers, biggest noticing feature will be the temperatures falling well below normal for mid May. Highs this Saturday and Sunday will remain in the upper 50s to low 60s as cold air pulls in from the north. Cloudy skies and showers will give more of a early spring or even a fall feeling, but temperatures will slowly build into the 60s and even low 70s by midweek. At the same time; troughing currently over the Pacific Northwest will work its way eastward, reaching the Great Lakes region returns chances of precip around the Wednesday/Thursday timeframe. Ensemble guidance depicts this system weakening with time and lingering across the region through the rest of the week. Light- scattered showers will continue this pattern of dreary weather to close out the forecast period. Poor organization and a lack of deep atmospheric moisture will keep rain amounts low and any risk of severe weather at a minimum. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 136 PM EDT Fri May 16 2025 VFR CIGs will be the rule through the afternoon amid a breezy SW flow gusting to 25kts at times, especially for MBL, TVC, and MBL. Cold front approaches this evening, bringing the development of showers and thunderstorms after 00z, with potential for another night of CBs. Some of these storms may produce gusty winds with their passage. This should clear from west to east around or just after 06z, perhaps a little later for CIU and APN. Winds turn more westerly Saturday with MVFR to IFR CIGs at times as cooler air and showery weather prevail. && .APX WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 2 AM EDT Sunday for LMZ323-341-342- 344>346. && $$ UPDATE...HAD SHORT TERM...MSB LONG TERM...SJC AVIATION...HAD ####018010231#### FXUS62 KMHX 161737 AFDMHX Area Forecast Discussion National Weather Service Newport/Morehead City NC 137 PM EDT Fri May 16 2025 .SYNOPSIS... Inland troughing is expected today, followed by a cold front passage on Saturday. High pressure then builds in late in the weekend and into early next week. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... As of 1015 AM Friday... KEY MESSAGES - Another conditional risk of severe weather late today - Humid with above normal heat today Previous shift's forecast remains in good shape for now. It should be noted that some new machine learning guidance (namely the 06z NCAR NN HRRR) has shown a noticeable uptick in probability of some severe weather impacting areas north of Highway 264 (50-60% chance, up from 30-40%), zoning in on an MCS crossing the Appalachians and riding the ridge along the NC/VA state line. 12z CAMs and guidance will hopefully offer more confidence in this potential solution. Prev disc...Yesterday's severe thunderstorms formed on the periphery of a stout mid/upper level ridge that has been anchored over the Southeast U.S. of late. That ridge is forecast to build a bit further north today, with an even stronger cap expected compared to yesterday. Meanwhile, heating of a moist boundary layer beneath a stout EML plume will once again support an area of moderate to strong instability over ENC, with MLCAPE reaching, or exceeding, 3000j/kg. The majority of deterministic guidance suggests a moderate to strong cap will remain in place through the day, which would be a significant limiting factor for sustained deep convection. Not all guidance shows this, though. Adding to the limitations is the mid/upper ridging near the region, providing an area of large-scale subsidence. The effect of ridging may be short-lived, though, as guidance suggests the ridge will flatten late in the day as an upper trough pivots east across the Ohio Valley. What appears likely is that there will be several clusters of severe thunderstorms well upstream associated with the upper trough. Guidance differs on the evolution of these clusters of storms, but upscale growth, and the upper pattern, favors one, or more, MCS' translating east from the OH/TN Valleys to the Mid- Atlantic/Carolinas. This convection will encounter the strong cap mentioned above, making it unclear whether or not convection can survive all the way to ENC. Should sufficient erosion of the cap occur, as some guidance suggests, there would be sufficient shear and instability to support MCS maintenance and an attendant risk of damaging winds. Some hail could occur as well, but wind appears to be the primary risk. Stay tuned for updates through the day on this potential. For now, we'll continue to hold with a low chance of thunderstorms focused north of HWY 70. This is also where the cap may be the "weakest", and where the greatest risk of severe weather would be focused. Otherwise, moderate to strong heating, plus warming thicknesses beneath the ridge, should support highs reaching the 90s inland, and 80s along the coast. With dewpoints in the 60s and 70s, this should allow the "feels like" temperature to reach the mid to upper 90s for much of the area. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 AM SATURDAY/... As of 200 AM Friday... KEY MESSAGES - Conditional severe thunderstorm risk may linger into tonight The mid/upper level ridge over the region will continue to get flattened tonight as an upper trough shifts east from the OH Valley to the Northern Mid-Atlantic. Guidance suggests multiple MCS' may be ongoing upstream of ENC, and the environment may support some continuation of this activity into the eastern Carolinas with an associated risk of gusty to damaging winds. Given the expectation of a strong cap in place, any MCS may tend to weaken with time as it approaches the area, but stay tuned for updates on this potential. && .LONG TERM /SATURDAY THROUGH THURSDAY/... As of 0430 Friday...A series of weak cold fronts pushes through the area this weekend with a more significant system to impact the area late next week. Weekend...Upper low over Great Lakes drifts Eward toward New England coast with ridging over the Gulf remaining in place. Hot again on Saturday in downsloping flow, pushing highs into the lower or mid 90s with dew points still in the upper 60s leading to heat indices in the mid 90s. Line of showers and storms associated with the front approaching from the from the W forecast to dissipate before crossing over I95. However, guidance shows the clearing early Saturday will allow ample time for destabilization thanks to strong warm up. Continue to carry SChc- Chc showers/tstorms when the prefrontal trough environment begins to interact with the the seabreeze in the afternoon and early evening hours. SBCAPE on the order of 2-3kJ/kg with bulk shear>40-50kt shows potential for tstorm organization that could lead to damaging wind gusts and large hail should cells be able to flourish. The front is forecast to slowly sink S of the FA through Sunday before stalling over the region. Next week...Quiet and relatively cool compared to the weekend earlyweek with downsloping NWerly flow aloft between the departing low and shortwave ridging briefly amplifying over SECONUS. The next vertically stacked low to dig toward the Carolinas midweek upping cloudiness and rain chances again through the end of the week. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /through 12z Saturday/... As of 130 PM Friday... KEY MESSAGES - Low confidence TSRA risk over the next 24 hrs Mid to upper level ridging will be nosing into the area today, with some subsidence and a fairly stout cap. It will be sufficiently unstable for TSRA, but ridging and the cap calls into question whether or not TSRA will impact ENC over the next 24 hrs. Guidance hints at two chances for thunderstorms, with one this evening into the early overnight hours and the second near dawn tomorrow morning. Large uncertainty still exists within the models regarding TSRA occurrence, so have opted to keep a VFR TAF for all terminals with an added PROB30 group. The focus through tomorrow morning will be TSRA well upstream across the TN and OH Valleys. Some guidance suggests this activity will survive the trek across the Appalachians and the piedmont of the Carolinas, eventually reaching ENC late this afternoon or tonight. Should this scenario play out, the environment appears supportive of strong wind gusts of 30-50kt+ and sub-VFR conditions. Some guidance also indicates some potential for TSRA around dawn tomorrow morning, but both periods remain uncertain. Stay tuned for updates in case confidence were to increase regarding the TSRA potential. Outside of the TSRA potential, the risk of LLWS impacts after 06z tonight (associated with a modest southwesterly low-level jet) has decreased some. Thus, have removed LLWS mention from TAFs; however, some potential still remains. This will continue to be monitored. LONG TERM /Saturday through Tuesday/... As of 0400 Friday...Series of weak cold fronts push through the FA this weekend bringing chances of showers and tstorms which represent subVFR potential. && .MARINE... SHORT TERM /through tonight/... As of 130 AM Friday... KEY MESSAGES - Breezy winds and elevated seas to continue through tonight - The thunderstorm risk appears generally lower through tonight A modest pressure gradient across the area this morning will tighten later today through tonight, supporting a continuation of modest southwesterly flow (10-20kt) across area waters. For the coastal waters, this will keep seas elevated (3-5 ft). In general, the thunderstorm risk appears much lower today compared to yesterday. That said, at least some guidance suggests a cluster of thunderstorms may impact the central and northern waters later today through this evening. Should this occur, there would be an increased risk of 30-50kt+ wind gusts. LONG TERM /Saturday through Tuesday/... As of 0430 Friday...SCA issued for Saturday afternoon-Sunday morning. Boating conditions deteriorate Saturday ahead of the next cold front to cross area waters leading to SCA conditions in SWerly 15-25G30kt winds SAT afternoon and evening. Secondary backdoor front sinks S across waters late Sunday. High pressure builds in with Nerly surge late SUN night/MON AM. Generally 10-15kt winds slowly through early week N-NEerly Tuesday becoming Eerly Wednesday as offshore high departs SEward and next low approaches from the W. && .CLIMATE... Record High temps for May 16th, Friday. LOCATION TEMP/YEAR New Bern 95/1933 (KEWN ASOS) Cape Hatteras 84/1994 and 1991 (KHSE ASOS) Greenville 94/1962 (COOP - Not KPGV AWOS) Morehead City 89/1995 (COOP - Not KMRH ASOS) Kinston 96/1941 (COOP - Not KISO AWOS) Jacksonville 91/1998 (NCA ASOS) Record High temps for May 17th, Saturday. LOCATION TEMP/YEAR New Bern 95/1941 (KEWN ASOS) Cape Hatteras 86/1991 (KHSE ASOS) Greenville 95/1915 (COOP - Not KPGV AWOS) Morehead City 85/1991 (COOP - Not KMRH ASOS) Kinston 96/1941 (COOP - Not KISO AWOS) Jacksonville 93/1990 (NCA ASOS) && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory from noon to 11 PM EDT Saturday for AMZ135. Small Craft Advisory from 11 AM Saturday to 2 AM EDT Sunday for AMZ152-154-156-158. && $$ SYNOPSIS...MHX NEAR TERM...RM/MS SHORT TERM...RM LONG TERM...CEB AVIATION...RM/CEB/ZC MARINE...RM/CEB CLIMATE...MHX ####018006933#### FXUS61 KPBZ 161737 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 137 PM EDT Fri May 16 2025 .SYNOPSIS... There is potential for strong to severe storms today and tonight as a cold front approaches. Drier and cooler conditions return Sunday through early next week. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: - Convoluted environment today will maintain low-moderate confidence in the presence of storms, but a higher confidence in severe potential given initiation. - A decaying MCS in possible tonight somewhere in the Appalachians, but confidence in location is low. ------------------------------------------------------------------- The lack of overnight storms south of I-80 completely changes the severe forecast for today. Given CAM guidance before 12Z showed a worked over environment across the area, it poorly represents current conditions. So the forecast will heavily rely on initialization at and after 12Z. Given a look at the current wind field and satellite, there is some indication of a convergence zone in to low levels settling in across southwest PA, eastern OH, and the northern WV panhandle. In addition, there is a residual outflow boundary from overnight convection in the I-80 corridor. If an area was favored for convection, it would be along an east-west axis passing near the Pittsburgh area. Looking at the 12 sounding showing ~1400 MLCAPE and ~900 DCAPE, the atmosphere would be primed for severe convection, particularly if updrafts drive into and wet-bulb the 6km to 12km later. There intense updrafts in a high DCAPE environment would have a primary risk of damaging winds and hail. There is a chance the DCAPE is lower later in the day, though this would rely on upstream convection to contaminate the environment, which is still of moderate uncertainty. After initiation, would would expect the primary storm motion to be to the northeast as outflow combined with synoptic wind. If there is an area to watch for flooding, it would be on the south side of convection, where outflow would be fighting the synoptic wind field, resulting in training. Uncertainty snowballs tonight as convection will rely on two factors: 1) Where and if the environment has been tainted by daytime convection. 2) Where storms fire upstream during the day today. If todays storms put do an outflow, it is very likely overnight convection stays south of it. This boundary will be important in distinguishing the threat as scenarios range everywhere from no outflow to outflow far south of the area. The farther north and/or a lack of an outflow means higher severe chances tonight. Second, there is initiation today. The farther north storms in the northern Ohio Valley initiate today, the higher the chance our region is impacted by a progressive, decaying MCS. With both of these factors together, the best chances of severe tonight increases the farther south of Pittsburgh you go. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... KEY MESSAGES: - A cold front crosses the area, ending thunderstorm activity and ushering cooler and drier weather into the region. ---------------------------------------------------------------- Showers and storms depart the area to the east on Saturday as a cold front sweeps through the area, ushering in cooler and drier weather under deep-layer northwesterly flow. Showers could linger in the ridges through Saturday evening with weak upslope occurring in the wake of the front, but by overnight hours that activity too should wane, with temperatures then dropping into the low to mid 50s by early Sunday morning. && .LONG TERM /SUNDAY THROUGH THURSDAY/... KEY MESSAGES: - Cooler and drier pattern returns Sunday through Tuesday. - Precipitation chances return Tuesday into Wednesday with another low pressure system - Potential for heavy rain mid-week that warrants monitoring ------------------------------------------------------------------- Models have been consistent that troughing over the Great Lakes and northeast CONUS will maintain northwest flow over the local area Sunday into Monday, keeping temperatures seasonable and the weather dry through that time. Probability of precipitation increases again late Tuesday into Wednesday with a new low ejecting out of the Rockies and tracking east across the Plains. A few model scenarios note a stationary boundary straddling south of Pittsburgh with this passing low. If that scenario plays out, heavy rain could pose a threat for portions of the region around mid-week. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... A tough and uncertain forecast lies ahead. At this time it looks likely that much of the TAF period can be VFR. The possible interruptions to this are two separate periods of thunderstorms: one this afternoon and another during the overnight hours. Latest satellite shows a broad expanse of cirrus overspreading the region originating from convection to our south. This cirrus will act to limit heating across the southern portion of our region and could mitigate some risk to see thunderstorms fire near MGW/ZZV/HLG. Farther north along a BVI/IDI line there remains a boundary left over from last nights convection, which will likely be the focus for afternoon convection. This boundary has shuffled southward through the day and poses a low threat to allow thunderstorms near PIT/AGC/LBE, this has been included as a PROB30 through the afternoon. BVI/FKL/DUJ have a slightly higher chance to see thunderstorms this afternoon. Any of these storms can bring gusty winds, and briefly lower VIS and CIG. Storms overnight remain more uncertain as the complex that they are associated with has not yet formed in the MO/IL region. This complex is expected to move NE'ward towards us but models diverge on the exact track as some favor a dive southward along the CAPE gradient and some favor somewhat of a split where storms miss much of our region. At this time I have moved our TEMPO groups back to PROB30 for the overnight period with growing uncertainty in track. A period of MVFR showers may trail behind any MCS-like system tonight. Outlook... Patchy restrictions in scattered showers are expected Saturday and Saturday night under a crossing upper trough. VFR returns Monday under high pressure. Restriction and rain potential returns with a Tuesday warm front. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Cermak/Hefferan NEAR TERM...Milcarek SHORT TERM...Cermak LONG TERM...Cermak/Hefferan AVIATION...AK/WM ####018007556#### FXUS66 KPDT 161738 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1038 AM PDT Fri May 16 2025 .Updated for Aviation... .AVIATION... 18Z TAFS...VFR conditions are expected through the day today and into tonight. By early Saturday morning, there could be some MVFR conditions at BDN/RDM as SHRA begins to move in. Otherwise SHRA will impact all sites through the period except for PSC, ALW where the best chances of SHRA will occur after 17/18Z. Winds will generally be 10 kts or less except at PDT, where winds will gust around 20 kts this afternoon and DLS who could see some gusts in the 15 to 20 kt range as well and possibly higher. && .PREV DISCUSSION... /issued 309 AM PDT Fri May 16 2025/ SHORT TERM...Today through Sunday...Satellite imagery tonight shows a weak shortwave pushing light rain showers across the intermountain PacNW, with skies gradually clearing across the western third of the forecast area. The shortwave will exit the region later this morning, with the bulk of shower activity diminishing area-wide. Light orographic showers will continue across the Cascades, Blues, and Wallowas through this afternoon as a northwest flow aloft develops behind the shortwave exit. By this evening, a brief dry period will develop as flow aloft turns more zonal, then to the southwest ahead of an upper trough approach. Tonight, an upper trough will arrive to the PacNW, the first in a series of upper low pressure features that will impact the region. Shower chances along the Cascades and the eastern mountains will increase through the overnight hours into tomorrow morning as the trough moves inland. Weak elevated instability with modest mid- level lapse rates will develop out ahead of the trough axis tonight, allowing slight chances (around 15%) of isolated thunderstorms to develop mainly over the mountainous terrain of Grant and eastern Crook counties. The upper trough will continue to dive southeast into the Great Basin Saturday morning, allowing the next upper trough to dive across the PacNW Saturday through Sunday. Guidance does indicate that the upper trough will develop into a closed low over the PacNW during it's southeastward descent, though there are minor differences in the timing and position of the closed low. Nonetheless, the second upper low feature will continue to bring shower activity area-wide the first half of Saturday, with shower activity diminishing across the lower elevations as the upper low moves overhead through Saturday night and Sunday morning. During the day Saturday, increasing surface based instability(200-500 J/kg) and modest low to mid level lapse rates will result in isolated to widely scattered thunderstorm chances (15-30%) mixing in with showers across the forecast area Saturday afternoon through the late evening (confidence 50-70%). Through Saturday night, there is a 65-90% chance for rain accumulations of 0.25 inches across the mountain zones, including the Grande Ronde valley...55-85% chance for 0.1 inches in the lower elevations. Winds will increase through the Cascade Gaps and into portions of the Columbia Basin and Central OR as cold air advection under the upper trough/low passages will result in a strengthening of the cross-Cascade surface pressure gradient. Winds Saturday will increase to 20-30mph with gusts up to 40mph through the Cascade gaps, and 15-25mph with gusts up to 35mph elsewhere in the lower elevations (confidence 70-80%). Sunday, rain/snow showers will mainly be confined to the Cascades, Blues, and Wallowa county as the upper low continues to push southeast. By Sunday late afternoon and evening, shower activity will diminish across the aforementioned areas as the upper low crosses into the Great Basin to the southeast. Surface winds will continue to strengthen Sunday, with a 75-90% chance that wind gusts will reach or exceed 45mph through the Kittitas valley and a 60-75% chance through the eastern Columbia River Gorge. Elsewhere in the lower elevations, winds will continue to be 15-25mph with gusts up to 35mph (confidence 65-80%). Lawhorn/82 LONG TERM...Monday through Friday...Models key in on a relatively progressive pattern next work week, albeit one without much in the way of significant sensible weather impacts as the synoptic pattern looks to be zonal in nature. As a result, the weather threats next week look to be comprised of breezy downslope winds, slight chance to chance PoPs for our mountain zones, and generally seasonable temperatures, save for early Monday morning when northerly flow trailing a departing system may make for a potential overnight freeze across some of our elevated valley zones. The synoptic pattern evolves as thus: a low digging into the Four Corners region will make for northerly flow heading into Monday, leading to a chilly morning as central Oregon, the Grande Ronde Valley, and the Wallowa Valley all stand to see a chance of freezing temperatures (20-30%, 10-20%, and 50-60%, respectively). Flow aloft then turns zonal, before a shortwave develops off the Pacific coast Tuesday into Wednesday, introducing a slight amount of instability, enough to trigger low-end thunderstorm chances (10-20%) for the eastern mountains Tuesday afternoon, but the threat looks to be isolated given the lack of moisture advection with this shortwave. Models start to diverge Wednesday onward, with ensembles generally suggesting a return to zonal conditions and thus benign weather for the rest of the period, however the deterministic GFS and ECMWF do suggest the possibility of shortwaves embedded within the zonal flow that could lead to at least slight widespread PoPs for the forecast area. Given that ensemble guidance doesn't currently reflect this, however, confidence in this occurring is low. Such patterns generally lead to breezy conditions downslope of the Cascades, so expect the Cascade Gaps and east slopes to see recurring days of gusts over 25 mph so long as we remain under zonal flow. Some ensemble members suggest high pressure building in by the tail end of the period, which could lead to a warming trend, however other members insist on keeping at least a weak zonal pattern in place. Confidence in the forecast Wednesday and beyond remains low (30-40%). Evans/74 AVIATION...12z TAFs...VFR conditions expected through the period. Light rain will end early this morning, leaving us with partially clearing skies during the day at sct-bkn 5-10 kft. Clouds will build back in this evening, becoming ovc at 10-15 kft by nightfall. Winds will generally be W to SW, except NW for DLS, BDN, and RDM, at less than 15 kts. Evans/74 && .PRELIMINARY POINT TEMPS/POPS... PDT 66 48 65 43 / 20 20 80 70 ALW 64 50 64 44 / 50 10 80 90 PSC 71 49 71 45 / 10 10 70 60 YKM 71 50 69 42 / 10 20 70 10 HRI 71 48 70 45 / 10 20 80 50 ELN 66 47 65 42 / 10 40 80 20 RDM 66 42 61 34 / 0 30 70 20 LGD 59 43 58 39 / 40 20 90 90 GCD 62 43 56 37 / 10 60 100 80 DLS 68 51 68 46 / 10 30 60 10 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...82 LONG TERM....74 AVIATION...77 ####018007141#### FXUS61 KBTV 161739 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 139 PM EDT Fri May 16 2025 .SYNOPSIS... Warm and humid conditions will continue to support chances of showers and thunderstorms over the next several days. The greatest potential for precipitation will be late today and again on Saturday afternoon, with cooler conditions arriving on Sunday that will linger into the first half of next week. && .NEAR TERM /THROUGH SATURDAY/... As of 130 PM EDT Friday...It's been fairly quiet so far early this afternoon with a few showers and a rarer thunderstorm ongoing. Showers and thunderstorms are poised to become more numerous as instability maximizes with a line of elevated instability also moving through this afternoon. Otherwise, conditions are quite muggy with temperatures in the upper 70s to low 80s and dew points in the 60s. Previous Discussion...An upper level low centered over the Great Lakes will continue to meander eastward, with several associated frontal boundaries and shortwaves moving through the region, bringing daily chances for showers and thunderstorms both today and Saturday. Patchy fog has developed across parts of the region this morning, but should quickly dissipate after sunrise. Daytime highs will continue to be warm, with another day of upper 70s and low 80s expected across the region. By the afternoon, conditions look to become more favorable for convective development, with CAPE values in excess of 500 J/kg across most of the region. Looking at model soundings, heavy rainfall and some slower-moving storms look to be the main concern this afternoon. Shower activity will wane Friday night, although a few lingering showers may be possible. Overnight lows will continue to be on the mild and muggy side, only dropping into the mid 50s and 60s. The showery and active pattern continues into Saturday with several rounds of showers and possible thunderstorms expected, with the first round of showers moving through in the early morning and then additional convection in the afternoon. There is still some uncertainty in regards to how Saturday plays out, especially given the multiple rounds of precipitation. The latest HREF guidance suggests that cloud cover may linger throughout much of the day Saturday, which may limit any convection for Saturday afternoon. If enough clearing is able to take place by the early afternoon, there could be enough instability for a few stronger to locally severe thunderstorms to develop, with SPC maintaining a Marginal Risk across the region for Saturday. With plenty of moisture available, any storms that do develop will likely feature heavy rainfall. Between both Friday and Saturday, rainfall amounts between 0.50 and 1.0 inches can be expected, with locally higher amounts possible within thunderstorms. WPC does have a Marginal Risk for excessive rainfall across the region for both Friday and Saturday given the potential for heavy rainfall and slower storm motions, but there are no flood concerns at this time. Temperatures during the Saturday will continue to be on the warm side, generally in the 70s to near 80 degrees. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... As of 407 AM EDT Friday...The second half of the weekend will feature a drastic shift as an upper low pivots directly over our forecast area. Remnants of Saturday's showers and thunderstorms will quickly exit to the east Saturday night, but any break in the precipitation will be fairly short lived. The upper low will swing down along or just south of the international border late Saturday night through Sunday, and expect a resurgence of showers in response. Winds will turn to the west and eventually northwest as the low moves to our east, ushering in a much colder airmass. Highs on Sunday will likely only be in the mid 50s to low 60s, with perhaps some places locations in the southern Champlain Valley/CT River Valley nudging into the mid 60s. Showers will become focused in the northern mountains by Sunday afternoon. Winds will be a touch gusty, but not overly so with gusts generally topping out around 25 mph. Showers will wane Sunday night as we lose daytime heating, though still expect at least scattered precipitation overnight. Lows will mainly be in the 40s, though the Adirondacks could dip into the upper 30s by early Monday. && .LONG TERM /MONDAY THROUGH FRIDAY/... As of 407 AM EDT Friday...The cool and showery weather will persist through at least Monday as we remain on the western periphery of the upper low. Highs on both Monday and Tuesday will be in the 50s, though some of the colder spots in the Adirondacks and east of the Green Mountains could well struggle to get out of the 40s, especially on Monday. The pattern becomes more uncertain thereafter, with guidance indicating a complex interplay between an upper shortwave digging into the Great Lakes/near Hudson Bay while another upper trough moving into the Midwest, perhaps phasing into a cutoff low somewhere over the eastern CONUS. The main theme is that shower chances will continue through much of the week, and temperatures will remain below normal. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... Through 18Z SATURDAY...VFR conditions will persist until showers become more numerous. Best chances for showers will be 20-01Z with a few embedded thunderstorms as well. It will be tough to pin down which terminals will have thunderstorms, but west to east motion will favor terminals other than BTV mainly due to the stabilizing influence of Lake Champlain. Lake Breeze is setting up along the west shore of Lake Champlain given the heat, so a few TS could fire along the lake breeze front this afternoon potentially impacting PBG. Overnight MPV stands the best chance at seeing some fog, but PBG could get some as well should heavier rain showers or a thunderstorm occur. Deep moisture favors lowering/thickening CIGs tomorrow east of the Greens, so EFK/MPV could have MVFR CIGs after sunrise. Shower chances increase after 12Z with thunderstorm chances increasing after 16Z. Widely scattered showers are anticipated. Outlook... Saturday Night: Mainly VFR, with local MVFR possible. Chance SHRA, Slight chance TSRA. Sunday: Mainly MVFR, with local IFR possible. Likely SHRA. Sunday Night: Mainly MVFR, with local IFR possible. Chance SHRA. Monday: Mainly MVFR, with areas VFR possible. Chance SHRA. Monday Night: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Tuesday: Mainly MVFR, with local IFR possible. Slight chance SHRA. Tuesday Night: Mainly MVFR, with local IFR possible. NO SIG WX. Wednesday: MVFR. Chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Kremer NEAR TERM...Boyd/Kremer SHORT TERM...Hastings LONG TERM...Hastings AVIATION...Boyd