####018009689#### FXUS61 KBGM 161755 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 155 PM EDT Fri May 16 2025 .SYNOPSIS... Unsettled weather with multiple rounds of showers and thunderstorms will persist through Saturday. Cooler weather with a few lingering showers is expected on Sunday. Drier, mostly sunny but cool weather is then expected heading into early next week. Another low pressure system looks to bring additional rain chances by middle to latter portion of next week. && .NEAR TERM /THROUGH SATURDAY/... 140 PM Update: All showers and thunderstorms have moved well east of the area towards the coast and the area is currently rain-free. Skies have cleared across most of the area and a secondary round of showers and thunderstorms are still expected to develop later this afternoon. Conditions are not ideal for organized severe weather, but a thunderstorm or two may become strong to severe. Made some minor adjustments to PoPs once again to reflect latest radar trends. 1055 AM Update: Made some minor adjustments to PoPs for the next few hours, but otherwise the forecast remains on track. The line of showers and thunderstorms have weakened as expected and are currently located mainly across the Poconos-Catskills. These will exit the area within the next hour or two, with partial clearing behind it. This clearing trend will destabilize the atmosphere and set the stage for some additional scattered showers and thunderstorms this afternoon. 645 AM Update A line of showers and embedded thunderstorms is approaching the western portion of the forecast area currently, and is basically right on schedule with the previous forecast. Little change was needed with this update. The thunderstorms are no longer severe and are expected to gradually weaken through the mid to late morning hours as they approach the I-81 corridor. A few storms could produce heavy rain and cloud to ground lightning still. 430 AM Update Main concerns in this period are the potential for isolated strong to severe t'storms with heavy downpours, gusty winds and hail today...and another round of isolated to scattered severe t'storms is expected on Saturday. Today features a level 1 out of 5 Marginal Risk for severe storms from SPC across just about the entire forecast area. There is also a level 1 out of 4 Marginal Risk for excessive rainfall and flash-flooding for the entire CWA today from WPC. SPC has issued a Slight Risk (level 2 out of 5) for areas along and east of Syracuse--Ithaca--Towanda for Saturday. Patchy fog and stratus clouds are in place across portions of CNY/NE PA early this morning. An incoming line of convection is slowly approaching from Lake Erie/WNY/WPA early this morning as well. Latest CAMs have slowed down the timing of this line, with it now looking to reach Steuben county around 8-9 AM, I-81 by 9-11AM before it fizzles out east of Binghamton late this morning. Behind this initial morning line of showers and embedded t'storms there will be some breaks of sun...which will allow instability to quickly builds over the region. By early afternoon MLCAPE values of 800-1800 J/kg, along with LIs down to around -7 are expected. Deep layer shear begins to increase, between about 20-35 kts is expected in the 0-6km layer. Good directional shear and up to around 15kts of 0-1km shear are also expected; bringing SRH values around 100m2/s2 in the 0-1 layer...this combines with forecast LCLs around 600m to also bring an isolated tornado potential. The bigger threat from this storms today will likely be strong to possibly damaging wind gusts as DCAPE values rise to around 900-1000 J/Kg...which is a strong signal for downburst/microburst with some of the stronger storms that do develop. The main timing for severe storms looks to be from about 2-9 PM this afternoon and evening. Outside of the scattered storms it will be warm, humid and partly sunny with highs in the upper 70s to mid-80s expected. Dew points will be well into the 60s today, making it feel quite humid out there. Scattered showers and possibly even another round of thunderstorms will continue tonight as an Elevated Mixed Layer (EML) is overhead producing mid level lapse rates of 6.5 to 7.5C/km. It is difficult to pin down the timing of any nocturnal convection as some of the CAMs showing it redeveloping in place over the region, while other CAMs show t'storms advecting in from the Ohio Valley overnight. Up to around 500 J/Kg of MLCAPE remains in place overnight due to the warm and humid air mass that will be situated across CNY and NE PA. Mild and humid night expected with lows in the upper 50s to low 60s for most locations. Saturday brings a stronger cold front into the area late in the day or evening as a large mid/upper level low moves across the Great Lakes and into souther Canada. It will remain warm, humid and unstable out ahead of this front. Scattered to numerous showers and thunderstorms will develop over the forecast area...becoming widespread in the afternoon and early evening. CAPE values of between 500-1500 J/Kg are most likely to develop; although there remains substantial differences in some of the model guidance at this time. Deep layer shear is even stronger between 35-50 kts in the 0-6km layer, and this will help storms to become better organized. Temperatures will begin to fall late in the day and evening as the cold front moves through. Highs are expected to reach the mid-70s to lower 80s, with dew points falling and it becoming much less humid in the evening. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... 345 AM Update... The frontal system that moves across the region during the daytime hours should be just about through by the late evening hours. Lingering showers and thunderstorms will remain possible until it exits the region. Then an upper low swings through the region late Saturday night and during the daytime on Sunday. This system will bring the next round of showers to the region. There will be no instability present, so thunderstorms are not expected. A cooler airmass will also drop in with this system resulting in a cool and rainy end to the weekend. Winds will be breezy Sunday as the pressure gradient tightens up around a surface low that will be just north of the region. As this system moves east of the region Sunday night, northwest flow will continue to advect cool air southward as showers continue. Temperatures will fall into the upper 40s and mid 50s Saturday night. Then temps will struggle to rebound much as highs will only be in the upper 50s to mid 60s. Portions of the Wyoming Valley be close to 70 as skies are expected to clear some across the far southern portions of the region. Lows on Sunday will be in the 40s for most of the region. && .LONG TERM /MONDAY THROUGH FRIDAY/... 345 AM Update... Dry but cool conditions are in store for early next week as a ridge of high pressure builds into the region. Temperatures will be below normal throughout the long term period. Winds will remain breezy Monday as the aforementioned system continues to move through. This will result in blustery conditions, at least for this time of year, during the morning hours. Patchy frost will be possible Monday night/early Tuesday morning as temperatures plummet under mostly clear skies and calming winds. Dry conditions will continue through at least Tuesday and likely into part of Tuesday night as guidance has slowed down the arrival of the next system. Another upper low will move into the Great Lakes region midweek as a surface low develops along the coast. This system will bring widespread rain to the region Wednesday and Wednesday night with rain then continuing Thursday. Coverage on Thursday may not completely cover the area depending on the location of the surface low by then. There is some spread between guidance on where the lows set up and how quickly they move through, so similarly to previous updates, NBM guidance continues to be favored for this time period. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... Mainly VFR conditions are expected this afternoon, but scattered showers and thunderstorms are expected to develop, which may result in brief MVFR restrictions. If a heavier shower/thunderstorm moves right over a terminal, brief IFR restrictions cannot be ruled out, but confidence was not high enough to include IFR restrictions at this time. Conditions are expected to return to VFR tonight and remain that way through most of the rest of the current TAF period (at least through 18Z Saturday). Another round of showers and thunderstorms will be possible late Saturday morning into the afternoon, but confidence was not high enough at this time to include thunder in the TAFs. Outlook... Saturday afternoon...Scattered showers and thunderstorms may result in brief restrictions. Sunday...Scattered rain showers possible, especially at the Central NY terminals, which may result in occasional restrictions. Sunday night through Tuesday...Mainly VFR expected. Wednesday...Restrictions likely with rain showers. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MJM NEAR TERM...BJG/MJM SHORT TERM...BTL LONG TERM...BTL/ES AVIATION...BJG ####018004504#### FXUS66 KMTR 161755 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1055 AM PDT Fri May 16 2025 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 250 AM PDT Fri May 16 2025 Wind and cooler temps on tap for the weekend as a potent system enters the Great Basin. Warm and dry with fair weather expected mid-next week. && .SHORT TERM... (Today and tonight) Issued at 250 AM PDT Fri May 16 2025 Another quintessential California day on the docket with mostly clear skies and breezy northwest flow. A quick check of the nighttime satellite shows some upper level cloudiness moving through the region associated with a subtle shortwave trough. This will likely lend a hand to some elevated cloud layers through this afternoon, but shouldn't cause any concern. && .LONG TERM... (Saturday through Thursday) Issued at 250 AM PDT Fri May 16 2025 By late Friday night we will start to see the impacts of a potent system progged to dig into the Great Basin. Gusty NW winds are expected to develop by midday Saturday lasting through Sunday evening. Confidence in the overall pattern is high as ensemble guidance has largely held steady for the past few days. One big change this morning, however. The latest guidance depicts a more open wave, which would ultimately lead to the upper low ejecting out into the Central Plains a bit earlier than previously expected. Where previous forecasts called for offshore winds through Monday morning, this morning's forecast package advertises less of an offshore wind component. Still looking at gusty N/NW winds early Monday morning, which will result in downsloping winds in the higher terrain of the interior North Bay. This will still lead to elevated fire danger for these areas through Monday where humidities will be low due to compressional heating and continental airmass influence. All in all, winds look to gust into the 30-40 mph range across inland areas and 40-50 mph along the coast and favored NW-SE oriented valleys and gaps. A longwave ridge pattern is restored by the middle of next week, promoting a drying trend and high temps warmer than seasonal normals. && .AVIATION... (18Z TAFS) Issued at 1055 AM PDT Fri May 16 2025 It's VFR except for a lingering patch of stratus over the Monterey Bay. VFR prevailing today with VFR extending into the evening, otherwise increasing coastal stratus and patchy fog /IFR-MVFR/ tonight and Saturday morning with patchy light coastal drizzle possible. Gusty northwest winds aloft resulting in low level wind shear over KSTS Airport 12z-17z Saturday morning. Vicinity of SFO...VFR. Light northeast wind until early afternoon then shifting to westerly and increasing with gusts near 30 knots during the afternoon and evening. Gusty westerly wind tonight and Saturday. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...MVFR-VFR improving to VFR by early afternoon under diurnal surface warming and mixing winds. MVFR due to coastal stratus developing tonight, a few patches of light drizzle are possible as well. MVFR Saturday morning. Onshore winds 5 to 15 knots, strongest during the afternoon and early evening. && .MARINE... (Today through Wednesday) Issued at 1045 AM PDT Fri May 16 2025 Gusty to strong northwest winds will continue over the coastal waters today through the weekend, including much of early to mid next week. Hazardous marine conditions with rough to very rough seas will continue through Tuesday night. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 3 PM this afternoon to 3 PM PDT Saturday for Mry Bay-SF Bay N of Bay Bridge. Gale Warning until 3 PM PDT Saturday for Pt Arena to Pt Reyes 0- 10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0- 10 nm. Small Craft Advisory until 3 PM PDT Saturday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm. Gale Warning until 3 AM PDT Saturday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...Behringer LONG TERM....Behringer AVIATION...Canepa MARINE...Canepa Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea ####018004450#### FXUS65 KTFX 161756 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1156 AM MDT Fri May 16 2025 Aviation Section Updated. .KEY MESSAGES... - Another round of showers this afternoon, mainly near terrain. - Next more widespread precipitation system develops late tomorrow night into Sunday, lasting into early Monday. - Low-end opportunities for showers most afternoons toward the middle of next week, with temperatures slowly rising back to near or a touch above average by Wednesday. && .DISCUSSION... /Issued 503 AM MDT Fri May 16 2025/ - Meteorological Overview: A deep upper level low has exited eastern MT and the Dakotas early this morning, leaving a zonal flow aloft across the Northern Rockies. Weak waves within this flow will maintain mainly afternoon shower opportunities, though showers at any point over the next day or so will be fair game. In the meantime, areas that see some clearing this morning will be candidates for fog development. Looking toward this weekend, two separate southeastward diving waves within a building trough across the west will interact/ pivot around each other off to the south beginning late Saturday, lasting into early Monday. This will result in a period of lower elevation rain and mountain snow, with the most likely period for heavier precipitation being Sunday. Snow levels do look to fall with this system, falling lowest as the system begins to pull away late Sunday night into early Monday morning. 50th percentile snow levels during this timeframe are around 5,500 ft, with 10th percentile snow levels (Reasonable low scenario) between 4,500 and 5,000 ft. The lowest snow levels are likely to follow the location of the highest precipitation rates, which are not high confidence yet. After this system departs Monday, a zonal flow looks to develop and persist through much of the week. Weak waves within this flow aloft will promote low-end opportunities for showers and a few thunderstorms, though confidence in timing any particular wave is low at this time. Temperatures do look to trend closer to normal after Monday, however. -AM - Forecast Confidence & Scenarios: The two greatest points of uncertainty are related to the system late Saturday night through Monday morning. Ensemble averaged precipitation amounts for this system still show less than stellar confidence in location of greatest amounts given the large, broad bullseye of precipitation amounts encompassing most of the region. To give a little perspective regarding the uncertainty, NBM 10th to 90th percentile spread (Difference between reasonable high end amounts and low end amounts) is greater than one inch north of I-90, and is around three quarters of an inch south of I-90. In most cases the low end scenario (90% chance for more than this amount) is still only around a tenth of an inch of total precipitation for most locations away from terrain. The story is similar with respect to snow levels. The difference between reasonable high end and low end snow levels is still more than 2,000ft. Trends will continue to be monitored for any late breaking consensus for the Late Saturday night through Monday system. -AM && .AVIATION... 16/18Z TAF Period Periods of MVFR clouds linger across the Southwest and Central MT this afternoon. Isolated to scattered showers will impact terminals this afternoon and evening. MVFR cigs can accompany showers. There's a low chance for lightning with showers, but the probability is too low to include in the TAF. After showers move out in the evening, scattered to broken MVFR cigs linger in Southwest MT overnight. -Wilson Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 61 39 65 46 / 50 30 30 60 CTB 59 36 63 41 / 50 30 20 50 HLN 61 41 66 46 / 40 30 40 70 BZN 58 38 64 42 / 40 60 40 70 WYS 51 32 58 35 / 70 70 40 80 DLN 55 37 62 40 / 60 50 30 80 HVR 64 40 67 43 / 20 50 60 40 LWT 57 38 61 42 / 50 50 70 60 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls ####018013877#### FXUS63 KLOT 161758 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 1258 PM CDT Fri May 16 2025 .KEY MESSAGES... - A threat of rapid fire spread exists this afternoon due to a combination of strong winds and low relative humidity. - A threat of severe thunderstorms exists late this afternoon and early evening (Threat level 1 to 2 out of 5). && .MESOSCALE... Issued at 1208 PM CDT Fri May 16 2025 Main focus for severe thunderstorms late this afternoon and early this evening continues to be across my southeastern counties of eastern central IL into northwestern IN. This includes areas generally along and east of I-55 and along and south of I-80. Prior to the severe storm threat, strong gusty winds and low afternoon RH's will promote a high fire danger for portions of northern IL. Mainly clear skies and a parched airmass overhead is fostering deep boundary layer mixing that is allowing temperatures to quickly warm through the lower 80s as of 11 AM. Continued mixing of this very warm and dry boundary layer is expected this afternoon, likely mixing in excess 8,000 ft. This deep mixing will promote steady (or even falling) surface dewpoints in the 40s as surface temperatures warm into the middle to upper 80s, and will also result in increasingly gusty south-southwest winds through the day. The strongest wind gusts this afternoon and evening are generally expected along and northwest of the I-55 corridor, where gusts of 45 to perhaps as high as 55 mph are anticipated. This has prompted the recent issuance of a wind advisory for this area, as well as a targeted Red Flag Warning within portions of this wind advisory. While a parched and very deeply mixed boundary layer is not typically associated with storm development, we are expecting a rather impressive northward surge of low-level moisture (surface dew points up around 60) along and east of the I-55 corridor very late this afternoon (after 4 PM) and into the evening just in advance of an eastward shifting cold front/dryline feature. This corridor of better low-level moisture currently resides across southern MO and IL, and is noted by a late morning uptick in CU development on regional Satellite imagery. This increasingly moist and unstable airmass is expected to foster isolated to widely scattered thunderstorm development across parts of eastern MO and southwestern IL into early this afternoon. Thereafter, storm coverage is expected increase as large scale forcing for ascent increases in response to a notable mid-level impulse over the mid-Missouri Valley quickly swinging eastward along the southern periphery of the upper low residing in the Upper Midwest. As storm coverage increases, severe storms will develop northward across IL through the afternoon ahead of the dry line feature within the northward surging airmass. The area we are most concerned with for these severe thunderstorms are in areas generally along and east of I-55 and along and south of I-80, with the main timeframe looking to be from 4 to 10 pm this evening. More isolated storm coverage is possible northwest of this area. The presence of very steep low-to-mid level lapse rates and inverted V-type soundings with high DCAPE (in excess of 1,000 j/kg) will foster very strong downdrafts and outflow with these storms. Accordingly, the primary severe weather threat with this activity looks to be damaging winds, some perhaps destructive (75+ mph). Some instances of large hail also cannot be ruled out. Expect the storm threat to wane by mid to late evening as the cold front/dry line shifts east of the area. KJB && .DISCUSSION... Issued at 247 AM CDT Fri May 16 2025 Through Saturday: Two primary forecast concerns through early this evening, severe weather potential and windy, dry conditions for possible wildfires. Please see the fire weather section below. Much drier air has spread across western and northern IL with dewpoints in the upper 40s. The models are in good agreement with low level moisture surging back north late this afternoon into early this evening, with dewpoints back into the upper 50s to possibly lower 60s along and east of I-55. A cold front will be approaching from the west and scattered thunderstorms are expected to develop east of I-55. Coverage further north into the Chicago Metro area is more uncertain with perhaps only isolated thunderstorms. Strong winds aloft along with ample instability will allow any storms that develop to quickly become severe with large hail and damaging winds the main threats. Given the wind profiles in the soundings, isolated damaging gusts into the 60-65kt range will be possible. Before the storms, southwesterly winds will steadily increase this morning with gusts into the 40-45 mph range expected. There is a narrow window this afternoon, where gusts could frequently be at or above 45 mph, which is wind advisory criteria. Confidence is too low to issue a windy advisory at this time, but trends will need to be monitored. Gusts will diminish a bit this evening, into the 25-30 mph range but will remain gusty through sunset Saturday evening. Another period of higher gusts in the 35-40 mph is possible as the colder air spreads into the area late this evening. Previous forecast included patchy blowing dust for today for the western cwa and made no changes. There were stripes of heavier rainfall from the storms Thursday afternoon that will limit this potential for those areas. High temperatures today are expected to reach into the middle, to perhaps upper 80s for most locations. Wind directions may remain southerly enough to keep temps cooler along the north lakeshore. Low temps will drop into the lower/mid 50s Saturday morning. High temps will be cooler on Saturday ranging from mid 60s north to around 70 south. cms Saturday Night through Thursday: A sprawling ~1030 mb high will build east across Ontario and the Hudson Bay on Sunday with mid-level shortwave ridging forecast to build in across the local forecast area. This high to our north with send a robust afternoon and evening lake breeze/backdoor front through the entire region. This will end up holding lakeside highs in the mid/upper 50s, while inland locales will likely warm into the 70s prior to the lake breeze push. While some guidance hints at the potential for some intermittent lower cloud cover on Sunday, most indications are that any morning cloud cover should scatter into the afternoon. On Sunday night into Monday, a sharpening warm frontal zone well to our south will slowly advance northward into southern Iowa, northeast Missouri, and southern Illinois. Increasing low-level warm advection in response to strengthening 925-850 mb southwesterlies overtopping this frontal zone will lead to the development of showers and thunderstorms, but given the current location of the aforementioned boundary and MUCAPE gradient, most/all of this activity through Sunday night looks to remain well to our south. Even into the day on Monday any activity locally currently looks like it should remain isolated to scattered, with deeper moisture still relegated to our south. Forecast soundings off the GFS in particular look like they'd be more supportive of intermittent drizzle/showers as opposed to thunderstorms. On Monday night into Tuesday, guidance pushes a modest surface low (near 1000 mb) towards northern Missouri/southern Iowa as a robust shortwave pivots across the central plains. During this time, the northward progress of the returning warm front is forecast to slow, with the boundary overall becoming quasistationary across central to downstate Illinois. Isentropic upglide will increase once again, likely leading to a nocturnal expansion of showers and storms which--depending on the precise location of the stalled front--may begin to push into our forecast area, particularly south of about I-80. Could end up being a locally heavy rainfall threat somewhere in the vicinity with this setup. Thereafter, guidance generally depicts a complex upper pattern developing, with a series of upper lows/gyres pinwheeling around one another into the middle of the week. This general evolution will keep the threat for intermittent periods of rain with embedded thunderstorms going in the vicinity, at least into Wednesday. There's a signal for things to dry out into the end of the week. Carlaw && .AVIATION /18Z TAFS THROUGH 00Z SUNDAY/... Issued at 1258 PM CDT Fri May 16 2025 Forecast concerns for the terminals... - Gusty south-southwest winds this afternoon with 35-40 kt gusts likely. - Scattered thunderstorms expected late this afternoon and evening (22-02z). A few storms may be severe with damaging winds and hail as the main threat. - Period of MVFR ceilings tonight into Saturday morning. - Winds become westerly behind cold front with gusts in the 25-30 kt range tonight through Saturday. Winds have continued to increase as diurnal mixing has commenced across the area this afternoon. While gusts have generally be around 30 kts thus far, gusts are expected to peak in the 35-40 kt range this afternoon and early evening. A cold front will move through the area this evening which will turn winds from south-southwest to westerly where they will remain through the rest of the period. Gusts are expected to subside a bit overnight as diurnal mixing weakens, but 28-30 kt gusts should prevail overnight before easing into the 25-30 kt range on Saturday. Outside of the winds, there is also the potential for scattered thunderstorms to develop later this afternoon and evening (between 22z and 02z) especially over far northeast IL and northwest IN. Confidence on storms occurring has increased slightly since this morning as a plume of low-level moisture has started to move towards the area from southern MO. However, a fair amount of uncertainty remains in storm coverage particularly with northward extent. Therefore, have maintained the TEMPO groups at the Chicago area terminals but did decided to include a VCSH mention at RFD. Given that the threat for storms is around 20% at RFD and most guidance has storms developing east of the airport, feel the confidence is still to low for a formal TS mention. Additionally, any storms that develop will have the capability of producing winds in excess of 50 kts and large hail possibly up to golf ball size. The greatest severe threat is maximized southeast of a ORD to PNT line. Finally, a period of MVFR ceilings is expected to develop tonight as the upper low over the Dakotas swings overhead. Ceilings should generally be in the 2500-3000 ft range but lower clouds may develop in southern WI and near RFD. MVFR conditions should lift back to VFR by mid-morning on Saturday with skies gradually clearing through the end of the period. Yack && .MARINE... Issued at 245 AM CDT Fri May 16 2025 Southerly winds are expected to gust to gales to 35 kt this afternoon for mainly the IL nearshore waters and through Gary in the IN nearshore. Winds will shift westerly this evening as a cold front moves across southern Lake Michigan. Winds may continue to gust to near gale force with and just behind this cold front. Gusts will then diminish slightly, into the 25-30kt range which will continue through early Saturday evening. cms && .FIRE WEATHER... Issued at 245 AM CDT Fri May 16 2025 A fire weather watch remains in effect for all of northeast IL this afternoon. Much drier air has spread across western and northern IL and is expected to remain in place through mid afternoon. Dewpoints may lower a few more degrees, into the mid 40s and combined with high temperatures in the middle, to perhaps upper 80s, minimum relative humidity levels in the 20 to 25 percent range are possible this afternoon. Southwesterly winds will steadily increase this morning into this afternoon with gusts into the 40-45 mph range expected this afternoon. This combination of low relative humidity and strong winds will create the potential for rapid wildfire spread. A limiting factor is that some areas received heavier rainfall from the storms Thursday afternoon. Low level moisture is expected to surge back north late this afternoon into early this evening, with dewpoints in the upper 50s, perhaps lower 60s, east of I-55. There will also be a chance of thunderstorms late this afternoon into early this evening for areas along and east of I-55. The combination of rising relative humidity levels as well as possible rainfall will end the wildfire risk by early this evening. cms && .LOT WATCHES/WARNINGS/ADVISORIES... IL...Wind Advisory until midnight CDT tonight for ILZ003-ILZ004- ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-ILZ012-ILZ013-ILZ019- ILZ020-ILZ021-ILZ032-ILZ103-ILZ104-ILZ105-ILZ106-ILZ107. Red Flag Warning until 7 PM CDT this evening for ILZ010-ILZ011- ILZ012-ILZ019-ILZ020-ILZ021. IN...None. LM...Gale Warning until 10 PM CDT this evening for Winthrop Harbor IL to Gary IN. Small Craft Advisory until 10 PM CDT this evening for Gary to Burns Harbor IN-Burns Harbor to Michigan City IN. && $$ Visit us at weather.gov/chicago ####018004467#### FXUS63 KDDC 161758 AFDDDC Area Forecast Discussion National Weather Service Dodge City KS 1258 PM CDT Fri May 16 2025 .KEY MESSAGES... - Breezy and mild Friday - Storm chances return Saturday evening - Impactful severe weather potential in central Kansas shaping up Sunday afternoon and evening && .DISCUSSION... Issued at 202 AM CDT Fri May 16 2025 07z surface observations and upper air analysis shows a passing 500- 700 mb shortwave along the Kansas-Colorado border and an associated surface low and cold front roughly around Syracuse. A mid and upper level cloud deck is situated along and northeast of the surface low in northwest Kansas and the leading edge of the cooler air is entering into our northwest zones. Overall for today the progression of the wave and surface low should move into central and eastern Kansas during the late morning and early afternoon and the associated mixing and tighter pressure gradient should lead to breezy northwesterly winds during the day. Sustained winds will be 15-25 mph with gusts around 30 mph. Highs today should be around our seasonal averages as we get into the upper 70s to lower 80s. Tonight a weak backdoor front will move through southwest Kansas in response to a surface high in southern Nebraska and a developing surface low in northeast New Mexico. This boundary will set the stage for thunderstorm potential Saturday evening. Most of the day on Saturday should be dry but as the surface low deepens in northeast New Mexico with an upper level shortwave moving out of the desert southwest we should see increasing frontogenesis in central Kansas and good moisture advection as the winds turn back to a southeast direction during the afternoon. Short term models have the best area of moisture and associated lift moreso into central Oklahoma and southeast Kansas however with dewpoints forecast to reach into the lower to middle 50s in our south central counties we have a slight chance (20%) of storms mainly along and east of highway 283 Saturday night into Sunday morning. Sunday is showing increasing confidence in an impactful severe weather event for central Kansas. In our county warning area specifically the areas that are showing the higher risk of impactful severe weather would be along and north of a Pratt to Ness City line. Long range ensembles are showing a large longwave trough in the Rockies turning negatively tilted by Sunday afternoon with strong PVA entering into southwest Kansas by late in the afternoon on Sunday. At the surface a low develops in eastern Colorado with an associated warm front and large area of moisture along and north of the warm front which is situated roughly from Pratt to near Goodland. South of the front a strong dryline will move through southwest Kansas and based off of NBM probabilities of dew point temperatures greater than 55 degrees we see that areas from Dighton to Dodge City to Ashland on west are 10% or less (negating any storm or severe threat) and areas from Medicine Lodge to Ness City on east are 70-90%. Bulk shear values are forecast to increase to 50 kts as the 850 mb winds increase after 21Z. Skew t soundings are showing a shallow moist layer with drier mid levels in the 700 mb range and hodograph soundings show good veering with height and turning almost straight towards the anvil layer. The cap should weaken during the afternoon as the much warmer and drier air moves into central Kansas. All this is to say that any thunderstorm development with this setup we see 3 days out will have an environment for large hail (>2 inches) with some potential for giant (up to softball sized) hail and tornadoes in central Kansas. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1253 PM CDT Fri May 16 2025 Northwest winds at 15 kts will become light this evening as weak surface high pressure settles over the high plains. Winds will shift to the east by 09-12z and increase to 12-15 kts as surface low pressure forms on the southern high plains. VFR conditions are expected, but MVFR CIGS will develop just after the period at KDDC as moisture surges northward. && .DDC WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Tatro AVIATION...Finch ####018006474#### FXUS61 KCAR 161759 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 159 PM EDT Fri May 16 2025 .SYNOPSIS... A front will settle across Northern Maine today. Low pressure will slowly cross the area Saturday through Sunday, then slowly exit to the east Monday through Tuesday. && .NEAR TERM /THROUGH TONIGHT/... Update... A nearly stationary frontal boundary will remain across northern Maine this afternoon. Convergence along the boundary, along with diurnal heating, will support shower development along with isolated/scattered thunderstorms across northern and central areas through the afternoon. Any slow moving thunderstorms could produce locally heavy rain. Isolated afternoon showers are possible Downeast. Otherwise, expect partly sunny/mostly cloudy skies across the region this afternoon. Afternoon high temperatures will range from around 70 to the upper 70s across much of the forecast area, with lower to the mid 60s along the Downeast coast. Have updated to adjust for current conditions along with expected afternoon temperatures and clouds. Previous Discussion... The main feature today will be a backdoor cold front that will get hung up over the Central Highlands this afternoon. The front will become the focus for shower and thunderstorm development this afternoon into this evening. The threat area looks to be from around Moosehead Lake towards Baxter State Park and the North Woods. Model soundings show a tall, skinny CAPE profile, and almost no storm motion. This favors thunderstorms that move slowly (if at all) and produce heavy rainfall. As such, the Weather Prediction Center (WPC) has placed these areas in a slight risk for excessive rainfall. The shower and thunderstorm threat will end later this evening as instability diminishes with the loss of daytime heating. South to southeast winds will prevent more than an isolated rain shower for Bangor and Downeast today. Patchy to areas of fog will be a concern once again tonight south of Katahdin. Lows tonight will be in the upper 40s along the New Brunswick border and at the coast. Elsewhere, expect lower to mid 50s. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... An occluded front will continue to lift northeastwards through the forecast area during the day on Saturday. This area of lift will spur rain showers throughout the region through the day. Most rain showers will be on the lighter side, though some more moderate rainfall is quite possible, especially along the immediate boundary and associated with any mesoscale boundaries that may develop through the day. The center of the occluded low will likely enter the forecast area Saturday night, then slowly cross the region from west to east through the day on Sunday. As the center pushes through, steadier rain is likely, with light to moderate rainfall through the night. By Sunday, the center of the low pressure should be moving out into the Canadian Maritimes, with showers continuing to wrap around the backside of the low through the day. Rain showers will likely continue across the entire forecast area through the day on Sunday as well as through the night Sunday night. && .LONG TERM /MONDAY THROUGH FRIDAY/... As the occluded low continues to slowly churn off into the Canadian Maritimes, rain showers will likely continue to wrap around into the forecast area Monday through Tuesday. NW flow with the cold conveyor belt wrapping around the backside of the departing low will lead to temperatures falling below average, and will remain so through the middle of the week. Shower activity may lessen into the day on Wednesday, but as an upper level trough remains over the area, even though there is a break between two systems, there could still be enough instability for diurnal showers to develop. The next low pressure system could approach the area from the southwest into the day on Thursday. Of the global deterministic guidance suite, the CMC is the slowest with this system. In fact, the CMC has further slowed the system in the recent 00z run such that the area remains under local narrow ridging on Thursday. The other solution that most other guidance is locked onto brings a low near or over the area on Thursday, with another round of rain and the possibility for increased winds as the low could rapidly deepen through or just south of the Gulf of Maine. All that said, at this time range either of these solutions remain in play, and great uncertainty remains at this time. && .AVIATION /18Z FRIDAY THROUGH TUESDAY/... NEAR TERM: Variable conditions this afternoon. Generally VFR/MVFR, local LIFR. Showers along with isolated/scattered thunderstorms across northern and central areas. Thunderstorms could produce locally heavy rain. Isolated afternoon showers Downeast. VFR/MVFR local IFR early tonight, then MVFR/IFR occasional LIFR overnight with fog. Showers along with isolated/scattered thunderstorms early tonight, with isolated/scattered showers overnight. Across northern areas, east/southeast winds 5 to 10 knots today, with south/southeast winds 5 to 10 knots Downeast. South/southeast winds 5 to 10 knots regionwide tonight. SHORT TERM: Sat - Sun: IFR in rain. Brief LIFR fog possible at coastal terminals through Sat. SE winds 5 to 10 kts shifting N Sun. Sun night - Mon night: MVFR with brief IFR possible in lingering showers, particularly at northern terminals. N winds increasing to 10 to 15 kts. Tues: MVFR with gradual improvement towards VFR possible. N winds 5 to 15 kts. && .MARINE... NEAR TERM: Winds/seas below small craft advisory levels today through tonight. Areas of fog today through tonight. SHORT TERM: Winds and seas will likely remain well below small craft advisory levels through the weekend and into early next week. Fog is likely to remain over the waters Saturday through Sunday. Additionally, scattered rain showers becoming more steady could also lead to a decrease in visibility. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && $$ Near Term...Norcross/Clark Short Term...AStrauser Long Term...AStrauser Aviation...Norcross/AStrauser Marine...Norcross/AStrauser ####018003555#### FXUS65 KBOU 161759 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1159 AM MDT Fri May 16 2025 .KEY MESSAGES... - Breezy to windy conditions through Friday with fewer showers, mainly over the mountains in the afternoons. A small increase in the showers Saturday. - Windy again with increased shower and thunderstorm activity expected starting Sunday. && .DISCUSSION /Through Thursday/... Issued at 338 PM MDT Thu May 15 2025 We bumped up PoPs through early evening as there's a pretty good crop of light showers over northwestern Colorado heading east. They'll be fighting the downslope, so we only made minor changes for the I-25 corridor, but there's a pretty good chance of off and on showers in the mountains through early evening. The snow level is still around 8,000 feet, but it's warm enough that accumulations should be limited to areas above 10,000 feet with just light amounts above that. Winds are gradually decreasing overall. There may be a little pop of stronger winds in the foothills west of Denver and Boulder later tonight as a weak shortwave trough passes. This should be fading again in the morning. Friday will be drier, but still some low PoPs. There will also still be some wind, but it will be less than this afternoon. There's fair agreement now on some increase in moisture over northern areas on Saturday, so we'll have a modest increase in PoPs for the afternoon and evening. Sunday through Tuesday remains a question mark. The models have trended back towards each other and the idea of two shortwaves rotating around the mean trough. One would pass Sunday and another late Monday or early Tuesday. There's still some wobble in the latitude of the low on Sunday, which would decide whether it's a stormy day or a warm/dry/windy day. Current NBM solution has this gradient over our area, which seems reasonable. It's not the best setup for severe weather across most of our area, but there could be some dryline action out near the eastern border if it all sets up right. While the upper level features are uncertain, we should get a surge of cooler and moister low level air. That will be reinforced Tuesday behind the second part of the trough. Right now it looks like just a little cooling with increased moisture, which could create an increased severe threat, though the cooler temperatures and position north of the jet should reduce the ingredients. We'll be warmer and drier again for Wednesday and Thursday, either under a weak ridge, or possibly with a shortwave passing north of us or approaching by Thursday. NBM PoPs through all of this are looking better today, although they may still be too high Sunday, and too low Tuesday. && .AVIATION /18Z TAFS through 18Z Saturday/... Issued at 1139 AM MDT Fri May 16 2025 VFR conditions are expected through the TAF period. NNW winds gusting up to 25 kts have started to push through, although these gusts may be a little less frequent at DIA. Winds should decrease by 03-05Z and turn VRB before transitioning to drainage around 10Z. A Denver cyclone is expected to form tomorrow morning which will bring ENE winds by 18-21Z. There is a chance for -SHRA with 25kt gusts around that time as well, so a PROB30 has been introduced into the TAF for DIA. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Gimmestad AVIATION...Ideker