####018006946#### FXUS65 KRIW 161746 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1146 AM MDT Fri May 16 2025 .KEY MESSAGES... - A drier and milder day today with only around a 1 in 4 chance of a shower or thunderstorm in northern Wyoming. - A better chance of showers and storms Saturday, with strong storms possible over southwestern Wyoming. - Turning much cooler Sunday and Monday with rain and mountain snow across much of the area. && .DISCUSSION... Issued at 317 AM MDT Fri May 16 2025 Active weather will continue as we head through the next several days. We do have signs summer is coming though. The first sign is the predawn light when I go out to prepare the weather balloon for launch. This is around 4:45 am. Another sign is twilight still in the sky when I drive to work around 9:45 pm for my favorite shift, the midnight shift. (Yes, I am one of those weird people who prefers working at night). It will not feel like summer the next several days though, and some locations will feel like winter at times, especially early next week. Today looks like one of the least active days of the next several. Shortwave ridging will move across Wyoming and bring a lull in the persistent showers and storms. There will be a weak trailing shortwave that could being some showers this afternoon and evening, but these would be restricted to northern Wyoming and most of the population centers should stay mainly dry. Temperatures will also be somewhat warmer, but still only around 5 degrees below normal for most. And the shortwave will bring gusty wind to Johnson County for another day, but there should not be 60 mph gusts like yesterday. Ensemble guidance only gives a 1 in 3 chance of gusts past 40 mph for most at this time. Things start getting more active on Saturday, as an upper level low moves onshore in the Pacific Northwest and increases moisture across the area once again. Saturday should start dry for most, but coverage of showers and thunderstorms will increase as the low approaches. And things may get a little interesting. There will be decent upper level divergence across the area, and some morning sunshine may destabilize the atmosphere somewhat. Lifted indices will be negative and CAPE values will increase to 500 J/kg at times across southwestern Wyoming. The Storm Prediction Center has put this portion of Wyoming under a Marginal risk, with the main threat being strong wind gusts. The most numerous storms will be across western Wyoming. In areas east of the Divide, southwesterly flow will raise some high temperatures to around 70 degrees. It is also likely to keep most areas dry most of the time, with the average chance of a shower or thunderstorm around 1 out of 4 in this area. The aforementioned upper level low will then dive southeastward through the weekend and into Monday, with lee cyclogenesis likely occurring Sunday night into Monday in eastern Colorado and lifting into the Plains, with another upper level low developing over the western states. As a result showers will become more numerous across the area on Sunday, with another chance of afternoon thunderstorms, this time with thunder mainly east of the Divide where the best instability will be. And this will be the day we may make a transition back into winter for some locations. As flow turns northerly behind the low, much colder air will move in. Some model guidance drops 700 millibar temperatures as low as minus 5C across western Wyoming Sunday night, and this could lead to snow levels falling as low as 6000 to 6500 feet, possibly bring a coating of snow to the western valleys. The colder air then spreads east of the Divide Sunday night and especially Monday. And this is where the bulk of the precipitation will be that day. The air won't be quite as cold here, with 700 millibar temperatures generally bottoming out at around minus 7C, which would put snow levels around 5000 feet. And, given the position of the low and north-northeasterly flow, the Bighorns would be the most impacted area. Some probabilities for over 6 inches of snow include around 3 out of 4 in the higher elevations of the Bighorns and Wind River Range, with about a 3 out of 5 chance in the Tetons and Absarokas through Monday night. Chances of a foot are generally only 1 out of 2 at the very highest elevations so if highlights are needed it would likely be Advisories. This also looks to be a wet storm, with most locations east of the Divide and the northern mountains having at least a 1 out of 2 chance of a half an inch or more of QPF and favored north- northeast upslope locations like Buffalo, Thermopolis and Lander having a 1 in 2 chance of an inch of QPF or more. As for flooding, areas northeast of a Casper to Cody line have a marginal risk of excessive rainfall on Sunday and areas along and east of Interstate 25 have one for Monday. The rain will fall over a fairly long period though. In addition, with the colder air moving in, rain on snow is not likely as the higher elevations would see mainly snow. We will watch it though. Monday will be the coldest day of the week, with many locations having highs in the 40s. We should begin to dry out as the low moves away on Tuesday, although some lingering moisture will keep a few showers around, especially in eastern Wyoming. Flat ridging should then hold for the rest of the period, bringing more seasonal temperatures. Another shortwave may bring some showers and storms by midweek, but timing is all over the place this far out. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1144 AM MDT Fri May 16 2025 VFR flight conditions are expected this TAF period at all terminals. There is a low chance (30%) of showers at KCOD, KJAC, and northwest Wyoming this afternoon and early evening. There is less than a 20% chance for showers at KBPI, KPNA, and KRIW through 02Z Saturday. A few rumbles of thunder cannot be ruled out, however this probability is low. Conditions are expected to remain VFR but a brief period of MVFR flight conditions in a heavier shower is not out of question. Shower and thunderstorm chances increase again late in the TAF period (after 16Z) on Saturday at KRKS and this is communicated as a PROB30 group. Otherwise, expect gusty winds around 20kts at all west of the Divide terminals and KCPR this afternoon and early evening. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Hattings AVIATION...Gerhardt ####018007636#### FXUS66 KLOX 161746 AFDLOX Area Forecast Discussion...UPDATED National Weather Service Los Angeles/Oxnard CA 1046 AM PDT Fri May 16 2025 Updated Aviation Section .SYNOPSIS...16/923 AM. Strong onshore flow and a deep marine layer will bring cool weather through Saturday. Gusty onshore winds are expected in the Antelope Valley during the afternoon and evening. Night through morning drizzle or light rain is possible Saturday. A warming trend will be will begin Sunday and continue through next week as high pressure develops. Temperatures more typical of the summer season are likely away from the coast for the latter half of next week. && .SHORT TERM (TDY-SUN)...16/933 AM. ***UPDATE*** The marine layer has deepened to around 3000 feet this morning in response to the next upper level trough approaching the West Coast. Onshore flow is trending strongly onshore today and that will continue into Saturday. Temperatures are already trending cooler this morning across coast and valleys, in some areas by as much as 10 degrees. Overall, most areas will end up 3-6 degrees cooler than yesterday, with the marine layer only slowly clearing through the morning and early afternoon. ***From Previous Discussion*** Saturday, when the marine influence looks to be greatest, looks to the be the coolest day of the period. Temperatures around the 60s to lower 70s will be common across the coastal and valley areas and clouds will likely struggle to clear and there may be some areas of drizzle. Gusty onshore winds will develop between Saturday and Sunday night due to strong onshore pressure gradients. Advisory level winds are likely along the coastal areas and across the interior valleys, especially each afternoon and evening. The dying frontal boundary will slide south over the area on Saturday and the pattern will shift the wind from southwest to west on Saturday to west to northwest between Saturday night and into Sunday. Wind advisories will likely be needed for most coastal areas and the Antelope Valley on Saturday and Sunday, and through the Interstate 5 Corridor and across southern Santa Barbara County on Saturday night and into Sunday. The northerly pressure gradient will likely tighten again on Sunday night into Monday. There is a low-to-moderate chance of warning level winds developing through the Interstate 5 Corridor and across southern Santa Barbara County. A few solutions of the EPS members indicate warning level gusts at KSDB, while the latest NAM-WRF solutions indicate 45-50 knots of wind at 850 mb across the Transverse Ranges on Sunday night. Further hinting at the possibility, ECMWF EFI values highlight the Transverse Ranges on Sunday night, while NAEFS standardized anomalies nosing 850-700 mb winds between 3 and 4 standard deviation versus the CFSR period over the Central Coast. Wind advisories are likely to be issued for Sunday night when the timing and finer details come together, but the High Wind Warning potential will need to be watched closely. .LONG TERM (MON-THU)...16/405 AM. Gusty northerly winds are likely to persist into Monday morning as the surface pressure gradients remain tight. Confidence remains high for a warming trend for next week as high pressure aloft will build in over the region. While there is some uncertainty for Monday, EPS 500 mb height means climb through at least Thursday. By Wednesday or Thursday, EPS high temperature means suggest values in the 90s being common for the valleys, foothills, and desert, while temperatures in the 80s to lower 90s could be common across the coast. Deterministic ECMWF solutions support the idea of warming as pressure gradients weaken substantially to near neutral or light offshore. NBM solutions give about a 15 percent chance of KPMD and KWJF of hitting 100 degrees, which if it occurred would be about three weeks earlier than normal. Away from the coast, the temperature forecast leans more heavily into the 75th percentile of NBM solutions between the period between Wednesday and Thursday night. Experimental NWS heat risk values climb for Wednesday and Thursday, trending toward a period potentially dangerous heat. && .AVIATION...16/1746Z. At 1640Z at KLAX, the marine inversion was around 3000 feet deep. The top of the inversion was 4500 feet with a temperature of 14 degrees Celsius. High confidence in TAFs for KWJF and KPMD. Moderate confidence in TAFs for remaining sites. There is a 30% chance for IFR to MVFR cigs between 12Z and 18Z at KPRB. Coastal sites forecast to clear have a 30% chance of not clearing, and 30% chance for sites forecast to not clear to SCT. Dissipation of cigs may be off +/- 2 hours, and arrival may be off +/- 3 hours. Minimum flight cat may be off by one cat for KSBP/KSMX. KLAX...Moderate confidence in TAF. There is a 30% chance for cigs to SCT between 20Z and 03Z. Cigs may SCT tomorrow between 20Z and 00Z. There is a 20-40% chance for an east wind component of 8 kts between 11Z and 18Z. Best chances between 14Z and 18Z. KBUR...Moderate confidence in TAF. Return of cigs may be off +/- 3 hours, and there is a 20% chance for cigs 007-009. && .MARINE...16/806 AM. For the Outer Waters, moderate confidence in current forecast. Today through Tuesday, high confidence in combination of Small Craft Advisory (SCA) level winds and seas. For Saturday afternoon through Sunday night, there is a 50-60% chance of Gale force winds, with higher chances Sunday afternoon through late night. For the Inner Waters, moderate confidence in current forecast. Today through Sunday night, high confidence in SCA level winds, especially in the afternoon and evening hours. There is a 50% chance of Gale force winds Saturday afternoon through Sunday evening. For Monday through Tuesday, there is a 50-70% chance of SCA level winds continuing. For the Inner Waters south of Point Conception, moderate confidence in current forecast. Through Saturday morning, high confidence in winds and seas remaining below SCA levels. For Saturday through Sunday night, high confidence in SCA level winds, focus through the Santa Barbara and western sections of the southern Inner Waters. Additionally, there is a 50% chance of Gale force winds across the Santa Barbara Channel Saturday evening through Saturday night, with a 30% chance Sunday afternoon through late night. For Monday through Tuesday, high confidence in winds and seas remaining below SCA levels. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory in effect from 10 AM to 9 PM PDT Saturday for zones 381-383. (See LAXNPWLOX). PZ...Small Craft Advisory in effect from 3 PM this afternoon to 9 PM PDT this evening for zone 645. (See LAXMWWLOX). Gale Watch in effect from Saturday afternoon through late Saturday night for zones 645-670-673-676. (See LAXMWWLOX). Gale Watch in effect from Saturday evening through late Saturday night for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 2 PM PDT Saturday for zones 670-673-676. (See LAXMWWLOX). && $$ PUBLIC...MW/Hall AVIATION...Lewis MARINE...RAT/Lewis SYNOPSIS...MW/Hall weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox ####018007513#### FXUS65 KCYS 161748 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY Issued by National Weather Service Riverton WY 1148 AM MDT Fri May 16 2025 .KEY MESSAGES... - Seasonable temperatures into this weekend with isolated thunderstorms returning on Saturday. - Active weather pattern late this weekend and possibly early next week as another Pacific storm system impacts the region. There is a chance for strong to severe thunderstorms on Sunday across the eastern plains. - Drier weather with a slow warming trend for mid to late next week. && .SHORT TERM /THROUGH SATURDAY/... Issued at 130 AM MDT Fri May 16 2025 Pretty quiet early this morning across southeast Wyoming and western Nebraska with a few rain/snow showers across Carbon and Albany counties. Winds have briefly decreased and should stay that way until just after sunrise later this morning. Most areas should stay dry, but high res guidance does show some wrap around rainfall edging into the far northern Nebraska panhandle. Harrison and Chadron Nebraska might see some off/on rainfall this morning into early this afternoon. Otherwise, Friday looks to remain dry but windy across much of the forecast area as a shortwave ridge will move into southern Wyoming through the afternoon. Winds shouldn't be quite as strong as yesterday (Thursday), but west to northwest winds may gust as high as 40 to 45 mph. These winds are expected to diminish mid to late afternoon as 700mb winds lower through the day. Increasing midlevel subsidence associated with the shortwave ridge axis should suppress most convective initiation into the evening hours. Convective parameters suggest some fair weather CU development, but expect little or no shower activity through the evening hours. It should be slightly warmer today with 700mb temperatures increasing between 0C to 5C, which should translate to highs in the upper 50s to mid 60s across southeast Wyoming and upper 60s to low 70s for western Nebraska. It will remain windy, but winds should start to ease in the mid to late afternoon hours as the storm system across the Great plains lifts northeast into the Great Lakes Region. As we head into Saturday, models continue to show showers and thunderstorms returning to the region as the mid to upper level flow backs into the southwest bringing some warm air advection and better thermodynamic profiles. High temperatures will trend a bit higher Saturday afternoon as 700mb temperatures climb above 5c. Should see highs in the low to mid 70s across western Nebraska and maybe portions of far eastern Wyoming with low to mid 60s along and west of the I-25 corridor. Models continue to indicate a weak shortwave disturbance lifting northeast ahead of the next Pacific storm system moving into the Great Basin region late on Saturday. This disturbance will aid in initiating scattered rain showers and widely scattered thunderstorms across southeast Wyoming. Can't rule out a few stronger thunderstorms later on Saturday and Saturday evening as models show considerable moisture advection ahead of the next storm system as surface winds shift into the south and southeast. Brief gusty winds and frequent lightning look like the primary threats. This activity may linger past midnight late Saturday night across the Nebraska panhandle. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Issued at 230 AM MDT Fri May 16 2025 Primary forecast concern is in the medium range as the next Pacific storm system redevelops across the central High Plains on Sunday. Still tracking a potent Pacific disturbance which is forecast to move across the eastern Great Basin region and into the Front Range on Sunday. All models indicate a pretty dynamic system setting up across the area with ample frontogenesis and cyclogenesis across far southeast Wyoming and western Nebraska through Sunday night. Thermodynamic profiles do not look quite as good as they did yesterday with MLCAPE and SBCAPE values a little lower compared to yesterday, but 0-6km shear is still there. Can't rule out strong to severe thunderstorms Sunday and Sunday night, but would like to see the surface low a bit further north. 00z models have trended further south with the center of this low with the warm sector barely clipping portions of western Nebraska. In addition, model soundings show low clouds and CIN lingering through most of the day with east to southeast surface winds. Surface winds do shift more into the east through the day leading to stronger veering wind profiles aloft as we head into the late afternoon hours. This set up bares watching as we head into the weekend as this pattern has done well in the past, but confidence is limited at this time. Otherwise, there is a good chance for some moderate to heavy precipitation rates as the first disturbance lifts northeast with very good forcing present. As we head into early next week, models are in much better agreement with the second portion of this storm system. Secondary disturbance, which will lag behind the first one on Sunday and dig south into the four corners region, is expected to slow down and force the first system to drift north or retrograde westward into Wyoming on Monday. The energy associated with the secondary disturbance will likely be absorbed by the primary storm system to our east. As a result, cool temperatures and a resurgence of rainfall is expected to start off the week. The main question is how much of the forecast area this will cover...and how cool will it get. Models have trended colder with 700mb temperatures as low as -5c into Tuesday. This is cold enough for snow down to around 7000 feet this time of the year. Increased POP with the second part of this system due to much better model agreement. Ensembles have also seem to come on board with this overall solution. Monday is forecast to be relatively chilly with highs struggling to reach into the 50s for most locations. Areas above 6000 feet may remain in the 40s through the day depending on cloud cover and precipitation rates. Based on the 00z ECMWF, rainfall may linger into Tuesday before the upper level low finally ejects eastward into the Great Plains. For mid to late next week, models show a gradual warming trend as a broad flat ridge axis shifts east into Colorado and Wyoming. Models now show drier conditions Wednesday and Thursday with a limited coverage of showers/thunderstorms. Expect high temperatures to return to the 70s by Thursday afternoon. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1147 AM MDT Fri May 16 2025 MVFR to VFR conditions will continue today over CDR as light precipitation moves east and our low pressure system departs today. Expect improving sky conditions through the day here. Elsewhere, VFR is expected with mid-level clouds expected to reach SCT or BKN coverage through the day, but clouds will quickly diminish around sunset. Westerly winds will gust upwards of 30kts at RWL and LAR and possibly BFF/CYS before dropping off this evening. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...CG LONG TERM...MAC/WFO-RIW AVIATION...WFO-RIW ####018006527#### FXUS64 KJAN 161748 AAA AFDJAN Area Forecast Discussion...UPDATED National Weather Service Jackson MS 1248 PM CDT Fri May 16 2025 ...New AVIATION... .MESOSCALE UPDATE... Issued at 946 AM CDT Fri May 16 2025 Similar to yesterday morning at this time, the morning stratus was showing sings of breaking up on satellite imagery. This will allow for decent warming this afternoon and temperatures are expected to top out much warmer than normal again. Surface analysis still had a ridge across the northern Gulf from the east and a stalled front well to our northwest. The gusty southwest wind today will continue to help maintain low level moisture and despite the decent insolation this afternoon, the 12Z Fri JAN sounding showed a stout inversion at 950mb and no precipitation is expected in our CWA until this evening. The current forecast remains on track. /22/ && .DISCUSSION... Issued at 328 AM CDT Fri May 16 2025 Today through Saturday Night... The forecast remains on track for the short term period with global guidance continuing to show the ridge axis flattening across the southeast region today. This will allow for quasi-zonal flow to prevail across the CWA through the weekend with afternoon highs peaking into the upper 80s/lower 90s areawide. With this qusai-zonal flow expected across the region today, an unstable airmass will begin to move into the region. This airmass, combined with a couple of upper-level disturbances aloft and some northerly moisture flow from the Tennessee Valley, will allow for rain/storm chances across central/northern portions of our CWA later tonight through the Sunday evening/night timeframe. Strong to severe thunderstorms will be across northern portions of our forecast area including portions of southeast Arkansas and portions of northeast Louisiana. The "Marginal" risk (1 out of 5) for tonight will continue to be advertised with no changes made to the outlook. The main hazards will be damaging winds and hail up to quarter size for areas highlighted in the "Marginal" risk. No changes have been made to the severe graphic at this time for tonight and a "Slight" risk (2 out of 5) will continue to be advertised for northwest portions of our CWA. Damaging wind gust up to 60-70 mph and hail up to golf ball size will be the main concerns for areas highlighted in the "Slight" risk. A brief spin up tornado cannot be ruled out. Isolated severe storms will continue across our forecast area looking ahead into Saturday afternoon/evening with afternoon highs peaking in the upper 80s/lower 90s. Depending how the rain pans out come Saturday afternoon, it is possible that a couple of areas along and south of I-20 could see heat indices around 100 degrees. Regardless, the "Marginal" risk will continue to be advertised for areas along and north of the I-20 corridor. Damaging wind gusts and hail up to quarter size will be the main hazards for areas highlighted in the "Marginal" risk. A "Slight" risk will continue to be advertised for portions of the Delta including portions of southeast Arkansas. Some of the storms could produce heavy rainfall at times, with rainfall totals ranging between 0.5-1 inches with local higher amount possible especially for areas along and north of Hwy 82. Given that this system will moving quite fast across our CWA, flash flooding concerns will be low; however, some localized flash flooding cannot be ruled out. Sunday through Thursday... Another round of thunderstorms will occur heading into Sunday afternoon/evening with a few strong/isolated severe t-storms possible mainly for areas north of I-20. A "Marginal" risk has been introduced for Sunday, however there are some discrepancies that remain regarding the uncertainty of this system for Sunday. Nevertheless, trends will continued to be monitored and details will be ironed out as we get closer to Sunday. Rain chances will begin to decrease Sunday night into the new work week as a sfc ridge builds over the southeast CONUS. Quiet conditions will continue across much of our forecast area with a slight chance of scattered showers across portions of the Golden Triangle heading into Monday afternoon. Quiet weather conditions will occur across the area looking ahead into Tuesday morning as future global guidance shows the ridge axis beginning to slowly push east away from our forecast area giving us a small little break from the rain. A significant 1004mb low pressure system hovering over the Central Plains will push east towards the Ohio River Valley region Tuesday afternoon/evening. The associated cold front over southern Texas will track east towards the southeast region late Tuesday evening. This combined with southerly moisture flow from the Gulf will help reintroduce isolated to scattered showers/t-storm chances across our entire CWA. Storm chances will continue heading into Wednesday as the cold pushes east across our forecast area. Rain chances will start to diminish across the region looking ahead into Thursday as the cold front tracks southeast out of our forecast area towards the Gulf Coast giving us a nice little break from the rain. Weather conditions will remain quiet heading into Friday with mostly sunny skies by the weekend. /CR/ && .AVIATION... (18Z TAFS) Issued at 1241 PM CDT Fri May 16 2025 VFR conditions along with a gusty 20-25kt sw-s wind WL prevail areawide this aftn. The gusty wind will gradually subside after 23Z and VFR conditions wl continue to prevail until after 08Z Sat when MVFR cigs wl redevelop. There is a low chance of VCTS across the north 10z-14Z and IFR cigs are psbl in the south by 10Z. Conditions wl begin to improve after 15Z and VFR conditions are expected areawide by 17Z. /22/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 91 74 91 71 / 0 20 30 20 Meridian 92 72 91 71 / 0 20 40 20 Vicksburg 90 74 91 72 / 0 30 30 20 Hattiesburg 94 74 94 72 / 0 0 20 10 Natchez 89 74 91 72 / 0 10 10 10 Greenville 89 72 89 73 / 10 70 20 40 Greenwood 90 71 89 72 / 10 70 30 40 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ 22/CR/22 ####018005327#### FXUS63 KGID 161748 AFDGID Area Forecast Discussion National Weather Service Hastings NE 1248 PM CDT Fri May 16 2025 .KEY MESSAGES... - Strong northwest winds today. Gusts to 60 MPH are possible, mainly near and north of Highway 92. A High Wind Warning is in effect for these areas. - Light rain showers today. Most areas will not see measurable rain. - Severe thunderstorms are possible on both Sunday and Monday. && .DISCUSSION... Issued at 414 AM CDT Fri May 16 2025 Currently, a band of sprinkles stretches from northwest Kansas into central Nebraska. This band will continue eastward into the morning hours, but measurable precipitation is unlikely. A strong upper low passing to our north will push gusty northwest winds into the area today. The ECMWF/EPS have consistently shown wind gusts approaching/exceeding high-wind criteria (50kts...58 mph) for several runs. Forecast gusts from the high=resolution CAMs aren't quite as optimistic, but HRRR/RAP forecast soundings still indicate deep mixing with wind speeds at or above 50 kt at the top of the mixed layer. Additionally, some light rain showers are expected to push into northern parts of the area late this morning into the afternoon, potentially providing additional enhancement for winds. All this being considered, a High Wind Warning was issued for the areas that are most likely to see severe (58 MPH+) gusts. The rest of the area will be quite windy as well, with sustained wind speeds ranging from 25-40 MPH and gusts of 40-55 MPH (highest north). These winds, combined with with humidity in the 20-25 percent range, will also result in near-critical fire weather conditions, mainly for southern portions of the area where they see the least cloud cover. Any rain showers this afternoon will be light, and likely will remain confined to areas north of Highway 92. The probability for even 0.05" of rain is only 10-15% in these areas. Winds gradually diminish this evening into tonight. Clearing skies should allow temperatures to fall into the 40s in most areas...and possibly into the upper 30s in northern and western parts of the forecast area (Valley and Dawson counties). Saturday should be a very pleasant day across the area. Seasonable temperatures (70s), light winds, and mostly clear skies are expected. A weak shortwave will to move through the central Plains. Low chances for rain showers return late Saturday night, but any severe convection is expected to remain to our southeast. On Sunday, an upper trough is expected to deepen over the Rockies, pushing more warm/moist air into the central Plains. Exact details remain uncertain, but a surface low is expected to develop over eastern Colorado, with a warm front lifting northward across the area and a dryline setting up to our southwest. Convective parameters are favorable for supercells (40-50kt+ effective shear...MLCAPE 1500-2500J/kg+), but capping/coverage of storms remains the primary uncertainty. A strengthening LLJ will then keep some severe threat going well into the overnight hours. The latest NBM has a 60-90% chance for rain/thunderstorms across most of the area Sunday night, but beneficial rain is far from a "guarantee," but the northeastern half of the area dues show a 60% chance for 0.25" or more per the 00Z global ensembles. On Monday, another round of thunderstorms is possible as the upper trough ejects through the central Plains. Again, convective details are very uncertain at this range, but parameters appear favorable for at least some severe threat...especially eastern-southeastern parts of the area as indicated by the SPC outlook and AI-NWP convective forecasts. Some showers could continue into Tuesday, but the severe threat decreases as we move into a cooler post-frontal airmass. High temperatures on Tuesday are "only" expected to reach the 60s. Northern areas could even be stuck in the upper 50s! The forecast dries out for the middle of next week, but spotty chances for thunderstorms do return by the end of next week into the weekend. Temperatures also return to the 70s and 80s by the end of next week. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1237 PM CDT Fri May 16 2025 For KGRI/KEAR Airports: Main concern for this TAF period lies in roughly the first 6hrs, with strong NWrly winds continuing across the entire forecast area. Not out of the question that gusts near 50 MPH could occur, mainly during the early-mid afternoon hours. Speeds are expected to gradually decrease this evening/tonight...looking to be closer to 15 MPH by around sunrise Sat, lingering through the end of this period. This afternoon, SCT/BKN lower level CU will remain in place, but ceilings should remain VFR. Similar to yesterday, some isolated/scattered showers are not out of the question through the afternoon hours...with the rest of the period expected to be dry. && .GID WATCHES/WARNINGS/ADVISORIES... NE...High Wind Warning until 8 PM CDT this evening for NEZ039>041- 046>049. KS...None. && $$ DISCUSSION...Mangels AVIATION...ADP ####018004969#### FXUS63 KMPX 161748 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1248 PM CDT Fri May 16 2025 .KEY MESSAGES... - Gusty winds as high as 40-50mph today. - Cooler weather continues this weekend into next week. - Next chance for rain arrives Monday into Tuesday. && .DISCUSSION... Issued at 254 AM CDT Fri May 16 2025 Satellite imagery shows an impressive system across multiple channels including IR, water vapor, and nighttime microphysics as the system which brought our severe weather on Thursday continues to churn over the region. Water vapor imagery shows just how far the cold front has moved since the afternoon as the angle of the front has shifted to being WNW to ESE with clear skies across most of Wisconsin as the upper level low remains occluded this far into the system's life cycle. Due to the low pressure center being stacked underneath the occlusion over northwest Minnesota by this afternoon, today is expected to be quite raw compared to what we have been used to thus far in May with winds at 20 to 30 and gusts as high as 50mph strongest in western Minnesota closer to the center of the low. Rain showers are also expected to persist as the surface low spins over the region, favoring western Minnesota through much of the day until the system begins to accelerate eastwards into western Wisconsin by later tonight. Rain amounts will not be significant for any single area with around a quarter inch up to a half inch in western Minnesota diminishing to less than a tenth of an inch for the Twin Cities and western Wisconsin. By 18z Saturday the upper level low will be over eastern Michigan with a wedge of cool air flowing into the region allowing for overnight lows to fall into the 30s in western Minnesota on Sunday morning, with a chance for frost in western Minnesota. There is little chance for frost for southern Minnesota and western Wisconsin including the Twin Cities metro as the 850mb nose of coolest air will stall in western Minnesota. As we head into the start of the week, global deterministic guidance is showing another system moving eastwards over the Rockies approaching the region later in the day Monday lingering through Tuesday, bringing out next chance of widespread rain showers to the region. While there are some differences within the greater ensemble suite, the mean upper level low is situated over western Nebraska/SoDak by Tuesday morning dragging a stationary front over southeastern Minnesota where the greatest chance for showers exists. The biggest differences within guidance arrives as the system progresses eastwards by early Wednesday with showers generally ending early on Wednesday. This system will have much cooler air wrapped within compared to the system that will move out in the next 48 hours, so severe weather potential seems quite limited despite decent synoptic forcing. Upper level flow breaks down with low forecast confidence by late week with significant differences between ensemble members and different models. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1236 PM CDT Fri May 16 2025 Occasional light rain and gusty SW winds will continue through much of the afternoon in MN and will overspread western WI over the next several hours. Cigs have been slower to drop than guidance had suggested but still seeing cigs drop into MVFR shortly after the onset of light rain, and will eventually see IFR this evening and overnight. Winds are currently about the strongest we will see today with a slight decrease through the afternoon. They will then increase again overnight following a shift to NWerly. Rain will exit from west to east late tonight with IFR cigs continuing into the morning hours. KMSP...Light rain has started and will continue off-and-on through the evening, gradually tapering off after 09Z. SWerly crosswind continues through the afternoon with some gusts to 35kt possible over the next 1-2 hours, but these should decrease to below 30kts after 19-20Z. Wind shift to westerly will arrive around 01Z, and continue to veer to NWerly by 03Z. Some increase in gusts to as high as 30 kts possible overnight after this wind shift with decreasing gusts tomorrow morning and afternoon. /OUTLOOK FOR KMSP/ SUN...VFR. Wind NE 5-10 kts. MON...Mainly VFR. Chance MVFR/SHRA. Wind E 10-15G25kts. TUE...Mainly VFR. Chance MVFR/SHRA. Wind E 10-15G25kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...Wind Advisory until 7 PM CDT this evening for Blue Earth-Brown- Chippewa-Faribault-Freeborn-Lac Qui Parle-Le Sueur-Martin- Nicollet-Redwood-Renville-Sibley-Steele-Waseca-Watonwan- Yellow Medicine. WI...None. && $$ DISCUSSION...TDH AVIATION...DPH ####018008123#### FXUS63 KABR 161749 AAC AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 1249 PM CDT Fri May 16 2025 .KEY MESSAGES... - West to northwest winds will potentially gust to 55 to 65 mph across western South Dakota today, while central and northeastern South Dakota experience west to northwest winds potentially gusting to 45 to 55 mph. - The probability of low temperatures falling to 36F degrees or colder Saturday night is 60 to 90 percent in areas along and north of the US Highway 212 corridor. - Another round of showers and thunderstorms will impact the area Sunday through Tuesday. The probably of seeing 0.75 inches of rain over a 24 hour period, ending at 7 am Tuesday, is 40 to 70 percent. && .UPDATE... Issued at 1237 PM CDT Fri May 16 2025 Aviation discussion updated below for the 18Z TAFs. UPDATE Issued at 1036 AM CDT Fri May 16 2025 Will continue to see areas of showers wrap around the low pressure system off to our northeast. Additional rainfall amounts likely less than a half inch for most areas, but did make some adjustments to PoPs based on current radar trends. Will leave wind headlines as is for right now as we'll continue to see winds gusting over 45 mph for much of the region, and could top out around 60 mph over portions of central SD. && .SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/... Issued at 331 AM CDT Fri May 16 2025 At 3am CDT, skies are cloudy, and showers, rotating around the upper low centered near the Dakotas/MN tri-state border region, cover portions of north central and northeast South Dakota. With a 982hpa surface low analyzed over Richland Co, ND, west winds have been consistently running 25 to 40 mph sustained, with gusts ranging from roughly 45 to 65 mph. High Wind Warning/Wind Advisory headlines continue. Starting with winds today, model guidance definitely supports down- turn in the strength of winds and wind gusts today across northeast South Dakota. Will allow the High Wind Warning in place for the Prairie Coteau and a couple of tiers of counties east of the Missouri River valley to expire at 7am CDT this morning. Further west, though, guidance suggests those gusts to 58mph or higher are still possible for, at least, the first half of the today period (guidance is really pinging the west-river half of South Dakota with a high-wind warning type of signal for low level/boundary layer winds). CWA-wide, though, wind advisory strength wind potential will persist pretty much all day, with a down-turn in wind/gusts overnight tonight. The upper low and surface low will move away from the region today into tonight, affording some mid/upper level ridging to begin building over the CWA heading into Saturday. At the surface, the pressure gradient begins to relax from west to east, most noticeably out over the Missouri River valley (west river) forecast zones heading into sunshine hours on Saturday. This pesky/persistent low stratus cloud layer is progged to stick around today and tonight before potentially beginning to break up strato-cu out on Saturday. The western edge of the stratus is progged to be moving into or nearing the western edge of the CWA between ~4am CDT and ~7am CDT Saturday, when winds could be diminishing below 10mph. So, there is a little bit of frost potential spilling over into (for the time being) portions of Corson/Dewey counties for a few hours early Saturday morning. A colder than normal airmass in place now, makes that potential for frost early Saturday morning. In fact, temperatures (based off model low level thermal progs) today through Saturday will be well below normal (20 to 25 degrees below normal) for both daytime and night-time temperatures. Low level CAA does continue across northeast South Dakota and west central Minnesota today and tonight, but wind and clouds should help keep temperatures in check. TROWAL-forced showers of rain are in full swing, per low to mid- level thermal advection progs and water vapor satellite imagery early this morning. This set-up should continue to produce numerous to widespread coverage of showers, during the first half of today, that wraps from north to south and west to east around the back and bottom sides of this upper circulation. By the end of the day, though, areal coverage should be diminishing to isolated pockets of rain shower activity for a few hours this evening before either completely ending or moving out of this CWA. That should leave the rest of tonight into Saturday dry. && .LONG TERM /SATURDAY EVENING THROUGH THURSDAY/... Issued at 331 AM CDT Fri May 16 2025 Lets start off with frost potential Sunday morning. Aloft we have a ridge axis overhead, with a shortwave over the 4-Corners region lifting northeast. Mid level warm advection ahead of the shortwave will result in cloud cover above 8kft coming in from the southwest, though NAM BUFKIT doesn't really get going till after 09Z. Thus, radiational conditions will not be inhibited by clouds for most of the area much of the night. At the surface, a ridge extends down out of Canada along the Red River valley into western Minnesota. Thus, low level flow is light and easterly. NBM deterministic low temperatures right now are right about the freezing mark from Bowdle to Groton and north of Redfield, with a broader region encompassing most of the northeast part of the state of a 50 to 90% probability of falling below 36F. With the approaching wave, focus shifts to precipitation chances. Even by 12Z, NAM BUFKIT for Pierre still has a deep dry subcloud layer below 8kft, although the GFS is a bit more aggressive with scouring out the dry air. The surface low associated with the shortwave really doesn't get going until late Sunday, and through the day we're stuck with mainly low POPs across western/central SD under broadly diffluent flow. NBM moisture probabilities through the end of Sunday are about 50/50 for the Pierre area at 0.25 inches, about the same for Miller and Mobridge for 0.1 inches, with probables dropping precipitously from there northeast. Monday is where most of the moisture is at, as the low lifts into Nebraska and weakens into an inverted trough and the upper wave lifts northeast and then weakens. An upper low then develops over the eastern CONUS, with more zonal flow across the western CONUS. The pattern that is responsible for drawing down this cooler near surface airmass, and ample/widespread precipitation weakens and we see closer to climatological temperatures and lower probables for moisture. Also, not seeing any days of concern from the AI/machine learning severe weather algorithms in the upcoming mid/late week timeframe. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1237 PM CDT Fri May 16 2025 Terminals KABR,KATY,KPIR,KMBG Generally MVFR CIGs will continue to affect the region through the TAF period. There may be some patches of IFR clouds as well late tonight into early Saturday morning. Also, clouds are forecast to be on the decrease from west to east across the region on Saturday, and have reflected this in a TEMPO group for SCT conditions towards the end of the TAF period across KPIR/KMBG. Areas of -SHRA/SHRA/-RA and BR will continue to affect the area today, with precipitation eventually coming to an end this evening. Periodic MVFR (potentially IFR?) VSBY is possible with precipitation. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...High Wind Warning until 7 PM CDT /6 PM MDT/ this evening for SDZ003-015-033-045. Wind Advisory until 7 PM CDT this evening for SDZ004>011-016>023- 034>037-048-051. MN...None. && $$ UPDATE...TMT SHORT TERM...10 LONG TERM...07 AVIATION...TMT ####018008821#### FXUS62 KJAX 161749 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 149 PM EDT Fri May 16 2025 ...New AVIATION... .UPDATE... Issued at 956 AM EDT Fri May 16 2025 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf Little changes to the forecast this morning. Low clouds and fog continue to rapidly dissipate, with a mainly sunny and hot day in store with highs flirting with record values by this afternoon. Excellent mixing this afternoon should allow dew points to drop into the low 60s over the interior, and therefore avoid any significant heat indices towards advisory criteria. && .NEAR TERM... (Today and Tonight) Issued at 344 AM EDT Fri May 16 2025 Low stratus clouds and some potential for patchy to areas of fog will expand across the Suwannee Valley and portions of inland southeast GA through the predawn and early morning hours, with this low cloud cover likely reaching the U.S. Highway 301 corridor towards sunrise. Lower clouds should remain west of the I-95 corridor this morning, with mixing after sunrise likely allowing these lower ceilings to lift by mid-morning at inland locations. Periods of mostly thin cirrus will continue to spill overtop of the ridge and across our area through tonight. Otherwise, west- southwesterly low level flow will delay the development of the Atlantic sea breeze boundary to the early to mid afternoon hours at coastal locations. A dry and increasingly subsident atmosphere will allow for dewpoints to potentially fall to around 60 at inland locations this afternoon as filtered sunshine allows temperatures to soar to the mid and upper 90s at inland locations. These values will challenge daily record high temperatures at our designated climate sites (see "Climate" section below for details). This dry air mass will keep maximum heat index values in the upper 90s to around 100, with coastal locations more likely to experience "feels-like" temperatures near the century mark as the afternoon sea breeze moves slowly inland, bumping coastal dewpoints back to the upper 60s to around 70 by the mid to late afternoon. This sea breeze will struggle to reach the I-95 corridor during the late afternoon, and its delayed development will yield highs in the lower 90s all the way to area beaches during the early to mid afternoon hours before an onshore breeze drops temperatures back to the upper 80s before sunset. Another round of low stratus and potentially some fog development is expected across the Suwannee Valley and portions of inland southeast GA after midnight, with some potential for eastward expansion of these low stratus ceilings and fog towards sunrise. Light westerly low level winds will otherwise prevail overnight, with lows only falling to the upper 60s inland and around 70 at coastal locations. && .SHORT TERM... (Saturday through Sunday night) Issued at 344 AM EDT Fri May 16 2025 High pressure will be centered to the southeast Saturday, with ridging extending west across southern FL. A cold front will drop into central GA Saturday afternoon. This pattern will then linger through Sunday night. The real question this period will be whether the front sinks far enough to be a focus for convection into SE GA. A few weak upper waves pass along the frontal zone during the period, which could cause the boundary to waiver a bit from north to south, otherwise there is not much support to push boundary into forecast area. So, at this point precipitation chances will be kept on the low side this period over SE GA, and NE FL will be kept dry. Temperatures will remain above seasonal averages throughout this period. With dewpoints largely in the 60s throughout this time frame, heat will not make it to advisory levels. With the prevailing flow from the west southwest between the ridge and the front, the heat will make it all the way to the beaches, with little, if any afternoon push inland of the east coast sea breeze. && .LONG TERM... (Monday through Thursday) Issued at 344 AM EDT Fri May 16 2025 The high pressure ridge will lift to the north into central FL Monday into Tuesday, with frontal boundary also moving further to the north. A ridge will be in place at 500mb. Subsidence under these two ridges and moisture still on the low side will provide dry weather for the start of the week. The ridge will move away to the southeast Tuesday night, as an upper trough digs into the southeastern US, and a cold front moves into southeastern US. Long term models have timing differences in the cold frontal passage, but in general looking at the Wednesday afternoon to Thursday afternoon time frame. Too early to determine potential strength of storms on the frontal passage, but indications are that there will be a fairly significant thermal boundary with it, suggesting it could be a strong passage. Temperatures will continue above average throughout this period. Thursday would start a trend toward lower readings. && .AVIATION... (18Z TAFS) Issued at 140 PM EDT Fri May 16 2025 VFR conditions will continue through at least the first part of tonight as dry high pressure is in control. Winds near or just above 10 knots will also be common through about sunset, especially at coastal terminals. Some FU could also continue over the next few hours at JAX due to the nearby garage fire. Chances for FG and low stratus will be expected again at inland terminals late tonight and into Saturday Morning, which could expand as far east as JAX/CRG as well. && .MARINE... Issued at 344 AM EDT Fri May 16 2025 Atlantic high pressure will continue to extend its axis across the Florida peninsula through the weekend and early next week, keeping a prevailing offshore wind flow in place across our local waters. The afternoon sea breeze will shift winds to south and southeasterly for the near shore waters through around sunset, with winds shifting to southerly during the evening hours. Seas of 2 to 4 feet will prevail both near shore and offshore during the next several days. A weakening frontal boundary will enter the southeastern states late this weekend, but this front will stall to the north of the Georgia waters. An isolated late afternoon or evening thunderstorm is possible over the Georgia waters on Sunday. The next significant frontal boundary will move across our local waters by late Wednesday or Thursday, possibly accompanied by widely scattered showers and thunderstorms. Rip Currents: Prevailing offshore winds and low surf heights should keep the risk low through at least midweek next week. Afternoon sea breezes will increase surf heights somewhat, but a weak easterly ocean swell will not raise the risk appreciably. && .FIRE WEATHER... Issued at 344 AM EDT Fri May 16 2025 A dry and increasingly hot air mass will result in minimum relative humidity values falling to the 30-35 percent range at most locations today and again on Saturday. Breezy westerly transport winds will create good daytime dispersion values this afternoon. Westerly transport winds will strengthen even further on Saturday and will combine with elevated mixing heights to create high to very high daytime dispersion values on Saturday and Sunday. The Atlantic sea breeze should remain pinned to the east of I-95 through the mid to late afternoon hours today and again on Saturday, with this boundary expected to push further inland on Sunday afternoon. && .CLIMATE... Issued at 344 AM EDT Fri May 16 2025 Daily Record High Temperatures through Tuesday at our designated climate sites: Fri 5/16 Sat 5/17 Sun 5/18 Mon 5/19 Tues 5/20 -------------------------------------------------- Jacksonville 96/1995 96/1995 96/1899 97/1960 99/1962 Gainesville 98/1896 96/1915 97/1930 99/1899 97/1938 Alma, GA 95/1990 94/2001 95/2001 97/1960 99/1962 Craig Airport 94/1994 93/2001 93/2001 92/2006 97/2006 && .PRELIMINARY POINT TEMPS/POPS... AMG 69 92 71 92 / 0 0 0 20 SSI 71 91 75 89 / 0 0 0 10 JAX 68 96 70 96 / 0 0 0 10 SGJ 70 95 69 93 / 0 0 0 0 GNV 67 93 67 95 / 0 0 0 0 OCF 67 93 67 94 / 0 0 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ ####018006375#### FXUS63 KGRB 161749 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 1249 PM CDT Fri May 16 2025 Updated aviation portion for 18Z TAF issuance .KEY MESSAGES... - Gusty southwest winds are expected today with highest gusts up to 40 mph, primarily between Fox Valley and Lake Michigan. - Scattered showers and thunderstorms are expected this afternoon. Damaging wind gusts and small hail may be possible with any stronger storms. && .DISCUSSION... Issued at 1205 AM CDT Fri May 16 2025 A warm and windy day is in store for today. The low will be over northwest MN at 7AM this morning and should make it to Duluth around 7PM. A lobe of vorticity is expected to swing up from IA through eastern WI during the day. Vorticity advection and also upper divergence from the left exit region of an upper jet will provide synoptic forcing to allow for showers and storms. Forecast soundings show very steep low and mid level lapse rates during the afternoon, with 500 to 1000 j/kg CAPE. Some models show a weak cap while others try to mix us all the way up to 10kft. The winds through the profile are very strong with SW winds up to 43kt at 5kft and 50 to 60kt at 10kft. There will probably be a weak cap that will help keep our wind gusts in check today, but a few gusts over 39kt (wind advisory criteria) are not out of the question. If gusts begin to over-achieve by noon today, we will know we need a wind advy for the afternoon. Despite the weak cap, the overall synoptic forcing should be enough for scattered thunderstorm development. The CAPE values and low freezing level of 9 or 10kft support the chance for small hail, with a report of two of 1 inch hail possible. There is strong shear. The main threat for any stronger storms that develop is the damaging wind potential, since the strong winds aloft will efficiently mix down with momentum transfer. As the upper low tracks across MN today, another frontal boundary will push into north central and eastern WI. This will feature cooler temperatures, low clouds, and rain or drizzle. Northern WI will be fully engulfed in these damp, brisk conditions Friday night. Saturday, expect breaks in the clouds as the upper low starts to exit the region. With steep low level lapse rates and lingering low level moisture, scattered showers are expected, although coverage is still uncertain. In addition, expect gusty west winds up to 30 mph during peak daytime heating/mixing. Saturday highs will range from the upper 50s north central to the mid 60s east. MRC Saturday night through next Thursday Upper trough exits across the eastern Great Lakes Saturday night with ridging aloft beginning to build from the plains into the western Great Lakes. Surface high pressure over Manitoba and northern Ontario will ridge into MN and WI Saturday night with more influence of ridging by Sunday night. The ridge will bring dry weather and also the risk of frost Saturday night and/or Sunday night. PWATs lower Sunday night, but with high more off to the north than the east, the area will keep some wind in lowest 1kft with tighter pressure gradient on southern edge of high. It still appears that temps could drop into the mid 30s north Saturday night and/or Sunday night. NBM probabilities of min temps less than 35 are 30 to 40 percent Saturday night over Vilas County, but increase and expand to 40-80 percent Sunday night north of highway 29. If and where winds become light, some frost could occur either of these nights, though Sunday night looks more favorable at this point. Troughing over the western CONUS late this weekend shifts east early next week, bringing the next chance of showers and storms to the area Monday night into Tuesday. One trend that seems to be emerging though is the dry east flow out of the high to the north may restrict chances of rain only to the southern part of the forecast area on into southern WI. Risk of any stronger storms also is well to the south of the area. Given these trends, its feasible that much of northern WI could stay dry early this week. Whatever chances of rain occur will shift south and east of the western Great Lakes Wed into Thu as broad 850-700mb low shifts across lower Great Lakes. Cool flow in wake of the low flowing across the region could lead to more clouds and a small chance of spotty showers by Thursday. Overall a cooler than normal stretch is expected for the coming week with highs in the upper 50s to mid 60s. JLA. && .AVIATION...for 18Z TAF Issuance Issued at 1249 PM CDT Fri May 16 2025 Mostly clear skies and VFR conditions were observed for most early this afternoon; however, satellite imagery shows mid-clouds starting to enter central WI. The main feature was the winds with SSW gusts to around 30 kts. Scattered showers and thunderstorms are likely to develop this afternoon, but exact location is difficult to pinpoint. Coverage will not be as widespread as yesterday, but the chance (30-45%) exists everywhere. Main time window is 20Z-24Z. Included TEMPO groups to account for this. Precip chances will be minimal the rest of the evening into Saturday morning. A few spotty showers are possible, but coverage/confidence was too low to include in TAFs this issuance. Cloud bases will lower late this evening with a mix of MVFR/IFR cigs tonight (approx. 06Z) through Saturday morning. Winds will also increase again and peak late Saturday morning through the afternoon with gusts up to 30 kts. && .MARINE... Issued at 1205 AM CDT Fri May 16 2025 Gusty south-southwest winds are expected today, highest over land. Cooler lake water should keep wind gusts below gale force, so a Small Craft Advisory goes into effect mid morning. We initially set the end time of 7PM this evening, but after a brief lull in the winds tonight, gusty westerly winds will develop. Therefore, we extended the end time all the way until 7PM Saturday. MRC. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION..... AVIATION.......KLJ MARINE......... ####018006032#### FXUS63 KDTX 161749 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 149 PM EDT Fri May 16 2025 .KEY MESSAGES... - Showers and thunderstorms are likely again early tonight. The potential exists for storms to become strong to severe between 9 pm and 1 am, capable of producing damaging winds and large hail. - Cooler conditions this weekend, with westerly wind gusts 30 to 40 mph on Saturday. && .AVIATION... Ample dry air noted through most of the column per 16.12Z KDTX RAOB has held onto VFR SKC conditions into the afternoon hours. Coverage of FEW to SCT cumulus now showing up on satellite as the afternoon progresses, along with deepening mixed-layer to around 6 or 7 kft AGL. Expect some occasional gusts of 15-20 knots to mix down during peak heating, otherwise, sub-10 knot surface winds steadily back toward the southeast with time. Monitoring potential for another round (or two) of storms late this evening and overnight with a potent shortwave moving through. In addition to lightning, these storms could produce a brief period of gusty wind, including a microburst or two. Time of arrival and intensity differences still exist from north to south with this convective activity. For DTW/D21 Convection...Potential exists for convection tonight, mainly from 04Z to 07Z. Low chance also exists earlier for the three Metro-area terminals from 02Z to 04Z, prior to the arrival of the main. Dry air aloft lends a gusty wind threat and a non-zero chance for a microburst. THRESHOLD PROBABILITIES... * Medium for ceiling at or below 5000 feet tonight, then high Saturday morning and midday. * Moderate in thunderstorms after 02Z tonight. && .PREV DISCUSSION... Issued at 409 AM EDT Fri May 16 2025 DISCUSSION... The cutoff upper low responsible for the early morning MCS continues to meander over the upper Midwest today. Sunny conditions are expected through the daylight hours as mid-level subsidence dominates in the wake of the morning convection. Deep southwesterly flow brings in a secondary warm sector with highs reaching the mid 80s. Strong daytime mixing will cause dew points to fall to the lower to mid 50s - offering a less humid feel compared to yesterday. Southerly wind becomes breezy to around 20 to 25 mph, eventually advecting in dew points back into the mid to upper 50s by the evening. Meanwhile, mid-level cooling commences late in the day as the upper trough begins to pivot into the central Great Lakes, allowing instability to build as 700-500mb lapse rates increase to around 8 C/km. Forcing is disorganized through the early evening hours suggesting little potential to overcome the resident cap near 700mb. After 00z, upper flow becomes increasingly unbalanced at the nose of a 90 kt jet streak as the trough takes on a negative tilt - providing better support for synoptic lift and convective initiation as a pre-frontal surface trough lifts northeast across the area. Given the timing near and after sunset, there remains uncertainty regarding whether the cap will erode and instability (~750 to 1000 J/kg MLCAPE) will become realized at the surface before storms move through. Bulk 0-6km wind shear of 40 to 50 kt is supportive of a broken line of strong to severe storms with damaging wind and large hail the main threats. Severe potential is highest between 8pm and 1am before the trough sweeps through, then lingering showers and sub- severe storms may persist into the morning hours as the cold front trails behind. Most areas will receive around or less than 0.25" of rain tonight, but localized areas may see up to around 1". The stacked low pressure system slowly advances into northern Lake Huron on Saturday with a much cooler air mass working in through the day. Highs reach the 60s as a tight pressure gradient produces gusty westerly winds to 30 to 40 mph. Moisture wrapping around the low and weak instability will bring a continued chance for light showers at times through the day. Mid-level ridging then begins to settle into the area Sunday into the early work week to favor surface high pressure with dry and cool conditions. The next period to watch will be Tuesday night into Thursday as a closed low tracks from the Midwest toward the Great Lakes and Ohio Valley. This will provide the next opportunity for showers and storms. MARINE... Southerly 15-20kt winds develop today following the passage of last night's warm front as the surface low tracks over Lake Superior. Stubborn areas of fog likely linger through at least the morning though with dewpoints falling, expectation is the decreasing humidity should allow for a gradual diminishing trend for the latter half of the day. Respectable cold front is set to sweep across the region late tonight supporting another round of showers and thunderstorms in advance. Set up is not as favorable compared to Thursday night with coverage likely limited to a broken line with any strong to severe embedded storms being more isolated in nature. Moderate west-southwest winds follow Saturday with the strongest winds (20-30kts) expected over the southern half of the region where the gradient is strongest. Small craft advisories are warranted for most if not all nearshore waters as a result. Low fully departs Sunday shifting winds to the northwest. Gusts peak near 20kts during the day before weakening overnight as weak high pressure slides overhead. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....KGK DISCUSSION...TF MARINE.......KDK You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.