####018005598#### FXUS63 KABR 151926 AFDABR Area Forecast Discussion National Weather Service Aberdeen SD 226 PM CDT Thu May 15 2025 .KEY MESSAGES... - West to northwest winds will gust to 45 to 60 mph across central and northeastern South Dakota through Friday. - 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. && .SHORT TERM /THIS EVENING THROUGH TONIGHT/... Issued at 225 PM CDT Thu May 15 2025 As of 9z, A deep surface low continues of move east over eastern SD. There is an area of precipitation over central and eastern SD following behind this low as another boundary moves in from southern SD heading towards the north. This line is bringing some storms into northeastern SD and will continue to move north through the morning, though these storms appear to be loosing steam as they move into northeastern SD. Once this initial line of storms moves through, abundant low level moisture will start to move into eastern SD. A bit of instability happens over eastern SD after 14z, with models showing some surface based CAPE around/ slightly above 500 J/kg. Another boundary then looks to move through eastern SD around/after 14z, which will provide a source of lift to help showers and storms to develop in addition to the moisture and instability in the area. There is also some shear in eastern SD, which will help with the potential development of supercell. With there being strong mid to low level CAA over central and eastern SD, the vertical growth of the storms will be limited. This could lead to the development of low topped supercells that have the ability to produce severe wind, hail, and possibility and isolated tornado. The chances for storms decreases this evening. However, the chance for rain continues through the day Friday, as precipiation looks to wrap around As the surface low moves to the east, it will strengthen, with models showing the low dropping to around 984-982mb. With the low being so low, a tight pressure gradient has developed around it over central and eastern SD. This tight pressure gradient will lead to an increase in winds aloft the could be pushed to the surface with the CAA moving in behind the cold front. The strongest winds look to be west of the Missouri River Thursday, with the potential for these winds to gust over 55 mph. Areas to the east will have only slightly weaker winds, with some areas having the potential to gust 45 to 50 mph. Strong winds look to continue through Friday, though they don't look to be as strong as the low and its tight pressure gradient move east. && .LONG TERM /FRIDAY THROUGH THURSDAY/... Issued at 225 PM CDT Thu May 15 2025 The period begins on Friday with an anomalously strong surface low pressure system near eastern ND or western MN. West-northwesterly winds will continue impacting the forecast area throughout Friday, with a 40-75 percent chance gusts exceed 45 mph west of the James River valley. A wind headline may be need on Friday. High temperatures on Friday will definitely be cold with readings in the 40s and low 50s. The NBM probability of seeing highs under 50 degrees is 30 to 75 percent, with the highest potential over the western half of the CWA. These readings will be 15 to 25 degrees below average for this time of year. The storm system departs the region by Friday night, leaving behind cool temperatures and diminishing winds. Low temperatures Saturday morning may drop into the 30s, with frost possible. Temperatures remain cool Sunday morning with a large portion of the CWA seeing a 50 to 85 percent chance of lows below 36 degrees. Increasing cloud cover and rain chances may limit the frost potential over the southwest CWA, or the Pierre and Murdo area. Another storms system will cross the Plains into the midwest with additional showers and thunderstorms expected, mainly Sunday afternoon through Tuesday. The slow moving nature of the storms should produce plentiful rainfall. The probably of seeing 0.75 inches over a 24 hour period, ending at 7 am Tuesday, is 40 to 75 percent. With cool temperatures, highs mostly in the 50s and low 60s, along with limited instability, severe weather is not expected with this storm system. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1224 PM CDT Thu May 15 2025 Terminals KABR,KATY,KPIR,KMBG A slow moving low pressure system will bring mainly MVFR conditions to all terminals through the valid TAF period. Periods of IFR conditions with heavier showers will be possible. West to northwesterly winds will impact all terminals with gusts exceeding 35 knots. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...High Wind Warning until 7 PM CDT /6 PM MDT/ Friday for SDZ003- 015-033-045. Wind Advisory until 7 PM CDT Friday for SDZ004-009-016>019-022- 023-034>037-048-051. Wind Advisory until 7 PM CDT Friday for SDZ005-010. Wind Advisory until 7 PM CDT Friday for SDZ006>008-011-020-021. MN...None. && $$ SHORT TERM...SRF LONG TERM...SD AVIATION...SD ####018005951#### FXUS65 KVEF 151927 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 1227 PM PDT Thu May 15 2025 .SYNOPSIS...Temperatures will continue to warm through Friday before another potent weather system drops into the region over the weekend, bringing strong gusty winds, a chance of precipitation, and a drop in temperatures. Calmer and warmer weather is expected next week. && .SHORT TERM...Tonight through Sunday. Low impact weather is expected through Friday. Weak height rises are expected tonight which will keep winds calm and skies clear. On Friday, a weak shortwave embedded in the mean flow will shift through the region. This feature will be dry in the low levels but have some mid to upper level moisture associated with, there will be increasing clouds from northwest to southeast through the day, but no rain is expected. An uptick in winds is possible as this piece of energy moves through, but gusts should remain under 20 MPH in most locations with gusts up to 25 MPH possible in the Mojave Desert wind- prone areas. High temperatures on Friday will be a few degrees warmer than today, which will be near normal for this time of the year. A stronger, more impactful trough will dig into the region this weekend, which will bring potentially impactful winds and precipitation chances. The main concern will be winds as widespread gusty southwest winds will set up on Saturday as the pressure gradient increases with the deepening system. A strengthening jet also sets up across the Western Mojave Desert through southern Nevada into Arizona. Probabilities for over 40 MPH gusts are over 50% through this region, and many ensemble members show 40-50MPH gusts on Saturday. Decided to issue a Wind Advisory for these areas as confidence is high enough for wind impacts on Saturday. May need to add some locations if confidence increases for gusty winds and wind impacts, especially in Death Valley and the Sierra into the Owens Valley, but did not have enough confidence that widespread wind impacts will occur at this time in those areas. A few ensemble members around Barstow, CA as well as Desert Rock, NV show 55 MPH+ wind gusts on Saturday, but do not have enough confidence for a High Wind Watch/Warning now. Later shifts can now focus on adjusting headlines and wind impact levels as we enter the hi-res model domain and changes in probabilities lead to higher confidence. Southwest winds will slowly diminish Saturday evening, with gusty wind and wind impacts lingering the longest through the Western Mojave Desert. On Sunday, winds will turn northwest as the trough axis moves through. The best chance for wind impacts with gusts over 40 MPH on Sunday will be in Esmeralda, central Nye, and northern parts of Inyo County as the front washes out as it moves further south. Additional wind headlines may be needed on Sunday in parts of the Southern Great Basin or the Owens Valley, but held off as confidence was lower and it was uncertain how widespread the north wind impacts would be on Sunday. The best chance for precipitation will be through southern Nevada and northern Mohave County where showers and thunderstorms may develop Saturday and Sunday. This is where PWATs will increase to 125 to 175 percent of normal (generally between 0.50 and 0.75 inches), which will allow for moderate-to-heavy rain rates beneath any thunderstorms that develop, but generally light rainfall is elsewhere. At this time, it looks like the greatest threat of thunderstorms will be across central Nye and northern Lincoln counties Saturday and across central Nye and the remainder of Lincoln County Sunday. Further west, the forecast is trending drier as moisture will be scoured out too quickly behind the trough axis. Other than some light precipitation on the Sierra Crest, most of the California zones should remain dry. Temperatures Saturday and Sunday will cool slightly each day as the system moves inland. .LONG TERM...Monday through Wednesday. Behind the trough, ridging sets up for the start of the work week that will result in Las Vegas chances for 90 degrees rapidly increasing through the week and "Moderate" HeatRisk (Level 2 on a scale from 0 to 4) returning to the low valleys. && .AVIATION...For Harry Reid...For the 18Z Forecast Package...Winds will remain light and variable until after 00Z when west- southwesterly wind below 10kt. These winds will continue through the night before becoming lighter from the northeast in a typical diurnal pattern. Winds pick up Friday afternoon with south- southwest winds gusting at times to near 20kt. FEW-SCT high clouds with bases AOA 15kft will come through at times on Friday. For the rest of southern Nevada, northwest Arizona and southeast California...For the 18Z Forecast Package...Light and variable winds are on tap across the area into early afternoon today. Mainly west to southwesterly winds will pick up this afternoon with speeds below 10kt everywhere except DAG where westerly wind gusting to near 20kt can be expected. Typical diurnal trends can be expected tonight. Gusty southerly wind to 20kt will pick up at the Colorado River TAF sites Friday afternoon. A shield of FEW- SCT clouds will move across the area from northwest to southeast through the day Friday but no significant CIGS are anticipated. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Nickerson LONG TERM...Soulat AVIATION...Berc For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter ####018005767#### FXUS64 KBRO 151927 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 227 PM CDT Thu May 15 2025 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Tonight through Friday night) Issued at 216 PM CDT Thu May 15 2025 - Wind Advisory in place for inland Cameron County until 4 PM today. - Unseasonably warm conditions continue. Special Weather Statement for heat index values between 105-110 degrees, occasionally up to 113, in place for portions of Starr, Hidalgo, Brooks, and Kenedy counties. Upper level ridging will maintain hot, near-record breaking temps through the end of the workweek. A localized enhanced pressure gradient will aid a low level jet at 850mb, enhancing warm air advection and supporting a warm nose aloft, curbing cooling overnight. Gusty conditions today east of I-69C (gusts up to 42 mph observed at BRO) will diminish this evening. Not as gusty tomorrow as pressure gradient relaxes, though gusts around 25 kts will persist through Friday. A dryline will enter the area and stall over Zapata/Starr/Jim Hogg counties this evening. South-southeasterly winds allow for temperatures to remain elevated under upper level ridging. High temperatures tomorrow a touch cooler than today - but before you rejoice, south-southeasterly winds will transport some moisture back into the atmosphere. This will raise heat index values tomorrow higher than todays, with maximum apparent temperatures up to 115 possible. While this is higher than Heat Advisory criteria (111 degF), precluding an issuance this forecast package due to lacking temporal and spatial coverage. Another Special Weather Statement is likely for portions of Kenedy, Brooks, Starr, and Hidalgo counties tomorrow if next forecast package precludes Heat Advisory. A majority of the CWA tomorrow is under a Major Risk (level 3 of 4) of heat-related illness. Continue to be mindful of heat safety by avoiding strenuous activity during peak heating, stay hydrated, and LOOK before you LOCK. Children and pets should never be left unattended in vehicles. There is a High Risk of rip currents at local beaches through this evening. Tomorrow, the risk of rip currents decreases to Moderate. && .LONG TERM... (Saturday through next Thursday) Issued at 216 PM CDT Thu May 15 2025 The heat is on! Oppressively hot temperatures will plague the region in the long term period as high pressure remains stationary over the Gulf through early week. Surface winds out of the southeast will advect moisture into the region and while no precipitation is expected this will lead to higher humidity levels with max apparent temperatures potentially reaching Heat Advisory criteria on Friday and Saturday across central and northeastern portions of the CWA. Apparent temperatures will still be quite warm (between 105 and 110) Sunday and Monday with increasing potential for Heat Advisory criteria again for Tuesday. Wednesday and Thursday zonal flow aloft will cool temperatures slightly with max apparent temperatures remaining below criteria for Heat Advisory. Heat Risk will generally remain the in Major category (level 3 out of 4) though some pockets of Extreme Risk (level 4 out of 4) are possible in portions of the northern Ranchlands through Tuesday. Wednesday much of the area will fall back into a Moderate Heat Risk (level 2 out of 4) and Minor Risk (level 1 out of 4) on Thursday. On Wednesday and Thursday we could still see some pockets of higher risk. && .AVIATION... (18Z TAFS) Issued at 1227 PM CDT Thu May 15 2025 VFR conditions present at all sites this afternoon. Thursday night, low clouds build and bring possible MVFR conditions through sunrise. A low level jet in place is causing gusty winds of 35+ kts, which will continue through the afternoon. A wind advisory is in place until 4 PM for HRL and BRO. Low level wind shear is possible with this LLJ along with any inversion present. Inversion is keeping some light HZ trapped in the boundary layer this afternoon. && .MARINE... Issued at 216 PM CDT Thu May 15 2025 Now through Friday night: A south-southeast fresh breeze tonight will gradually diminish to moderate into Friday night. Moderate seas will persist throughout the short term. Conditions will slowly improve; Small Craft Advisory conditions should diminish by tonight, leaving Small Craft Exercise Caution headlines. Over Friday night, these headlines should drop off. Saturday through Thursday...Slightly adverse marine conditons are expected through much of the period with Exercise Caution expected due to elevated winds. There is a potential for periods of Small Craft Advisory conditions, mainly Monday into early Tuesday due to higher winds and seas. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 79 95 78 93 / 0 0 0 0 HARLINGEN 78 95 76 96 / 0 0 0 0 MCALLEN 79 98 79 99 / 0 0 0 0 RIO GRANDE CITY 77 101 77 102 / 0 0 0 0 SOUTH PADRE ISLAND 78 87 78 86 / 0 0 0 0 BAYVIEW/PORT ISABEL 78 88 76 91 / 0 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...Wind Advisory until 4 PM CDT this afternoon for TXZ255. High Rip Current Risk until 7 PM CDT this evening for TXZ451-454- 455. GM...Small Craft Advisory until 7 PM CDT this evening for GMZ130-132- 135-150-155-170-175. && $$ SHORT TERM...69-HK LONG TERM....68-AM AVIATION...69-HK ####018005467#### FXUS63 KARX 151927 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 227 PM CDT Thu May 15 2025 .KEY MESSAGES... - Severe weather possible through 8 PM tonight. Large hail (possibly in the excess of 2.5" in diameter), tornadoes, and damaging winds (60-70 mph wind gusts) are all possible. - 35 to 50 mph wind gusts (60-90% probability of wind gusts of 45 mph or greater west of the Mississippi River) on Friday. A Wind Advisory will be likely needed west of the Mississippi River. && .DISCUSSION... Issued at 227 PM CDT Thu May 15 2025 This afternoon and early evening At 2 PM, a cold front was located near Interstate 35 and warm front was located near Interstate 94. There was an occluded front that extends northwest back to a low pressure area near the Intersection of North Dakota/South Dakota/west-central Minnesota. In the warm sector of this system the MVFR deck of clouds is starting to break-up. Temperatures have warmed into the lower and mid-80s and dew points are in the lower to mid-60s. This is resulting in surface-based CAPES of 2500-3500 J/kg. 900-600 mb lapse rates are near 9 C/km. Effective shear remain in the 40 to 45 knot shear, so we have ample shear for supercell development. The SPC Mesoscale Analysis shows that CIN has eroded across southeast Minnesota and northeast Iowa, and it will dissipate across the remainder of the area by 3 PM. Still see a variety of run to run solutions on when the storms will start to form. For example the HRRR was showing the initial development over west-central Wisconsin earlier this morning. It has now trended west over east-central and southeast Minnesota. We are starting to see some thunderstorm development west of the Twin Cities and south-central Minnesota just west of Interstate 35. Soundings west of the Mississippi River are a bit less favorable for very large hail than those over west-central and central Wisconsin where the NCAPEs are much greater. Hail will likely occur between a half hour to hour after supercell development. There could potentially be some isolated reports of hail greater than 2.5" in diameter in Wisconsin. The better 0-1 km helicity look to be from east-central Minnesota southeast through west-central, central, and southeast Wisconsin. These areas have a higher tornado potential. As a result, a Tornado Watch has been issued until 8 PM for part of this area. Particularly concerned about central Wisconsin where the supercells will have time to mature and where there discrete, southern supercells will have the better potential to ingest unimpeded instability and low-level helicity. This area would have the potential of stronger tornadoes. With DCAPEs of 1000-1500 J/kg, dry air aloft, and 40-50 knot winds between 800 and 600 mb, there will be the potential for damaging winds. Currently thinking that these winds will be in the 60 to 70 mph range. Friday into Saturday A closed low will be move slowly east from Minnesota into the Great Lakes. As shortwaves rotate around this low, there will be periodic showers. There may be even some thunderstorms on Friday afternoon as the mean surface CAPES climb up to 1000 J/kg. Rainfall totals will range from a tenth to a half inch. The highest rain totals will be mainly north of Interstate 90. From late Friday morning into Friday evening, the soundings show steep surface to 800 mb (lapse rates around 8 C/km). Soundings suggest wind gusts will be in the 35 to 50 mph. The LREF has a probability of 60-90% that the wind gusts will be 45 mph or greater during the afternoon. A Wind Advisory will be likely needed west of the Mississippi River. Monday through Wednesday A low pressure area will move slowly east from the Central Plains into the Ohio River Valley. North of this low there is a high pressure system. Still plenty of uncertainty on the northern edge of this rainfall. This is especially the case on Monday and Wednesday. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1229 PM CDT Thu May 15 2025 A swath of high-end MVFR ceilings are moving out of the RST terminal with VFR ceilings expected for much of the period. Storms have started to form along the arcing cold front across south central Minnesota. Mesoanalysis shows soundings across our area becoming uncapped earlier than expected so have included TEMPO groupings for these storms at both terminals. There is lower confidence with the RST TEMPO but enough to include it based on current observations. This line of storms will quickly move through the area with winds out of the south veering more to the west/southwest behind the front this evening. Some LLWS will be possible at both sites overnight so have included with this package but fine tuning may be needed with future updates. Wrap-around precipitation from the low pressure system will start to impact the RST terminal late in the period so have added in a PROB30 for this timeframe but increased confidence with the next update may warrant changing that to a prevailing group with the next package. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Boyne AVIATION...Barendse ####018006261#### FXUS61 KCTP 151928 AFDCTP Area Forecast Discussion National Weather Service State College PA 328 PM EDT Thu May 15 2025 .SYNOPSIS... * Daily chances for thunderstorms continue through Saturday with potential for damaging winds and localized flooding. * Temperatures trend warmer Friday and Saturday with a notable uptick in humid/sticky weather. * A cold front will bring much colder temperatures and less rainy/more sunny weather later this weekend and early next week with breezy conditions. && .NEAR TERM /THROUGH TONIGHT/... All the area has seen sunshine break though with many places mostly sunny this aftn. Trough axis aloft over wrn PA is under otherwise high heights, but still touching off SHRA/TSRA over the nrn/wrn mtns. Best instability (<1000J/kg) over the CWA is there, and only meger deep-layer shear (25-30KTs) is found in the same location. The rainfall is not moving very much at this point, but FFG is on the high side (esp vs the srn tier). No shear to speak of over the eastern third of the CWA where CAPE is under 500J/kg. We do expect the SHRA/TSRA over the N to continue until close to sunset, but the waning instability with loss of heating will allow it to drop off in coverage and intensity perhaps even before sunset. Lingering SHRA may stick around thru midnight. The next issue of note is later tonight as forcing associated with the left-exit region of a complex jet pattern over the Midwest and OH valley approaches. A complex of storms should develop thru the night over Upper Great Lakes and drop into OH/wrn PA toward morning. SPC still has the wrn 2/3rds of the CWA in a MRGL risk for SVR (mainly hail/wind threat, but a very minimal tor threat in the SW). Precip arrives late tonight, perhaps a little earlier in the SW. Rain rates should not be excessive, but coule be briefly heavy. Pondered a FF watch for the SW where it's been very wet and stream flows are running high. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Newes guidance is highly aligned with prev forecasts. There should be a lull after the morning convection. Don't have much to add to the disc below. Prev... Latest guidance indicates a lull in the precipitation during the late morning and afternoon on Friday following the passage of the warm front. Southwest flow will continue to funnel moisture up into the northeast US as dewpoints reach their highest values so far this year (in the mid to upper 60s). It will feel noticeably humid as well. Highs in the 80s across the area appear likely with the only exception being if thunderstorms can fire up in the afternoon. Another round of convection appears likely Friday night into Saturday morning (yet again decaying as it moves across Pennsylvania from the Midwest). Severe weather appears a bit more likely with this round as 2500J/kg of MLCAPE overlaps with sufficient shear in the evening. The SPC Slight Risk gets into southwest PA, but would not be surprised to see an eastward expansion across southern PA with subsequent updates. By Saturday, a cold front will approach the Commonwealth with a convective outflow boundary likely surging out ahead of it from the previous night's convection. The outflow boundary will encounter a warm and moist airmass that could lead to development of sustained strong thunderstorms on Saturday afternoon. Still some uncertainty with how quickly a line of thunderstorms will congeal Saturday afternoon, but southeast PA would be favored for a primarily damaging wind threat, as outlined by SPC's Slight Risk (level 2 out of 5) that covers York and Lancaster County. With all 3 rounds of storms, progressive storm motions should limit the risk of signficant flooding, but cannot rule out some isolated issues for locations who's soil moistures/creeks are already running high. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Latest guidance is consistent with prev, with a dry period for Sun thru Tues. Some SHRA may pop up in the nrn mtns Sun aftn, but these would be isolated. Mon and Tues are certainly dry. A storm system gathers over the mid-MS and OH valleys during that time. The system looks like it should broaden to the west and make us wet for another few days straight. && .AVIATION /10Z THURSDAY THROUGH TUESDAY/... Ceilings are gradually rising this afternoon across Central PA, with VFR conditions expected area-wide after 20Z. Scattered showers and a few thunderstorms have developed over western Pennsylvania and could produce brief periods of heavy rain at BFD into the early evening. Model soundings suggest that IFR ceilings will return tonight for much of Central PA and there is around a 30% chance of LIFR ceilings developing at MDT and LNS. There also appears to be at least some potential (< 30%) for fog to develop at those two sites as well. The main concern for tonight will be a line of thunderstorms that will track through the region in the 09-14Z timeframe. PROB30 groups have been added to all sites except MDT and LNS to highlight the most likely timeframe for impacts. These thunderstorms will likely be weakening as they move in from the west and encounter a more stable environment, but we can't rule out a few strong wind gusts, especially at western airfields. Conditions gradually improve during the late morning behind the line of storms, but additional thunderstorms will likely develop Friday afternoon/evening. Outlook... Sat...Mainly VFR, isolated PM showers/storms. Sun...Some improvement, as a series of cold fronts move southeast of the area. Mon...Mainly dry with VFR conditions. Perhaps a shower early at BFD and JST, with MVFR CIGS early at these sites. Tue...VFR with showers developing late. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Jurewicz/Banghoff NEAR TERM...Jurewicz/Banghoff/Dangelo SHORT TERM...Jurewicz/Banghoff/Dangelo LONG TERM...Jurewicz/Banghoff/Dangelo AVIATION...Bauco ####018004105#### FXUS61 KILN 151929 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 329 PM EDT Thu May 15 2025 .SYNOPSIS... Warmer temperatures will be observed through the end of the week. A series of disturbances will bring the potential for thunderstorms mainly late in the day into tonight and again Friday and Friday night. Cooler temperatures and drier weather will follow heading into the weekend. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Mid-level ridge axis centered over the middle Ohio Valley will be shunted to the east late tonight as the first in a series of shortwaves arrives from the upper Midwest. Despite favorable instability and wind shear for thunderstorms, forcing will focused to the north of our CWA. Severe parameters are robust in a few of the latest CAMs. Therefore, will keep PoPs in the chance range (highest in the north and west) while closely monitoring any robust updrafts that can take advantage of the parameter space. If storms develop, all hazards will be possible. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... After a lull in the active weather Friday morning, a more significant shortwave will approach the region during the afternoon. This time, a warm front will initially be the focus of the forcing, starting across the Tri-State during the evening and lifting through the rest of the CWA just after midnight. Instability across our southern counties will peak around 3000J/kg from late afternoon into the evening, while bulk shear is likely to exceed 50 knots in the evening. Some CAMs show a warm air advection wing lifting northeast with potential discreet supercells. Behind this, it's likely a QLCS will bring the threat of damaging winds and a line- embedded tornadoes late. There is also the possibility that the line could be slowed across the south with west to east training convection bringing the threat of flash flooding. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Closed low will track across the Great Lakes to start the period which will push a cold front through the area. Most likely, this will come through dry, but there could be enough deep forcing to allow for some showers along the northern tier of the forecast area. Ridging will build in for Sunday and Monday resulting in dry conditions with temperatures near or even slightly below normal. The mid level pattern becomes blocky again towards midweek with the usual uncertainties as the flow transitions. At this point, it appears most likely that a closed low will move out of the central Plains and track into the Ohio Valley while getting absorbed into another closed low retrograding across eastern Canada. This will bring another period of wet weather. Highs will remain slightly below normal with lows closer to normal. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... Mid-level ridge will ensure VFR conditions continue through this afternoon into the early evening. Western trough will send an initial shortwave into the ridge late this evening. This will cause a fast- moving line of thunderstorms to develop to our west, bringing a chance of storms heading toward midnight. Likely the highest chance will be from DAY to CMH/LCK... though can't rule out an isolated storm for the rest of the terminals. Strengthening low pressure over the upper Midwest will likely keep southerly winds persisting through the overnight. There is a signal of MVFR clouds developing near sunrise near the Cincinnati airports, but have only added a scattered layer due to uncertainty. Otherwise, most of Friday should remain favorable until thunderstorms become increasingly possible during CVG's extended TAF period. OUTLOOK...Thunderstorms are possible through Saturday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...AR NEAR TERM... SHORT TERM... LONG TERM... AVIATION... ####018005620#### FXUS63 KFSD 151929 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 229 PM CDT Thu May 15 2025 .KEY MESSAGES... - Strong winds and persistent rain to rain showers are expected to drift back southward on Friday. - Wind gusts over 50 mph may be possible at times through Friday afternoon. Wind advisories have been issued and local upgrades to high wind warnings possible. - After a quiet and cool weekend, moderate to high probabilities of rain (90%) return Monday and Tuesday. && .DISCUSSION... Issued at 225 PM CDT Thu May 15 2025 THIS AFTERNOON: A large upper low continues to track northeast through the Dakotas, likely to end up in northeastern Minnesota by Friday morning. Persistent stratus will rotate around this trough through the afternoon, but showers may lift northward by 00z. Enough clearing is taking place near or south of the MO river for some instability showers to form, which may continue into the evening. Winds are continuing to increase this afternoon as 40 to 50 mph winds mix down. TONIGHT: Lingering instability showers dissipate early this evening. More persistent light rains may drift north of Highway 14 this evening and into the overnight hours. Winds may also subside south of I-90 and will allow wind advisory to expire in some areas along and south of I-90. Moisture rotating around the western side of the upper trough will begin to sink back southward towards daybreak Friday, bringing showers southward with it. More uncertain is the potential for persistent mix down of 45 to 55 mph winds with the showers into Friday morning. CAMS certainly suggest potential for high wind warning gusts along the 14 corridor, but these models may also overdue strong winds overnight. FRIDAY: The upper low begins to settle back southward and fill on Friday, pushing rain chances across the CWA through the day. Rain amounts won't be significant, but persistent showers may add up to a tenth or two. Winds however will also increase and any breaks in the clouds will push stronger gusts downward. Will extend a wind advisory across the entire CWA. SATURDAY: Dry air gets pulled into this system Friday night into Saturday, bringing rain to and end, but likely keeping stratus around into Saturday morning. Lows will be quite chilly falling into the lower 40s. Highs on Saturday afternoon are expected to remain well below normal, only climbing into the lower to middle 50s in most locations, and a few 60s near the Missouri River. SUNDAY: Mid-lvl warm advection and moisture return begins on Sunday, pulling an increase in cloud cover and potential for light sprinkles to showers through central South Dakota during the first half of the day. Elsewhere, drier easterly surface flow will keep temperatures cool with highs in the 60s. MONDAY-WEDNESDAY: Medium range guidance remains in strong agreement that a large upper trough will move through the western CONUS and begin to influence the Plains early in the week. Broad warm advection showers and thunderstorms develop over the Central Plains Sunday night, and will spread northward into the Mid and upper Missouri River valley on Monday. Rainfall probabilities remain high at nearly 90%, with 1" QPF probabilities from the GEFS/ECMWF pushing 50% in some areas. More uncertainty develops in regards to the track and depth of the upper low that moves into the Plains Tuesday into Wednesday. ECMWF remains slightly further north with the upper low than the GFS/CMC keeping a rain chance over the entire CWA through Tuesday. Outside of some initial elevated convection during the onset of the event, severe weather risks remain low through the period. Temperatures are also expected to remain near to slightly below seasonal normals. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1219 PM CDT Thu May 15 2025 Upper low will continue to deepen and then fill across northern Minnesota by Friday morning. The result will be MVFR ceilings and scattered rain lifting north of the CWA later this afternoon and evening. VFR conditions are likely in most areas, outside of Highway 14 overnight. Gusty westerly winds will persist into the evening, with potential for 40 to 50 mph winds at times. The upper low pivots back south on Friday, pushing MVFR stratus and showers southward through the Tri-State area during the day. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory until 9 PM CDT this evening for SDZ060>062- 065>071. Wind Advisory from 1 AM to 7 PM CDT Friday for SDZ060>062- 065>070. Wind Advisory from 7 AM to 7 PM CDT Friday for SDZ071. Wind Advisory until 7 PM CDT Friday for SDZ038>040-050-052>059- 063-064. MN...Wind Advisory until 9 PM CDT this evening for MNZ089-090-098. Wind Advisory from 1 AM to 7 PM CDT Friday for MNZ089-090-098. Wind Advisory until 7 PM CDT Friday for MNZ071-072-080-081-097. IA...Wind Advisory until 9 PM CDT this evening for IAZ001>003- 012>014-020>022-031-032. Wind Advisory from 1 AM to 7 PM CDT Friday for IAZ001-002. Wind Advisory from 7 AM to 7 PM CDT Friday for IAZ003-012>014- 020>022-031-032. NE...Wind Advisory until 9 PM CDT this evening for NEZ013-014. Wind Advisory from 7 AM to 7 PM CDT Friday for NEZ013-014. && $$ DISCUSSION...Dux AVIATION...Dux ####018007140#### FXUS63 KGLD 151929 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 129 PM MDT Thu May 15 2025 .KEY MESSAGES... - Overall drier Thursday but a 10-15% chance for severe downbursts associated with virga/sprinkles/showers are possible Thursday afternoon mainly west of Highway 25. - Breezy winds are forecast to continue through the weekend and into the start of next week. - A more active pattern then sets up this weekend and into the start of the week with daily chances for storms Saturday through Monday. Severe weather may be possible each day with the current favored day being Sunday. && .SHORT TERM /THROUGH FRIDAY NIGHT/... Issued at 126 PM MDT Thu May 15 2025 A large low pressure system is currently spinning across South Dakota attributing to a breezy wind field continuing for the forecast area through the day with wind gusts around 40 mph. Not anticipating any blowing dust concerns today but some very localized reductions in visibilities near fields may be possible as we did receive an MPing report of some dust near a field in northern Sherman county during the morning hours, have not had any details of what the visibility was. As the low continues to spin some vorticity maxima along with additional support with a 500mb shortwave increases the mid level moisture some. Am continuing to think that some virga, sprinkles or spotty showers are possible with this forcing, however with dry low levels in wake of yesterday's front do think any form precipitation will be hard pressed to reach the surface. I do still have some concerns of severe downburst potential in the dissipating stages of any updraft as Corfidi downshear vectors remain around 60 knots and inverted v soundings in place. HREF max wind gusts also do support this potential as well as hinting at some splotchy instances of 50-55 mph winds primarily along and west of Highway 25 into the evening hours; given how strong the Corfidi downshear vectors are and the winds at the top of the inverted v soundings do think there is some potential for sporadic wind gusts of 55-65 mph. Friday, the low pressure system across the northern Plains begins to move to the east and as it does so wind across the norther portion of the forecast area increases in response to this, would not be surprised if we have some 45 to even 50 mph winds across SW Nebraska. May need have an increase in fire spread potential especially if those winds do pan out as RH values are then forecast to fall into the upper teens to low 20s as the majority of out SW Nebraska counties missed out on any rainfall. Saturday, troughing across the western CONUS begins to take shape and moisture begins to return to the area from the southeast. Winds do look to become breezy with the southeastern winds as well gusting to 35-40 mph during the afternoon hours. High temperatures in the mid 70s to low 80s are currently forecast. The majority of the day does look to be dry but during the afternoon a mid level shortwave does look to move into the northwest portions of the area. Dew points are fairly meager in the 40s based on current model guidance but wind shear is more than adequate around 40 knots to support some potential organization of storms. Large hail at this time looks to be the primary hazard. An even more conditional threat may be further south as moisture will be a little bit better along the northern extent of the moisture advection. The forcing further south is not nearly as good but does need watching. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 126 PM MDT Thu May 15 2025 For the extended period, Sunday is currently the day to watch. A deep trough continues to move towards the area as a surface low begins to develop across southern Colorado and is forecast to eject northward across the CWA. Moisture is forecast to continue to stream into the area ahead of these features. Fog and stratus may be present as well during the morning hours Sunday with the continued stream of moisture advection. As the low moves to the north additional mid level forcing associated with the incoming trough ejects into the area. As the surface low begins to eject this will create a dry line to the east and a warm front moving to the north. All of these features combined sets up for a classic severe weather event for portions of the area. Forecast soundings show 1500-2500 j/kg and near 50 knots of effective shear in place across the area. Forecast soundings do show a cap in place through the afternoon so that may hinder development some but 12Z NAM runs indicate loaded gun soundings in place. As of current model guidance the difference between this set up and the other more conditional cap issue days is that the area has additional and closer to the area forcing that should help overcome this. Everything mentioned above all aligns with the current Day 4 15% outlook that the Storm Prediction Center has over the majority of the CWA. Will continue to monitor trends but at this time all hazards may be in play during the afternoon and evening hours for the CWA. Monday, the trough continues to move across the area and the surface low does some retrograding across Nebraska which may again brings some concern for some thunderstorm potential, severe potential for the CWA is a little iffy at this time based on the quality of moisture across the area. Winds do remain breezy as well throughout the day again gusting around 30-40 mph during the afternoon. Another breezy day is in store Tuesday as this low finally departs the area, on the back side of the system the GFS is currently indicating a 700mb jet of 45-55 knot wind gusts if this trend continues then winds may need to be increased a bit in future forecasts. Wednesday and through the remainder of the extended period, am seeing an increased signal for ridging developing across the western CONUS. If this continues then a reprieve from active and maybe even breezy conditions and a warm up may ensue. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1054 AM MDT Thu May 15 2025 VFR conditions are currently forecast to continue for each terminal along with breezy winds continuing through the afternoon hours as winds gusts 30-35 knots continue. There is a 10-15% chance for some virga,sprinkles, showers to develop this afternoon and evening capable of downburst, perhaps severe downburst winds. Chances of that impacting a terminal are even less than the formation so will leave out of the TAF for now. WInds are then forecast to some shifting to the west and then back to the northwest again with winds returning. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ SHORT TERM...Trigg LONG TERM...Trigg AVIATION...Trigg