####018006910#### FXUS63 KMQT 161820 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 220 PM EDT Fri May 16 2025 .KEY MESSAGES... - Thunderstorms this afternoon may be capable of producing damaging winds and large hail across central Upper Michigan. - Dry period expected to begin Sunday and linger through at least Wednesday. High temperatures in this period are expected mostly in the 50s to low 60s each day. && .SHORT TERM /THROUGH TODAY/... Issued at 133 PM EDT Fri May 16 2025 This morning we found ourselves caught within the dry sector of a surface low spinning just upstream in Minnesota. This provided Upper Michigan with clear skies through the morning, with some clouds beginning to push into the west and some cumulus development near noon EDT. Temperatures in this window have warmed into the 70s while mixing has allowed for gusty winds near 30 mph to mix to the surface here and there, alongside drier air aloft. Minimum RH values so far have fallen into the 30s. Current SPC Mesoanalysis pings the region with ~500-1500 j/kg SBCAPE alongside effective bulk shear of 30-50kts. With continued destabilization expected across central Upper Michigan this afternoon, showers and thunderstorms may develop as synoptic support helps provide a window for additional lift. CAMS are in relatively good agreement that thunderstorm initiation could begin between 4- 6pm this afternoon central, then shift eastward into the evening hours. Model soundings show very good mixing into a core of 50-60kts aloft, DCAPE between 500-1000j/kg, and steep mid-level lapse rates that support a window with a damaging wind and large hail risk with any storms that develop. Greatest risk area appears to be the middle third of Upper Michigan. Outside of this risk, strong southerly winds across the area may become more widespread and increase to ~40mph given the increased mixing that's expected this afternoon. However, given that we appear to be underperforming the higher end guidance packages at the moment, I don't yet see a need for a wind headline. Will continue to monitor the higher wind threat for the time being though. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 220 PM EDT Fri May 16 2025 Upper level low traversing the area tonight will continue to shift east through the Great Lakes this weekend while mid-level ridging shifts east through middle America. At the surface, low pressure will also progress eastward tonight then exit into Ontario by Saturday afternoon followed by a high moving into Hudson and James Bay. This transition will allow any showers and thunderstorms that develop this afternoon/evening to end tonight for our forecast area, then wrap around showers to press downwind into Upper Michigan's north through the day Saturday while a cooler airmass pours into the area. By afternoon, areas in the south-central should begin drying out. Sunday, showers should begin to diminish in the north as the effects of the ridging over the region becomes more dominant. Dry conditions look to hold fast over the area into at least the middle of next week, at which point a shortwave dropping southeast just east of Lake Superior Monday night begins to slowly phase with an upper level low pressing eastward through the mid-Mississippi River Valley. By Wednesday night/Thursday, the resultant upper level low may provide enough synoptic support for another round of rain. Confidence is low though given the uncertainty in this feature and it's surface reflection's position. Temperatures will slide this weekend as the cooler airmass from the north expands into the Upper Great Lakes. Highs Saturday in the 50s to low 60s will feel warm compared to Sunday's widespread 40s. We should warm afterwards back into 50s to low 60s for most of the coming week. Overnight lows will follow the same trend; expect 40s tonight with 30s afterwards, save near 40 by the lakeshores. Some high 20s can't be ruled out in the interior west half Sunday and Monday nights. The effect of the dry air, temperatures, and daytime mixing next Monday-Wednesday should be enough to support afternoon RH values falling into the 30s and 20s, potentially into the teens, in interior locations while gusty northeasterly winds near 20 mph mix down to the surface. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 133 PM EDT Fri May 16 2025 Gusty winds near 30kts will continue this afternoon into the evening hours. Otherwise, VFR conditions give way to thunderstorms developing this afternoon which are expected to effect KSAW. Some strong storms may be able to support strong or damaging winds and hail. Elsewhere, increasing low level moisture is expected to fill in the skies this afternoon and evening. Tonight, expect all sites to fall to MVFR/IFR with potential for rain showers. Low ceilings and rain shower activity is expected to continue Saturday at all sites. && .MARINE... Issued at 220 PM EDT Fri May 16 2025 Low pressure will gradually shift east through Lake Superior through Saturday. Ahead of the low this afternoon/evening, strong low level jet will be capable of producing winds near 30kts. There is some gale potential, but the increasing low level temperature profile over the lake this afternoon will create greater stability and make it difficult for these strong winds to mix down to the surface. That being said though, showers and thunderstorms that develop later this afternoon/evening could provide enough extra support for isolated pockets of stronger winds over eastern Lake Superior, particiarly if a stronger storm develops. If a strong storm gets organized, 50+ knot winds will be possible. Winds shift to the northwest Saturday afternoon/evening in the lee of the low, allowing for a period of cold air advection. This looks to create another opportunity for near 30kt winds, but the profile isn't expected to be cold enough for significant lake-induced instability, so gale potential is low (<25%). Winds look to lighten through the day Sunday, falling back below 20kts lake-wide by afternoon. Tighther pressure gradient looks to develop Monday and Tuesday, mainly in western Lake Superior thanks to a high shifting through Hudson Bay and a low moving east into the middle-Mississippi River Valley. This may produce northeast winds near 30kts going down into Duluth Harbor. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JTP LONG TERM...JTP AVIATION...JTP MARINE...JTP ####018005643#### FXUS64 KTSA 161821 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 121 PM CDT Fri May 16 2025 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Issued at 255 AM CDT Thu May 15 2025 - Shower and thunderstorm chances for northwest AR through mid afternoon today, then, a slight chance for storms for far southeast OK during the late afternoon. Some storms could be severe, with large hail the primary threat. - An unsettled weather pattern continues through the weekend and into early next week. Severe thunderstorms are expected at times. - Cooler and drier weather for the middle of next week. && .SHORT TERM... (The rest of this afternoon ) Issued at 106 PM CDT Fri May 16 2025 A surface boundary is advancing east through the area, currently it stretches from northwest AR back into south-central OK. Earlier, showers and storms had formed in the unstable air ahead of this boundary but have since moved east. CAMs are in good agreement that the next round of storms will form right as they are exiting southeast OK this afternoon. This may occur if sufficient surface heating breaks the capping inversion. Forecast profiles support all severe hazards, but large hail in particular. With that said, all areas east of the boundary should remain alert for potential severe weather. By early evening, any storms should be south or east of the area. Due to the cooler and drier air behind the boundary, temperatures will drop into the 50s north of I-40 tonight. It will be a bit warmer south of I-40 where some moisture return will begin, with lows generally in the low to mid 60s. && .LONG TERM... (Tonight through Friday) Issued at 106 PM CDT Fri May 16 2025 During the day Saturday the boundary will drift back to the north, with deep moisture filling in near and south of I-40. Meanwhile, another weak cold front will sag south out of the north, combining with the existing boundary near I-40 for the middle part of the day. This merged boundary will then gradually lift back north and wash out, with deep moisture filling the forecast area by late afternoon or evening. With plenty of moisture, deep instability, and good wind shear, thunderstorms (some of which could be severe) are expected. Lift will increase later in the day as an approaching upper level wave passes through. Storms will focus south of I-40 through mid afternoon before spreading north and east into the late afternoon and evening. The threat of storms will continue overnight, especially north of I-40 and towards northwest AR. Temperatures will be warm Saturday, with highs in the 80s and lows in the 60s. Model guidance is in pretty good agreement that storm activity will light up along the remnant 850 hPa frontal boundary Sunday afternoon into the overnight hours, which should be oriented NW- SE, roughly in the vicinity of northeast OK into west-central AR. With very high PWAT near 1.5" (dewpoints into the low 70s) and strong warm advection, areas of heavy rainfall and isolated severe storms are likely. We will remain within the warm sector Monday, with dew points again surging into the 70s. Additionally, stronger lift and shear will spread into the area as the upper level trough approaches. Forecast soundings are concerning, with most forecast metrics looking conducive for higher end severe weather potential. The expectation is that during the afternoon storms will develop along the dry line before moving east across the area. All severe hazards would be possible with any discrete storms, perhaps transitioning to more of a QLCS system with time. The SPC has already increased severe weather probabilities to slight to enhanced (15-30%) for this period, which seems well warranted given the parameter space. A cold front will push through later Monday, bringing much drier and cooler air. This should set is up for a quieter period mid week. Better moisture and storm chances return by late week. && .AVIATION... (18Z TAFS) Issued at 1244 PM CDT Fri May 16 2025 Scattered to broken mid and high clouds will continue to move east northeast this afternoon across southeast Oklahoma and northwest Arkansas ahead of a cold front moving through the region. Storm chances remain this afternoon ahead of the front, and will add a brief Prob30 group for KFSM. Behind the front, mostly clear to passing high clouds are expected this evening and tonight for the CWA. For Saturday morning, high level clouds are forecast to increase over the CWA along with moisture lifting into the region. There is potential for MVFR ceilings at KMLC/KFSM toward the end of the period. Storm chances Saturday look to be just outside of this TAF period. Winds start out breezy from the west and become variable tonight into Saturday. && .PRELIMINARY POINT TEMPS/POPS... TUL 57 83 64 82 / 0 20 50 50 FSM 62 89 68 87 / 0 30 50 40 MLC 61 86 68 85 / 0 40 30 30 BVO 51 80 60 81 / 0 10 60 60 FYV 55 85 63 82 / 0 20 60 60 BYV 56 84 61 82 / 0 10 60 60 MKO 58 85 64 82 / 0 30 50 50 MIO 53 80 61 81 / 0 10 70 70 F10 59 85 66 82 / 0 30 40 40 HHW 65 86 68 83 / 10 50 30 30 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...06 LONG TERM....06 AVIATION...20 ####018003204#### FXUS62 KTBW 161821 AFDTBW Area Forecast Discussion National Weather Service Tampa Bay Ruskin FL 221 PM EDT Fri May 16 2025 ...New DISCUSSION, AVIATION, MARINE, FIRE WEATHER... .DISCUSSION... Issued at 220 PM EDT Fri May 16 2025 Broad upper ridging over the gulf extends northeastward over Florida and along the eastern seaboard. This persistent ridge will become more west-east oriented over the weekend and into next week and will shift slightly eastward. On the surface, high pressure ridging across Florida remains the dominant weather feature through the weekend and first half of next week. This will lead to rain-free conditions and above average temperatures across west central and southwest Florida for a majority of the forecast period. The only weather concern will be the heat each afternoon with daytime highs topping out in the upper 80's along the coast, to the mid 90's over the interior. Heat indices will reach 100-105 degrees as well each afternoon. By next Wednesday, the upper ridge and surface high pressure shifts southward as upper troughing and a frontal boundary moves through the southeast U.S. This front will bring a slight chance of showers to the area Wednesday evening through Thursday afternoon. This will also bring some relief to the oppressive heat bringing temperatures down a few degrees closer to average, as well as some lower humidity, for the latter part of next week. && .AVIATION... (18Z TAFS) Issued at 220 PM EDT Fri May 16 2025 VFR, rain-free conditions and winds less than 10 knots persist through the forecast period. && .MARINE... Issued at 220 PM EDT Fri May 16 2025 High pressure ridging across the Florida peninsula and into the eastern gulf will remain the dominant weather feature through the weekend and into next week. Winds will remain around 10 knots or less, seas 2 feet or less and rain-free conditions expected each day. && .FIRE WEATHER... Issued at 220 PM EDT Fri May 16 2025 High pressure remains over the area with rain-free conditions and hot weather expected through the weekend and into next week. Humidity values will drop to near critical levels over the interior each of the next couple afternoons, but light winds will preclude the need for a Red Flag Warning. Patchy high dispersion indices are forecast for Saturday afternoon, mainly over the Nature Coast. && .PRELIMINARY POINT TEMPS/POPS... TPA 76 92 76 92 / 0 0 0 0 FMY 74 92 75 93 / 0 0 0 10 GIF 70 96 71 96 / 0 0 0 10 SRQ 74 90 74 90 / 0 0 0 0 BKV 66 92 67 93 / 0 0 0 0 SPG 77 89 77 89 / 0 0 0 0 && Sea Breeze Thunderstorm Regime For Saturday: 4 Sea Breeze Thunderstorm Regime For Sunday: 1 For additional information on sea breeze regimes, go to: https://www.weather.gov/tbw/ThunderstormClimatology && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ DISCUSSION/AVIATION/MARINE/FIRE WEATHER...Wynn DECISION SUPPORT/UPPER AIR...Pearce ####018012303#### FXUS61 KBOX 161824 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 224 PM EDT Fri May 16 2025 .SYNOPSIS... Weakening low pressure will bring scattered showers or thunderstorms at times through the end of the week as it reaches New England, but a majority of the time will be dry. A cold front moves through Saturday night behind the storms, drying and cooling the region. Even with mostly dry conditions, scattered showers remain possible Sunday with a cold pool aloft, then the pattern turns unsettled again toward midweek. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Key Messages: * Fog and stratus disperses around mid to late morning, but lingers over the Cape and Islands most of the day. * Scattered t-storms possible late in the day (after 3 PM) in western New England, but severe weather is not expected. Details: Mild and moist early-morning across Southern New England, with an extensive field of stratus blanketing a large portion of the Northeast. Fog has developed in most locations as well, but so far visibilities have been lowest along the coast, at times as low as one-quarter mile but they've generally been at or around half a mile. Coordinated with NWS New York City on special weather statement for fog through 13z along the South Coast/South Shore, Cape and Islands. Otherwise temps were in the low 60s with similar dewpoints. On the larger scale, we're in a period of midlevel subsidence/weak geopotential height rises, though that stands to change later this afternoon as we start to feel increasing height falls associated with a seasonably strong upper low over the Gt Lakes region. Probably won't see substantial improvement/scattering of fog and stratus until mid-morning at earliest in western and northern MA into CT, and around late morning to noontime for the Boston to Providence corridor. Given the marine boundary layer, stratus may linger for much of the day along the South Coast, Cape and Islands. Should be generally dry for most given the subsidence aloft; however some threat for scattered showers and thunderstorms still looks to materialize late in the day (probably not earlier than 3 PM and tending to down-trend by sundown) and mainly west of Fitchburg to Worcester to Willimantic with the onset of geopotential height falls. In what still is best characterized as a weakly-forced setup, the suite of convective-permitting guidance has been all over the place as far as placement goes, but looks like the greatest coverage of storms will be more to our north and west, and we'll have to watch to see if storms can make it over the Berkshires/southern VT. Some instability (around 1000-1200 J/kg) from diurnal heating should be present in western portions of the CWA, but low to midlevel flow is pretty weak and that limits shear magnitudes to less than 30 kt. Given this, probably not seeing much in the way of severe weather potential with this activity but lightning and brief downpours are still threats. Since this activity would stem from last night's round of severe weather in the Gt Lakes region, any smaller- scale impulse from that activity could modify that thinking, and that's something to watch as we move through today, but currently don't see indication of that in obs upstream. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... Key Messages: * Fog and stratus develop again tonight, and it may linger for quite a while into Saturday. * Possible round of scattered t-storms Saturday morning in most areas. * Better chance at t-storms between 2-8 PM west of Worcester. Some could become strong. Details: Tonight and Saturday: Any showers or storms in western New England should weaken/dissipate early tonight. We will end up seeing stratus and fog return northward from the waters again tonight. What will also be taking place in mid and upper levels late tonight and into Saturday is the potent upper low over the Great Lakes will continue to make eastward progress into the eastern part of Michigan. This will induce greater height falls and diffluent flow aloft to overspread much of the Northeast. Given the moist airmass in place, it won't take much heating or much of a shortwave triggering mechanism at all to get showers and t-storms going. What is also unclear is how today's severe weather setup in the Ohio Valley may influence shower/t-storm coverage or development. There are unfortunately quite a bit of uncertainties as it pertains to thunderstorm potential as we move into Saturday, which is problematic given the number of outdoor events happening, and makes it a difficult call as far as timing and strength of storms goes. The potential exists for a couple rounds of storms, possibly as early as the pre- dawn/early-morning Saturday period in some model solutions; and although this would not likely become strong, it could still be capable of some lightning. There is some loose consensus on a second round of scattered storms during the midafternoon to early evening hours, and it's this second round that may have the better potential for severe weather mainly for interior Southern New England near/west of Worcester. With this second round, low and midlevel flow increases to the point where forecast hodographs become pretty curved in a low-LCL setting, As indicated in the machine-learning progs, potential for locally strong winds and/or a tornado could develop in western MA/CT if storms can root themselves at the surface. That leads to the next source of uncertainty, in that we may still be dealing with quite a bit of stratus and low clouds from the overnight lingering even into the afternoon. The longer those low clouds stick around, the less likely we'll destabilize enough. Took the approach of keeping thunder probs low in the morning hours, with an isolated mention of thunderstorms. Although I still carry an isolated thunder mention in eastern MA and RI, I opted to instead increase probs for thunder in western MA and CT with the second round of possible storms. Felt uncertainties that I described were too much to include any enhanced wording but that might need to be considered later. Those with outdoor plans on Saturday will want to keep a close eye to the forecast and monitor for changes. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Key Messages: * Cold front moves through Saturday night, drying and cooling the region * Unsettled weather makes a return later in the week Details... Any lingering showers or storms will clear out Saturday night as a cold front passes through southern New England. Generally, the timing for the end of these storms is still somewhat uncertain. Some CAMs are hinting at a line moving through the region after 8 PM, which will be something to monitor. This would depend on how much energy and general instability is left following what moves through in the afternoon/evening, though. Behind the front, drier and cooler conditions with a cold pool settling in aloft that will likely continue into the start of next week. Some scattered showers do remain possible through Sunday as the mid-level low continues its exit offshore into the Gulf of Maine and the cold pool lingers. High temperatures will likely remain in the 60s and low 70s in some spots with less cloud cover Monday, then as the cold pool lingers highs through midweek will likely remain in the 60s. Some brief mid-level ridging will shift towards southern New England with surface high pressure to start the work week, but the pattern turns unsettled once again towards midweek as another mid-level low over the Great Lakes strengthens and an associated surface low shifts to the northeast from the Ohio River Valley. Some guidance indicates a surface low splitting off from this one in the OH River Valley and moving along the east coast, which could end up impacting southern New England in the form of increased cloud cover and rain chances. However, it is still quite far out in time for any finer details. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18z TAF Update: This Afternoon: Moderate confidence. MVFR-VFR cigs this afternoon. Low chance for an isolated SHRA/TS mainly near and northwest of a BDL-ORH line after 19z ending closer to or just after sundown. Light S winds with more SE seabreeze at BOS. Tonight: Moderate confidence. IFR-LIFR ceilings and visibilities return from the coastal waters mainly after 00z. Low chance of an isolated SHRA after 06z. Saturday: Moderate confidence overall, but lower on timing both sub-VFR improvement and on timing SHRA/TS. IFR-LIFR stratus likely to begin Sat. Slow improvement late morning through early afternoon with MVFR, improving over the west terminals first then eastward. West terminals improve toward VFR mid afternoon. Lower confidence in timing of further improvements across the east terminals in the afternoon, likely not until late afternoon if it does scatter out. Convective showers/storms possible in the morning 13-16z, but will be isolated- widely scattered. Another round for western airports after 18z and closer to 00z. Timing lower confidence. Some storms could become strong, with a better chance for strong activity in the 2nd round of storms for BAF- BDL- ORH. Winds mainly SE to S around 5-10 kt. KBOS TAF...Moderate confidence. Seabreeze til 23z. IFR cigs move in after 00z with lowering visibilities from BR. Slow improvements in ceilings Saturday morning with MVFR cigs. Low chance for convective showers 14-16z around the terminal. SE winds 5-12 kts. KBDL TAF...Moderate confidence. ISO SHRA/TS through 00z. IFR/LIFR overnight. Gradual improvements after 15z toward MVFR and VFR later in afternoon. Few rounds of thunderstorms possible in the afternoon and early evening. Timing lower confidence. Few stronger storms possible, more likely with the early evening round of storms. Outlook /Saturday Night through Wednesday/... Saturday Night: VFR. Chance SHRA. Sunday through Sunday Night: Mainly VFR, with local MVFR possible. Breezy. Slight chance SHRA. Monday through Tuesday: VFR. Breezy. Tuesday Night: VFR. Slight chance SHRA. Wednesday: Chance SHRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. High confidence overall. Expect sub-SCA conditions to prevail on the waters. Fog and reduced visibility will be the biggest potential hazard for mariners today and tonight, with S winds around 10 kt and seas 4 ft or less. Risk for thunderstorms could develop as soon as pre-dawn Saturday over the southern waters, with another round of storms possible into Saturday afternoon. Outlook /Saturday Night through Wednesday/... Saturday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain showers, isolated thunderstorms. Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft. Sunday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers. Monday: Winds less than 25 kt. Areas of seas approaching 5 ft. Monday Night through Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft. Tuesday Night: Winds less than 25 kt. Wednesday: Winds less than 25 kt. Seas up to 5 ft. Chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Loconto/Hrencecin NEAR TERM...Loconto SHORT TERM...Loconto LONG TERM...Hrencecin AVIATION...Loconto/Hrencecin/Mensch MARINE...Loconto/Hrencecin ####018008878#### FXUS64 KHUN 161824 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 124 PM CDT Fri May 16 2025 ...New AVIATION... .NEAR TERM... (Rest of Today and Tonight) Issued at 954 AM CDT Fri May 16 2025 A frontal boundary remains oriented through the middle of the Ohio Valley southwest into NW Arkansas and NW Texas. A large occluded surface/upper low over western Wisconsin/eastern south Dakota is pushing this front very slowly eastward today into tonight. A large area of severe convection has been ongoing into southern Kentucky ahead of this front over northeastern Arkansas and western Tennessee. This is being forced by a weak shortwave and increasingly strong nose of a low level jet over those areas. The good news is that most guidance moves this forcing primarily to the northeast today. RAP13 wants to produce QPF well south of the earlier mentioned activity this morning into the afternoon hours. Based on 7 AM soundings (especially from WFO Birmingham), a very strong low level inversion is in place over the area. Believe our conditions are closer to the environmental sounding in Birmingham, AL than the Nashville, TN 7 AM sounding. Mainly, based on how much closer to the front is to Nashville, TN. RAP13, is also a outlier even from most new 7 AM model guidance. This very strong inversion and the displacement of the mid/upper level forcing to our north should keep convection from firing over northern Alabama and our TN counties today into the very early evening hours. Therefore, keeping similar timing with convective initiation over the area later tonight as did the previous shift. The main window for severe storms still as below: 1. Franklin (AL) NW Lincoln County (TN) - 10 PM to 2 AM 2. SW Lawrence County (AL) to Sewanee (TN) - Midnight to 3 AM 3. SE Cullman County (AL) to Fort Payne (AL) - 2 AM to 5 AM If mid/upper level forcing does arriver earlier, then supercells and a larger hail/stronger tornado threat could exist. However, that is not expected at this time. Cloudy conditions should continue much of the day with a few breaks here or there from time to time. Highs should still be able to make it up to the mid to upper 80s despite the cloud cover. Enough MUCAPE or SBCAPE (700 - 1500 J/KG) or slightly more in some guidance could linger ahead of the front over the area into the overnight hours (mainly before 3 AM). This CAPE does drop off as you go further SW in the area. However, strong shear continues to be shown ahead of the front and 0-3 km helicity climbs to between 200 and 350 m2/s2 as the forcing moves into the area during the timeframes mentioned above. Expect there could be some embedded supercells (producing large hail initially) that move into the area. Still thinking this will form into a more widespread damaging wind threat with a few tornadoes possible. Though very low confidence, a strong tornado threat does look possible mainly in our TN counties and west of the I-65 corridor (unless instability drops off quicker overnight). && .SHORT TERM... (Tonight through Sunday) Issued at 303 AM CDT Fri May 16 2025 Morning update: SPC has expanded the Enhanced Risk (level 3 of 5) to cover far NW portions of AL and southern middle TN. Confidence has increased that severe storms will not enter the area until 10pm or after tonight. Damaging winds remain the primary concern, especially along any bowing segments that may occur. Confidence in the threat for hail and tornadoes remains low. Previous discussion: There is a low-medium chance of strong to severe storms tonight into Saturday morning- bringing threats of damaging winds, hail, and tornadoes. Primary timing for these threats is 10 PM tonight through 7 AM Saturday, which we have medium confidence in. As the aforementioned upper level low continues further into the Great Lakes region, a cold front is forecast to stem southwestward through the OH River Valley and into the Deep South. High pressure in the Gulf will allow southwesterly flow to advect moisture into the area ahead of the cold front arriving in the TN Valley. An increasing LLJ (~60 kts) will provide additional forcing for convective development ahead of the front. Current thinking is that it will be supercellular in storm mode NW of our area before upscaling into a linear system as it continues into the Tennessee Valley. Our mean wind, if relatively tall storms are realized, is around 50 kts. Therefore, storm motion will be fast as it continues southeastward through the area. This, combined with DCAPE values of 800+ J/kg as well as steep mid level lapse rates allows us to continue advertising strong to damaging winds as the primary threat with hail as a secondary threat. Tornadoes will also be possible as low level streamwise vorticity continues to appear in model hodographs. Outside of the severe threat, we also have a low threat of flash flooding. Model sounding PWAT values are ranging from 1.5-1.7", which is near or above the 90th percentile per BMX sounding climatology. However, with fast-moving storms, this will continue to be a low threat. We will be having to monitor the capping inversion and if we are able overcome it as model soundings have consistently shown a weak to moderate cap over the area. Another complication is that CAMs continue to have slight disagreements in timing- with some pushing it later than what we currently have forecast. If this were to occur, we would have less instability to work with as we lose diurnal heating deeper into the overnight hours. By Saturday morning, the line of storms should move out of the area to the southeast by around 12Z. Dry conditions are forecast to pursue the area behind the front with mostly clear skies, however, this will be short lived as medium to high rain chances (40-70%) return to the area by Sunday. This will be due to the previously mentioned frontal boundary lifting back northeastward- causing a potential MCS as it moves across the area. While there is still model disagreement in our potential environment, there could be enough instability to warrant another low end severe threat with damaging winds as the primary hazard. Be sure to check back in for updates on this system through the weekend. && .LONG TERM... (Sunday night through Thursday) Issued at 1048 PM CDT Thu May 15 2025 Shower/thunderstorm chances are forecast to decrease Sunday evening into the overnight hours as the aforementioned potential MCS continues northeastward. However, low chances (30% or less) of rain remain north of the TN River as the front is forecast to stall out to our NE through the early part of the week. Another upper level low is forecast to move through the Central Plains early in the week as well- forcing a weak ridge over the Tennessee Valley to continue eastward and PVA to take over the area by Tuesday. This will allow increasing shower/storm chances over the area, once again, as we continue to remain in an active pattern through the long term period. Since this is several days out, there is still uncertainty in specific placement of the potential trough through mid week and subsequent threats for strong storms. Therefore, we continue to encourage everyone to check back in for updates with this active weather pattern we remain in. Otherwise, we will generally cool through this period as highs go from the 80s on Monday to the 70s on Thursday. Overnight lows are forecast to drop into the 60s-70s. && .AVIATION... (18Z TAFS) Issued at 124 PM CDT Fri May 16 2025 VFR conditions are expected at both terminals through 04Z at KMSL and 06Z at KHSV. Expect LLWS to pick up to around 40 knots around 00Z at KMSL and 01Z at KHSV from 220 degrees. Around 04Z at KMSL and 06Z at KHSV, expected -TSRA to impact the terminals at times as convection develops and moves into the terminals. This will likely produce MVFR conditions primarily. However, included a tempo group for TSRA and IFR VSBYS or CIGS. LLWS should pick up as well to between 45 and 50 knots between roughly 06Z and 09Z. Some scattered (30 percent) -TSRA could linger from 09Z through 12Z at times, but only included a PROB30 due to the limited coverage of convection expected. MVFR CIGS will likely continue during that time and IFR CIGs/VSBYS could occur if that activity moves directly over either terminal. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...KTW SHORT TERM....HC LONG TERM....HC AVIATION...KTW ####018006277#### FXUS61 KBUF 161824 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 224 PM EDT Fri May 16 2025 .SYNOPSIS... A broad closed low over the Upper Midwest today will gradually cross the Great Lakes through the weekend, resulting in several opportunities for showers and thunderstorms through at least Saturday night. Much cooler and generally drier weather behind this system expected to last through the first half of next week before becoming unsettled again by later Wednesday. && .NEAR TERM /THROUGH SATURDAY/... Mainly dry conditions across the forecast area expected this afternoon. A few showers and thunderstorms will possible east of the Genesee Valley as a weak shortwave trough tracks through the region and increasing sunshine allows for some destabilization. While instability values will increase closer to the 750-1000 J/kg and even a bit high toward Central NY, there isn't going to be much in the way of shear. DCAPE values of around 500 J/kg may translate to some gusty winds in a storm or two that develops. Afternoon temperatures today will be in the low 70s to mid 80s, with the coolest temperatures closer to the lakes where onshore wind is present. The remnants of the earlier passing front will shift north across the area tonight as a weak warm front, and as a weak sfc low tracks northeast across the Ohio Valley and into Ontario. This will increase the potential for showers and some thunderstorms tonight into Saturday morning. There will be a break for a few hours before the main cold front associated with the large occluded system in the Midwest tracks through the area. With this frontal boundary, additional showers and thunderstorms are expected along and just ahead of the front from mid-morning through mid-afternoon from west to east. Shear profiles look a little stronger along with some instability ahead of the front. This will increase the chance for some strong to severe thunderstorms, especially for the eastern half of the forecast area. Temperatures on Saturday warm to the upper 60s to mid 70s ahead of the cold front and quickly drop by around 10 degrees within a few hours behind the frontal passage. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... Cooler with chances for showers Sunday, especially east of Lake Ontario. Further west, spotty showers and drizzle Sunday morning then drier weather will eventually take over as the closed low exits off to our east. That said...given some lingering low-level moisture in concert with a fairly chilly airmass overhead it's likely we won't see much clearing until late in the day. It will also be breezy with winds gusting up to 30 mph at times. Highs on Sunday will be in the 50s to low 60s. Low pressure continues to pull away Sunday night with any lingering showers ending across the region. We should see skies begin to clear from west to east and winds will also to lessen. Lows in the 40s, with a few isolated spots dipping back into the 30s east of Lake Ontario. Dry quiet weather expected Monday as high pressure wedges in across the Lower Lakes. Highs peaking in the 50s to low 60s. Clear skies anticipated Monday night and chilly with light winds overnight. Will need to monitor the potential for FROST. Lows will be found in the 30s to low 40s. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Fair dry weather Tuesday as the narrow ridge of high pressure remains over the Lower Lakes. Unsettled weather returns Wednesday and Thursday with multiple shortwaves collecting to form another closed low over the Great Lakes, with cool showery weather through the end of the week. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... Mainly VFR flight conditions for the rest of today and most of tonight. Periods of MVFR and brief IFR CIGs will be possible as showers with a few thunderstorms track across the area from southwest to northeast, mainly after midnight. The best chance for brief IFR conditions will occur within showers over the higher terrain. Saturday, earlier showers should clear northeast of the North Country during the first few hour of daylight, with mainly VFR conditions expected after earlier showers end. Another area of showers and thunderstorms will develop over WNY and track east as a cold front approaches during the mid-morning hours (~14Z). Locally moderate to heavy downpours will be possible as the showers and thunderstorms move through the forecast area from mid-morning through mid-afternoon, especially for the eastern portions of the area where slightly later timing will allow for some better daytime heating and instability. MVFR CIGs and VSBY can be expected within the showers and behind the front as low level moisture persists. Brief reductions to IFR for CIGs and VSBY may be possible within the heavier showers/storms. There may be gusty winds with some of the thunderstorms that develop. Outlook... Sunday...Mainly VFR with scattered showers east of KROC. Monday and Tuesday...Mainly VFR. Wednesday...some restrictions possible with showers in the area. && .MARINE... Southwest winds on Lake Erie of around 15kts for a few hours this afternoon will cause a small chop on the waters. Mainly drier weather expected over the waters this afternoon through early tonight. Another pair of frontal boundaries will then cause showers and thunderstorms to move back in from the southwest late tonight, with a drying trend first across Lake Erie late Saturday morning, with Lake Ontario to follow Saturday afternoon through Sunday. Southwest winds on both lakes are expected to increase by Saturday afternoon with SCA conditions likely on both lakes through at least a portion of Sunday, with the east end of Lake Ontario possibly lasting into Sunday night. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...PP NEAR TERM...SW SHORT TERM...AR LONG TERM...AR/Thomas AVIATION...SW MARINE...PP