####018004172#### FXUS62 KILM 160603 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 203 AM EDT Fri May 16 2025 .SYNOPSIS... Above normal temperatures near record levels are expected through late week. A weak cold front will move through Saturday night which could then return back north into or through the area toward mid next week. && .NEAR TERM /THROUGH TONIGHT/... Little in the way of convection expected through Friday under mostly clear/partly cloudy skies and warm temperatures for the season. Lows tonight will fall to the upper 60s to lower 70s with highs Friday away from the beaches in the low to mid 90s. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... Key Messages/Highlights: *Above normal temps w/ record high temps possible Saturday *Isolated damaging winds and/or large hail possible Saturday aftn/eve, especially in NC Confidence: *Moderate to High Details: A mostly zonal upper flow is expected with an inland surface trough giving way to a pretty weak cold front likely passing through Sat night. Limited moisture and forcing should preclude widespread rainfall but a few showers/storms are possible during the aftn/eve. There looks to be quite a bit of instability/shear for any storms to tap into so can't rule out a few damaging wind gusts and/or some large hail, mainly in NC. Temps should be the big story though as they will be well above normal, especially Saturday when they could reach record levels in the lower to mid 90s (see Climate section below for details). && .LONG TERM /SUNDAY THROUGH THURSDAY/... Key Messages/Highlights: *Above normal temps through the period *Mainly dry through at least Tue *No significant severe storm/flood risk until possibly Wed Confidence: *Moderate to High through Tue *Low to Moderate Tue night through Thu Details: Zonal to weak ridging pattern aloft should give way to more troughing late in the period although confidence is low regarding the timing/strength of the trough and associated surface frontal system. The previous front that had pushed south of the area over the weekend should push back north toward mid week ahead of the aforementioned frontal system developing farther to the west. Thus, it should remain fairly dry through at least Tue before rain chances increase although for now we are being fairly conservative given the uncertainty. Temps should stay above normal until possibly as early as Wed when they could fall back closer or even below normal. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... VFR conditions expected through the forecast period, as a building mid-level ridge keeps convection suppressed. Extended Outlook...Mainly VFR conditions are expected through the period. && .MARINE... Through Friday...Expect S to SW winds 10 to 15 KT with higher gusts and seas of 3 to 4 FT. Friday night through Tuesday...Moderate to high confidence this period. A weak cold front should move through Sat night with a marginal Small Craft Advisory possible for gusts to around 25 kt Sat aftn/eve prior to the frontal passage. Otherwise, a fairly weak pressure gradient is expected through the period w/ no headlines anticipated as seas stay mostly 4 ft or less. && .CLIMATE... High temperature records may be challenged Friday and Saturday as anomalously warm air overspreads the region ahead of a cold front. Record highs for our four climate sites are as follows: For Friday, May 16th... Wilmington, NC: 94F (1915) Lumberton, NC: 96F (1962, 1941) Florence, SC: 93F (2022) N. Myrtle Beach, SC: 91F (1941) Saturday, May 17th... Wilmington, NC: 92F (1960, 1990) Lumberton, NC: 96F (1941) Florence, SC: 93F (1977) N. Myrtle Beach, SC: 92F (1941) && .ILM WATCHES/WARNINGS/ADVISORIES... NC...None. SC...None. MARINE...None. && $$ SYNOPSIS...ILM NEAR TERM...31 SHORT TERM...RJB LONG TERM...RJB AVIATION...SHK MARINE...RJB/31 CLIMATE... ####018006219#### FXUS63 KPAH 160603 AFDPAH Area Forecast Discussion National Weather Service Paducah KY 103 AM CDT Fri May 16 2025 .KEY MESSAGES... - Some risk for hail and locally damaging winds with thunderstorms over SEMO and West KY this morning. - A significant/dangerous severe weather outbreak is expected Friday afternoon into Friday evening. Strong/intense, and potentially long tracked tornadoes are possible and widespread and potentially significant damaging wind is also possible. - More unsettled weather returns Sunday night through Wednesday with more severe weather potential, especially on Tuesday. && .DISCUSSION... Issued at 103 AM CDT Fri May 16 2025 Right now a large and strong upper level low is swirling over the northern Plains with a broad 120 kt upper jet maxima southeast of it from WI down to AR. This jet has a very slight diffluent curvature in its exit region. Another shortwave is evident on water vapor over southeastern Colorado. Linear extrapolation and model guidance puts that trough in range of influencing our weather by about 20-21z (3-4 pm CT). Our thermodynamic situation based on observed and model (RAP/NAM/HRRR/GFS) soundings is that we remain capped with a dry and warm layer around 850mb, although steady weak ascent through the evening has likely eroded this cap somewhat. As well as this afternoon/evening's 'virga bomb' showers that caused cooling and evaporation in that layer and led to 40-50 mph wind gusts. A sharp dryline/front is set up over roughly our northwestern CWA counties or just northwest of there with dewpoints in the high 40s to 50s to the west and upper 60s to 70s to the southeast. A few showers are developing in AR/MO along this front and the steady ascent through the overnight will likely partially aid in getting this activity going through the next few hours. Elevated parcels above the residual cap would have about 1200-1500 J/kg of CAPE to work with and given the shear and antecedent conditions this could pose a hail risk. Then the really hard part. That shortwave over Colorado looks to spark a spike in the lower level wind fields that advects warmer air and richer moisture (70+ degree dewpoints) into the area. This turns our SW to NE dryline into more of an E to W warm front and sends it north into the area as the main parent trough also approaches from the northwest from 21-00z. This increases our 850mb flow to about 45-55 kts from the southwest with westerly flow at 250mb increasing to around 140 kt as the upper height gradient maximizes as the two shortwaves combine/approach. Forcing for ascent seems to maximize across portions of northern SEMO and southern Illinois and into southwest Indiana, where the higher resolution models seem to be suggesting at least a whiff of a surface low that serves as a sort of triple point between the advancing warm front and approaching cold front. I'm wary this will serve as a volatile region for severe with MLCAPEs progged around 3000 J/kg and 0-1km SRH values around 300 m2/s2 with STP values 4-8 in most guidance progs. CAMs mostly initiate initially discrete supercells in northern SEMO tracking eastward upscaling fairly quickly into an MCS/QLCS system. Further southeast CAMs tend to support more discrete supercellular activity longer. SPC HREF/GEFS probs like the SRN IL/SWIN corridor for the highest overall potential. Somewhere just south or along whatever theta-e gradient exists probably will end up with the highest tornado/significant damaging wind potential and guidance has been consistent in showing that for this area. The HRRR and other CAMs also tend to want to fire up discrete open warm sector supercells over western Kentucky by late afternoon where residual capping may hold on a little longer before larger ascent arrives. It appears to me to be impossible to judge the likelihood of this until we see some cu fields set up later in the morning - possibly from residual boundaries from the developing convection to our west. Limiting factors overall may be a bit of storm-scale interference as multiple cells fire in very rich low level moisture but that would probably accelerate the development into a potentially significant line of storms. Summarizing, this appears to be an exceptionally volatile environment and discrete supercells that form would pose a risk for strong/intense tornadoes anywhere/anytime they develop this afternoon. Those cells could and probably will then develop into an intense line of storms that would be entirely capable of 70-80 mph wind gusts across a broad area, as well as brief, but potentially significant, tornadoes through early evening as the storms move west to east across the area. Another significant storm system is forecast on Tuesday as a sharp upper low phases with the polar and subtropical jet just northwest of our region and spins up a fairly strong surface low just north of the area. There are fairly significant differences between GFS/ECMWF in how that is handled exactly and we will just have to focus our attention to that after this current event wraps up. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1109 PM CDT Thu May 15 2025 Convection is expected to develop overnight, with KCGI/KPAH/KOWB the most likely terminals to be impacted. This activity may linger into Friday morning across west Kentucky before moving out by 14-15z. A lull is expected late morning into early afternoon before additional development in the form of severe storms develops mid-late afternoon and continues into the evening tomorrow. Included PROB30's for the most likely timing of heaviest convection at any one terminals. Will see reductions in cigs/vsbys associated with storms, along with the possibility of very large hail, 70 mph wind gusts, and strong tornadoes. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ DISCUSSION...JGG AVIATION...SP ####018006789#### FXUS64 KHUN 160604 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 104 AM CDT Fri May 16 2025 ...New AVIATION... .NEAR TERM... (Rest of tonight and Friday) Issued at 900 PM CDT Thu May 15 2025 A closed low continues to move eastward into the Great Lakes region as high pressure exists in the Gulf, allowing the Tennessee Valley to be encapsulated in an area of moderately strong mid level flow between the two systems. A strong LLJ (~40 kts) is forecast to move into the region overnight, with higher forcing to our NW. Assisted by WAA, there could be some shower development from what is left of a lingering MCS earlier this evening as it continues southeastward near our area. Primary timing for showers would be between 4-7 AM. While we continue to be outlooked by SPC for a low chance of strong to severe storms through 7 AM, we continue to have low confidence in any thunderstorms materializing. Low level lapse rates are weak and we are influenced by a capping inversion. Therefore, we are advertising a very low chance of a strong storm tonight with the potential for gusty winds up to 30-40 mph. However, the WAA should keep lows relatively warm as temperatures only drop into the low to mid 70s. Friday, dry weather returns for most of the day as high temperatures warm into the mid to upper 80s. Gusty, southwesterly winds up to 20-25 mph are forecast as an increased low level jet moves into the area and begins to mix down. We will be monitoring a low-medium risk for strong to severe storms Friday night into Saturday morning, however, more on that in the short term section below. && .SHORT TERM... (Friday night through Sunday) Issued at 1048 PM CDT Thu May 15 2025 There is a low-medium chance of strong to severe storms Friday night into Saturday morning- bringing threats of damaging winds, hail, and tornadoes. Primary timing for these threats is 10 PM Friday through 7 AM Saturday, which we have low-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... (06Z TAFS) Issued at 104 AM CDT Fri May 16 2025 VFR conditions will persist through the overnight hours with light southerly winds that will ultimately veer to the southwest and increase throughout the day. MVFR cigs are forecast to move in through the morning hours but VFR conditions will return during the afternoon. Wind gusts up to 20kts will be possible at times. Dry conditions are forecast through the afternoon hours, but chances for showers and thunderstorms will increase by the late evening and overnight hours. Some storms could be strong to severe overnight, and we will have to monitor for wind shear as this system moves through. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...HC SHORT TERM....HC LONG TERM....HC AVIATION...25