####018011305#### FXUS63 KMKX 161519 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 1019 AM CDT Fri May 16 2025 .KEY MESSAGES... - Gusty non-thunderstorm winds are expected across southern Wisconsin today. Be sure to secure any loose outdoor objects and furniture before heading out this morning. - Scattered showers and thunderstorms are expected this afternoon, with peak potential (~30-60% chances) being between 3-8 PM. Widespread severe weather is unlikely, though a few storms could produce large hail and strong wind gusts. - Much cooler conditions this weekend through the beginning of next week, with below-normal high temps forecast each day. - Next shower and thunderstorm chances (~30-60%) return Monday through Tuesday. - Temperatures return to near-normal late next week. && .UPDATE... Issued 959 AM CDT Fri May 16 2025 Still looking at gusty south-southwesterly winds around 30-40 mph around the the deep surface low tracking across central MN into northern WI. Wind should remain below wind advisory criteria. Otherwise, still keeping an eye on the potential for isolated to scattered showers and storms later this afternoon into the early evening. Looking upstream there are two area of lingering showers, a line along the cold front back across southern MN and another cluster across southern IA associated with a mid-level ripple of vorticity rounding the base of the upper-level trough. Based on the morning CAM guidance this southern IA wave looks to be the focus for our shower/storm development this afternoon/evening as it lifts northeastward across the area. While it looks to push into southwesterly WI late this morning/early afternoon, there seems to be enough CIN (50-150 J/kg) and limited moisture (PWATs less than 0.7 inches) present to limit this activity to light showers. However, as we heat up into the afternoon, the cap looks to erode as moisture from MN creeps into the area. Thus, increasing our shower/storm chances between the 3-8 PM CDT east of I-39 corridor. Mainly expecting isolated to scattered coverage given the drier airmass, but as the LLJ increase late afternoon evening cannot rule out a stronger storm or two which could be capable of mixing down the stronger gusty to damaging winds. Also if a storm can grow tall enough, some hail could not be ruled out with any of this activity as well. Again, still would need to overcome the drier airmass, but the lower end potential remains. Wagner && .SHORT TERM... Issued 358 AM CDT Fri May 16 2025 Today through Tonight: Synopsis/Mesoanalysis: GOES water vapor imagery places an upper trough over the ND-MN border vicinity early this morning. Positioned beneath the wave, surface low pressure is apparent just to the south of Fargo, ND. An occluded front---the same boundary responsible for yesterday afternoon's severe convection---branches out from the surface low, with 3 AM observations showing the front extending across Lake Superior toward Lake Huron. A surface ridge trails the occluded front, which has allowed winds to temporarily lighten across southern Wisconsin. Surface pressures fall once more moving west toward the Missouri River vicinity, where a secondary cold front is positioned. Both this front and the aforementioned upper trough will cross southern Wisconsin today, resulting in increasing southeasterly winds from late morning into the afternoon. Said winds will be gusty at times, with the highest gusts expected during the 12-6 PM time frame. Lift from the passing surface front & upper trough will also support scattered showers and thundershowers this afternoon, with potential peaking during the 3-8 PM time period. This activity won't be nearly as intense as the storms occurring yesterday, though a few storms could produce large hail and strong wind gusts. Shower/thundershower chances will gradually taper as the upper trough & surface front move east of the area tonight. Today: South-southwest, non-thunderstorm winds will become gusty ahead of an approaching front by early this afternoon. Have carried gusts of 35-40 MPH range in the current forecast, with the highest readings favored during the 12-6 PM time frame. Locally higher gusts in the 40-45 MPH range are possible during this time period. Whether/not more widespread 45 MPH gusts can materialize will depend on the depth of boundary mixing that occurs through this afternoon, with forecast soundings from different meso models depicting slightly different boundary depths & momentum transfer. In coordination with surrounding offices, thus elected to hold off on any Wind Advisories in the overnight forecast, though trends will be closely monitored. Also anticipate scattered shower & thundershower development during the afternoon hours, with potential peaking during the 3-8 PM time frame. While widespread severe weather is unlikely, a combination of cold air aloft/steep mid-level lapse rates, strong synoptic wind fields, & deeply mixed boundary layers/efficient momentum transfer will support some potential for large hail and damaging wind gusts in the strongest cells. Expect this potential to be maximized to the east of I-39, where surface- based instability is progged to be greatest. Cloud to ground lightning will also be a concern in/around the strongest cells. Stay weather aware if planning to be outdoors this afternoon/early evening, and move indoors if a storm approaches your area. Quigley && .LONG TERM... Issued 358 AM CDT Fri May 16 2025 Saturday through Thursday: The upper level trough over the central Great Lake Region will continue northeast out of the area toward the New England States. Breezy west winds are expected to continue through the early morning hours as the pressure gradient will remain tight until the low pulls out of the region. Cooler air will be ushered into southern Wisconsin with these breezy winds leading to highs in the mid 60s across the forecast area. As the low pressure pulls out, there could be some lingering showers in the early morning hours. Not expecting much more than some light rain as there will be dry air moving in with the westerly flow. Strong high pressure will build in across Manitoba and Ontario Canada Sunday. Dry weather and lighter winds are expected for Wisconsin as this ridge moves through the region. Under the weaker winds, a backdoor cold front/aggressive lake breeze should move inland and drop temperatures across east central and lake shore counties. These areas can expect highs in the 50s with inland areas in the mid to upper 60s. The next chance for rain looks to be Tuesday into Wednesday as a low pressure system tracks east from the central plains. Guidance has this area of low pressure tracking just the south of the state, which should provide southern Wisconsin with some nice wetting rain. Not anticipating anything severe as we should be on the northern edge of the low and dealing with more or a stratiform rain set up. Still a bit of uncertainty in how far south this low may travel and just how much rain we might see, but overall a very solid set up. Mild and comfortable temperatures are expected through mid week with highs in the 60s for inland areas and slightly cooler temperatures near the lake shore in the 50s. Patterson && .AVIATION... Issued 1015 AM CDT Fri May 16 2025 VFR conditions will prevail through the forecast period as the main aviation concern will be the gusty winds and isolated/scattered shower and thunderstorm chances this afternoon. Looking at strong south-southwest winds with gusts of 30-35 kt possible late this morning through the early afternoon as a deep low pressure tracks across central MN into northern WI. Will see winds weaken a bit later this afternoon and evening as a cold front works its way across the area. However, southwesterly gusts up to around 20-25 kt will linger overnight behind the front. Otherwise, looking at isolated to scattered showers and thunderstorms to develop this afternoon and early evening mainly between 20z-01z. Given the dry airmass and isolated to scattered nature of the coverage, will maintain PROB30 for this activity. As the low shifts east will begin to see some lower ceilings work their way into the area overnight into Saturday morning as well bring some MVFR conditions. Wagner && .MARINE... Issued 358 AM CDT Fri May 16 2025 Currently situated along the North Dakota-Minnesota border, low pressure near 990 mb will progress into northwestern Wisconsin today, ultimately crossing northern Lake Michigan tonight. Southerly winds will increase ahead of the approaching today, becoming gusty from late morning through the afternoon hours. Widespread gusts between 25-30 knots are forecast across all of the open waters during this time frame. A few gusts could briefly approach gale thresholds, though widespread gale potential is low. Have thus held off on gale headlines in the overnight forecast. The approaching surface low will be accompanied by scattered showers and thunderstorms. Widespread severe storms are unlikely, though some storms could produce small hail. Winds will shift out of the west on Saturday as 994 mb low pressure moves into Ontario. Rain chances will continue, particularly across the northern half the open waters. Thunderstorms are not anticipated. Winds will turn out of the northwest Saturday night, when 1016 mb high pressure will build into the Upper Mississippi River Valley. Gusty south to southeasterly winds and elevated wave heights will result in Small Craft Advisory conditions today in all nearshore zones. A few gusts could briefly approach gale thresholds, particularly from North Point to Sheboygan. Gusts could occasionally approach gale thresholds this afternoon, particularly from North Point to Sheboygan, though any such conditions would be brief. Have thus replaced the previous Gale Watch with a Small Craft Advisory in the overnight forecast update. Scattered showers and storms are expected this afternoon. Widespread severe storms aren't expected, though a few storms could produce hail. Winds and waves will briefly dip below advisory thresholds after midnight, prior to increasing to Small Craft Advisory levels once more Saturday morning. Have thus maintained the Small Craft Advisory through 7 PM CDT Saturday evening, when conditions will begin to steadily improve. Quigley && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 7 PM Saturday. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSMilwaukee www.twitter.com/NWSMilwaukee www.youtube.com/NWSMilwaukee ####018006611#### FXUS61 KILN 161520 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 1120 AM EDT Fri May 16 2025 .SYNOPSIS... Warm and humid conditions will fuel the development of thunderstorms today. The potential exists for some of the storms to be severe late this afternoon into tonight. Cooler temperatures and drier weather will follow heading into the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Increased PoPs across the south with the morning update based on radar trends with convection focused mostly over northern Kentucky. In addition, the cloud shield associated with these storms have led to slightly lower max temps this afternoon. Latest CAMs have started backing off storm development for late this afternoon into the evening. Will need to monitor these trends for more significant grid updates. Previous discussion: Main focus today is the potential for a significant severe weather outbreak. In the warm sector strong instability is expected to develop today with SBCAPE values of 2500-3500 J/kg. This combined with increasing deep layer shear (effective shear around 60 kts) will lead to the threat for strong to severe storms. CAM solutions continue to show a very good signal for storm development to our west - which organizes into bowing segments as they move eastward into the Ohio Valley. This complex of strong to severe storms is expected to impact the area late this afternoon into this evening. Exact timing is still somewhat uncertain but the greatest impacts look to occur as early as 5 pm across eastern Indiana/southwest Ohio and northern Kentucky and then spread quickly east across the area thru the evening. All severe weather hazards are possible from these storms. The greatest threat area for significant severe weather is across the Cincinnati Tri-state region. There is also the possibility of locally heavy rain which could result in flash flooding. Make sure you have multiple ways to receive warnings and a plan in place should a warning be issued. In the humid airmass high temperatures will top out in the lower and middle 80s. Southwest winds increase to 10 to 15 mph with gusts up to 30 mph. Storms diminishing quickly late this evening into the overnight hours. A low pop shower or storm threat will continue across the far northern counties overnight in response to a shortwave rotating around the upper low moving into the Great Lakes. Lows tonight range from near 60 north to the lower 60s south. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... Mid and upper level low pressure to track thru Great Lakes on Saturday. Shortwave energy rotating around this low will lead to a low chance of a shower and perhaps an embedded thunderstorm across the extreme northeast counties. In the wake of a surface cold front southwest to west winds to gust up to 30 mph. In less humid and cooler conditions high temperatures to range from the upper 60s northwest to the upper 70s southeast. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A building upper ridge in the Plains will result in increasing heights over the Ohio Valley through at least Monday evening. The ridge axis still remains to the w over WI although heights in our area will level out with the amplitude of the ridge decreasing in response to encroaching low pressure from the west. Models begin to diverge Tues afternoon, leading to lower confidence in mass fields beyond this time. The next threat of rainfall will occur in the southwest Monday morning as a strong lobe of s/w energy undercuts the upper level ridge and then tracks se in the mean downstream upper flow. Overnight Monday and Tuesday stand the best chance for widespread rain affecting the entire CWA as a surface warm front sets up w-e near the Ohio River. At this time, upper level ridge weakens and s/w energy continues to race eastward across CWA. A surface low will follow the warm front eastward and into the CWA. Placement and timing differences are noted but the overall picture is that the low will be situated over the CWA, bringing an increased potential for widespread rainfall. Sfc low moves east, but axis of the upper low has yet to cross the Ohio Valley and a lingering potential for rain exists through Wed. A seasonable temperature range is dominant in the forecast. Highs in the low-mid 70s Sun drop to the upper 60s/low 70s Mon, slightly cooler by 1-3 deg Tues. Northwest flow at the end of the forecast has highs in the mid 60s Wed, and near 60 Thurs. Overnight lows take a similar trajectory with low-mid 50s Sat/Sun nights, upper 40s to upper 50s Mon night, low-mid 50s Tues night, near 50 Wed night and in the upper 40s Thurs night. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... Mid level ridge axis has shifted east of the area leaving strong southwesterly flow aloft. An embedded shortwave will lead to scattered morning showers/thunderstorms which should stay mainly south of the TAF sites. Will have to watch KCVG and KLUK as these storms continue to develop but for now have left this morning potential out of the TAF forecast. In the warm sector strong instability is expected to develop today with SBCAPE of 2500-3500 J/kg. This combined with increasing deep layer shear will lead to the threat for strong to severe storms late in the day into this evening. CAM solutions continue to show a very good signal for storm development to our west - which organizes as it moves eastward into the Ohio Valley. This complex of strong to severe storms is expected to impact the TAF/s late in the day into this evening. Exact timing is still somewhat uncertain but the greatest impacts look to occur as early as 22Z across KCVG and KLUK thru about 03Z at KCMH/KLCK. All severe weather hazards are possible from these storms. Expect VFR conditions until storms develop with LIFR conditions in storms. Storms end later this evening with VFR conditions continuing overnight as drier air begins to advect into the region. Surface winds increase out of the southwest with sustained winds of 10-15kts and gusts up to 25 kts. OUTLOOK...No significant weather expected. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...AR NEAR TERM... SHORT TERM...AR LONG TERM...Franks AVIATION...AR ####018010438#### FXUS63 KLMK 161523 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 1123 AM EDT Fri May 16 2025 .KEY MESSAGES... * SIGNIFICANT SEVERE WEATHER OUTBREAK POSSIBLE LATE THIS AFTERNOON INTO THIS EVENING. * All severe weather hazards are on the table, including damaging winds, large hail, tornadoes, and torrential rainfall. A few strong tornadoes and instances of very large hail are possible. * Strong to severe thunderstorms are also possible this morning west of Interstate 65, with large hail as the main hazard. && .UPDATE... Issued at 1123 AM EDT Fri May 16 2025 A large area of convection continues to push through central and eastern Kentucky this morning. This rainfall is being forced by strong warm advection along with lift associated with a southwest low-level jet axis. While the surface layer is pretty stable from nocturnal cooling, we do have an EML aloft with fairly steep low-mid level lapse rates. There was capping overnight until the cap mixed out due to nocturnal cooling and convection has taken off. Storms have been on/off severe this morning with mainly marginally severe hail being reported in the storms. Given the near surface stability, gusty winds have been observed on occasion, but nothing near severe levels. With PWATs well above 1.50 inches, we're seeing torrential rainfall with these storms as well. Going forward, main area of severe convection will be from roughly south of a line from Butler County northeast to Harrison County. In this area storms capable of torrential rainfall, and hail up to 1 inch in diameter in the strongest cores will be possible. A more concentrated wind threat may emerge with a small scale bow/MCS that is trying to take shape near Hopkinsville. This activity will surge eastward along the KY/TN border this morning. Have done a local extension of WW259 through noon EDT. We did cut off the northern area of that watch where additional severe weather is not anticipated. Rainfall amounts have been impressive with an inch to an inch and three quarters falling along a line from Mayfield northeast through the Elizabethtown area. We expect portions of the Bluegrass and southern KY to pickup on similar rainfall through the morning, most likely an inch to an inch and a half. Given recent rains from this morning and expected additional rainfall this afternoon/evening, have coordinated with JKL and hoisted a Flood Watch for the southern half/two-thirds of the LMK forecast area. As for the afternoon hours...Somewhat of a complicated forecast here as ongoing clouds and convection is likely to linger over central and eastern KY into the afternoon. Recent satellite imagery does show back edge of the clouds clearing the Paducah area and working eastward. The overall theme that we have been messaging seems to OK at the moment. That is, we expected additional thunderstorms to fire out across eastern MO/NE AR/W KY/S IL in the next few hours. Parameter space out that way will support discrete supercells with very large hail, damaging winds, and strong tornadoes (some long track possible). This activity will move eastward toward central KY while growing up scale into a large or a couple of MCS/QLCS's resulting in widespread damaging winds and spinup tornadoes within the line. The actual evolution of this afternoon/evening's activity remains the most challenging. It appears that a two pronged scenario could develop across the region. First, ongoing convection across southern KY may end up stalling out and leaving some sort of baroclinic boundary in place. As skies clear out, this boundary will become the focus for convective development this afternoon. It is possible that we could see isolated-scattered supercells develop along this boundary from roughly Paducah eastward to Bowling Green and toward Somerset. This boundary could then lift north/northeast into the evening hours. Parameter space across KY would support all modes of severe weather. However, given ongoing cloud cover and shorter time of insolation, not overly confident how unstable we could become. Meanwhile back to the west, expected supercell development should be ongoing while developing upscale into 1 or more lines. These QLCSs should then plow eastward resulting in damaging winds, spin up tornadoes within the line, along with some isolated-scattered large hail. This scenario has support from many of the 12Z CAMs though though the question is how far north could the baroclinic boundary lift prior to the QLCS coming in from the west. The HRRR is most aggressive with its northward movement taking it as far north as I- 64. On the other hand the WRF ARW/NSSL WRF and the RRFS all keep the boundary more over southern KY while plowing the QLCS out to the west eastward rather quickly. MPAS runs are not in yet, but will evaluate them early this afternoon. && .SHORT TERM /THROUGH TONIGHT/... Issued at 407 AM EDT Fri May 16 2025 A significant severe weather outbreak is possible later this afternoon and this evening across the Ohio Valley. Storms developing ahead of an incoming cold front will quickly become severe in a very unstable and strongly sheared environment. All severe weather hazards, including widespread damaging winds, very large hail, and strong tornadoes are possible, as well as localized flash flooding. Main bust potential hinges on the evolution of storms this morning, which have developed over western Kentucky. These storms will have a large hail threat of their own, especially west of Interstate 65. While they will at least temporarily stabilize the atmosphere, strong warm advection is likely to win out, allowing a fairly quick recovery this afternoon. With around 3000 J/kg of mixed-layer CAPE, 1000 J/kg of downdraft CAPE, and 60 kt of effective shear, initially discrete storms will organize into at least bowing segments. A few of the discrete cells could produce very large hail and/or strong tornadoes, and line segments could produce hurricane-force wind gusts. Spin-up tornadoes will also be in play with any of the bowing structures as well. The peak severe threat could be slightly delayed depending on how quickly the atmosphere can reload after morning convection, but the threat will mainly be focused on the evening hours. Initial discrete cells could develop in the late afternoon. It's also worth noting that in the late evening, the line will become more east-west oriented, opening the door for excessive rainfall especially over south-central Kentucky. Confidence in the exact placement is low at this time, but it bears watching as the event unfolds. Bottom line, significant severe weather is possible late this afternoon and this evening. Make sure you have multiple ways to receive warnings and a plan in place should a warning be issued! && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 352 PM EDT Thu May 15 2025 By Saturday morning, the actual cold front will be pushing through the area with most of the showers and storms exiting to our east. The associated upper low will be over the Great Lakes with the longwave trough axis extending south over the OH and TN Valleys before flattening out against the subtropical ridge over the Gulf. Weak CAA behind the front will result in climatological normal temperatures for the weekend with highs in the mid to upper 70s to lower 80s accompanied by breezy WSW winds on Saturday. Overall, most will experience a fair weather weekend. Southern KY will see a slight chance of showers on Sunday as the southern edge of the new airmass begins to lift northward due to the next low pressure system strengthening over the Central Plains. This will begin another period of unsettled weather as we enter the beginning of the new work week. By Monday, a warm front will begin lifting across the region resulting in warm and moist air advection, as PWATs surge into the upper percentiles of SPC's sounding climatology. Models tend to agree on convection from our west moving into our area by Monday morning with another round Monday evening. The warm front appears to stall over the region, prolonging our shower and storm chances into Tuesday and Wednesday before the occluded low pushes through on Wednesday. With model soundings advertising sufficient instability and ML guidance also showing enhanced severe probabilities, severe weather can not be ruled out. Details remain hazy this far out, but will continue to monitor closely with subsequent forecast packages. Stay tuned. && .AVIATION /12Z TAFS THROUGH 18Z SATURDAY/... Issued at 712 AM EDT Fri May 16 2025 Main challenge in this TAF set is timing and impacts of two different waves of convection. Ongoing convection this morning will mainly produce brief IFR vis in the heaviest rain, but cigs should remain VFR with the exception of LEX and perhaps RGA. First wave of storms will push east of the terminals by 15-17Z, giving way to mainly mid-level cigs this afternoon with gusty SSW winds. Next wave of more vigorous storms is expected early this evening. Given the wind threat, opted to include a TEMPO with convective winds starting around 23Z in HNB/BWG, closer to 00Z at SDF, and 01- 02Z in LEX and RGA. This will also be the better shot at MVFR cigs and IFR vis, and could warrant a prevailing mention in later TAF issuances. Some uncertainty between waves at BWG and RGA as we could have a lingering boundary draped across to focus convection sooner. Should be a fairly sharp cutoff and clearing out of lower clouds after the storms pass around midnight. Light SW winds and cirrus ceilings heading into Sat morning. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...Flood Watch through late tonight for KYZ026>028-039>041- 045>049-053>057-061>067-070>078-081-082. IN...None. && $$ UPDATE.......MJ SHORT TERM...RAS LONG TERM....CG AVIATION.....RAS