WW 253 TORNADO IL WI 152005Z - 160300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 253 NWS Storm Prediction Center Norman OK 305 PM CDT Thu May 15 2025 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Far Northern Illinois Central/Eastern/Southern Wisconsin * Effective this Thursday afternoon and evening from 305 PM until 1000 PM CDT. * Primary threats include... A few tornadoes and a couple intense tornadoes possible Scattered large hail and isolated very large hail events to 3 inches in diameter likely Scattered damaging wind gusts to 70 mph likely SUMMARY...Thunderstorms are expected to develop along a warm front and move into the region over the next several hours. Environmental conditions support supercells capable of all severe hazards, including large to very large hail and tornadoes. The tornado watch area is approximately along and 60 statute miles east and west of a line from 40 miles northeast of Wausau WI to 20 miles south southwest of Janesville WI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 251...WW 252... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 21030. ...Mosier Read more

WW 0252 Status Updates
STATUS REPORT ON WW 252 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 WNW LIT TO 25 W ARG TO 35 SSW FAM. ..THORNTON..05/15/25 ATTN...WFO...LZK...MEG...PAH...SGF... STATUS REPORT FOR WS 252 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC021-031-037-055-063-067-075-093-111-121-145-147-152240- AR . ARKANSAS COUNTIES INCLUDED ARE CLAY CRAIGHEAD CROSS GREENE INDEPENDENCE JACKSON LAWRENCE MISSISSIPPI POINSETT RANDOLPH WHITE WOODRUFF KYC039-075-105-152240- KY . KENTUCKY COUNTIES INCLUDED ARE CARLISLE FULTON HICKMAN MOC023-069-133-143-155-181-207-223-152240- MO . MISSOURI COUNTIES INCLUDED ARE BUTLER DUNKLIN MISSISSIPPI Read more

WW 0251 Status Updates
STATUS REPORT ON WW 251 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 ESE LSE TO 30 N LSE TO 25 WSW EAU TO 20 ESE STC TO 25 NNW STC TO 15 E DTL. ..THORNTON..05/15/25 ATTN...WFO...DLH...MPX...FGF...ARX... STATUS REPORT FOR WT 251 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MNC001-003-009-021-025-035-059-065-095-097-115-153-159-152240- MN . MINNESOTA COUNTIES INCLUDED ARE AITKIN ANOKA BENTON CASS CHISAGO CROW WING ISANTI KANABEC MILLE LACS MORRISON PINE TODD WADENA WIC003-005-007-013-017-019-031-033-035-051-053-081-095-099-107- 109-113-119-129-152240- WI . WISCONSIN COUNTIES INCLUDED ARE ASHLAND BARRON BAYFIELD BURNETT CHIPPEWA CLARK DOUGLAS DUNN EAU CLAIRE IRON JACKSON MONROE POLK PRICE RUSK ST. CROIX SAWYER TAYLOR WASHBURN Read more

WW 251 TORNADO MN WI 151745Z - 160100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 251 NWS Storm Prediction Center Norman OK 1245 PM CDT Thu May 15 2025 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central Minnesota West-Central Wisconsin * Effective this Thursday afternoon and evening from 1245 PM until 800 PM CDT. * Primary threats include... A few tornadoes likely with a couple intense tornadoes possible Scattered large hail and isolated very large hail events to 3 inches in diameter likely Scattered damaging wind gusts to 70 mph likely SUMMARY...Rapid thunderstorm development is anticipated within a narrow warm sector moving into the region. Strong buoyancy and robust deep-layer shear will support supercells capable of all severe hazards, including very large hail from 2" to 3" in diameter, strong gusts, and tornadoes, a few of which could be strong. The tornado watch area is approximately along and 70 statute miles north and south of a line from 15 miles south southwest of Alexandria MN to 55 miles east of Eau Claire WI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 20035. ...Mosier Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Thu May 15 2025 Valid 161200Z - 171200Z A dry, post-frontal air mass will push through portions of the Midwest this evening, priming northern Illinois for substantially lower relative humidity for Friday. As a surface low moves into the Great Lakes region along with accelerating mid-level winds, strong surface winds of 20-25 mph from the south and southwest will develop by late morning. The stronger winds combined with relative humidity falling into the 20-25 percent range will support elevated fire weather conditions across northern Illinois for Friday morning/early afternoon. Fire weather threat remains conditional for the Chicago area as line of showers and thunderstorms and subsequent rainfall expected this afternoon/evening could limit fire spread potential for Friday. ..Williams.. 05/15/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Thu May 15 2025/ ...Synopsis... Fire-weather potential across the CONUS is relatively low Friday. In the wake of the departing upper trough, shortwave ridging is expected over the southern Plains and Southwest. This will temporarily slow stronger mid-level flow as a Pacific front shifts eastward. With only modest flow aloft and at the surface, strong winds are not expected over the driest fuels of the Southwest. However, warm temperatures and low RH below 20% will remain likely. This could support some localized fire-weather risk where westerly winds could gust to 15 mph closer to the terrain. Otherwise, increasing surface moisture and recent rainfall will largely preclude fire-weather concerns Friday outside of localized dry and breezy conditions over parts of the Midwest. However, this is not expected to be widespread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Thu May 15 2025 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EAST-CENTRAL MINNESOTA....MUCH OF WISCONSIN...SOUTHERN AND WESTERN LOWER MICHIGAN...NORTHEAST ILLINOIS...NORTHERN INDIANA AND NORTHWEST OHIO... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF VIRGINIA AND NORTHEAST NORTH CAROLINA... ...SUMMARY... Severe thunderstorms are expected across parts of the upper Mississippi River Valley and Great Lakes this afternoon and evening. Tornadoes, some of which could be strong, and very large hail and damaging winds will be possible. Severe thunderstorms are also expected through the lower Ohio River Valley, Ozarks and in parts of the Mid-Atlantic. ...20z Update... Only minor changes were made to trim probabilities behind ongoing convective activity with this update. The Enhanced Risk across the Midwest remains unchanged. Thunderstorm activity has been ongoing in this region, with reports of a couple of tornadoes in western Minnesota. Expect thunderstorm activity to continue to strengthen in this area. See MCD#791 for more information on the short term threats. See previous discussion for more information concerning the broader Slight Risk across the Mid to upper Mississippi Valley and in the Central Appalachians and Mid-Atlantic below. ..Thornton/Mosier.. 05/15/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu May 15 2025/ ...Mid to Upper Mississippi Valley/Great Lakes/Ohio Valley... Recent satellite imagery shows an upper low over SD, with a negatively tilted shortwave trough moving into the Mid MO Valley. Surface analysis places an occluded surface low associated with this system over southeast ND, with an occluded front extending southeastward to a triple point over far southeast SD. A cold front extends south-southeastward from this front across far western IA and into far northeast MO before arcing more southwestward across far western MO and more southwestward across western OK. A warm front extends easterward from this triple point across southern MN and then more southeastward across southwest WI and northern IL. These boundaries, including the occluded front, will all act in tandem with increasing large-scale forcing for ascent to force thunderstorm development this afternoon and evening. The ongoing storms from eastern SD into central MN are confirmation of the buoyancy sampled in the 12Z MPX sounding. Expectation is for instability to build across the region as heating and low-level moisture advection occur amid steep mid-level lapse rates. Airmass destabilization and thunderstorm development is anticipated first from the eastern Dakotas into MN, the occluded front as it shifts northward as both the primary surface low and triple point low shift northwestward. Additional development is then anticipated farther southeast along the warm front across WI. Storms that develop in the vicinity of the occluded front will likely have elevated structures, with large hail as the primary risk. Some isolated very large hail (i.e. greater than 2" in diameter) is possible. Farther southeast, the corridor along the warm front appears very favorable for supercells capable of all severe hazards, including very large hail, strong wind gusts, and tornadoes. A locally higher tornado potential may exist from central into southeastern WI from 18Z-22Z. Deeper mixing is anticipated farther south into northern IL, but the overall environment will still support robust, organized updrafts. There may be some trend initially for these storms to quickly become outflow dominant, but strengthening mid-level flow across the region after 21Z should aid in maintaining a more organized mode. Upscale growth into a organized MCS appears probable after 00Z, with the potential for significant-severe gusts as this line moves eastward in southern Lower MI. The threat for damaging gusts and isolated hail will persist throughout the night across Lower MI and the middle/upper OH Valley. ...Ozarks into the TN Valley... Additional thunderstorm development is anticipated this afternoon across AR as a cold front pushes eastward across the region. Moderate to strong flow aloft should allow for storms to move off this boundary quickly into a strongly buoyant airmass downstream. Warm air aloft could limit overall storm longevity during the afternoon/early evening, but the warm/dry mid-levels are conducive for producing strong outflows capable of damaging gusts. Whether or not organization will occur along these outflows is uncertain, but a conditional risk for continued damaging gusts exists into TN. Additional thunderstorms are possible during the evening and overnight in the wake of the front. Persistent steep mid-level lapse rates and strong shear will support large hail with some of these storms. ...Central Appalachians/Mid-Atlantic... Large-scale height rises are expected across the region, but diurnal heating and orographic effects will aid in thunderstorm development across the higher terrain this afternoon. Northwesterly flow aloft will favor a southeastward storm motion within an environment of moderate/locally strong instability. 35-45 kts of northwesterly deep shear is anticipated, supporting supercell structures and clusters, posing a risk for large hail and damaging winds. The overall hodograph structure and resulting storm motion appears favorable for some very large hail over 2" in diameter as well. Read more

MD 0787 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF CENTRAL AND NORTHERN ARKANSAS INTO FAR SOUTHEASTERN MISSOURI
Mesoscale Discussion 0787 NWS Storm Prediction Center Norman OK 1255 PM CDT Thu May 15 2025 Areas affected...portions of central and northern Arkansas into far southeastern Missouri Concerning...Severe potential...Watch possible Valid 151755Z - 151930Z Probability of Watch Issuance...40 percent SUMMARY...The severe threat may increase into the afternoon if storms can become surface based. Severe hail and wind are the main concerns. Should storm increase in coverage/intensity, and root into the boundary layer, a Severe Thunderstorm Watch may be needed. DISCUSSION...Scattered thunderstorms ahead of a cold front persist atop a stout capping layer, and have fluctuated in intensity over the past few hours. Ahead of these storms, the boundary layer continues to destabilize as surface temperatures warm into the mid 80s F, amid 70+ F dewpoints beneath 8-9 C/km mid-level lapse rates, yielding 2000+ J/kg MLCAPE. 50-70 kts of 500 mb southwesterly flow supports over 50 kts of effective bulk shear. Hodographs via RAP forecast soundings are relatively straight, suggesting that multicells and splitting supercell structures will be the primary mode of convection, assuming storms can become surface based. Latest mesoanalysis and RAP forecast soundings show that a substantial degree of convective inhibition remains, so it is plausible that the ongoing storms may not intensify further, at least for a while. However, if storms manage to become surface based, a more prominent severe hail/wind threat may materialize, at which point a Severe Thunderstorm Watch may be needed. ..Squitieri/Mosier.. 05/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA... LAT...LON 34669451 35699311 36429213 37079085 36898998 36158984 35279026 35019055 34649154 34459234 34459365 34669451 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

MD 0788 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF EASTERN WEST VIRGINIA AND MUCH OF VIRGINIA
Mesoscale Discussion 0788 NWS Storm Prediction Center Norman OK 0123 PM CDT Thu May 15 2025 Areas affected...portions of eastern West Virginia and much of Virginia Concerning...Severe potential...Watch possible Valid 151823Z - 152000Z Probability of Watch Issuance...60 percent SUMMARY...The severe threat should increase over the next few hours. Multicells and supercells will be the primary storm mode, with severe wind and hail the main threats. A few instances of 2+ inch diameter hail are possible. A Severe Thunderstorm Watch will eventually be needed. DISCUSSION...Satellite imagery shows agitated cumulus along the WV/VA border, driven primarily by boundary layer destabilization, along with orographic lift associated with the Appalachians. Surface temperatures have already warmed into the mid to upper 70s F to the immediate lee of the Appalachians, where upper 60s F dewpoints, beneath the eastward extent of an EML plume, supports 1500+ J/kg MLCAPE. The 17Z RNK observed sounding shows 8 C/km 700-500 mb lapse rates and the freezing level around 600 mb, beneath where most of the CAPE resides, along with modestly elongated hodographs. Such conditions support supercells capable of severe gusts and large hail, including a few instances of 2+ inch in diameter stones. Given a gradually increasing severe threat, a Severe Thunderstorm Watch will eventually be needed. ..Squitieri/Mosier.. 05/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...LWX...RNK...RLX... LAT...LON 36608017 36768076 37298113 37938092 38388044 38797971 38967837 38617777 37937732 37257730 36797770 36637848 36608017 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

MD 0789 CONCERNING TORNADO WATCH 251... FOR TWIN CITIES VICINITY
Mesoscale Discussion 0789 NWS Storm Prediction Center Norman OK 0142 PM CDT Thu May 15 2025 Areas affected...Twin Cities Vicinity Concerning...Tornado Watch 251... Valid 151842Z - 151945Z The severe weather threat for Tornado Watch 251 continues. SUMMARY...A mesoscale corridor of greater tornado potential is evident near the Twin Cities. Tornado potential, perhaps strong, will be focused here over the next 1-2 hours. DISCUSSION...A broken line of supercells south of the Twin Cities is expected to continue northward. Low-level thermodynamics ahead of these storms continues to improve this afternoon with temperatures nearing 80 F. Given the backed surface winds, these supercells will have locally greater potential to produce a tornado. The VAD from KMPX has shown increasing 0-1 km SRH and objective mesoanalysis shows STP greater than 2. Mid-level lapse rates are also very steep per the 18Z MPX sounding. A strong tornado would be possible in this environment. ..Wendt.. 05/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ARX...MPX... LAT...LON 44329346 44639374 44819391 44959395 45099380 45289337 45279297 44979271 44609251 44259278 44099291 44049320 44329346 MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN Read more

MD 0790 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF CENTRAL AND NORTHEAST NORTH CAROLINA INTO FAR SOUTHEAST VIRGINIA
Mesoscale Discussion 0790 NWS Storm Prediction Center Norman OK 0157 PM CDT Thu May 15 2025 Areas affected...portions of central and northeast North Carolina into far southeast Virginia Concerning...Severe potential...Watch possible Valid 151857Z - 152030Z Probability of Watch Issuance...40 percent SUMMARY...The severe threat may be increasing across portions of central and northeast NC into far southeast VA. If storms can mature and sustain themselves, severe wind/hail may occur. Convective trends are being monitored for the need of a Severe Thunderstorm Watch. DISCUSSION...An agitated CU field is evident across portions of central NC, where a heated/mixed boundary layer beneath the eastward extent of an EML supports over 3000 J/kg MLCAPE. Strong west-northwesterly mid-level flow is also beginning to overspread the region, contributing to over 35 kts of effective bulk shear, which should only increase further into the afternoon. Kinematic and thermodynamic fields in place support multicells and supercells should storms mature and become sustained, with severe hail/wind being the main concerns. Questions remain how robust and widespread convective coverage will become. As such, convective trends are being monitored for greater storm coverage and the subsequent need of a Severe Thunderstorm Watch. ..Squitieri/Mosier.. 05/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH... LAT...LON 35477604 35247656 35177711 35217754 35517841 35797908 35987923 36247888 36607796 36907730 36767636 36167587 35477604 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

MD 0791 CONCERNING SEVERE POTENTIAL...TORNADO WATCH LIKELY FOR PARTS OF SOUTHERN WISCONSIN INTO NORTHERN ILLINOIS
Mesoscale Discussion 0791 NWS Storm Prediction Center Norman OK 0214 PM CDT Thu May 15 2025 Areas affected...Parts of southern Wisconsin into northern Illinois Concerning...Severe potential...Tornado Watch likely Valid 151914Z - 152115Z Probability of Watch Issuance...80 percent SUMMARY...A tornado watch will likely be needed this afternoon. Supercells capable of all severe hazards are expected within the next few hours. DISCUSSION...Cumulus continue to deepen both along a dryline and an area of confluence within the Mississippi Valley. Whether storms develop within the confluence or when the dryline reaches the Mississippi River remains a question. 40-50 kts of effective shear across these surface convergence zones will favor supercells as storms develop. Large to very large hail will be a concern as well as severe wind gusts. The 18Z DVN sounding sampled very steep mid-level lapse rates and a long hodograph. Tornado potential will also be present. Surface temperature/dewpoint spreads are near 20 F, but low-level shear and a supercellular mode will favor low-level rotation. The time frame of greater tornado potential will likely be 22-00Z when the low-level jet increases in southern Wisconsin. ..Wendt/Mosier.. 05/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GRB...LOT...MKX...DVN...ARX... LAT...LON 41418999 41579025 41819042 42309082 42909119 43299134 43549126 44009048 44358993 44438931 43978880 43168862 42128827 41798867 41418999 MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Thu May 15 2025 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS INTO ARKANSAS...AND OVER PARTS OF THE MID-ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible Saturday across parts of the Mid Atlantic and Northeast, and across parts of the southeastern Great Plains to Lower Mississippi Valley. ...Synopsis... An upper cyclone and attendant shortwave trough over the upper Great Lakes to the TN Valley will shift east on Saturday, becoming positioned from NY to offshore the Mid-Atlantic coast by Sunday morning. Meanwhile, an upper trough will dig across the western U.S. while upper ridging develops over much of the Plains. A belt of strong westerly flow associated with the eastern upper trough will overspread much of eastern U.S., while a sub-tropical jet streak moves across the southern Plain into the Lower MS Valley. At the surface, a cold front will surge east across the Ohio Valley through early afternoon, and the Mid-Atlantic and Northeast during the evening/overnight. The southwest extent of this surface boundary will extend from the Lower OH Valley into central OK Saturday morning. The boundary may sag southward across portions of the TN Valley, while the Plains portion of the boundary lifts northward into KS and southern MO during the evening/overnight. Meanwhile, a surface dryline will extend south/southwest from near western OK to the TX Big Bend vicinity. ...Southern Plains to Lower MS Valley... The building upper ridge over the Plains will likely suppress convection across portions of the region as an EML will be difficult to overcome without stronger large-scale ascent/height falls. However, low-level convergence along the dryline amid persistent low-level warm advection and forecast shortwave perturbations migrating through the upper ridge from the southern Rockies into the Red River vicinity may aid in isolated to widely scattered storm development during the afternoon. A very moist airmass will be in place (upper 60s/low 70s F dewpoints) beneath 7.5-8.5 C/km midlevel lapse rates. This will result in strong instability across the warm sector (MLCAPE greater than 2500 J/kg). Furthermore, supercell wind profiles are apparent in forecast soundings, with curved low-level hodographs become elongated/straight above 2-3 km. Any discrete cells that develop will pose a risk for large to very large hail. If sufficient storm coverage occurs, some clustering could result in upscale developing into an MCS moving across the ArkLaTex vicinity and into the Lower MS Valley during the evening/nighttime hours. If this occurs, a risk for damaging gusts will increase. ...Southeast... Convection may be ongoing/weakening across portions of MS/AL/GA/SC/NC Saturday morning. It is unclear how this activity may evolve, but an outflow boundary will likely extend across portions of MS/AL/GA. Given a very moist and unstable airmass by afternoon some redevelopment of thunderstorms is possible. Forcing for ascent will be nebulous across the Deep South, so coverage may remain sparse. Nevertheless, any storm that develops could produce strong gusts or hail. ...NC/VA into the Northeast... Convection may be ongoing across portions of NC/VA Saturday morning but likely will be weakening as outflow is expected to be surging across the Piedmont. It is unclear if redevelopment may occur ahead of the surface cold front during the afternoon/evening. While a very moist and unstable airmass will reside across the region, large-scale ascent will remain weak and focused further north toward the Northeast. If storms can develop, a risk for large hail and damaging gusts will be possible. Additional storms are expected to develop with northward extent into the Northeast beneath the upper low and ahead of the surface cold front. While boundary layer moisture will be more modest with northward extent, cool temperatures aloft will foster modest destabilization. Isolated to widely scattered storms will pose a risk for hail and gusty winds through early evening. ..Leitman.. 05/15/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Thu May 15 2025 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS INTO ARKANSAS...AND OVER PARTS OF THE MID-ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible Saturday across parts of the Mid Atlantic and Northeast, and across parts of the southeastern Great Plains to Lower Mississippi Valley. ...Synopsis... An upper cyclone and attendant shortwave trough over the upper Great Lakes to the TN Valley will shift east on Saturday, becoming positioned from NY to offshore the Mid-Atlantic coast by Sunday morning. Meanwhile, an upper trough will dig across the western U.S. while upper ridging develops over much of the Plains. A belt of strong westerly flow associated with the eastern upper trough will overspread much of eastern U.S., while a sub-tropical jet streak moves across the southern Plain into the Lower MS Valley. At the surface, a cold front will surge east across the Ohio Valley through early afternoon, and the Mid-Atlantic and Northeast during the evening/overnight. The southwest extent of this surface boundary will extend from the Lower OH Valley into central OK Saturday morning. The boundary may sag southward across portions of the TN Valley, while the Plains portion of the boundary lifts northward into KS and southern MO during the evening/overnight. Meanwhile, a surface dryline will extend south/southwest from near western OK to the TX Big Bend vicinity. ...Southern Plains to Lower MS Valley... The building upper ridge over the Plains will likely suppress convection across portions of the region as an EML will be difficult to overcome without stronger large-scale ascent/height falls. However, low-level convergence along the dryline amid persistent low-level warm advection and forecast shortwave perturbations migrating through the upper ridge from the southern Rockies into the Red River vicinity may aid in isolated to widely scattered storm development during the afternoon. A very moist airmass will be in place (upper 60s/low 70s F dewpoints) beneath 7.5-8.5 C/km midlevel lapse rates. This will result in strong instability across the warm sector (MLCAPE greater than 2500 J/kg). Furthermore, supercell wind profiles are apparent in forecast soundings, with curved low-level hodographs become elongated/straight above 2-3 km. Any discrete cells that develop will pose a risk for large to very large hail. If sufficient storm coverage occurs, some clustering could result in upscale developing into an MCS moving across the ArkLaTex vicinity and into the Lower MS Valley during the evening/nighttime hours. If this occurs, a risk for damaging gusts will increase. ...Southeast... Convection may be ongoing/weakening across portions of MS/AL/GA/SC/NC Saturday morning. It is unclear how this activity may evolve, but an outflow boundary will likely extend across portions of MS/AL/GA. Given a very moist and unstable airmass by afternoon some redevelopment of thunderstorms is possible. Forcing for ascent will be nebulous across the Deep South, so coverage may remain sparse. Nevertheless, any storm that develops could produce strong gusts or hail. ...NC/VA into the Northeast... Convection may be ongoing across portions of NC/VA Saturday morning but likely will be weakening as outflow is expected to be surging across the Piedmont. It is unclear if redevelopment may occur ahead of the surface cold front during the afternoon/evening. While a very moist and unstable airmass will reside across the region, large-scale ascent will remain weak and focused further north toward the Northeast. If storms can develop, a risk for large hail and damaging gusts will be possible. Additional storms are expected to develop with northward extent into the Northeast beneath the upper low and ahead of the surface cold front. While boundary layer moisture will be more modest with northward extent, cool temperatures aloft will foster modest destabilization. Isolated to widely scattered storms will pose a risk for hail and gusty winds through early evening. ..Leitman.. 05/15/2025 Read more

MD 0786 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PORTIONS OF SOUTHERN AND CENTRAL MINNESOTA INTO NORTHWEST WISCONSIN
Mesoscale Discussion 0786 NWS Storm Prediction Center Norman OK 1208 PM CDT Thu May 15 2025 Areas affected...Portions of southern and central Minnesota into Northwest Wisconsin Concerning...Severe potential...Watch likely Valid 151708Z - 151945Z Probability of Watch Issuance...80 percent SUMMARY...Severe storms capable of all severe hazards (including very large hail and strong tornadoes) are expected this afternoon. Timing of storm development is uncertain, but one or more watches are likely early this afternoon. DISCUSSION...Potent mid-level ascent continues to lift into southern and central Minnesota late this morning. Earlier elevated convection north of the Twin Cities has weakened substantially and very minimal outflow is evident from that activity. A narrow warm sector is lifting ahead of a dryline feature. Despite cloud cover, temperatures continue to warm into the low/mid 70s F and cumulus are beginning to deepen along the dryline. Given the forcing for ascent, initiation of stronger storms within the next 2-3 hours appears reasonable and is supported by most recent CAM guidance. Strong effective shear across the surface boundaries should support at least initially discrete storms. Strong forcing aloft may promote some areas of quicker upscale growth into line segments. Mid-level lapse rates advecting into the region will support large/very large hail. Low-level southeasterly winds will promote large low-level hodographs (already evident on the KMPX VAD). Tornadoes, some potentially strong, will be possible. The tornado risk will likely be greater with southeastward extent on account of the broader warm sector. Scattered severe gusts are also expected given convective transport of strong low-level flow to the surface. The timing of development remains the biggest uncertainty along with the relatively narrow zone of tornado risk in Minnesota. One ore more watches are likely early this afternoon. ..Wendt/Mosier.. 05/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...ARX...MPX...FGF... LAT...LON 44109429 45039564 45879603 46339554 46449406 45999278 45559214 44569190 43879237 43579286 44109429 MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN Read more

WW 0252 Status Updates
STATUS FOR WATCH 0252 HAS NOT BEEN ISSUED YET Read more

WW 252 SEVERE TSTM AR KY MO TN 151855Z - 160000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 252 NWS Storm Prediction Center Norman OK 155 PM CDT Thu May 15 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of North-Central into Northeast Arkansas Far Western Kentucky Far Southeast Missouri Far Northwest Tennessee * Effective this Thursday afternoon and evening from 155 PM until 700 PM CDT. * Primary threats include... Scattered large hail likely with isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph likely SUMMARY...Line of storms moving through north-central Arkansas continues to organize as it moves quickly eastward. The downstream airmass is warm and buoyant, suggesting the potential for this cluster to continue over the next few hours. Strong gusts and large to very large hail are possible with this cluster, as well any other storms that develop across the region. The severe thunderstorm watch area is approximately along and 75 statute miles east and west of a line from 15 miles east northeast of Poplar Bluff MO to 55 miles east southeast of Russellville AR. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 251... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26040. ...Mosier Read more

WW 0251 Status Updates
STATUS FOR WATCH 0251 HAS NOT BEEN ISSUED YET Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 PM CDT Thu May 15 2025 Valid 161200Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHEAST MISSOURI...SOUTHERN ILLINOIS/INDIANA...AND CENTRAL AND WESTERN KENTUCKY... ...SUMMARY... A regional outbreak of severe thunderstorms is likely across parts of the middle Mississippi and Ohio Valleys Friday afternoon into Friday night. This may include a few intense supercells posing a risk for large hail and tornadoes. During the evening into the overnight hours, this will include an upscale growing and organizing bowing line of storms posing a risk for strong, damaging winds and a continuing risk for tornadoes. ...A regional outbreak of severe storms is expected on Friday across portions of the Mid-South to the Ohio Valley... ...Synopsis... An upper cyclone over the Upper Midwest and attendant shortwave trough will develop east/northeast across much of the Midwest and TN Valley. A swath of strong mid/upper southwesterly flow will accompany this system. Forecast guidance shows a 70-90 kt 500 mb jet spreading across the Mid-MS to OH Valley, while 850-700 mb increases to 40-60 kt by midday. This will result in supercell wind profiles, support widespread organized convection. Favorable deep-layer shear will extend downstream into the central Appalachians and Mid-Atlantic vicinity as well. At the surface, low pressure will shift east from northern MN into the Upper Great Lakes. A warm from southern MO into the OH Valley Friday morning is forecast to lift northward through the afternoon, allowing rich boundary layer moisture (mid/upper 60s F dewpoints) to overspread much of the Lower OH Valley, with a large warm sector in place across a broad region from east TX to the Great Lakes and eastward toward the Mid-Atlantic coast. Corridors of moderate to strong destabilization during the day and into the nighttime hours will support several areas of severe storms from east Texas into much of the Midwest and the Mid-Atlantic, some of which could be significant. ...Mid-MS Valley into the OH/TN Valley Vicinity... Forecast guidance depicts potential for remnant convection from Day 1/Thu ongoing across KY or TN Friday morning. Current expectation is that this activity will dissipate or weaken as it shifts east toward the central Appalachians. Strong warm advection should allow for rapid airmass recovery in the way of any morning thunderstorm activity. By midday, a very moist (mid 60s to low 70s F dewpoints) airmass will be in place beneath steep midlevel lapse rates, fostering MLCAPE around 2500-3500 J/kg from southeast MO northward to around the I-70 corridor and east toward the IN/KY. One or more clusters of convection is expected to develop by early afternoon within the strong warm advection regime and as large-scale ascent increases with the approach of the upper trough and an eastward-advancing cold front extending from eastern IA/western MO into central OK/TX around midday. Supercell wind profiles with enlarged low-level hodographs becoming elongated above 2-3 km within a volatile thermodynamic environment suggests convection will rapidly intensify. Any convection that remains discrete will pose a risk for very large hail (up to 3.5 inches), tornadoes (a few may be strong), and damaging gusts. With time, consolidation of thunderstorm clusters is expected and an organized bow is forecast to move across the OH/TN Valley region. Intense, damaging gusts greater than 70 kt will be possible once this occurs. Additional convection is expected to develop during the evening ahead of the advancing cold front from northern AR into western TN/KY. If this activity can remain discrete, supercells will pose an all-hazards severe risk. Eventually, this activity should become linear, but will still have an attendant wind/tornado risk, with a gradual weakening trend during the overnight hours expected across MS/AL/GA. ...Central Appalachians to Mid-Atlantic... Thunderstorms may be ongoing Friday morning across parts of PA and spread east/southeast through early afternoon as a lead upper shortwave impulse moves across the Northeast. Moistening and heating ahead of this activity will support moderate to strong destabilization, especially from the Chesapeake Bay vicinity southward across the VA/NC Piedmont. The initial round of thunderstorms may pose a risk for locally strong gusts and hail before moving offshore the NJ/DE/MD coast during the early afternoon. During the evening/overnight hours, a mature bowing MCS is expected to move over the WV/VA/NC mountains and spread east across the region, posing a risk for swaths of strong to damaging wind gusts. Forecast guidance varies in timing and exact evolution of this system across the region, but portions of the area may need higher probabilities in subsequent outlooks. ...WI/MI... Thunderstorms are expected to develop ahead of the surface low and cold front during the afternoon and evening. Cold temperatures aloft will support steep midlevel lapse rates and weak to moderate instability despite more modest boundary layer moisture. Favorable shear will support organized convection capable of isolated damaging gusts and hail. ...ArkLaTex vicinity... A more conditional risk of significant severe thunderstorms will exist across northeast TX into southern AR/northwest LA. A very moist and strongly unstable airmass will be in place, and forecast guidance suggests capping should erode along/ahead of the surface dryline. Low-level convergence along the surface boundary is not expected to be strong, and large-scale ascent will be nebulous, with neutral height tendencies expected. Nevertheless, at least a few storms are expected to develop during/just after peak heating. Supercell wind profiles, with long/straight hodographs are apparent in forecast soundings. Furthermore, thermodynamic profiles will be very favorable for large hail, while steepening low-level lapse rates will support strong outflow winds. Isolated significant hail (to 2.5 inches) is possible in addition to sporadic damaging gusts. ..Leitman.. 05/15/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1137 AM CDT Thu May 15 2025 Valid 151700Z - 161200Z Cooler temperatures and lighter boundary layer winds will mitigate fire weather concerns across southeastern Arizona today, necessitating a slight pullback in Elevated highlights. Stronger mid-level winds and efficient mixing will continue to support an elevated fire weather threat across southern New Mexico into far west Texas. Downslope/leeward enhancement of surface winds should also occur across the High Plains of northeastern New Mexico. ..Williams.. 05/15/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Thu May 15 2025/ ...Synopsis... An upper trough will quickly move eastward over the central US with accompanying strong mid-level flow. A deepening lee cyclone will intensify further as it move into the Upper Midwest tonight. As the low deepens, a Pacific cold front and tailing dryline will move quickly through the Rockies, into the Plains and Midwest States. Cooler temperatures, gusty westerly winds and some precipitation are possible along and behind the front through tonight. Elevated fire-weather conditions are possible over parts of the southern Plains and Southwest. ...Southwest... Persistent westerly flow will continue across the Southwest today and tonight as a weak pacific front moves over the Rockies. This will support another day of dry and windy conditions across parts of eastern AZ and southern NM. Despite somewhat cooler temperatures behind the front, downsloping and deep vertical mixing will support RH below 20% and winds of 15-20% amidst dry fuels. Widespread elevated to locally critical conditions are expected. Some fire-weather risk may also extend into West TX behind an eastward mixing dryline. However, winds here may be somewhat weaker despite very warm surface temperatures and lower humidity. Locally elevated conditions are possible within drying fuels. ...Central plains and Midwest... Gusty westerly winds are possible behind the advancing cold front from parts of the central Plains into western IA and MO this afternoon. While gusts may reach 20-25 mph, RH values are not expected to be critical with cooler temperatures. Additionally, recent wetting rainfall may temporarily limit available fuels. This suggests any fire-weather concerns will be localized and short lived. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Thu May 15 2025 Valid 151630Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EAST-CENTRAL MINNESOTA...MUCH OF WISCONSIN...SOUTHERN AND WESTERN LOWER MICHIGAN...NORTHEAST ILLINOIS...NORTHERN INDIANA AND NORTHWEST OHIO... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF VIRGINIA AND NORTHEAST NORTH CAROLINA... ...SUMMARY... Severe thunderstorms are expected across parts of the upper Mississippi River Valley and Great Lakes this afternoon and evening. Tornadoes, some of which could be strong, and very large hail and damaging winds will be possible. Severe thunderstorms are also expected through the lower Ohio River Valley, Ozarks and in parts of the Mid-Atlantic. ...Mid to Upper Mississippi Valley/Great Lakes/Ohio Valley... Recent satellite imagery shows an upper low over SD, with a negatively tilted shortwave trough moving into the Mid MO Valley. Surface analysis places an occluded surface low associated with this system over southeast ND, with an occluded front extending southeastward to a triple point over far southeast SD. A cold front extends south-southeastward from this front across far western IA and into far northeast MO before arcing more southwestward across far western MO and more southwestward across western OK. A warm front extends easterward from this triple point across southern MN and then more southeastward across southwest WI and northern IL. These boundaries, including the occluded front, will all act in tandem with increasing large-scale forcing for ascent to force thunderstorm development this afternoon and evening. The ongoing storms from eastern SD into central MN are confirmation of the buoyancy sampled in the 12Z MPX sounding. Expectation is for instability to build across the region as heating and low-level moisture advection occur amid steep mid-level lapse rates. Airmass destabilization and thunderstorm development is anticipated first from the eastern Dakotas into MN, the occluded front as it shifts northward as both the primary surface low and triple point low shift northwestward. Additional development is then anticipated farther southeast along the warm front across WI. Storms that develop in the vicinity of the occluded front will likely have elevated structures, with large hail as the primary risk. Some isolated very large hail (i.e. greater than 2" in diameter) is possible. Farther southeast, the corridor along the warm front appears very favorable for supercells capable of all severe hazards, including very large hail, strong wind gusts, and tornadoes. A locally higher tornado potential may exist from central into southeastern WI from 18Z-22Z. Deeper mixing is anticipated farther south into northern IL, but the overall environment will still support robust, organized updrafts. There may be some trend initially for these storms to quickly become outflow dominant, but strengthening mid-level flow across the region after 21Z should aid in maintaining a more organized mode. Upscale growth into a organized MCS appears probable after 00Z, with the potential for significant-severe gusts as this line moves eastward in southern Lower MI. The threat for damaging gusts and isolated hail will persist throughout the night across Lower MI and the middle/upper OH Valley. ...Ozarks into the TN Valley... Additional thunderstorm development is anticipated this afternoon across AR as a cold front pushes eastward across the region. Moderate to strong flow aloft should allow for storms to move off this boundary quickly into a strongly buoyant airmass downstream. Warm air aloft could limit overall storm longevity during the afternoon/early evening, but the warm/dry mid-levels are conducive for producing strong outflows capable of damaging gusts. Whether or not organization will occur along these outflows is uncertain, but a conditional risk for continued damaging gusts exists into TN. Additional thunderstorms are possible during the evening and overnight in the wake of the front. Persistent steep mid-level lapse rates and strong shear will support large hail with some of these storms. ...Central Appalachians/Mid-Atlantic... Large-scale height rises are expected across the region, but diurnal heating and orographic effects will aid in thunderstorm development across the higher terrain this afternoon. Northwesterly flow aloft will favor a southeastward storm motion within an environment of moderate/locally strong instability. 35-45 kts of northwesterly deep shear is anticipated, supporting supercell structures and clusters, posing a risk for large hail and damaging winds. The overall hodograph structure and resulting storm motion appears favorable for some very large hail over 2" in diameter as well. ..Mosier.. 05/15/2025 Read more