Storm Prediction Center

WW 0133 Status Updates
STATUS REPORT ON WW 133 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 SW HUF TO 30 E LAF TO 35 W FWA TO 15 NW AZO. ..DEAN..04/18/26 ATTN...WFO...IND...IWX... STATUS REPORT FOR WT 133 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS INC039-085-169-180640- IN . INDIANA COUNTIES INCLUDED ARE ELKHART KOSCIUSKO WABASH MIC027-180640- MI . MICHIGAN COUNTIES INCLUDED ARE CASS THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 133 TORNADO IN MI LM 180245Z - 180700Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 133 NWS Storm Prediction Center Norman OK 1045 PM EDT Fri Apr 17 2026 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of West-Central and Northern Indiana Far Southwest Lower Michigan Lake Michigan * Effective this Friday night and Saturday morning from 1045 PM until 300 AM EDT. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph possible SUMMARY...A line of thunderstorms will pose a threat for scattered damaging winds and perhaps a couple of brief embedded tornadoes as it moves quickly east-northeastward late this evening into early Saturday morning before eventually weakening. The tornado watch area is approximately along and 30 statute miles east and west of a line from 25 miles north northeast of South Bend IN to 5 miles south southeast of Terre Haute IN. 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 131...WW 132... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26045. ...Gleason Read more

WW 0132 Status Updates
STATUS REPORT ON WW 132 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NE MKO TO 20 S UMN TO 20 SSW SGF TO 50 ESE TBN. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0489 ..DEAN..04/18/26 ATTN...WFO...TSA...SGF...OUN... STATUS REPORT FOR WS 132 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC007-180640- AR . ARKANSAS COUNTIES INCLUDED ARE BENTON THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 132 SEVERE TSTM AR KS MO OK 180145Z - 180700Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 132 NWS Storm Prediction Center Norman OK 845 PM CDT Fri Apr 17 2026 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Far Northwest Arkansas Extreme Southeast Kansas Southwest and South-Central Missouri Northern, Central, and Western Oklahoma * Effective this Friday night and Saturday morning from 845 PM until 200 AM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...A mix of mainly elevated supercells and some bowing clusters should continue to pose a threat for scattered large hail and damaging winds through the early morning hours. A tornado appears possible if a supercell can become surface based along/south of the cold front; but, confidence in this occurring is low. The severe thunderstorm watch area is approximately along and 40 statute miles north and south of a line from 45 miles west of Clinton OK to 25 miles east southeast of Fort Leonard Wood MO. 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 130...WW 131... 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. ...Gleason Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1153 PM CDT Fri Apr 17 2026 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER OHIO VALLEY TO THE APPALACHIANS... ...SUMMARY... Scattered strong to severe thunderstorms capable of damaging winds and hail will be possible on Saturday across the upper Ohio Valley and central Appalachians. Isolated severe hail is also possible across parts of central Texas. ...Synopsis... A large upper trough with elongated leading speed max will sweep across the Great Lakes and OH Valley during the day and into the Appalachians by Sunday morning. Meanwhile, moderate westerlies aloft will persist across TX with the aid of a subtropical jet. At the surface, a cold front will move across OH and KY through early afternoon, and into western NY, PA, and WV late in the day. This front will also extend far southwestward toward the northwestern Gulf Coast and into far southern TX. Ahead of the front, a narrow plume of 50s to lower 60s F dewpoints will exist as far north as OH and PA, with more robust moisture into TX with upper 60s F dewpoints. ...Upper Ohio Valley/Appalachians... A remnant line of showers and thunderstorms is expected to persist near the cold front this morning as it moves across the OH Valley and toward the lower Great Lakes. Daytime heating will help destabilize the air mass ahead of this activity, and storm rejuvenation is expected after 18Z from near Lake Erie into eastern KY. These storms will mature in the 21-00Z timeframe, affecting eastern OH, WV, and into PA and possibly southwest NY. Substantial southwest flow aloft will help to push these storms quickly east/northeast across the region, and deep-layer shear may favor scattered cells initially. Marginal hail will be possible, along with locally strong gusts, especially as storm mode becomes linear and peak heating has been achieved. Given the narrow instability axis, storms should wane after sunset. ...South-Central Texas... Scattered showers and elevated thunderstorms are expected throughout much of the day as the cold front rapidly undercuts a moist and unstable air mass. Forecast soundings show MUCAPE parcels rooted in the 850-700 mb layer, with effective deep-layer shear of 50-60 kt. Initial activity may develop over central TX during the morning and through midday, with additional new elevated development translating southward as the front continually lifts the moist air mass. A few hail reports at or above 1.00" will be possible. ..Jewell/Moore.. 04/18/2026 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1153 PM CDT Fri Apr 17 2026 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER OHIO VALLEY TO THE APPALACHIANS... ...SUMMARY... Scattered strong to severe thunderstorms capable of damaging winds and hail will be possible on Saturday across the upper Ohio Valley and central Appalachians. Isolated severe hail is also possible across parts of central Texas. ...Synopsis... A large upper trough with elongated leading speed max will sweep across the Great Lakes and OH Valley during the day and into the Appalachians by Sunday morning. Meanwhile, moderate westerlies aloft will persist across TX with the aid of a subtropical jet. At the surface, a cold front will move across OH and KY through early afternoon, and into western NY, PA, and WV late in the day. This front will also extend far southwestward toward the northwestern Gulf Coast and into far southern TX. Ahead of the front, a narrow plume of 50s to lower 60s F dewpoints will exist as far north as OH and PA, with more robust moisture into TX with upper 60s F dewpoints. ...Upper Ohio Valley/Appalachians... A remnant line of showers and thunderstorms is expected to persist near the cold front this morning as it moves across the OH Valley and toward the lower Great Lakes. Daytime heating will help destabilize the air mass ahead of this activity, and storm rejuvenation is expected after 18Z from near Lake Erie into eastern KY. These storms will mature in the 21-00Z timeframe, affecting eastern OH, WV, and into PA and possibly southwest NY. Substantial southwest flow aloft will help to push these storms quickly east/northeast across the region, and deep-layer shear may favor scattered cells initially. Marginal hail will be possible, along with locally strong gusts, especially as storm mode becomes linear and peak heating has been achieved. Given the narrow instability axis, storms should wane after sunset. ...South-Central Texas... Scattered showers and elevated thunderstorms are expected throughout much of the day as the cold front rapidly undercuts a moist and unstable air mass. Forecast soundings show MUCAPE parcels rooted in the 850-700 mb layer, with effective deep-layer shear of 50-60 kt. Initial activity may develop over central TX during the morning and through midday, with additional new elevated development translating southward as the front continually lifts the moist air mass. A few hail reports at or above 1.00" will be possible. ..Jewell/Moore.. 04/18/2026 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1153 PM CDT Fri Apr 17 2026 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER OHIO VALLEY TO THE APPALACHIANS... ...SUMMARY... Scattered strong to severe thunderstorms capable of damaging winds and hail will be possible on Saturday across the upper Ohio Valley and central Appalachians. Isolated severe hail is also possible across parts of central Texas. ...Synopsis... A large upper trough with elongated leading speed max will sweep across the Great Lakes and OH Valley during the day and into the Appalachians by Sunday morning. Meanwhile, moderate westerlies aloft will persist across TX with the aid of a subtropical jet. At the surface, a cold front will move across OH and KY through early afternoon, and into western NY, PA, and WV late in the day. This front will also extend far southwestward toward the northwestern Gulf Coast and into far southern TX. Ahead of the front, a narrow plume of 50s to lower 60s F dewpoints will exist as far north as OH and PA, with more robust moisture into TX with upper 60s F dewpoints. ...Upper Ohio Valley/Appalachians... A remnant line of showers and thunderstorms is expected to persist near the cold front this morning as it moves across the OH Valley and toward the lower Great Lakes. Daytime heating will help destabilize the air mass ahead of this activity, and storm rejuvenation is expected after 18Z from near Lake Erie into eastern KY. These storms will mature in the 21-00Z timeframe, affecting eastern OH, WV, and into PA and possibly southwest NY. Substantial southwest flow aloft will help to push these storms quickly east/northeast across the region, and deep-layer shear may favor scattered cells initially. Marginal hail will be possible, along with locally strong gusts, especially as storm mode becomes linear and peak heating has been achieved. Given the narrow instability axis, storms should wane after sunset. ...South-Central Texas... Scattered showers and elevated thunderstorms are expected throughout much of the day as the cold front rapidly undercuts a moist and unstable air mass. Forecast soundings show MUCAPE parcels rooted in the 850-700 mb layer, with effective deep-layer shear of 50-60 kt. Initial activity may develop over central TX during the morning and through midday, with additional new elevated development translating southward as the front continually lifts the moist air mass. A few hail reports at or above 1.00" will be possible. ..Jewell/Moore.. 04/18/2026 Read more

MD 0486 CONCERNING TORNADO WATCH 131... FOR PARTS OF EAST CENTRAL MISSOURI INTO ADJACENT PORTIONS OF ILLINOIS
Mesoscale Discussion 0486 NWS Storm Prediction Center Norman OK 0839 PM CDT Fri Apr 17 2026 Areas affected...parts of east central Missouri into adjacent portions of Illinois Concerning...Tornado Watch 131... Valid 180139Z - 180345Z The severe weather threat for Tornado Watch 131 continues. SUMMARY...An organized cluster of storms may be maintained across northwestern portions of Greater St. Louis through 9-11 PM CDT, with a continuing risk for damaging wind gusts and potential for a brief tornado or two. DISCUSSION...A sustained cluster of thunderstorms has become increasingly organized across and east of the Missouri Ozarks during the past few hours, with a well-defined lower/mid-tropospheric cyclonic circulation and associated evolving bow echo structure in radar reflectivities. It appears that the apex of the bow structure has accelerated east-northeastward in excess of 50 kt. If this motion is maintained, it is on track to surge across northwestern portions of Greater St. Louis through 02-03Z. This still appears to be perhaps just ahead of the leading edge of the surface cold front, as delineated by 2-4 mb 2-hourly surface pressures rises now east of Quincy IL south/southwestward through the Columbia and Sedalia vicinities. The boundary-layer has undergone warming and drying across the St. Louis area, where the temperature/dew point at Lambert is 81/57 F. However, thermodynamic profiles still appear sufficiently unstable to maintain convection with potential to produce damaging wind gusts. The risk for tornadoes is more unclear, but the environment might still be conducive immediately to the north of the front. ..Kerr.. 04/18/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILX...LSX...SGF... LAT...LON 38949180 39509044 39838933 39098870 38458965 38069075 38029216 38409185 38949180 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

MD 0488 CONCERNING TORNADO WATCH 131...133... FOR EASTERN ILLINOIS INTO WESTERN INDIANA
Mesoscale Discussion 0488 NWS Storm Prediction Center Norman OK 1019 PM CDT Fri Apr 17 2026 Areas affected...Eastern Illinois into western Indiana Concerning...Tornado Watch 131...133... Valid 180319Z - 180515Z The severe weather threat for Tornado Watch 131, 133 continues. SUMMARY...Severe winds and QLCS tornadoes will remain possible for the next couple of hours across eastern Illinois and into western Indiana. However, the early stages of a weakening trend are noted, suggesting that the severe threat should gradually wane with time. DISCUSSION...Over the past hour, several severe wind reports have been noted with an organized squall line as it moved across central IL. However, the early stages of a weakening trend are noted with the line across several metrics, including MRMS VIL, GOES IR cloud-top temperatures, and lightning counts. This weakening has been anticipated by recent high-res guidance during the 04-06 UTC period as the line migrates out of the primary buoyancy axis and into a drier air mass located downstream across central IN. The noted convective trends seem to be affirming these short-term forecasts, so further weakening appears likely as the line continues east. However, VWP observations downstream at KIND show an uptick in low-level wind shear with 0-1 km SRH recently increasing to around 550 m2/s2. This highly favorable low-level wind environment will continue to support the potential for severe winds and embedded QLCS tornadoes within the line at least for the next couple of hours as it crosses into western IN. How long this threat will persist downstream remains somewhat unclear given the ongoing weakening trend. ..Moore.. 04/18/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...IND...LOT...ILX... LAT...LON 39648873 40008822 40568796 41058788 41308788 41618782 41788763 41798743 41788716 41838695 41918677 41868585 41718569 41418570 40958589 40518615 39948655 39508699 39428736 39418797 39518854 39648873 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

WW 0131 Status Updates
STATUS REPORT ON WW 131 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 NW BLV TO 35 NNW STL TO 30 SW SPI TO 15 ENE SPI TO 15 ENE DEC TO 30 NNW DNV TO 35 WNW VPZ. PARTS OF REMAINING VALID PORTION OF WW MAY BE LOCALLY EXTENDED IN TIME AN HOUR OR TO BEYOND 18/04Z. ..KERR..04/18/26 ATTN...WFO...LSX...ILX...LOT... STATUS REPORT FOR WT 131 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-013-019-021-023-027-029-035-041-045-051-061-075-083-115- 117-119-121-135-139-147-173-183-189-180400- IL . ILLINOIS COUNTIES INCLUDED ARE BOND CALHOUN CHAMPAIGN CHRISTIAN CLARK CLINTON COLES CUMBERLAND DOUGLAS EDGAR FAYETTE GREENE IROQUOIS JERSEY MACON MACOUPIN MADISON MARION MONTGOMERY MOULTRIE PIATT SHELBY VERMILION WASHINGTON INC007-073-089-111-127-180400- IN . INDIANA COUNTIES INCLUDED ARE Read more

WW 0131 Status Updates
STATUS REPORT ON WW 131 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 NW BLV TO 35 NNW STL TO 30 SW SPI TO 15 ENE SPI TO 15 ENE DEC TO 30 NNW DNV TO 35 WNW VPZ. PARTS OF REMAINING VALID PORTION OF WW MAY BE LOCALLY EXTENDED IN TIME AN HOUR OR TO BEYOND 18/04Z. ..KERR..04/18/26 ATTN...WFO...LSX...ILX...LOT... STATUS REPORT FOR WT 131 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-013-019-021-023-027-029-035-041-045-051-061-075-083-115- 117-119-121-135-139-147-173-183-189-180400- IL . ILLINOIS COUNTIES INCLUDED ARE BOND CALHOUN CHAMPAIGN CHRISTIAN CLARK CLINTON COLES CUMBERLAND DOUGLAS EDGAR FAYETTE GREENE IROQUOIS JERSEY MACON MACOUPIN MADISON MARION MONTGOMERY MOULTRIE PIATT SHELBY VERMILION WASHINGTON INC007-073-089-111-127-180400- IN . INDIANA COUNTIES INCLUDED ARE Read more

WW 131 TORNADO IL MO LM 172030Z - 180400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 131 NWS Storm Prediction Center Norman OK 330 PM CDT Fri Apr 17 2026 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central and Northeast Illinois Northeast Missouri Lake Michigan * Effective this Friday afternoon and evening from 330 PM until 1100 PM CDT. * Primary threats include... A couple tornadoes possible Widespread damaging winds likely with isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible SUMMARY...Thunderstorms have intensified across northeast MO, with some additional intensification possible as they continued northeastward into central IL. The airmass across the region supports supercells capable of all severe hazards, including very large hail and tornadoes. Another round of storms will follow in the wake of the ongoing storms later this evening as a cold front moves across the region. Wind gusts will be the primary risk with the storms along the front, but line-embedded circulations are possible as well. The tornado watch area is approximately along and 75 statute miles east and west of a line from 50 miles west northwest of Valparaiso IN to 30 miles southeast of Jefferson City MO. 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. && OTHER WATCH INFORMATION...CONTINUE...WW 128...WW 129...WW 130... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Mosier Read more

WW 0133 Status Updates
STATUS FOR WATCH 0133 HAS NOT BEEN ISSUED YET Read more

WW 0132 Status Updates
STATUS FOR WATCH 0132 HAS NOT BEEN ISSUED YET Read more

MD 0484 CONCERNING TORNADO WATCH 129...131... FOR NORTHWEST ILLINOIS
Mesoscale Discussion 0484 NWS Storm Prediction Center Norman OK 0625 PM CDT Fri Apr 17 2026 Areas affected...Northwest Illinois Concerning...Tornado Watch 129...131... Valid 172325Z - 180130Z The severe weather threat for Tornado Watch 129, 131 continues. SUMMARY...A transition to a predominantly linear storm mode is likely underway and will result in an uptick in severe wind potential as well as embedded mesovorticies downstream across central/northern Illinois. DISCUSSION...Imagery out of KDVN shows signs of cold pool consolidation and expansion as convection continues to cluster and grow upscale, likely indicating the transition from semi-discrete cells and clusters to a more consolidated linear storm mode. Over the next couple of hours one or more organized lines should emerge across central to north-central IL. This will be accompanied by an increase in severe wind potential as well as the possibility of embedded mesovorticies, especially given steadily strengthening low-level flow/improving wind shear noted in downstream VWPs. Localized corridors of enhanced wind, and perhaps tornado, potential are expected where line-preceding convection (noted in west-central IL) eventually intersect the developing line, and could result in localized surges accompanied by swaths of stronger (potentially significant) winds. ..Moore.. 04/17/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...MKX...LSX...DVN... LAT...LON 40419175 40709132 41209087 41579060 41979046 42249042 42359025 42528902 42488881 42368866 42168867 41868873 41508878 41168882 40778894 40478917 40268950 40099007 39999048 39989091 39989136 40039167 40169180 40259182 40419175 MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

MD 0485 CONCERNING TORNADO WATCH 131... FOR CENTRAL ILLINOIS INTO NORTHWEST INDIANA
Mesoscale Discussion 0485 NWS Storm Prediction Center Norman OK 0809 PM CDT Fri Apr 17 2026 Areas affected...Central Illinois into northwest Indiana Concerning...Tornado Watch 131... Valid 180109Z - 180315Z The severe weather threat for Tornado Watch 131 continues. SUMMARY...A line of severe thunderstorms will continue to push east/southeast over the next few hours and will continue to pose a risk of severe wind and embedded circulations. DISCUSSION...A consolidated line of severe thunderstorms is now evident in MRMS imagery with several embedded surges noted across western and northwest IL. KILX radar velocity data shows swaths of higher winds within the surging segments with several gusts between 45-65 mph noted over the past 30 minutes along the line. Downstream, low-level winds continue to strengthen across central IL. The KILX VWP sampling winds between 50-55 knots below 1 km, and a recent 00z ILX RAOB sampled MLCAPE upwards of 1600 J/kg with 50 knots of effective bulk shear and around 200 m2/s2 effective SRH. Consequently, the downstream environment remains favorable for maintenance of the severe line as it continues east/southeast over the next few hours across IL. While the primary threat will remain swaths of severe winds (most likely between 60-70 mph, but possibly as high as 75 mph), favorable bulk shear values from the surface through 3 km will continue to favor the development of embedded circulations within the line. Eastward expansion of WW 131 will likely be needed in the coming hours across portions of eastern IL. Drier low-level conditions downstream across IN casts some uncertainty on how intense the line will be beyond roughly the 05-06 UTC time frame into IN, but convective trends will be monitored for the need for downstream watch issuance. ..Moore.. 04/18/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...IND...LOT...ILX...MKX...LSX...DVN... LAT...LON 39188775 39108832 39138888 39369064 39459087 39589096 39739100 39859069 40039036 40448997 41038952 41568919 42008896 42328872 42488847 42608799 42498768 41928747 41798734 41788704 41888679 41748656 41278645 40788660 39778708 39418753 39188775 MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Apr 17 2026 Valid 180100Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF ILLINOIS INTO NORTHEAST MISSOURI...AND OVER NORTHERN OKLAHOMA... ...SUMMARY... Damaging storms producing wind, hail and isolated tornadoes remain possible this evening from Illinois into Oklahoma. ...WI/MI into IL and MO... Supercells have largely merged into a broken line of assorted bows from far southeast WI across much of northern into western IL and trailing into northeast MO. The 00Z ILX sounding shows steep lapse rates aloft and large deep-layer shear, as well as veering winds with height. Low-level SRH will remain favorable for rotation to develop at least briefly anywhere within the line, with damaging winds the most likely threat. Storms have recently become better organized over central MO, and this activity may affect the St. Louis area later tonight. For lower MI into northern IN, the organized line of storms to the west along with a 60 kt low-level jet suggest at least isolated severe gusts may occur overnight despite lesser instability. For more information about Illinois, see mesoscale discussion 484. ...OK...Southeast KS...southwest MO...northwest AR... Scattered severe cells persist near and north of the cold front across much of northern OK and extending into southeast KS. Although the undercutting cold air will likely mitigate wind potential, steep lapse rates aloft along with ample deep-layer shear will continue to favor hail. Storm coverage may be more isolated into southwest OK later tonight, but the environment remains quite favorable for large hail. One corridor for possible damaging wind or even a tornado is over northeast OK into southwest MO. Here, the front is not surging as fast, and storms over Osage county are already oriented more favorably N-S relative to the deep-layer shear. A southwest low-level jet near 50 kt will further support low-level rotation. ..Jewell.. 04/18/2026 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Apr 17 2026 Valid 180100Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF ILLINOIS INTO NORTHEAST MISSOURI...AND OVER NORTHERN OKLAHOMA... ...SUMMARY... Damaging storms producing wind, hail and isolated tornadoes remain possible this evening from Illinois into Oklahoma. ...WI/MI into IL and MO... Supercells have largely merged into a broken line of assorted bows from far southeast WI across much of northern into western IL and trailing into northeast MO. The 00Z ILX sounding shows steep lapse rates aloft and large deep-layer shear, as well as veering winds with height. Low-level SRH will remain favorable for rotation to develop at least briefly anywhere within the line, with damaging winds the most likely threat. Storms have recently become better organized over central MO, and this activity may affect the St. Louis area later tonight. For lower MI into northern IN, the organized line of storms to the west along with a 60 kt low-level jet suggest at least isolated severe gusts may occur overnight despite lesser instability. For more information about Illinois, see mesoscale discussion 484. ...OK...Southeast KS...southwest MO...northwest AR... Scattered severe cells persist near and north of the cold front across much of northern OK and extending into southeast KS. Although the undercutting cold air will likely mitigate wind potential, steep lapse rates aloft along with ample deep-layer shear will continue to favor hail. Storm coverage may be more isolated into southwest OK later tonight, but the environment remains quite favorable for large hail. One corridor for possible damaging wind or even a tornado is over northeast OK into southwest MO. Here, the front is not surging as fast, and storms over Osage county are already oriented more favorably N-S relative to the deep-layer shear. A southwest low-level jet near 50 kt will further support low-level rotation. ..Jewell.. 04/18/2026 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Apr 17 2026 Valid 180100Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF ILLINOIS INTO NORTHEAST MISSOURI...AND OVER NORTHERN OKLAHOMA... ...SUMMARY... Damaging storms producing wind, hail and isolated tornadoes remain possible this evening from Illinois into Oklahoma. ...WI/MI into IL and MO... Supercells have largely merged into a broken line of assorted bows from far southeast WI across much of northern into western IL and trailing into northeast MO. The 00Z ILX sounding shows steep lapse rates aloft and large deep-layer shear, as well as veering winds with height. Low-level SRH will remain favorable for rotation to develop at least briefly anywhere within the line, with damaging winds the most likely threat. Storms have recently become better organized over central MO, and this activity may affect the St. Louis area later tonight. For lower MI into northern IN, the organized line of storms to the west along with a 60 kt low-level jet suggest at least isolated severe gusts may occur overnight despite lesser instability. For more information about Illinois, see mesoscale discussion 484. ...OK...Southeast KS...southwest MO...northwest AR... Scattered severe cells persist near and north of the cold front across much of northern OK and extending into southeast KS. Although the undercutting cold air will likely mitigate wind potential, steep lapse rates aloft along with ample deep-layer shear will continue to favor hail. Storm coverage may be more isolated into southwest OK later tonight, but the environment remains quite favorable for large hail. One corridor for possible damaging wind or even a tornado is over northeast OK into southwest MO. Here, the front is not surging as fast, and storms over Osage county are already oriented more favorably N-S relative to the deep-layer shear. A southwest low-level jet near 50 kt will further support low-level rotation. ..Jewell.. 04/18/2026 Read more

WW 0129 Status Updates
STATUS REPORT ON WW 129 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 ESE IRK TO 20 S MLI TO 25 WSW JVL TO 30 ENE MSN TO 10 SE MTW. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0484 ..MOORE..04/18/26 ATTN...WFO...ARX...DMX...DVN...LOT...MPX...GRB...MKX... STATUS REPORT FOR WT 129 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-011-037-067-071-073-099-103-109-111-141-155-187-195-201- 180140- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE BUREAU DE KALB HANCOCK HENDERSON HENRY LA SALLE LEE MCDONOUGH MCHENRY OGLE PUTNAM WARREN WHITESIDE WINNEBAGO WIC055-059-079-089-101-105-117-127-131-133-180140- WI . WISCONSIN COUNTIES INCLUDED ARE JEFFERSON KENOSHA MILWAUKEE OZAUKEE RACINE ROCK SHEBOYGAN WALWORTH WASHINGTON WAUKESHA Read more