Severe Storms

WW 0592 Status Updates
STATUS REPORT ON WW 592 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 E BRL TO 30 SSE RFD. ..LYONS..08/16/25 ATTN...WFO...DVN...ILX...LOT... STATUS REPORT FOR WS 592 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC011-095-123-143-155-175-179-203-160240- IL . ILLINOIS COUNTIES INCLUDED ARE BUREAU KNOX MARSHALL PEORIA PUTNAM STARK TAZEWELL WOODFORD 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 0592 Status Updates
STATUS REPORT ON WW 592 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 E BRL TO 30 SSE RFD. ..LYONS..08/16/25 ATTN...WFO...DVN...ILX...LOT... STATUS REPORT FOR WS 592 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC011-095-123-143-155-175-179-203-160240- IL . ILLINOIS COUNTIES INCLUDED ARE BUREAU KNOX MARSHALL PEORIA PUTNAM STARK TAZEWELL WOODFORD 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 0592 Status Updates
STATUS REPORT ON WW 592 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 E BRL TO 30 SSE RFD. ..LYONS..08/16/25 ATTN...WFO...DVN...ILX...LOT... STATUS REPORT FOR WS 592 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC011-095-123-143-155-175-179-203-160240- IL . ILLINOIS COUNTIES INCLUDED ARE BUREAU KNOX MARSHALL PEORIA PUTNAM STARK TAZEWELL WOODFORD 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 0592 Status Updates
STATUS REPORT ON WW 592 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 E BRL TO 30 SSE RFD. ..LYONS..08/16/25 ATTN...WFO...DVN...ILX...LOT... STATUS REPORT FOR WS 592 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC011-095-123-143-155-175-179-203-160240- IL . ILLINOIS COUNTIES INCLUDED ARE BUREAU KNOX MARSHALL PEORIA PUTNAM STARK TAZEWELL WOODFORD 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 0592 Status Updates
STATUS REPORT ON WW 592 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 E BRL TO 30 SSE RFD. ..LYONS..08/16/25 ATTN...WFO...DVN...ILX...LOT... STATUS REPORT FOR WS 592 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC011-095-123-143-155-175-179-203-160240- IL . ILLINOIS COUNTIES INCLUDED ARE BUREAU KNOX MARSHALL PEORIA PUTNAM STARK TAZEWELL WOODFORD 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 592 SEVERE TSTM IL 152345Z - 160400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 592 NWS Storm Prediction Center Norman OK 645 PM CDT Fri Aug 15 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Illinois * Effective this Friday evening from 645 PM until 1100 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...A well-organized cluster of storms with a history of 70+ mph wind gusts across eastern Iowa will continue southeastward into northern Illinois. Even with a weakening trend over time, damaging winds will remain a possibility, and perhaps some hail. The severe thunderstorm watch area is approximately along and 50 statute miles north and south of a line from 5 miles west northwest of Moline IL to 75 miles east of Moline IL. 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 590...WW 591... AVIATION...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 550. Mean storm motion vector 30040. ...Guyer Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Fri Aug 15 2025 Valid 160100Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS ACROSS PARTS OF CENTRAL AND EASTERN SOUTH DAKOTA...NORTHERN NEBRASKA...SOUTHWESTERN MINNESOTA...NORTHWESTERN IOWA...PARTS OF SOUTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN... ...SUMMARY... An organizing cluster of thunderstorms with potential to produce strong to severe wind gusts may still evolve later this evening into the overnight hours across parts of the middle Missouri Valley and adjacent Great Plains. ...01Z Update... Stronger westerlies remain generally confined to the higher latitudes, near/north of the Canadian/U.S. border. To the southwest of one significant embedded short wave trough crossing the Hudson Bay and northern Ontario vicinity, modest westerly mid-level flow (including speeds of 30-40 kt around 500 mb) is overspreading areas as far south as the Dakotas into Upper Midwest, near the northern periphery of mid-level ridging. Forcing associated with subtle perturbations embedded within this regime has contributed to several developing clusters of storms. A couple now propagating east of the upper Mississippi Valley appear to be in the process of weakening, likely due to some combination of weak/weakening lift and increasing inhibition beneath relatively warm mid-level temperatures encompassing much of the northern and central Great Plains into Midwest. Beneath steeper mid-level lapse rates upstream, boundary-layer moisture east of the lee surface trough across the high plains is still contributing to strong to extreme potential instability across much of central and eastern South Dakota/Nebraska, as scattered high based convection emerges from eastern Wyoming and northeastern Colorado. It appears possible that low-level forcing for ascent, near the nose of a nocturnally strengthening southerly low-level jet, could contribute to a consolidating and upscale growing cluster, particularly as activity acquires more unstable inflow later this evening into the overnight. Various model output, including the NAM and Rapid Refresh, suggest that the evolution of a notable convective perturbation is possible, which could be accompanied by a swath of strong to severe wind gusts. ..Kerr.. 08/16/2025 Read more

WW 0590 Status Updates
STATUS REPORT ON WW 590 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NNW ALO TO 40 SE RST. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1953. ..GRAMS..08/15/25 ATTN...WFO...ARX...DVN... STATUS REPORT FOR WS 590 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC015-073-085-131-161-195-152140- IL . ILLINOIS COUNTIES INCLUDED ARE CARROLL HENRY JO DAVIESS MERCER ROCK ISLAND WHITESIDE IAC005-011-019-031-037-043-045-055-061-065-095-097-103-105-107- 113-115-139-163-183-191-152140- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE BENTON BUCHANAN CEDAR CHICKASAW CLAYTON CLINTON DELAWARE DUBUQUE FAYETTE IOWA JACKSON JOHNSON JONES KEOKUK LINN LOUISA MUSCATINE SCOTT WASHINGTON WINNESHIEK Read more

WW 0590 Status Updates
STATUS REPORT ON WW 590 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NNW ALO TO 40 SE RST. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1953. ..GRAMS..08/15/25 ATTN...WFO...ARX...DVN... STATUS REPORT FOR WS 590 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC015-073-085-131-161-195-152140- IL . ILLINOIS COUNTIES INCLUDED ARE CARROLL HENRY JO DAVIESS MERCER ROCK ISLAND WHITESIDE IAC005-011-019-031-037-043-045-055-061-065-095-097-103-105-107- 113-115-139-163-183-191-152140- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE BENTON BUCHANAN CEDAR CHICKASAW CLAYTON CLINTON DELAWARE DUBUQUE FAYETTE IOWA JACKSON JOHNSON JONES KEOKUK LINN LOUISA MUSCATINE SCOTT WASHINGTON WINNESHIEK Read more

WW 0590 Status Updates
STATUS REPORT ON WW 590 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NNW ALO TO 40 SE RST. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1953. ..GRAMS..08/15/25 ATTN...WFO...ARX...DVN... STATUS REPORT FOR WS 590 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC015-073-085-131-161-195-152140- IL . ILLINOIS COUNTIES INCLUDED ARE CARROLL HENRY JO DAVIESS MERCER ROCK ISLAND WHITESIDE IAC005-011-019-031-037-043-045-055-061-065-095-097-103-105-107- 113-115-139-163-183-191-152140- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE BENTON BUCHANAN CEDAR CHICKASAW CLAYTON CLINTON DELAWARE DUBUQUE FAYETTE IOWA JACKSON JOHNSON JONES KEOKUK LINN LOUISA MUSCATINE SCOTT WASHINGTON WINNESHIEK Read more