Severe Storms

WW 0026 Status Updates
STATUS FOR WATCH 0026 HAS NOT BEEN ISSUED YET Read more

WW 0025 Status Updates
STATUS REPORT ON WW 25 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 ESE MMO TO 25 SW RAC. ..SPC..02/28/24 ATTN...WFO...DVN...LOT...ILX...MKX... STATUS REPORT FOR WT 25 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC031-091-097-197-280340- IL . ILLINOIS COUNTIES INCLUDED ARE COOK KANKAKEE LAKE WILL INC007-073-089-111-127-280340- IN . INDIANA COUNTIES INCLUDED ARE BENTON JASPER LAKE NEWTON PORTER WIC059-101-127-280340- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA RACINE WALWORTH Read more

WW 0025 Status Updates
STATUS REPORT ON WW 25 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 ESE MMO TO 25 SW RAC. ..SPC..02/28/24 ATTN...WFO...DVN...LOT...ILX...MKX... STATUS REPORT FOR WT 25 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC031-091-097-197-280340- IL . ILLINOIS COUNTIES INCLUDED ARE COOK KANKAKEE LAKE WILL INC007-073-089-111-127-280340- IN . INDIANA COUNTIES INCLUDED ARE BENTON JASPER LAKE NEWTON PORTER WIC059-101-127-280340- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA RACINE WALWORTH Read more

WW 0025 Status Updates
STATUS REPORT ON WW 25 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 ESE MMO TO 25 SW RAC. ..SPC..02/28/24 ATTN...WFO...DVN...LOT...ILX...MKX... STATUS REPORT FOR WT 25 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC031-091-097-197-280340- IL . ILLINOIS COUNTIES INCLUDED ARE COOK KANKAKEE LAKE WILL INC007-073-089-111-127-280340- IN . INDIANA COUNTIES INCLUDED ARE BENTON JASPER LAKE NEWTON PORTER WIC059-101-127-280340- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA RACINE WALWORTH Read more

WW 0025 Status Updates
STATUS REPORT ON WW 25 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 ESE MMO TO 25 SW RAC. ..SPC..02/28/24 ATTN...WFO...DVN...LOT...ILX...MKX... STATUS REPORT FOR WT 25 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC031-091-097-197-280340- IL . ILLINOIS COUNTIES INCLUDED ARE COOK KANKAKEE LAKE WILL INC007-073-089-111-127-280340- IN . INDIANA COUNTIES INCLUDED ARE BENTON JASPER LAKE NEWTON PORTER WIC059-101-127-280340- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA RACINE WALWORTH Read more

WW 0025 Status Updates
STATUS REPORT ON WW 25 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 ESE MMO TO 25 SW RAC. ..SPC..02/28/24 ATTN...WFO...DVN...LOT...ILX...MKX... STATUS REPORT FOR WT 25 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC031-091-097-197-280340- IL . ILLINOIS COUNTIES INCLUDED ARE COOK KANKAKEE LAKE WILL INC007-073-089-111-127-280340- IN . INDIANA COUNTIES INCLUDED ARE BENTON JASPER LAKE NEWTON PORTER WIC059-101-127-280340- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA RACINE WALWORTH Read more

WW 0025 Status Updates
STATUS REPORT ON WW 25 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 ESE MMO TO 25 SW RAC. ..SPC..02/28/24 ATTN...WFO...DVN...LOT...ILX...MKX... STATUS REPORT FOR WT 25 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC031-091-097-197-280340- IL . ILLINOIS COUNTIES INCLUDED ARE COOK KANKAKEE LAKE WILL INC007-073-089-111-127-280340- IN . INDIANA COUNTIES INCLUDED ARE BENTON JASPER LAKE NEWTON PORTER WIC059-101-127-280340- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA RACINE WALWORTH Read more

WW 25 TORNADO IA IL IN WI LM 272155Z - 280400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 25 NWS Storm Prediction Center Norman OK 355 PM CST Tue Feb 27 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southeast Iowa Northern Illinois Northwest Indiana Southeast Wisconsin Lake Michigan * Effective this Tuesday afternoon and evening from 355 PM until 1000 PM CST. * Primary threats include... A few tornadoes likely with a couple intense tornadoes possible Widespread large hail and isolated very large hail events to 3 inches in diameter likely Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms will intensify across the watch area in the next hour or two, with a few supercells possible. Very large hail and a tornado or two are the main threats through the evening. The tornado watch area is approximately along and 50 statute miles north and south of a line from 80 miles west of Marseilles IL to 35 miles north of Valparaiso IN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). 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 400. Mean storm motion vector 27035. ...Hart Read more

WW 0025 Status Updates
STATUS REPORT ON WW 25 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 N BMI TO 45 SW RFD TO 20 W RFD. ..SPC..02/28/24 ATTN...WFO...DVN...LOT...ILX...MKX... STATUS REPORT FOR WT 25 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-031-037-043-053-063-075-089-091-093-097-099-103-105-111- 141-197-201-280240- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE COOK DE KALB DUPAGE FORD GRUNDY IROQUOIS KANE KANKAKEE KENDALL LAKE LA SALLE LEE LIVINGSTON MCHENRY OGLE WILL WINNEBAGO INC007-073-089-111-127-280240- IN . INDIANA COUNTIES INCLUDED ARE BENTON JASPER LAKE NEWTON PORTER WIC059-101-127-280240- Read more

MD 0166 CONCERNING TORNADO WATCH 25... FOR NORTHERN ILLINOIS
Mesoscale Discussion 0166 NWS Storm Prediction Center Norman OK 0559 PM CST Tue Feb 27 2024 Areas affected...Northern Illinois Concerning...Tornado Watch 25... Valid 272359Z - 280130Z The severe weather threat for Tornado Watch 25 continues. SUMMARY...Severe thunderstorm clusters, including supercells with the possibility for tornadoes, will spread/develop east toward southern Lake MI over the next several hours. DISCUSSION...Secondary surface low appears to be evolving along the front over southeast IA/northwest IL. A multifaceted corridor of low-level convergence arcs east from this feature across northern IL. Over the last few hours significant boundary-layer moistening has advanced as far north as Rockford where surface dew points are now in the lower 50s. Over the next few hours, low-level flow may back slightly downstream, in advance of the low. This should aid convergence along the warm front currently draped from Henry-La Salle-Iroquois County IL. Several maturing thunderstorm clusters are currently located from south of Davenport IA to DeKalb IL. Significant rotation is now observed with several supercells embedded along this corridor. Given the steep lapse rates observed, very large hail can be expected with this activity. Tornado threat is also increasing as environmental parameters become more favorable along the warm front. This activity should spread toward the southern portions of Lake MI, including the metro Chicago area. ..Darrow.. 02/27/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...MKX...DVN... LAT...LON 42069020 42678699 41248699 40639022 42069020 Read more

MD 0165 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF CENTRAL AND SOUTHERN ILLINOIS INTO WESTERN INDIANA
Mesoscale Discussion 0165 NWS Storm Prediction Center Norman OK 0547 PM CST Tue Feb 27 2024 Areas affected...parts of central and southern Illinois into Western Indiana Concerning...Severe potential...Watch possible Valid 272347Z - 280115Z Probability of Watch Issuance...40 percent SUMMARY...Isolated storm development along the dryline is possible early this evening. Experimental WOFS guidance and environmental analysis suggest conditional severe potential if supercells are able to develop. DISCUSSION...As of 2230 UTC, regional satellite data showed towering altocumulus deepening across parts of central IL. Located along the dryline ahead of a subtle shortwave trough, multiple attempts at CI appear to be underway. The environment downstream of the dryline is conditionally favorable for deep convection, with dewpoints in the upper 50s to low 60s F and steep mid-level lapse rates supporting 1500-2000 J/kg of MLCAPE. Considerable MLCINH (-100 J/kg from mesoanalysis) remains in place, but if deep convection can initiate, 50+ kt of effective shear would favor storm organization with a supercellular mode. Hi-res and experimental forecast guidance has shown isolated storm development early this evening over several prior runs. Should this occur, the environment over eastern IL and western IN is favorable for supercells capable of all severe hazards. ESRH of 300-400 m2/s2, observed from area VWPs, may also support a risk for a strong tornado. While the risk remains very uncertain, given dry air entertainment and the loss of diurnal heating along the dryline, observational trends are being monitored for a possible weather watch. Storm development is much more likely later this evening as the cold front and stronger forcing for ascent approach from the west after 03z. ..Lyons/Edwards.. 02/27/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IND...PAH...ILX...LSX... LAT...LON 37958969 37818925 38028870 38298808 38718704 39138667 39608666 39778676 39958695 40108734 40118805 40038834 39808890 39598926 39298952 38418970 37958969 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Tue Feb 27 2024 Valid 280100Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA...AND FROM SOUTHEAST MISSOURI ACROSS MUCH OF THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms producing tornadoes, damaging hail and wind remain likely over parts of northern Illinois this evening, and through tonight into parts of the Ohio Valley. ...Northern Illinois and Vicinity... Supercells, some tornadic, have developed near the surface low just ahead of the cold front over northern IL, and along the east-west boundary which separates the greater theta-e to the south. Very steep lapse rates aloft exist across the warm sector, where mid to upper 50s F dewpoints are contributing to MUCAPE to 2000 J/kg. As the surface low continues to deepen, the low-level jet will strengthen across much of eastern IL, IN, and points south, enhancing shear. As such, hodograph enlargement should support a continued, and possibly increasing, significant-tornado threat across parts of northern IL and eventually northwest IN later this evening. The tornado threat may extend into southern Lower MI as well, coincident with the surface low. For more information, see mesoscale discussion 166. ...Southern IL and IN across much of the OH Valley Tonight... A dryline currently extends from central IL southwestward into northern AR, within the low-level lapse rate plume. Although farther south from the surface low, midlevel temperatures remain quite cool, resulting in steep lapse rates. In addition, boundary-layer theta-e remains robust with lower 60 F dewpoints, contributing to around 1000 J/kg MLCAPE. Several more hours of potential boundary-layer moistening will occur ahead of the cold front from AR toward the lower OH Valley tonight, as 850 mb winds increase to 60 kt. Although low-level winds may veer, forecast storm motions are expected to be over 50 kt which may allow for storms to remain just on or even ahead of the cold front. And, effective SRH is forecast to remain over 300 m2/s2. The end result will be storms focused along the front, possibly with linear segments or broken with discrete supercells, with tornado, damaging-wind, and hail potential. Strong-tornado potential will exist with any activity remaining along or just ahead of the cold front. For more information in the near term, see mesoscale discussion 165. ..Jewell.. 02/28/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Tue Feb 27 2024 Valid 280100Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA...AND FROM SOUTHEAST MISSOURI ACROSS MUCH OF THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms producing tornadoes, damaging hail and wind remain likely over parts of northern Illinois this evening, and through tonight into parts of the Ohio Valley. ...Northern Illinois and Vicinity... Supercells, some tornadic, have developed near the surface low just ahead of the cold front over northern IL, and along the east-west boundary which separates the greater theta-e to the south. Very steep lapse rates aloft exist across the warm sector, where mid to upper 50s F dewpoints are contributing to MUCAPE to 2000 J/kg. As the surface low continues to deepen, the low-level jet will strengthen across much of eastern IL, IN, and points south, enhancing shear. As such, hodograph enlargement should support a continued, and possibly increasing, significant-tornado threat across parts of northern IL and eventually northwest IN later this evening. The tornado threat may extend into southern Lower MI as well, coincident with the surface low. For more information, see mesoscale discussion 166. ...Southern IL and IN across much of the OH Valley Tonight... A dryline currently extends from central IL southwestward into northern AR, within the low-level lapse rate plume. Although farther south from the surface low, midlevel temperatures remain quite cool, resulting in steep lapse rates. In addition, boundary-layer theta-e remains robust with lower 60 F dewpoints, contributing to around 1000 J/kg MLCAPE. Several more hours of potential boundary-layer moistening will occur ahead of the cold front from AR toward the lower OH Valley tonight, as 850 mb winds increase to 60 kt. Although low-level winds may veer, forecast storm motions are expected to be over 50 kt which may allow for storms to remain just on or even ahead of the cold front. And, effective SRH is forecast to remain over 300 m2/s2. The end result will be storms focused along the front, possibly with linear segments or broken with discrete supercells, with tornado, damaging-wind, and hail potential. Strong-tornado potential will exist with any activity remaining along or just ahead of the cold front. For more information in the near term, see mesoscale discussion 165. ..Jewell.. 02/28/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Tue Feb 27 2024 Valid 280100Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA...AND FROM SOUTHEAST MISSOURI ACROSS MUCH OF THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms producing tornadoes, damaging hail and wind remain likely over parts of northern Illinois this evening, and through tonight into parts of the Ohio Valley. ...Northern Illinois and Vicinity... Supercells, some tornadic, have developed near the surface low just ahead of the cold front over northern IL, and along the east-west boundary which separates the greater theta-e to the south. Very steep lapse rates aloft exist across the warm sector, where mid to upper 50s F dewpoints are contributing to MUCAPE to 2000 J/kg. As the surface low continues to deepen, the low-level jet will strengthen across much of eastern IL, IN, and points south, enhancing shear. As such, hodograph enlargement should support a continued, and possibly increasing, significant-tornado threat across parts of northern IL and eventually northwest IN later this evening. The tornado threat may extend into southern Lower MI as well, coincident with the surface low. For more information, see mesoscale discussion 166. ...Southern IL and IN across much of the OH Valley Tonight... A dryline currently extends from central IL southwestward into northern AR, within the low-level lapse rate plume. Although farther south from the surface low, midlevel temperatures remain quite cool, resulting in steep lapse rates. In addition, boundary-layer theta-e remains robust with lower 60 F dewpoints, contributing to around 1000 J/kg MLCAPE. Several more hours of potential boundary-layer moistening will occur ahead of the cold front from AR toward the lower OH Valley tonight, as 850 mb winds increase to 60 kt. Although low-level winds may veer, forecast storm motions are expected to be over 50 kt which may allow for storms to remain just on or even ahead of the cold front. And, effective SRH is forecast to remain over 300 m2/s2. The end result will be storms focused along the front, possibly with linear segments or broken with discrete supercells, with tornado, damaging-wind, and hail potential. Strong-tornado potential will exist with any activity remaining along or just ahead of the cold front. For more information in the near term, see mesoscale discussion 165. ..Jewell.. 02/28/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Tue Feb 27 2024 Valid 280100Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA...AND FROM SOUTHEAST MISSOURI ACROSS MUCH OF THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms producing tornadoes, damaging hail and wind remain likely over parts of northern Illinois this evening, and through tonight into parts of the Ohio Valley. ...Northern Illinois and Vicinity... Supercells, some tornadic, have developed near the surface low just ahead of the cold front over northern IL, and along the east-west boundary which separates the greater theta-e to the south. Very steep lapse rates aloft exist across the warm sector, where mid to upper 50s F dewpoints are contributing to MUCAPE to 2000 J/kg. As the surface low continues to deepen, the low-level jet will strengthen across much of eastern IL, IN, and points south, enhancing shear. As such, hodograph enlargement should support a continued, and possibly increasing, significant-tornado threat across parts of northern IL and eventually northwest IN later this evening. The tornado threat may extend into southern Lower MI as well, coincident with the surface low. For more information, see mesoscale discussion 166. ...Southern IL and IN across much of the OH Valley Tonight... A dryline currently extends from central IL southwestward into northern AR, within the low-level lapse rate plume. Although farther south from the surface low, midlevel temperatures remain quite cool, resulting in steep lapse rates. In addition, boundary-layer theta-e remains robust with lower 60 F dewpoints, contributing to around 1000 J/kg MLCAPE. Several more hours of potential boundary-layer moistening will occur ahead of the cold front from AR toward the lower OH Valley tonight, as 850 mb winds increase to 60 kt. Although low-level winds may veer, forecast storm motions are expected to be over 50 kt which may allow for storms to remain just on or even ahead of the cold front. And, effective SRH is forecast to remain over 300 m2/s2. The end result will be storms focused along the front, possibly with linear segments or broken with discrete supercells, with tornado, damaging-wind, and hail potential. Strong-tornado potential will exist with any activity remaining along or just ahead of the cold front. For more information in the near term, see mesoscale discussion 165. ..Jewell.. 02/28/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Tue Feb 27 2024 Valid 280100Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA...AND FROM SOUTHEAST MISSOURI ACROSS MUCH OF THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms producing tornadoes, damaging hail and wind remain likely over parts of northern Illinois this evening, and through tonight into parts of the Ohio Valley. ...Northern Illinois and Vicinity... Supercells, some tornadic, have developed near the surface low just ahead of the cold front over northern IL, and along the east-west boundary which separates the greater theta-e to the south. Very steep lapse rates aloft exist across the warm sector, where mid to upper 50s F dewpoints are contributing to MUCAPE to 2000 J/kg. As the surface low continues to deepen, the low-level jet will strengthen across much of eastern IL, IN, and points south, enhancing shear. As such, hodograph enlargement should support a continued, and possibly increasing, significant-tornado threat across parts of northern IL and eventually northwest IN later this evening. The tornado threat may extend into southern Lower MI as well, coincident with the surface low. For more information, see mesoscale discussion 166. ...Southern IL and IN across much of the OH Valley Tonight... A dryline currently extends from central IL southwestward into northern AR, within the low-level lapse rate plume. Although farther south from the surface low, midlevel temperatures remain quite cool, resulting in steep lapse rates. In addition, boundary-layer theta-e remains robust with lower 60 F dewpoints, contributing to around 1000 J/kg MLCAPE. Several more hours of potential boundary-layer moistening will occur ahead of the cold front from AR toward the lower OH Valley tonight, as 850 mb winds increase to 60 kt. Although low-level winds may veer, forecast storm motions are expected to be over 50 kt which may allow for storms to remain just on or even ahead of the cold front. And, effective SRH is forecast to remain over 300 m2/s2. The end result will be storms focused along the front, possibly with linear segments or broken with discrete supercells, with tornado, damaging-wind, and hail potential. Strong-tornado potential will exist with any activity remaining along or just ahead of the cold front. For more information in the near term, see mesoscale discussion 165. ..Jewell.. 02/28/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Tue Feb 27 2024 Valid 280100Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA...AND FROM SOUTHEAST MISSOURI ACROSS MUCH OF THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms producing tornadoes, damaging hail and wind remain likely over parts of northern Illinois this evening, and through tonight into parts of the Ohio Valley. ...Northern Illinois and Vicinity... Supercells, some tornadic, have developed near the surface low just ahead of the cold front over northern IL, and along the east-west boundary which separates the greater theta-e to the south. Very steep lapse rates aloft exist across the warm sector, where mid to upper 50s F dewpoints are contributing to MUCAPE to 2000 J/kg. As the surface low continues to deepen, the low-level jet will strengthen across much of eastern IL, IN, and points south, enhancing shear. As such, hodograph enlargement should support a continued, and possibly increasing, significant-tornado threat across parts of northern IL and eventually northwest IN later this evening. The tornado threat may extend into southern Lower MI as well, coincident with the surface low. For more information, see mesoscale discussion 166. ...Southern IL and IN across much of the OH Valley Tonight... A dryline currently extends from central IL southwestward into northern AR, within the low-level lapse rate plume. Although farther south from the surface low, midlevel temperatures remain quite cool, resulting in steep lapse rates. In addition, boundary-layer theta-e remains robust with lower 60 F dewpoints, contributing to around 1000 J/kg MLCAPE. Several more hours of potential boundary-layer moistening will occur ahead of the cold front from AR toward the lower OH Valley tonight, as 850 mb winds increase to 60 kt. Although low-level winds may veer, forecast storm motions are expected to be over 50 kt which may allow for storms to remain just on or even ahead of the cold front. And, effective SRH is forecast to remain over 300 m2/s2. The end result will be storms focused along the front, possibly with linear segments or broken with discrete supercells, with tornado, damaging-wind, and hail potential. Strong-tornado potential will exist with any activity remaining along or just ahead of the cold front. For more information in the near term, see mesoscale discussion 165. ..Jewell.. 02/28/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Tue Feb 27 2024 Valid 280100Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA...AND FROM SOUTHEAST MISSOURI ACROSS MUCH OF THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms producing tornadoes, damaging hail and wind remain likely over parts of northern Illinois this evening, and through tonight into parts of the Ohio Valley. ...Northern Illinois and Vicinity... Supercells, some tornadic, have developed near the surface low just ahead of the cold front over northern IL, and along the east-west boundary which separates the greater theta-e to the south. Very steep lapse rates aloft exist across the warm sector, where mid to upper 50s F dewpoints are contributing to MUCAPE to 2000 J/kg. As the surface low continues to deepen, the low-level jet will strengthen across much of eastern IL, IN, and points south, enhancing shear. As such, hodograph enlargement should support a continued, and possibly increasing, significant-tornado threat across parts of northern IL and eventually northwest IN later this evening. The tornado threat may extend into southern Lower MI as well, coincident with the surface low. For more information, see mesoscale discussion 166. ...Southern IL and IN across much of the OH Valley Tonight... A dryline currently extends from central IL southwestward into northern AR, within the low-level lapse rate plume. Although farther south from the surface low, midlevel temperatures remain quite cool, resulting in steep lapse rates. In addition, boundary-layer theta-e remains robust with lower 60 F dewpoints, contributing to around 1000 J/kg MLCAPE. Several more hours of potential boundary-layer moistening will occur ahead of the cold front from AR toward the lower OH Valley tonight, as 850 mb winds increase to 60 kt. Although low-level winds may veer, forecast storm motions are expected to be over 50 kt which may allow for storms to remain just on or even ahead of the cold front. And, effective SRH is forecast to remain over 300 m2/s2. The end result will be storms focused along the front, possibly with linear segments or broken with discrete supercells, with tornado, damaging-wind, and hail potential. Strong-tornado potential will exist with any activity remaining along or just ahead of the cold front. For more information in the near term, see mesoscale discussion 165. ..Jewell.. 02/28/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Tue Feb 27 2024 Valid 280100Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA...AND FROM SOUTHEAST MISSOURI ACROSS MUCH OF THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms producing tornadoes, damaging hail and wind remain likely over parts of northern Illinois this evening, and through tonight into parts of the Ohio Valley. ...Northern Illinois and Vicinity... Supercells, some tornadic, have developed near the surface low just ahead of the cold front over northern IL, and along the east-west boundary which separates the greater theta-e to the south. Very steep lapse rates aloft exist across the warm sector, where mid to upper 50s F dewpoints are contributing to MUCAPE to 2000 J/kg. As the surface low continues to deepen, the low-level jet will strengthen across much of eastern IL, IN, and points south, enhancing shear. As such, hodograph enlargement should support a continued, and possibly increasing, significant-tornado threat across parts of northern IL and eventually northwest IN later this evening. The tornado threat may extend into southern Lower MI as well, coincident with the surface low. For more information, see mesoscale discussion 166. ...Southern IL and IN across much of the OH Valley Tonight... A dryline currently extends from central IL southwestward into northern AR, within the low-level lapse rate plume. Although farther south from the surface low, midlevel temperatures remain quite cool, resulting in steep lapse rates. In addition, boundary-layer theta-e remains robust with lower 60 F dewpoints, contributing to around 1000 J/kg MLCAPE. Several more hours of potential boundary-layer moistening will occur ahead of the cold front from AR toward the lower OH Valley tonight, as 850 mb winds increase to 60 kt. Although low-level winds may veer, forecast storm motions are expected to be over 50 kt which may allow for storms to remain just on or even ahead of the cold front. And, effective SRH is forecast to remain over 300 m2/s2. The end result will be storms focused along the front, possibly with linear segments or broken with discrete supercells, with tornado, damaging-wind, and hail potential. Strong-tornado potential will exist with any activity remaining along or just ahead of the cold front. For more information in the near term, see mesoscale discussion 165. ..Jewell.. 02/28/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 PM CST Tue Feb 27 2024 Valid 280100Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA...AND FROM SOUTHEAST MISSOURI ACROSS MUCH OF THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms producing tornadoes, damaging hail and wind remain likely over parts of northern Illinois this evening, and through tonight into parts of the Ohio Valley. ...Northern Illinois and Vicinity... Supercells, some tornadic, have developed near the surface low just ahead of the cold front over northern IL, and along the east-west boundary which separates the greater theta-e to the south. Very steep lapse rates aloft exist across the warm sector, where mid to upper 50s F dewpoints are contributing to MUCAPE to 2000 J/kg. As the surface low continues to deepen, the low-level jet will strengthen across much of eastern IL, IN, and points south, enhancing shear. As such, hodograph enlargement should support a continued, and possibly increasing, significant-tornado threat across parts of northern IL and eventually northwest IN later this evening. The tornado threat may extend into southern Lower MI as well, coincident with the surface low. For more information, see mesoscale discussion 166. ...Southern IL and IN across much of the OH Valley Tonight... A dryline currently extends from central IL southwestward into northern AR, within the low-level lapse rate plume. Although farther south from the surface low, midlevel temperatures remain quite cool, resulting in steep lapse rates. In addition, boundary-layer theta-e remains robust with lower 60 F dewpoints, contributing to around 1000 J/kg MLCAPE. Several more hours of potential boundary-layer moistening will occur ahead of the cold front from AR toward the lower OH Valley tonight, as 850 mb winds increase to 60 kt. Although low-level winds may veer, forecast storm motions are expected to be over 50 kt which may allow for storms to remain just on or even ahead of the cold front. And, effective SRH is forecast to remain over 300 m2/s2. The end result will be storms focused along the front, possibly with linear segments or broken with discrete supercells, with tornado, damaging-wind, and hail potential. Strong-tornado potential will exist with any activity remaining along or just ahead of the cold front. For more information in the near term, see mesoscale discussion 165. ..Jewell.. 02/28/2024 Read more