Severe Storms

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

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

WW 0025 Status Updates
STATUS REPORT ON WW 25 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 ENE BRL TO 35 E DBQ. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0166 ..THORNTON..02/28/24 ATTN...WFO...DVN...LOT...ILX...MKX... STATUS REPORT FOR WT 25 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-011-031-037-043-053-063-073-075-089-091-093-097-099-103- 105-111-123-141-155-175-195-197-201-280140- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE BUREAU COOK DE KALB DUPAGE FORD GRUNDY HENRY IROQUOIS KANE KANKAKEE KENDALL LAKE LA SALLE LEE LIVINGSTON MCHENRY MARSHALL OGLE PUTNAM STARK WHITESIDE WILL WINNEBAGO INC007-073-089-111-127-280140- IN . INDIANA COUNTIES INCLUDED ARE BENTON JASPER LAKE NEWTON PORTER Read more

MD 0164 CONCERNING SNOW SQUALL FOR EASTERN NEBRASKA...NORTHWEST IOWA...AND SOUTHERN MINNESOTA
Mesoscale Discussion 0164 NWS Storm Prediction Center Norman OK 0353 PM CST Tue Feb 27 2024 Areas affected...Eastern Nebraska...northwest Iowa...and southern Minnesota Concerning...Snow Squall Valid 272153Z - 280100Z SUMMARY...A heavy band of snow will continue east with occasional snow squall conditions possible. DISCUSSION...A band of snow along the 700mb front continues southeast this afternoon with brief snowfall rates in excess of 1 inch per hour. In addition, this snow band is within a broad synoptic environment featuring 20 to 30 knot northwesterly sustained surface winds. Therefore, this combination is leading to reduced visibility within the line from east-central Minnesota to eastern Nebraska. Guidance indicates this band of snow should maintain intensity as it moves east this evening. ..Bentley.. 02/27/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...ARX...MPX...DMX...FSD...OAX...GID...LBF... LAT...LON 42829748 43739671 45579412 45809319 45359234 43739250 41949524 41559595 40819741 40589860 40839917 41209902 42319785 42829748 Read more