Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 AM CST Mon Feb 26 2024 Valid 261200Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE SOUTHERN AND CENTRAL HIGH PLAINS.... ...Synopsis... Strong westerly flow aloft is forecast to overspread much of the central US as an upstream Pacific trough begins to merge with an enhanced subtropical jet. A strong lee low and trailing surface trough will develop across the Plains bolstering surface winds. Widespread low humidity and warm temperatures accompanying the strong winds will support elevated to critical fire-weather conditions. ...Southern and central Plains... Increasingly strong flow aloft is expected to overspread the southern and central Rockies/High Plains through the day today. Aided by a strengthening lee trough and the flow aloft, gusty west/southwesterly surface winds are likely across much of the Plains. Unusually warm surface temperatures in the 70s and 80s F along with downslope drying will favor afternoon RH values of 15-20%. Meteorological conditions will likely support widespread critical fire-weather conditions across parts of eastern CO/NM into west TX and OK where area fuels have undergone significant drying. Farther north, stronger downslope winds are expected in the lee of the central Rockies along with RH below 20%. Updated fuel guidance points to slightly more receptive fuels than the previous days. Widespread elevated to near-critical fire-weather conditions are possible from eastern WY and western NE to portions of the Midwest. ..Lyons.. 02/26/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 AM CST Mon Feb 26 2024 Valid 261200Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE SOUTHERN AND CENTRAL HIGH PLAINS.... ...Synopsis... Strong westerly flow aloft is forecast to overspread much of the central US as an upstream Pacific trough begins to merge with an enhanced subtropical jet. A strong lee low and trailing surface trough will develop across the Plains bolstering surface winds. Widespread low humidity and warm temperatures accompanying the strong winds will support elevated to critical fire-weather conditions. ...Southern and central Plains... Increasingly strong flow aloft is expected to overspread the southern and central Rockies/High Plains through the day today. Aided by a strengthening lee trough and the flow aloft, gusty west/southwesterly surface winds are likely across much of the Plains. Unusually warm surface temperatures in the 70s and 80s F along with downslope drying will favor afternoon RH values of 15-20%. Meteorological conditions will likely support widespread critical fire-weather conditions across parts of eastern CO/NM into west TX and OK where area fuels have undergone significant drying. Farther north, stronger downslope winds are expected in the lee of the central Rockies along with RH below 20%. Updated fuel guidance points to slightly more receptive fuels than the previous days. Widespread elevated to near-critical fire-weather conditions are possible from eastern WY and western NE to portions of the Midwest. ..Lyons.. 02/26/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0140 AM CST Mon Feb 26 2024 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential appears low on Wednesday. ...Synopsis... An upper trough oriented from the Upper Midwest to the southern Plains will pivot to the Northeast states by Thursday morning. A surface low will develop east/northeast across southern Ontario and Quebec, while a trailing cold front moves across much of the eastern third of the CONUS. Showers and thunderstorms will likely be ongoing Wednesday morning along the cold front from western Ohio southwest toward western TN. Modest boundary-layer moisture is forecast ahead of the front across the Ohio Valley to the central Appalachians. Widespread cloudiness and continued precipitation will limit downstream destabilization through the day. Nevertheless, strong southwesterly flow above 925 mb is forecast. Some gusty winds may accompany thunderstorms, especially along the Ohio Valley vicinity. However, given MLCAPE less than 200 J/kg for the most part and poor low-level lapse rates, severe convective gusts are not expected and probabilities appear too low to introduce a Marginal risk at this time. ..Leitman.. 02/26/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0140 AM CST Mon Feb 26 2024 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential appears low on Wednesday. ...Synopsis... An upper trough oriented from the Upper Midwest to the southern Plains will pivot to the Northeast states by Thursday morning. A surface low will develop east/northeast across southern Ontario and Quebec, while a trailing cold front moves across much of the eastern third of the CONUS. Showers and thunderstorms will likely be ongoing Wednesday morning along the cold front from western Ohio southwest toward western TN. Modest boundary-layer moisture is forecast ahead of the front across the Ohio Valley to the central Appalachians. Widespread cloudiness and continued precipitation will limit downstream destabilization through the day. Nevertheless, strong southwesterly flow above 925 mb is forecast. Some gusty winds may accompany thunderstorms, especially along the Ohio Valley vicinity. However, given MLCAPE less than 200 J/kg for the most part and poor low-level lapse rates, severe convective gusts are not expected and probabilities appear too low to introduce a Marginal risk at this time. ..Leitman.. 02/26/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0140 AM CST Mon Feb 26 2024 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential appears low on Wednesday. ...Synopsis... An upper trough oriented from the Upper Midwest to the southern Plains will pivot to the Northeast states by Thursday morning. A surface low will develop east/northeast across southern Ontario and Quebec, while a trailing cold front moves across much of the eastern third of the CONUS. Showers and thunderstorms will likely be ongoing Wednesday morning along the cold front from western Ohio southwest toward western TN. Modest boundary-layer moisture is forecast ahead of the front across the Ohio Valley to the central Appalachians. Widespread cloudiness and continued precipitation will limit downstream destabilization through the day. Nevertheless, strong southwesterly flow above 925 mb is forecast. Some gusty winds may accompany thunderstorms, especially along the Ohio Valley vicinity. However, given MLCAPE less than 200 J/kg for the most part and poor low-level lapse rates, severe convective gusts are not expected and probabilities appear too low to introduce a Marginal risk at this time. ..Leitman.. 02/26/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0140 AM CST Mon Feb 26 2024 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential appears low on Wednesday. ...Synopsis... An upper trough oriented from the Upper Midwest to the southern Plains will pivot to the Northeast states by Thursday morning. A surface low will develop east/northeast across southern Ontario and Quebec, while a trailing cold front moves across much of the eastern third of the CONUS. Showers and thunderstorms will likely be ongoing Wednesday morning along the cold front from western Ohio southwest toward western TN. Modest boundary-layer moisture is forecast ahead of the front across the Ohio Valley to the central Appalachians. Widespread cloudiness and continued precipitation will limit downstream destabilization through the day. Nevertheless, strong southwesterly flow above 925 mb is forecast. Some gusty winds may accompany thunderstorms, especially along the Ohio Valley vicinity. However, given MLCAPE less than 200 J/kg for the most part and poor low-level lapse rates, severe convective gusts are not expected and probabilities appear too low to introduce a Marginal risk at this time. ..Leitman.. 02/26/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0140 AM CST Mon Feb 26 2024 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential appears low on Wednesday. ...Synopsis... An upper trough oriented from the Upper Midwest to the southern Plains will pivot to the Northeast states by Thursday morning. A surface low will develop east/northeast across southern Ontario and Quebec, while a trailing cold front moves across much of the eastern third of the CONUS. Showers and thunderstorms will likely be ongoing Wednesday morning along the cold front from western Ohio southwest toward western TN. Modest boundary-layer moisture is forecast ahead of the front across the Ohio Valley to the central Appalachians. Widespread cloudiness and continued precipitation will limit downstream destabilization through the day. Nevertheless, strong southwesterly flow above 925 mb is forecast. Some gusty winds may accompany thunderstorms, especially along the Ohio Valley vicinity. However, given MLCAPE less than 200 J/kg for the most part and poor low-level lapse rates, severe convective gusts are not expected and probabilities appear too low to introduce a Marginal risk at this time. ..Leitman.. 02/26/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0140 AM CST Mon Feb 26 2024 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential appears low on Wednesday. ...Synopsis... An upper trough oriented from the Upper Midwest to the southern Plains will pivot to the Northeast states by Thursday morning. A surface low will develop east/northeast across southern Ontario and Quebec, while a trailing cold front moves across much of the eastern third of the CONUS. Showers and thunderstorms will likely be ongoing Wednesday morning along the cold front from western Ohio southwest toward western TN. Modest boundary-layer moisture is forecast ahead of the front across the Ohio Valley to the central Appalachians. Widespread cloudiness and continued precipitation will limit downstream destabilization through the day. Nevertheless, strong southwesterly flow above 925 mb is forecast. Some gusty winds may accompany thunderstorms, especially along the Ohio Valley vicinity. However, given MLCAPE less than 200 J/kg for the most part and poor low-level lapse rates, severe convective gusts are not expected and probabilities appear too low to introduce a Marginal risk at this time. ..Leitman.. 02/26/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST-CENTRAL MISSOURI INTO ILLINOIS...INDIANA...NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some near 2 inch diameter), damaging gusts, and a few tornadoes will be possible from late Tuesday afternoon, into the evening and overnight from parts of the mid Mississippi Valley, and southwestern Great Lakes. ...Mid-MS Valley/Southwest Great Lakes Vicinity... An upper trough over the northern Rockies/Intermountain West will shift east on Tuesday, becoming oriented from the Upper MS Valley and Mid-MO Valley by Wednesday morning. Fast deep-layer southwesterly flow ahead of this feature will overspread the Ozark Plateau into the Great Lakes. At the surface, a low will deepen as it shifts east from MN toward southern Ontario. A cold front attendant to the low will quickly shift east/southeast across the Plains and the Mid/Upper MS Valley during the afternoon and into the overnight period. Initial thunderstorm activity may develop in warm advection regime near the quasi-warm front/moisture gradient from northern IL into IN/NW OH/southern MI around 21-00z. Additional activity will then develop along the cold front as it develops east and the main upper wave ejects into the region around 00-03z. Warm advection and southerly low-level flow ahead of the front will allow for modest airmass modification into the Midwest. However, forecast dewpoints are only expected to reach into the 50s to near 60 F. Nevertheless, a plume of steep midlevel lapse rates will overspread the IL/IN/MI/OH vicinity from afternoon into the evening. This will support modest destabilization with MLCAPE generally forecast to be less than 1000 J/kg, though a narrow corridor of up to 1500 J/kg MLCAPE may be possible for a brief period around 00z. Forecast soundings across the region indicate most of available instability will be located above the 850-700 mb layer. Initial thunderstorm activity may be slightly elevated as some forecast soundings indicate a warm nose between 850-700 mb during late afternoon/early evening. Nevertheless, effective shear greater than 50 kt, and enlarged low-level hodographs becoming elongated above 3 km indicate initial supercells will be possible near the quasi-warm front/moisture gradient from northeast IL into northern IN and vicinity. With most instability focused above the 850-700 mb layer, and in conjunction with poor boundary-layer dewpoints, the tornado risk may be somewhat lower than typically expected given shear profiles in the 0-2 km layer. Nevertheless a couple tornadoes are possible, especially if greater moisture than forecast can make it this far north. Large hail, with a few instances near 2 inch diameter, will be possible with any semi-discrete supercells, along with damaging gusts. Once linear forcing along the front increases in the 00-03z period, a line of storms is forecast to develop east from the Mid-MS Valley toward the Lower OH Valley during the nighttime hours. Damaging gusts will be the main concern with this activity. ..Leitman.. 02/26/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST-CENTRAL MISSOURI INTO ILLINOIS...INDIANA...NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some near 2 inch diameter), damaging gusts, and a few tornadoes will be possible from late Tuesday afternoon, into the evening and overnight from parts of the mid Mississippi Valley, and southwestern Great Lakes. ...Mid-MS Valley/Southwest Great Lakes Vicinity... An upper trough over the northern Rockies/Intermountain West will shift east on Tuesday, becoming oriented from the Upper MS Valley and Mid-MO Valley by Wednesday morning. Fast deep-layer southwesterly flow ahead of this feature will overspread the Ozark Plateau into the Great Lakes. At the surface, a low will deepen as it shifts east from MN toward southern Ontario. A cold front attendant to the low will quickly shift east/southeast across the Plains and the Mid/Upper MS Valley during the afternoon and into the overnight period. Initial thunderstorm activity may develop in warm advection regime near the quasi-warm front/moisture gradient from northern IL into IN/NW OH/southern MI around 21-00z. Additional activity will then develop along the cold front as it develops east and the main upper wave ejects into the region around 00-03z. Warm advection and southerly low-level flow ahead of the front will allow for modest airmass modification into the Midwest. However, forecast dewpoints are only expected to reach into the 50s to near 60 F. Nevertheless, a plume of steep midlevel lapse rates will overspread the IL/IN/MI/OH vicinity from afternoon into the evening. This will support modest destabilization with MLCAPE generally forecast to be less than 1000 J/kg, though a narrow corridor of up to 1500 J/kg MLCAPE may be possible for a brief period around 00z. Forecast soundings across the region indicate most of available instability will be located above the 850-700 mb layer. Initial thunderstorm activity may be slightly elevated as some forecast soundings indicate a warm nose between 850-700 mb during late afternoon/early evening. Nevertheless, effective shear greater than 50 kt, and enlarged low-level hodographs becoming elongated above 3 km indicate initial supercells will be possible near the quasi-warm front/moisture gradient from northeast IL into northern IN and vicinity. With most instability focused above the 850-700 mb layer, and in conjunction with poor boundary-layer dewpoints, the tornado risk may be somewhat lower than typically expected given shear profiles in the 0-2 km layer. Nevertheless a couple tornadoes are possible, especially if greater moisture than forecast can make it this far north. Large hail, with a few instances near 2 inch diameter, will be possible with any semi-discrete supercells, along with damaging gusts. Once linear forcing along the front increases in the 00-03z period, a line of storms is forecast to develop east from the Mid-MS Valley toward the Lower OH Valley during the nighttime hours. Damaging gusts will be the main concern with this activity. ..Leitman.. 02/26/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST-CENTRAL MISSOURI INTO ILLINOIS...INDIANA...NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some near 2 inch diameter), damaging gusts, and a few tornadoes will be possible from late Tuesday afternoon, into the evening and overnight from parts of the mid Mississippi Valley, and southwestern Great Lakes. ...Mid-MS Valley/Southwest Great Lakes Vicinity... An upper trough over the northern Rockies/Intermountain West will shift east on Tuesday, becoming oriented from the Upper MS Valley and Mid-MO Valley by Wednesday morning. Fast deep-layer southwesterly flow ahead of this feature will overspread the Ozark Plateau into the Great Lakes. At the surface, a low will deepen as it shifts east from MN toward southern Ontario. A cold front attendant to the low will quickly shift east/southeast across the Plains and the Mid/Upper MS Valley during the afternoon and into the overnight period. Initial thunderstorm activity may develop in warm advection regime near the quasi-warm front/moisture gradient from northern IL into IN/NW OH/southern MI around 21-00z. Additional activity will then develop along the cold front as it develops east and the main upper wave ejects into the region around 00-03z. Warm advection and southerly low-level flow ahead of the front will allow for modest airmass modification into the Midwest. However, forecast dewpoints are only expected to reach into the 50s to near 60 F. Nevertheless, a plume of steep midlevel lapse rates will overspread the IL/IN/MI/OH vicinity from afternoon into the evening. This will support modest destabilization with MLCAPE generally forecast to be less than 1000 J/kg, though a narrow corridor of up to 1500 J/kg MLCAPE may be possible for a brief period around 00z. Forecast soundings across the region indicate most of available instability will be located above the 850-700 mb layer. Initial thunderstorm activity may be slightly elevated as some forecast soundings indicate a warm nose between 850-700 mb during late afternoon/early evening. Nevertheless, effective shear greater than 50 kt, and enlarged low-level hodographs becoming elongated above 3 km indicate initial supercells will be possible near the quasi-warm front/moisture gradient from northeast IL into northern IN and vicinity. With most instability focused above the 850-700 mb layer, and in conjunction with poor boundary-layer dewpoints, the tornado risk may be somewhat lower than typically expected given shear profiles in the 0-2 km layer. Nevertheless a couple tornadoes are possible, especially if greater moisture than forecast can make it this far north. Large hail, with a few instances near 2 inch diameter, will be possible with any semi-discrete supercells, along with damaging gusts. Once linear forcing along the front increases in the 00-03z period, a line of storms is forecast to develop east from the Mid-MS Valley toward the Lower OH Valley during the nighttime hours. Damaging gusts will be the main concern with this activity. ..Leitman.. 02/26/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST-CENTRAL MISSOURI INTO ILLINOIS...INDIANA...NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some near 2 inch diameter), damaging gusts, and a few tornadoes will be possible from late Tuesday afternoon, into the evening and overnight from parts of the mid Mississippi Valley, and southwestern Great Lakes. ...Mid-MS Valley/Southwest Great Lakes Vicinity... An upper trough over the northern Rockies/Intermountain West will shift east on Tuesday, becoming oriented from the Upper MS Valley and Mid-MO Valley by Wednesday morning. Fast deep-layer southwesterly flow ahead of this feature will overspread the Ozark Plateau into the Great Lakes. At the surface, a low will deepen as it shifts east from MN toward southern Ontario. A cold front attendant to the low will quickly shift east/southeast across the Plains and the Mid/Upper MS Valley during the afternoon and into the overnight period. Initial thunderstorm activity may develop in warm advection regime near the quasi-warm front/moisture gradient from northern IL into IN/NW OH/southern MI around 21-00z. Additional activity will then develop along the cold front as it develops east and the main upper wave ejects into the region around 00-03z. Warm advection and southerly low-level flow ahead of the front will allow for modest airmass modification into the Midwest. However, forecast dewpoints are only expected to reach into the 50s to near 60 F. Nevertheless, a plume of steep midlevel lapse rates will overspread the IL/IN/MI/OH vicinity from afternoon into the evening. This will support modest destabilization with MLCAPE generally forecast to be less than 1000 J/kg, though a narrow corridor of up to 1500 J/kg MLCAPE may be possible for a brief period around 00z. Forecast soundings across the region indicate most of available instability will be located above the 850-700 mb layer. Initial thunderstorm activity may be slightly elevated as some forecast soundings indicate a warm nose between 850-700 mb during late afternoon/early evening. Nevertheless, effective shear greater than 50 kt, and enlarged low-level hodographs becoming elongated above 3 km indicate initial supercells will be possible near the quasi-warm front/moisture gradient from northeast IL into northern IN and vicinity. With most instability focused above the 850-700 mb layer, and in conjunction with poor boundary-layer dewpoints, the tornado risk may be somewhat lower than typically expected given shear profiles in the 0-2 km layer. Nevertheless a couple tornadoes are possible, especially if greater moisture than forecast can make it this far north. Large hail, with a few instances near 2 inch diameter, will be possible with any semi-discrete supercells, along with damaging gusts. Once linear forcing along the front increases in the 00-03z period, a line of storms is forecast to develop east from the Mid-MS Valley toward the Lower OH Valley during the nighttime hours. Damaging gusts will be the main concern with this activity. ..Leitman.. 02/26/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST-CENTRAL MISSOURI INTO ILLINOIS...INDIANA...NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some near 2 inch diameter), damaging gusts, and a few tornadoes will be possible from late Tuesday afternoon, into the evening and overnight from parts of the mid Mississippi Valley, and southwestern Great Lakes. ...Mid-MS Valley/Southwest Great Lakes Vicinity... An upper trough over the northern Rockies/Intermountain West will shift east on Tuesday, becoming oriented from the Upper MS Valley and Mid-MO Valley by Wednesday morning. Fast deep-layer southwesterly flow ahead of this feature will overspread the Ozark Plateau into the Great Lakes. At the surface, a low will deepen as it shifts east from MN toward southern Ontario. A cold front attendant to the low will quickly shift east/southeast across the Plains and the Mid/Upper MS Valley during the afternoon and into the overnight period. Initial thunderstorm activity may develop in warm advection regime near the quasi-warm front/moisture gradient from northern IL into IN/NW OH/southern MI around 21-00z. Additional activity will then develop along the cold front as it develops east and the main upper wave ejects into the region around 00-03z. Warm advection and southerly low-level flow ahead of the front will allow for modest airmass modification into the Midwest. However, forecast dewpoints are only expected to reach into the 50s to near 60 F. Nevertheless, a plume of steep midlevel lapse rates will overspread the IL/IN/MI/OH vicinity from afternoon into the evening. This will support modest destabilization with MLCAPE generally forecast to be less than 1000 J/kg, though a narrow corridor of up to 1500 J/kg MLCAPE may be possible for a brief period around 00z. Forecast soundings across the region indicate most of available instability will be located above the 850-700 mb layer. Initial thunderstorm activity may be slightly elevated as some forecast soundings indicate a warm nose between 850-700 mb during late afternoon/early evening. Nevertheless, effective shear greater than 50 kt, and enlarged low-level hodographs becoming elongated above 3 km indicate initial supercells will be possible near the quasi-warm front/moisture gradient from northeast IL into northern IN and vicinity. With most instability focused above the 850-700 mb layer, and in conjunction with poor boundary-layer dewpoints, the tornado risk may be somewhat lower than typically expected given shear profiles in the 0-2 km layer. Nevertheless a couple tornadoes are possible, especially if greater moisture than forecast can make it this far north. Large hail, with a few instances near 2 inch diameter, will be possible with any semi-discrete supercells, along with damaging gusts. Once linear forcing along the front increases in the 00-03z period, a line of storms is forecast to develop east from the Mid-MS Valley toward the Lower OH Valley during the nighttime hours. Damaging gusts will be the main concern with this activity. ..Leitman.. 02/26/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST-CENTRAL MISSOURI INTO ILLINOIS...INDIANA...NORTHWEST OHIO AND SOUTHERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some near 2 inch diameter), damaging gusts, and a few tornadoes will be possible from late Tuesday afternoon, into the evening and overnight from parts of the mid Mississippi Valley, and southwestern Great Lakes. ...Mid-MS Valley/Southwest Great Lakes Vicinity... An upper trough over the northern Rockies/Intermountain West will shift east on Tuesday, becoming oriented from the Upper MS Valley and Mid-MO Valley by Wednesday morning. Fast deep-layer southwesterly flow ahead of this feature will overspread the Ozark Plateau into the Great Lakes. At the surface, a low will deepen as it shifts east from MN toward southern Ontario. A cold front attendant to the low will quickly shift east/southeast across the Plains and the Mid/Upper MS Valley during the afternoon and into the overnight period. Initial thunderstorm activity may develop in warm advection regime near the quasi-warm front/moisture gradient from northern IL into IN/NW OH/southern MI around 21-00z. Additional activity will then develop along the cold front as it develops east and the main upper wave ejects into the region around 00-03z. Warm advection and southerly low-level flow ahead of the front will allow for modest airmass modification into the Midwest. However, forecast dewpoints are only expected to reach into the 50s to near 60 F. Nevertheless, a plume of steep midlevel lapse rates will overspread the IL/IN/MI/OH vicinity from afternoon into the evening. This will support modest destabilization with MLCAPE generally forecast to be less than 1000 J/kg, though a narrow corridor of up to 1500 J/kg MLCAPE may be possible for a brief period around 00z. Forecast soundings across the region indicate most of available instability will be located above the 850-700 mb layer. Initial thunderstorm activity may be slightly elevated as some forecast soundings indicate a warm nose between 850-700 mb during late afternoon/early evening. Nevertheless, effective shear greater than 50 kt, and enlarged low-level hodographs becoming elongated above 3 km indicate initial supercells will be possible near the quasi-warm front/moisture gradient from northeast IL into northern IN and vicinity. With most instability focused above the 850-700 mb layer, and in conjunction with poor boundary-layer dewpoints, the tornado risk may be somewhat lower than typically expected given shear profiles in the 0-2 km layer. Nevertheless a couple tornadoes are possible, especially if greater moisture than forecast can make it this far north. Large hail, with a few instances near 2 inch diameter, will be possible with any semi-discrete supercells, along with damaging gusts. Once linear forcing along the front increases in the 00-03z period, a line of storms is forecast to develop east from the Mid-MS Valley toward the Lower OH Valley during the nighttime hours. Damaging gusts will be the main concern with this activity. ..Leitman.. 02/26/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 PM CST Sun Feb 25 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GREAT LAKES REGION... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Central Great Lakes Region... Strong northern-stream trough will dig southeast into the Great Basin by the end of the period. This evolution will suppress the height fields across most of the western US, and some coupling with the southern branch should occur over the southern Rockies region by 27/12z. Several low-amplitude disturbances will eject northeast within the southern current into the mid MS Valley region during the overnight hours. One of these features is expected to encourage significant strengthening of the LLJ across IN/lower MI by midnight. Late this evening, PW values remain seasonally low across most of the CONUS, with only a small region of near-1" values observed across deep south TX. While significant moisture is not expected to surge particularly fast toward high latitudes, sustained southerly low-level flow will permit gradual moistening across the MS Valley, and 1" PW values may approach central IN by midnight. Additionally, very steep midlevel lapse rates will be noted as this moisture advances north. Forecast soundings show substantial moistening at 850mb into this region which results in MUCAPE values exceeding 1500 J/kg where dew points are able to rise to near 8 C. Scattered convection should develop in response to the approaching disturbance and increasing LLJ, most likely after midnight. Some organization appears possible given the shear, and perhaps a few weak supercells may develop. If so, some risk for hail around 1" appears possible with the strongest updrafts. ..Darrow/Lyons.. 02/26/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 PM CST Sun Feb 25 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GREAT LAKES REGION... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Central Great Lakes Region... Strong northern-stream trough will dig southeast into the Great Basin by the end of the period. This evolution will suppress the height fields across most of the western US, and some coupling with the southern branch should occur over the southern Rockies region by 27/12z. Several low-amplitude disturbances will eject northeast within the southern current into the mid MS Valley region during the overnight hours. One of these features is expected to encourage significant strengthening of the LLJ across IN/lower MI by midnight. Late this evening, PW values remain seasonally low across most of the CONUS, with only a small region of near-1" values observed across deep south TX. While significant moisture is not expected to surge particularly fast toward high latitudes, sustained southerly low-level flow will permit gradual moistening across the MS Valley, and 1" PW values may approach central IN by midnight. Additionally, very steep midlevel lapse rates will be noted as this moisture advances north. Forecast soundings show substantial moistening at 850mb into this region which results in MUCAPE values exceeding 1500 J/kg where dew points are able to rise to near 8 C. Scattered convection should develop in response to the approaching disturbance and increasing LLJ, most likely after midnight. Some organization appears possible given the shear, and perhaps a few weak supercells may develop. If so, some risk for hail around 1" appears possible with the strongest updrafts. ..Darrow/Lyons.. 02/26/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 PM CST Sun Feb 25 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GREAT LAKES REGION... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Central Great Lakes Region... Strong northern-stream trough will dig southeast into the Great Basin by the end of the period. This evolution will suppress the height fields across most of the western US, and some coupling with the southern branch should occur over the southern Rockies region by 27/12z. Several low-amplitude disturbances will eject northeast within the southern current into the mid MS Valley region during the overnight hours. One of these features is expected to encourage significant strengthening of the LLJ across IN/lower MI by midnight. Late this evening, PW values remain seasonally low across most of the CONUS, with only a small region of near-1" values observed across deep south TX. While significant moisture is not expected to surge particularly fast toward high latitudes, sustained southerly low-level flow will permit gradual moistening across the MS Valley, and 1" PW values may approach central IN by midnight. Additionally, very steep midlevel lapse rates will be noted as this moisture advances north. Forecast soundings show substantial moistening at 850mb into this region which results in MUCAPE values exceeding 1500 J/kg where dew points are able to rise to near 8 C. Scattered convection should develop in response to the approaching disturbance and increasing LLJ, most likely after midnight. Some organization appears possible given the shear, and perhaps a few weak supercells may develop. If so, some risk for hail around 1" appears possible with the strongest updrafts. ..Darrow/Lyons.. 02/26/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 PM CST Sun Feb 25 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GREAT LAKES REGION... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Central Great Lakes Region... Strong northern-stream trough will dig southeast into the Great Basin by the end of the period. This evolution will suppress the height fields across most of the western US, and some coupling with the southern branch should occur over the southern Rockies region by 27/12z. Several low-amplitude disturbances will eject northeast within the southern current into the mid MS Valley region during the overnight hours. One of these features is expected to encourage significant strengthening of the LLJ across IN/lower MI by midnight. Late this evening, PW values remain seasonally low across most of the CONUS, with only a small region of near-1" values observed across deep south TX. While significant moisture is not expected to surge particularly fast toward high latitudes, sustained southerly low-level flow will permit gradual moistening across the MS Valley, and 1" PW values may approach central IN by midnight. Additionally, very steep midlevel lapse rates will be noted as this moisture advances north. Forecast soundings show substantial moistening at 850mb into this region which results in MUCAPE values exceeding 1500 J/kg where dew points are able to rise to near 8 C. Scattered convection should develop in response to the approaching disturbance and increasing LLJ, most likely after midnight. Some organization appears possible given the shear, and perhaps a few weak supercells may develop. If so, some risk for hail around 1" appears possible with the strongest updrafts. ..Darrow/Lyons.. 02/26/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 PM CST Sun Feb 25 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GREAT LAKES REGION... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Central Great Lakes Region... Strong northern-stream trough will dig southeast into the Great Basin by the end of the period. This evolution will suppress the height fields across most of the western US, and some coupling with the southern branch should occur over the southern Rockies region by 27/12z. Several low-amplitude disturbances will eject northeast within the southern current into the mid MS Valley region during the overnight hours. One of these features is expected to encourage significant strengthening of the LLJ across IN/lower MI by midnight. Late this evening, PW values remain seasonally low across most of the CONUS, with only a small region of near-1" values observed across deep south TX. While significant moisture is not expected to surge particularly fast toward high latitudes, sustained southerly low-level flow will permit gradual moistening across the MS Valley, and 1" PW values may approach central IN by midnight. Additionally, very steep midlevel lapse rates will be noted as this moisture advances north. Forecast soundings show substantial moistening at 850mb into this region which results in MUCAPE values exceeding 1500 J/kg where dew points are able to rise to near 8 C. Scattered convection should develop in response to the approaching disturbance and increasing LLJ, most likely after midnight. Some organization appears possible given the shear, and perhaps a few weak supercells may develop. If so, some risk for hail around 1" appears possible with the strongest updrafts. ..Darrow/Lyons.. 02/26/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 PM CST Sun Feb 25 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GREAT LAKES REGION... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Central Great Lakes Region... Strong northern-stream trough will dig southeast into the Great Basin by the end of the period. This evolution will suppress the height fields across most of the western US, and some coupling with the southern branch should occur over the southern Rockies region by 27/12z. Several low-amplitude disturbances will eject northeast within the southern current into the mid MS Valley region during the overnight hours. One of these features is expected to encourage significant strengthening of the LLJ across IN/lower MI by midnight. Late this evening, PW values remain seasonally low across most of the CONUS, with only a small region of near-1" values observed across deep south TX. While significant moisture is not expected to surge particularly fast toward high latitudes, sustained southerly low-level flow will permit gradual moistening across the MS Valley, and 1" PW values may approach central IN by midnight. Additionally, very steep midlevel lapse rates will be noted as this moisture advances north. Forecast soundings show substantial moistening at 850mb into this region which results in MUCAPE values exceeding 1500 J/kg where dew points are able to rise to near 8 C. Scattered convection should develop in response to the approaching disturbance and increasing LLJ, most likely after midnight. Some organization appears possible given the shear, and perhaps a few weak supercells may develop. If so, some risk for hail around 1" appears possible with the strongest updrafts. ..Darrow/Lyons.. 02/26/2024 Read more