Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1033 AM CST Mon Feb 26 2024 Valid 261700Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE SOUTHERN AND CENTRAL HIGH PLAINS... Minor adjustments were made to the Elevated area based on the most recent guidance. At least briefly elevated to near-critical fire weather is possible in parts of Missouri, eastern Iowa, and Illinois. Given the expected short duration and generally marginal fuels, no highlights will be added. ..Wendt.. 02/26/2024 .PREV DISCUSSION... /ISSUED 0201 AM CST Mon Feb 26 2024/ ...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. ...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 1033 AM CST Mon Feb 26 2024 Valid 261700Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE SOUTHERN AND CENTRAL HIGH PLAINS... Minor adjustments were made to the Elevated area based on the most recent guidance. At least briefly elevated to near-critical fire weather is possible in parts of Missouri, eastern Iowa, and Illinois. Given the expected short duration and generally marginal fuels, no highlights will be added. ..Wendt.. 02/26/2024 .PREV DISCUSSION... /ISSUED 0201 AM CST Mon Feb 26 2024/ ...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. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Mon Feb 26 2024 Valid 261630Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE OHIO VALLEY AND GREAT LAKES... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A mid-level trough will dig across the Pacific Northwest today with a mostly zonal mid-level pattern across the eastern CONUS. Within that zonal flow, a weak shortwave trough is forecast to move through the Great Lakes/Ohio Valley late tonight and could result in some thunderstorms capable of large hail. A gradual strengthening of the low-level jet is anticipated through the day today from the Ohio Valley into the Great Lakes as a mid-level trough advances eastward. This will lead to poleward moisture transport centered around 850mb. This moist plume combined with very steep (8-8.5 C/km) mid-level lapse rates will lead to increasing elevated instability during the overnight period. Convective initiation remains the primary question during the overnight period. A trough is present at both 850mb and 500mb in 12Z guidance, but they are not quite phased. This leads to weakening/veering 850mb flow during the period when height falls and 500mb dCVA arrives across the region. This is likely an explanatory factor for the lack of storm coverage by most CAM guidance. Nonetheless, global guidance continues to show significant convective precipitation from southern Michigan to northern Tennessee. Given 1000 to 2000 J/kg MUCAPE and effective shear of 45-50 knots (highest across southern Indiana), a conditional threat for elevated supercells capable of large hail exists tonight. Have expanded the marginal risk farther south in Indiana to account for this threat. It is worth mentioning there is at least some threat farther south into Kentucky where strong instability and shear are present which would support supercells also. However, have confined the marginal risk to areas where better mid-level support is expected early Tuesday morning. ..Bentley.. 02/26/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Mon Feb 26 2024 Valid 261630Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE OHIO VALLEY AND GREAT LAKES... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A mid-level trough will dig across the Pacific Northwest today with a mostly zonal mid-level pattern across the eastern CONUS. Within that zonal flow, a weak shortwave trough is forecast to move through the Great Lakes/Ohio Valley late tonight and could result in some thunderstorms capable of large hail. A gradual strengthening of the low-level jet is anticipated through the day today from the Ohio Valley into the Great Lakes as a mid-level trough advances eastward. This will lead to poleward moisture transport centered around 850mb. This moist plume combined with very steep (8-8.5 C/km) mid-level lapse rates will lead to increasing elevated instability during the overnight period. Convective initiation remains the primary question during the overnight period. A trough is present at both 850mb and 500mb in 12Z guidance, but they are not quite phased. This leads to weakening/veering 850mb flow during the period when height falls and 500mb dCVA arrives across the region. This is likely an explanatory factor for the lack of storm coverage by most CAM guidance. Nonetheless, global guidance continues to show significant convective precipitation from southern Michigan to northern Tennessee. Given 1000 to 2000 J/kg MUCAPE and effective shear of 45-50 knots (highest across southern Indiana), a conditional threat for elevated supercells capable of large hail exists tonight. Have expanded the marginal risk farther south in Indiana to account for this threat. It is worth mentioning there is at least some threat farther south into Kentucky where strong instability and shear are present which would support supercells also. However, have confined the marginal risk to areas where better mid-level support is expected early Tuesday morning. ..Bentley.. 02/26/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Mon Feb 26 2024 Valid 261630Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE OHIO VALLEY AND GREAT LAKES... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A mid-level trough will dig across the Pacific Northwest today with a mostly zonal mid-level pattern across the eastern CONUS. Within that zonal flow, a weak shortwave trough is forecast to move through the Great Lakes/Ohio Valley late tonight and could result in some thunderstorms capable of large hail. A gradual strengthening of the low-level jet is anticipated through the day today from the Ohio Valley into the Great Lakes as a mid-level trough advances eastward. This will lead to poleward moisture transport centered around 850mb. This moist plume combined with very steep (8-8.5 C/km) mid-level lapse rates will lead to increasing elevated instability during the overnight period. Convective initiation remains the primary question during the overnight period. A trough is present at both 850mb and 500mb in 12Z guidance, but they are not quite phased. This leads to weakening/veering 850mb flow during the period when height falls and 500mb dCVA arrives across the region. This is likely an explanatory factor for the lack of storm coverage by most CAM guidance. Nonetheless, global guidance continues to show significant convective precipitation from southern Michigan to northern Tennessee. Given 1000 to 2000 J/kg MUCAPE and effective shear of 45-50 knots (highest across southern Indiana), a conditional threat for elevated supercells capable of large hail exists tonight. Have expanded the marginal risk farther south in Indiana to account for this threat. It is worth mentioning there is at least some threat farther south into Kentucky where strong instability and shear are present which would support supercells also. However, have confined the marginal risk to areas where better mid-level support is expected early Tuesday morning. ..Bentley.. 02/26/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Mon Feb 26 2024 Valid 261630Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE OHIO VALLEY AND GREAT LAKES... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A mid-level trough will dig across the Pacific Northwest today with a mostly zonal mid-level pattern across the eastern CONUS. Within that zonal flow, a weak shortwave trough is forecast to move through the Great Lakes/Ohio Valley late tonight and could result in some thunderstorms capable of large hail. A gradual strengthening of the low-level jet is anticipated through the day today from the Ohio Valley into the Great Lakes as a mid-level trough advances eastward. This will lead to poleward moisture transport centered around 850mb. This moist plume combined with very steep (8-8.5 C/km) mid-level lapse rates will lead to increasing elevated instability during the overnight period. Convective initiation remains the primary question during the overnight period. A trough is present at both 850mb and 500mb in 12Z guidance, but they are not quite phased. This leads to weakening/veering 850mb flow during the period when height falls and 500mb dCVA arrives across the region. This is likely an explanatory factor for the lack of storm coverage by most CAM guidance. Nonetheless, global guidance continues to show significant convective precipitation from southern Michigan to northern Tennessee. Given 1000 to 2000 J/kg MUCAPE and effective shear of 45-50 knots (highest across southern Indiana), a conditional threat for elevated supercells capable of large hail exists tonight. Have expanded the marginal risk farther south in Indiana to account for this threat. It is worth mentioning there is at least some threat farther south into Kentucky where strong instability and shear are present which would support supercells also. However, have confined the marginal risk to areas where better mid-level support is expected early Tuesday morning. ..Bentley.. 02/26/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Mon Feb 26 2024 Valid 261630Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE OHIO VALLEY AND GREAT LAKES... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A mid-level trough will dig across the Pacific Northwest today with a mostly zonal mid-level pattern across the eastern CONUS. Within that zonal flow, a weak shortwave trough is forecast to move through the Great Lakes/Ohio Valley late tonight and could result in some thunderstorms capable of large hail. A gradual strengthening of the low-level jet is anticipated through the day today from the Ohio Valley into the Great Lakes as a mid-level trough advances eastward. This will lead to poleward moisture transport centered around 850mb. This moist plume combined with very steep (8-8.5 C/km) mid-level lapse rates will lead to increasing elevated instability during the overnight period. Convective initiation remains the primary question during the overnight period. A trough is present at both 850mb and 500mb in 12Z guidance, but they are not quite phased. This leads to weakening/veering 850mb flow during the period when height falls and 500mb dCVA arrives across the region. This is likely an explanatory factor for the lack of storm coverage by most CAM guidance. Nonetheless, global guidance continues to show significant convective precipitation from southern Michigan to northern Tennessee. Given 1000 to 2000 J/kg MUCAPE and effective shear of 45-50 knots (highest across southern Indiana), a conditional threat for elevated supercells capable of large hail exists tonight. Have expanded the marginal risk farther south in Indiana to account for this threat. It is worth mentioning there is at least some threat farther south into Kentucky where strong instability and shear are present which would support supercells also. However, have confined the marginal risk to areas where better mid-level support is expected early Tuesday morning. ..Bentley.. 02/26/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Mon Feb 26 2024 Valid 261630Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE OHIO VALLEY AND GREAT LAKES... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A mid-level trough will dig across the Pacific Northwest today with a mostly zonal mid-level pattern across the eastern CONUS. Within that zonal flow, a weak shortwave trough is forecast to move through the Great Lakes/Ohio Valley late tonight and could result in some thunderstorms capable of large hail. A gradual strengthening of the low-level jet is anticipated through the day today from the Ohio Valley into the Great Lakes as a mid-level trough advances eastward. This will lead to poleward moisture transport centered around 850mb. This moist plume combined with very steep (8-8.5 C/km) mid-level lapse rates will lead to increasing elevated instability during the overnight period. Convective initiation remains the primary question during the overnight period. A trough is present at both 850mb and 500mb in 12Z guidance, but they are not quite phased. This leads to weakening/veering 850mb flow during the period when height falls and 500mb dCVA arrives across the region. This is likely an explanatory factor for the lack of storm coverage by most CAM guidance. Nonetheless, global guidance continues to show significant convective precipitation from southern Michigan to northern Tennessee. Given 1000 to 2000 J/kg MUCAPE and effective shear of 45-50 knots (highest across southern Indiana), a conditional threat for elevated supercells capable of large hail exists tonight. Have expanded the marginal risk farther south in Indiana to account for this threat. It is worth mentioning there is at least some threat farther south into Kentucky where strong instability and shear are present which would support supercells also. However, have confined the marginal risk to areas where better mid-level support is expected early Tuesday morning. ..Bentley.. 02/26/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Mon Feb 26 2024 Valid 261630Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE OHIO VALLEY AND GREAT LAKES... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A mid-level trough will dig across the Pacific Northwest today with a mostly zonal mid-level pattern across the eastern CONUS. Within that zonal flow, a weak shortwave trough is forecast to move through the Great Lakes/Ohio Valley late tonight and could result in some thunderstorms capable of large hail. A gradual strengthening of the low-level jet is anticipated through the day today from the Ohio Valley into the Great Lakes as a mid-level trough advances eastward. This will lead to poleward moisture transport centered around 850mb. This moist plume combined with very steep (8-8.5 C/km) mid-level lapse rates will lead to increasing elevated instability during the overnight period. Convective initiation remains the primary question during the overnight period. A trough is present at both 850mb and 500mb in 12Z guidance, but they are not quite phased. This leads to weakening/veering 850mb flow during the period when height falls and 500mb dCVA arrives across the region. This is likely an explanatory factor for the lack of storm coverage by most CAM guidance. Nonetheless, global guidance continues to show significant convective precipitation from southern Michigan to northern Tennessee. Given 1000 to 2000 J/kg MUCAPE and effective shear of 45-50 knots (highest across southern Indiana), a conditional threat for elevated supercells capable of large hail exists tonight. Have expanded the marginal risk farther south in Indiana to account for this threat. It is worth mentioning there is at least some threat farther south into Kentucky where strong instability and shear are present which would support supercells also. However, have confined the marginal risk to areas where better mid-level support is expected early Tuesday morning. ..Bentley.. 02/26/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0650 AM CST Mon Feb 26 2024 Valid 261300Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF LOWER MICHIGAN...INDIANA...AND OHIO... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A primarily zonal mid-level flow field in place across much of the U.S. today will gradually amplify through tonight, as a trough digs southeastward across the northwestern quarter of the country. As this occurs, a cold front oriented east-northeast to west-southwest is forecast to advance southeastward across the northern half of the Intermountain West and, later, the northern Plains through Tuesday morning. Elsewhere, a rather nondescript surface pattern will prevail. ...Parts of Indiana/Ohio/Lower Michigan... As a lead/subtle mid-level short-wave trough shifts across the Midwest tonight, some strengthening of a southwesterly low-level jet is expected across this region. Resulting quasi-geostrophic ascent may support development of showers and isolated thunderstorms, atop a stable lower troposphere where steep mid-level lapse rates may support upwards of 1000 to 1500 J/kg CAPE through the cloud-bearing layer. With moderately strong mid-level west-southwesterly flow accompanying the short-wave trough, shear sufficient for mid-level updraft rotation is evident. With that said, model guidance -- both parameterized and convection-allowing -- in general indicates minimal overall convective development, in part due to questions regarding potential for ample moist advection/saturation above the inversion so as to support deep convective development. Still, presuming a few deeper convective cells can become organized/sustained tonight, severe-caliber hail would be possible. ..Goss/Broyles.. 02/26/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0650 AM CST Mon Feb 26 2024 Valid 261300Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF LOWER MICHIGAN...INDIANA...AND OHIO... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A primarily zonal mid-level flow field in place across much of the U.S. today will gradually amplify through tonight, as a trough digs southeastward across the northwestern quarter of the country. As this occurs, a cold front oriented east-northeast to west-southwest is forecast to advance southeastward across the northern half of the Intermountain West and, later, the northern Plains through Tuesday morning. Elsewhere, a rather nondescript surface pattern will prevail. ...Parts of Indiana/Ohio/Lower Michigan... As a lead/subtle mid-level short-wave trough shifts across the Midwest tonight, some strengthening of a southwesterly low-level jet is expected across this region. Resulting quasi-geostrophic ascent may support development of showers and isolated thunderstorms, atop a stable lower troposphere where steep mid-level lapse rates may support upwards of 1000 to 1500 J/kg CAPE through the cloud-bearing layer. With moderately strong mid-level west-southwesterly flow accompanying the short-wave trough, shear sufficient for mid-level updraft rotation is evident. With that said, model guidance -- both parameterized and convection-allowing -- in general indicates minimal overall convective development, in part due to questions regarding potential for ample moist advection/saturation above the inversion so as to support deep convective development. Still, presuming a few deeper convective cells can become organized/sustained tonight, severe-caliber hail would be possible. ..Goss/Broyles.. 02/26/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0650 AM CST Mon Feb 26 2024 Valid 261300Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF LOWER MICHIGAN...INDIANA...AND OHIO... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A primarily zonal mid-level flow field in place across much of the U.S. today will gradually amplify through tonight, as a trough digs southeastward across the northwestern quarter of the country. As this occurs, a cold front oriented east-northeast to west-southwest is forecast to advance southeastward across the northern half of the Intermountain West and, later, the northern Plains through Tuesday morning. Elsewhere, a rather nondescript surface pattern will prevail. ...Parts of Indiana/Ohio/Lower Michigan... As a lead/subtle mid-level short-wave trough shifts across the Midwest tonight, some strengthening of a southwesterly low-level jet is expected across this region. Resulting quasi-geostrophic ascent may support development of showers and isolated thunderstorms, atop a stable lower troposphere where steep mid-level lapse rates may support upwards of 1000 to 1500 J/kg CAPE through the cloud-bearing layer. With moderately strong mid-level west-southwesterly flow accompanying the short-wave trough, shear sufficient for mid-level updraft rotation is evident. With that said, model guidance -- both parameterized and convection-allowing -- in general indicates minimal overall convective development, in part due to questions regarding potential for ample moist advection/saturation above the inversion so as to support deep convective development. Still, presuming a few deeper convective cells can become organized/sustained tonight, severe-caliber hail would be possible. ..Goss/Broyles.. 02/26/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0650 AM CST Mon Feb 26 2024 Valid 261300Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF LOWER MICHIGAN...INDIANA...AND OHIO... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A primarily zonal mid-level flow field in place across much of the U.S. today will gradually amplify through tonight, as a trough digs southeastward across the northwestern quarter of the country. As this occurs, a cold front oriented east-northeast to west-southwest is forecast to advance southeastward across the northern half of the Intermountain West and, later, the northern Plains through Tuesday morning. Elsewhere, a rather nondescript surface pattern will prevail. ...Parts of Indiana/Ohio/Lower Michigan... As a lead/subtle mid-level short-wave trough shifts across the Midwest tonight, some strengthening of a southwesterly low-level jet is expected across this region. Resulting quasi-geostrophic ascent may support development of showers and isolated thunderstorms, atop a stable lower troposphere where steep mid-level lapse rates may support upwards of 1000 to 1500 J/kg CAPE through the cloud-bearing layer. With moderately strong mid-level west-southwesterly flow accompanying the short-wave trough, shear sufficient for mid-level updraft rotation is evident. With that said, model guidance -- both parameterized and convection-allowing -- in general indicates minimal overall convective development, in part due to questions regarding potential for ample moist advection/saturation above the inversion so as to support deep convective development. Still, presuming a few deeper convective cells can become organized/sustained tonight, severe-caliber hail would be possible. ..Goss/Broyles.. 02/26/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0650 AM CST Mon Feb 26 2024 Valid 261300Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF LOWER MICHIGAN...INDIANA...AND OHIO... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A primarily zonal mid-level flow field in place across much of the U.S. today will gradually amplify through tonight, as a trough digs southeastward across the northwestern quarter of the country. As this occurs, a cold front oriented east-northeast to west-southwest is forecast to advance southeastward across the northern half of the Intermountain West and, later, the northern Plains through Tuesday morning. Elsewhere, a rather nondescript surface pattern will prevail. ...Parts of Indiana/Ohio/Lower Michigan... As a lead/subtle mid-level short-wave trough shifts across the Midwest tonight, some strengthening of a southwesterly low-level jet is expected across this region. Resulting quasi-geostrophic ascent may support development of showers and isolated thunderstorms, atop a stable lower troposphere where steep mid-level lapse rates may support upwards of 1000 to 1500 J/kg CAPE through the cloud-bearing layer. With moderately strong mid-level west-southwesterly flow accompanying the short-wave trough, shear sufficient for mid-level updraft rotation is evident. With that said, model guidance -- both parameterized and convection-allowing -- in general indicates minimal overall convective development, in part due to questions regarding potential for ample moist advection/saturation above the inversion so as to support deep convective development. Still, presuming a few deeper convective cells can become organized/sustained tonight, severe-caliber hail would be possible. ..Goss/Broyles.. 02/26/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0650 AM CST Mon Feb 26 2024 Valid 261300Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF LOWER MICHIGAN...INDIANA...AND OHIO... ...SUMMARY... Isolated late-night hail is possible across portions of the central Great Lakes region. ...Synopsis... A primarily zonal mid-level flow field in place across much of the U.S. today will gradually amplify through tonight, as a trough digs southeastward across the northwestern quarter of the country. As this occurs, a cold front oriented east-northeast to west-southwest is forecast to advance southeastward across the northern half of the Intermountain West and, later, the northern Plains through Tuesday morning. Elsewhere, a rather nondescript surface pattern will prevail. ...Parts of Indiana/Ohio/Lower Michigan... As a lead/subtle mid-level short-wave trough shifts across the Midwest tonight, some strengthening of a southwesterly low-level jet is expected across this region. Resulting quasi-geostrophic ascent may support development of showers and isolated thunderstorms, atop a stable lower troposphere where steep mid-level lapse rates may support upwards of 1000 to 1500 J/kg CAPE through the cloud-bearing layer. With moderately strong mid-level west-southwesterly flow accompanying the short-wave trough, shear sufficient for mid-level updraft rotation is evident. With that said, model guidance -- both parameterized and convection-allowing -- in general indicates minimal overall convective development, in part due to questions regarding potential for ample moist advection/saturation above the inversion so as to support deep convective development. Still, presuming a few deeper convective cells can become organized/sustained tonight, severe-caliber hail would be possible. ..Goss/Broyles.. 02/26/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CST Mon Feb 26 2024 Valid 291200Z - 051200Z ...DISCUSSION... Severe potential will generally be low through Day 6/Sat. A weak upper shortwave trough will move from the southern Plains through the Southeast Days 4-5/Thu-Fri. However, boundary-layer moisture will remain limited by initially strong surface high pressure behind a cold frontal passage in the Day 3/Wed period. On Day 6/Sat, an upper trough is forecast to dig across the western U.S., emerging into the Plains on Day 7/Sun. As this occurs, southerly low-level flow will develop over the Gulf of Mexico into the Plains in response to a deepening lee cyclone. Low-level moisture will increase across parts of the southern Plains into the Mid-MS Valley through Day 8/Mon as a cold front sweeps eastward. Some increase in severe potential could accompany this system Days 7-8/Sun-Mon from the southern Plains toward the MS Valley. However, uncertainty remains regarding northward extent of quality moisture, and in timing of both surface and upper level features. While confidence currently is too low to include probabilities, they may become necessary in subsequent outlooks. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CST Mon Feb 26 2024 Valid 291200Z - 051200Z ...DISCUSSION... Severe potential will generally be low through Day 6/Sat. A weak upper shortwave trough will move from the southern Plains through the Southeast Days 4-5/Thu-Fri. However, boundary-layer moisture will remain limited by initially strong surface high pressure behind a cold frontal passage in the Day 3/Wed period. On Day 6/Sat, an upper trough is forecast to dig across the western U.S., emerging into the Plains on Day 7/Sun. As this occurs, southerly low-level flow will develop over the Gulf of Mexico into the Plains in response to a deepening lee cyclone. Low-level moisture will increase across parts of the southern Plains into the Mid-MS Valley through Day 8/Mon as a cold front sweeps eastward. Some increase in severe potential could accompany this system Days 7-8/Sun-Mon from the southern Plains toward the MS Valley. However, uncertainty remains regarding northward extent of quality moisture, and in timing of both surface and upper level features. While confidence currently is too low to include probabilities, they may become necessary in subsequent outlooks. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CST Mon Feb 26 2024 Valid 291200Z - 051200Z ...DISCUSSION... Severe potential will generally be low through Day 6/Sat. A weak upper shortwave trough will move from the southern Plains through the Southeast Days 4-5/Thu-Fri. However, boundary-layer moisture will remain limited by initially strong surface high pressure behind a cold frontal passage in the Day 3/Wed period. On Day 6/Sat, an upper trough is forecast to dig across the western U.S., emerging into the Plains on Day 7/Sun. As this occurs, southerly low-level flow will develop over the Gulf of Mexico into the Plains in response to a deepening lee cyclone. Low-level moisture will increase across parts of the southern Plains into the Mid-MS Valley through Day 8/Mon as a cold front sweeps eastward. Some increase in severe potential could accompany this system Days 7-8/Sun-Mon from the southern Plains toward the MS Valley. However, uncertainty remains regarding northward extent of quality moisture, and in timing of both surface and upper level features. While confidence currently is too low to include probabilities, they may become necessary in subsequent outlooks. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CST Mon Feb 26 2024 Valid 291200Z - 051200Z ...DISCUSSION... Severe potential will generally be low through Day 6/Sat. A weak upper shortwave trough will move from the southern Plains through the Southeast Days 4-5/Thu-Fri. However, boundary-layer moisture will remain limited by initially strong surface high pressure behind a cold frontal passage in the Day 3/Wed period. On Day 6/Sat, an upper trough is forecast to dig across the western U.S., emerging into the Plains on Day 7/Sun. As this occurs, southerly low-level flow will develop over the Gulf of Mexico into the Plains in response to a deepening lee cyclone. Low-level moisture will increase across parts of the southern Plains into the Mid-MS Valley through Day 8/Mon as a cold front sweeps eastward. Some increase in severe potential could accompany this system Days 7-8/Sun-Mon from the southern Plains toward the MS Valley. However, uncertainty remains regarding northward extent of quality moisture, and in timing of both surface and upper level features. While confidence currently is too low to include probabilities, they may become necessary in subsequent outlooks. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CST Mon Feb 26 2024 Valid 291200Z - 051200Z ...DISCUSSION... Severe potential will generally be low through Day 6/Sat. A weak upper shortwave trough will move from the southern Plains through the Southeast Days 4-5/Thu-Fri. However, boundary-layer moisture will remain limited by initially strong surface high pressure behind a cold frontal passage in the Day 3/Wed period. On Day 6/Sat, an upper trough is forecast to dig across the western U.S., emerging into the Plains on Day 7/Sun. As this occurs, southerly low-level flow will develop over the Gulf of Mexico into the Plains in response to a deepening lee cyclone. Low-level moisture will increase across parts of the southern Plains into the Mid-MS Valley through Day 8/Mon as a cold front sweeps eastward. Some increase in severe potential could accompany this system Days 7-8/Sun-Mon from the southern Plains toward the MS Valley. However, uncertainty remains regarding northward extent of quality moisture, and in timing of both surface and upper level features. While confidence currently is too low to include probabilities, they may become necessary in subsequent outlooks. Read more