SPC Feb 27, 2024 0700 UTC Day 2 Convective Outlook

1 year 5 months ago
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CST Tue Feb 27 2024 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL APPALACHIANS WEDNESDAY MORNING... ...SUMMARY... Isolated strong to severe thunderstorms will pose a risk of damaging gusts Wednesday morning from eastern Kentucky into far southern Ohio and West Virginia. ...Central Appalachians... A narrow corridor of strongly forced convection will be ongoing Wednesday morning along a cold front from central KY into southeast OH. Strong vertical shear will be present, with a 50-60 kt southwesterly 850 mb jet overspreading the region ahead of the main upper trough over the Great Lakes and Mid-MS Valley. Modest midlevel lapse rates will be in place, though boundary-layer dewpoints generally in the 55-59 F range will largely limit stronger surface-based instability. Still, around 150-400 J/kg MLCAPE is forecast, supporting isolated thunderstorms along the strongly forced line of convection. Background gradient winds will already be strong in the vicinity of the front, but a few convectively enhanced damaging gusts are possible for a few hours during the morning. More focused large-scale ascent will lift northeast with time and instability will generally wane with eastward extent as convection develops eastward through the afternoon. ..Leitman.. 02/27/2024 Read more

SPC Feb 27, 2024 0700 UTC Day 2 Convective Outlook

1 year 5 months ago
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CST Tue Feb 27 2024 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL APPALACHIANS WEDNESDAY MORNING... ...SUMMARY... Isolated strong to severe thunderstorms will pose a risk of damaging gusts Wednesday morning from eastern Kentucky into far southern Ohio and West Virginia. ...Central Appalachians... A narrow corridor of strongly forced convection will be ongoing Wednesday morning along a cold front from central KY into southeast OH. Strong vertical shear will be present, with a 50-60 kt southwesterly 850 mb jet overspreading the region ahead of the main upper trough over the Great Lakes and Mid-MS Valley. Modest midlevel lapse rates will be in place, though boundary-layer dewpoints generally in the 55-59 F range will largely limit stronger surface-based instability. Still, around 150-400 J/kg MLCAPE is forecast, supporting isolated thunderstorms along the strongly forced line of convection. Background gradient winds will already be strong in the vicinity of the front, but a few convectively enhanced damaging gusts are possible for a few hours during the morning. More focused large-scale ascent will lift northeast with time and instability will generally wane with eastward extent as convection develops eastward through the afternoon. ..Leitman.. 02/27/2024 Read more

SPC Feb 27, 2024 0700 UTC Day 2 Convective Outlook

1 year 5 months ago
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CST Tue Feb 27 2024 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL APPALACHIANS WEDNESDAY MORNING... ...SUMMARY... Isolated strong to severe thunderstorms will pose a risk of damaging gusts Wednesday morning from eastern Kentucky into far southern Ohio and West Virginia. ...Central Appalachians... A narrow corridor of strongly forced convection will be ongoing Wednesday morning along a cold front from central KY into southeast OH. Strong vertical shear will be present, with a 50-60 kt southwesterly 850 mb jet overspreading the region ahead of the main upper trough over the Great Lakes and Mid-MS Valley. Modest midlevel lapse rates will be in place, though boundary-layer dewpoints generally in the 55-59 F range will largely limit stronger surface-based instability. Still, around 150-400 J/kg MLCAPE is forecast, supporting isolated thunderstorms along the strongly forced line of convection. Background gradient winds will already be strong in the vicinity of the front, but a few convectively enhanced damaging gusts are possible for a few hours during the morning. More focused large-scale ascent will lift northeast with time and instability will generally wane with eastward extent as convection develops eastward through the afternoon. ..Leitman.. 02/27/2024 Read more

SPC Feb 27, 2024 0600 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1156 PM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID MS AND LOWER OH VALLEYS INTO THE SOUTHERN GREAT LAKES.... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... Low-amplitude, split mid-level flow over much of the central and western CONUS will gradually consolidate and amplify through the forecast period, as a northern-stream shortwave trough merges with strong southwesterly flow from the southern stream. Multiple weak perturbations embedded within the increasingly strong southern-stream flow ahead of the main vort max will aid in deepening a broad surface cyclone along a cold front over the northern Plains. As the surface low and trailing front advance, warm advection will draw limited, but sufficient, moisture northward into the lower OH Valley and Great Lakes. Strong to severe thunderstorms are possible ahead of the low and along the trailing front through early Wednesday. ...Mid MS and Lower OH Valley... Early in the forecast period, isolated to widely scattered thunderstorms may be ongoing within a strong low-level warm advection regime over the lower OH Valley. Ahead of the main surge of deeper surface moisture, these storms are expected to remain primarily elevated through the mid morning. Elevated buoyancy, steep lapse rates and sufficient vertical shear for supercells may support a conditional risk for large hail through mid morning. Continued warm advection should gradually transport upper 50s to low 60s F surface dewpoints northward into parts of southern and central IL, IN and western OH by mid afternoon. A diffuse moisture gradient along a surface pressure trough/weak dryline should become established across western/central IL into far eastern MO by late afternoon. Strong surface heating and confluence along this feature may support isolated convective development by 21-00z across central/northern IL. At the same time, warm advection along an expected differential-heating zone near the nose of the returning surface moisture may allow for scattered thunderstorm development across portions of northern IN, southern lower MI and northwestern OH. Model soundings show moderate MLCAPE (1500-2000 J/kg) and strong effective shear of 40-50 kt favorable for supercells. A prominent EML for February, with lapse rates of 8 C/km, will favor strong updrafts with efficient hail growth and a risk for significant hail. Later in the evening, the approach of the deepening mid-level trough and surface pressure falls ahead of the surface low across northern IL will yield increasing mass response across the warm sector. Model soundings show enlarged low-level hodographs potentially supporting a few tornadoes and damaging gusts. As the cold front and low move eastward, additional storm development is possible along the surface pressure trough and the surging cold front across portions of far eastern MO and southern IL. Uncertainty on storm mode and coverage remains fairly high, with some CAM solutions suggesting more isolated development ahead of the line, while other show mostly linear growth along the front. Regardless, these storms should continue eastward overnight across southern IN, northern KY and into southwestern OH with the potential for hail and damaging gusts. Should more discrete development occur and be maintained ahead of the building squall line, increasingly strong low-level shear (0-1km SRH of 250-400 m2/s2) could support a risk for tornadoes. The severe threat should gradually diminish into Wednesday morning as the frontal squall line pushes eastward into parts of eastern OH and the central Appalachians with decreasing buoyancy. ..Lyons/Darrow.. 02/27/2024 Read more

SPC Feb 27, 2024 0600 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1156 PM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID MS AND LOWER OH VALLEYS INTO THE SOUTHERN GREAT LAKES.... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... Low-amplitude, split mid-level flow over much of the central and western CONUS will gradually consolidate and amplify through the forecast period, as a northern-stream shortwave trough merges with strong southwesterly flow from the southern stream. Multiple weak perturbations embedded within the increasingly strong southern-stream flow ahead of the main vort max will aid in deepening a broad surface cyclone along a cold front over the northern Plains. As the surface low and trailing front advance, warm advection will draw limited, but sufficient, moisture northward into the lower OH Valley and Great Lakes. Strong to severe thunderstorms are possible ahead of the low and along the trailing front through early Wednesday. ...Mid MS and Lower OH Valley... Early in the forecast period, isolated to widely scattered thunderstorms may be ongoing within a strong low-level warm advection regime over the lower OH Valley. Ahead of the main surge of deeper surface moisture, these storms are expected to remain primarily elevated through the mid morning. Elevated buoyancy, steep lapse rates and sufficient vertical shear for supercells may support a conditional risk for large hail through mid morning. Continued warm advection should gradually transport upper 50s to low 60s F surface dewpoints northward into parts of southern and central IL, IN and western OH by mid afternoon. A diffuse moisture gradient along a surface pressure trough/weak dryline should become established across western/central IL into far eastern MO by late afternoon. Strong surface heating and confluence along this feature may support isolated convective development by 21-00z across central/northern IL. At the same time, warm advection along an expected differential-heating zone near the nose of the returning surface moisture may allow for scattered thunderstorm development across portions of northern IN, southern lower MI and northwestern OH. Model soundings show moderate MLCAPE (1500-2000 J/kg) and strong effective shear of 40-50 kt favorable for supercells. A prominent EML for February, with lapse rates of 8 C/km, will favor strong updrafts with efficient hail growth and a risk for significant hail. Later in the evening, the approach of the deepening mid-level trough and surface pressure falls ahead of the surface low across northern IL will yield increasing mass response across the warm sector. Model soundings show enlarged low-level hodographs potentially supporting a few tornadoes and damaging gusts. As the cold front and low move eastward, additional storm development is possible along the surface pressure trough and the surging cold front across portions of far eastern MO and southern IL. Uncertainty on storm mode and coverage remains fairly high, with some CAM solutions suggesting more isolated development ahead of the line, while other show mostly linear growth along the front. Regardless, these storms should continue eastward overnight across southern IN, northern KY and into southwestern OH with the potential for hail and damaging gusts. Should more discrete development occur and be maintained ahead of the building squall line, increasingly strong low-level shear (0-1km SRH of 250-400 m2/s2) could support a risk for tornadoes. The severe threat should gradually diminish into Wednesday morning as the frontal squall line pushes eastward into parts of eastern OH and the central Appalachians with decreasing buoyancy. ..Lyons/Darrow.. 02/27/2024 Read more

SPC Feb 27, 2024 0600 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1156 PM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID MS AND LOWER OH VALLEYS INTO THE SOUTHERN GREAT LAKES.... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... Low-amplitude, split mid-level flow over much of the central and western CONUS will gradually consolidate and amplify through the forecast period, as a northern-stream shortwave trough merges with strong southwesterly flow from the southern stream. Multiple weak perturbations embedded within the increasingly strong southern-stream flow ahead of the main vort max will aid in deepening a broad surface cyclone along a cold front over the northern Plains. As the surface low and trailing front advance, warm advection will draw limited, but sufficient, moisture northward into the lower OH Valley and Great Lakes. Strong to severe thunderstorms are possible ahead of the low and along the trailing front through early Wednesday. ...Mid MS and Lower OH Valley... Early in the forecast period, isolated to widely scattered thunderstorms may be ongoing within a strong low-level warm advection regime over the lower OH Valley. Ahead of the main surge of deeper surface moisture, these storms are expected to remain primarily elevated through the mid morning. Elevated buoyancy, steep lapse rates and sufficient vertical shear for supercells may support a conditional risk for large hail through mid morning. Continued warm advection should gradually transport upper 50s to low 60s F surface dewpoints northward into parts of southern and central IL, IN and western OH by mid afternoon. A diffuse moisture gradient along a surface pressure trough/weak dryline should become established across western/central IL into far eastern MO by late afternoon. Strong surface heating and confluence along this feature may support isolated convective development by 21-00z across central/northern IL. At the same time, warm advection along an expected differential-heating zone near the nose of the returning surface moisture may allow for scattered thunderstorm development across portions of northern IN, southern lower MI and northwestern OH. Model soundings show moderate MLCAPE (1500-2000 J/kg) and strong effective shear of 40-50 kt favorable for supercells. A prominent EML for February, with lapse rates of 8 C/km, will favor strong updrafts with efficient hail growth and a risk for significant hail. Later in the evening, the approach of the deepening mid-level trough and surface pressure falls ahead of the surface low across northern IL will yield increasing mass response across the warm sector. Model soundings show enlarged low-level hodographs potentially supporting a few tornadoes and damaging gusts. As the cold front and low move eastward, additional storm development is possible along the surface pressure trough and the surging cold front across portions of far eastern MO and southern IL. Uncertainty on storm mode and coverage remains fairly high, with some CAM solutions suggesting more isolated development ahead of the line, while other show mostly linear growth along the front. Regardless, these storms should continue eastward overnight across southern IN, northern KY and into southwestern OH with the potential for hail and damaging gusts. Should more discrete development occur and be maintained ahead of the building squall line, increasingly strong low-level shear (0-1km SRH of 250-400 m2/s2) could support a risk for tornadoes. The severe threat should gradually diminish into Wednesday morning as the frontal squall line pushes eastward into parts of eastern OH and the central Appalachians with decreasing buoyancy. ..Lyons/Darrow.. 02/27/2024 Read more

SPC Feb 27, 2024 0600 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1156 PM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID MS AND LOWER OH VALLEYS INTO THE SOUTHERN GREAT LAKES.... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... Low-amplitude, split mid-level flow over much of the central and western CONUS will gradually consolidate and amplify through the forecast period, as a northern-stream shortwave trough merges with strong southwesterly flow from the southern stream. Multiple weak perturbations embedded within the increasingly strong southern-stream flow ahead of the main vort max will aid in deepening a broad surface cyclone along a cold front over the northern Plains. As the surface low and trailing front advance, warm advection will draw limited, but sufficient, moisture northward into the lower OH Valley and Great Lakes. Strong to severe thunderstorms are possible ahead of the low and along the trailing front through early Wednesday. ...Mid MS and Lower OH Valley... Early in the forecast period, isolated to widely scattered thunderstorms may be ongoing within a strong low-level warm advection regime over the lower OH Valley. Ahead of the main surge of deeper surface moisture, these storms are expected to remain primarily elevated through the mid morning. Elevated buoyancy, steep lapse rates and sufficient vertical shear for supercells may support a conditional risk for large hail through mid morning. Continued warm advection should gradually transport upper 50s to low 60s F surface dewpoints northward into parts of southern and central IL, IN and western OH by mid afternoon. A diffuse moisture gradient along a surface pressure trough/weak dryline should become established across western/central IL into far eastern MO by late afternoon. Strong surface heating and confluence along this feature may support isolated convective development by 21-00z across central/northern IL. At the same time, warm advection along an expected differential-heating zone near the nose of the returning surface moisture may allow for scattered thunderstorm development across portions of northern IN, southern lower MI and northwestern OH. Model soundings show moderate MLCAPE (1500-2000 J/kg) and strong effective shear of 40-50 kt favorable for supercells. A prominent EML for February, with lapse rates of 8 C/km, will favor strong updrafts with efficient hail growth and a risk for significant hail. Later in the evening, the approach of the deepening mid-level trough and surface pressure falls ahead of the surface low across northern IL will yield increasing mass response across the warm sector. Model soundings show enlarged low-level hodographs potentially supporting a few tornadoes and damaging gusts. As the cold front and low move eastward, additional storm development is possible along the surface pressure trough and the surging cold front across portions of far eastern MO and southern IL. Uncertainty on storm mode and coverage remains fairly high, with some CAM solutions suggesting more isolated development ahead of the line, while other show mostly linear growth along the front. Regardless, these storms should continue eastward overnight across southern IN, northern KY and into southwestern OH with the potential for hail and damaging gusts. Should more discrete development occur and be maintained ahead of the building squall line, increasingly strong low-level shear (0-1km SRH of 250-400 m2/s2) could support a risk for tornadoes. The severe threat should gradually diminish into Wednesday morning as the frontal squall line pushes eastward into parts of eastern OH and the central Appalachians with decreasing buoyancy. ..Lyons/Darrow.. 02/27/2024 Read more

SPC Feb 27, 2024 0600 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1156 PM CST Mon Feb 26 2024 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID MS AND LOWER OH VALLEYS INTO THE SOUTHERN GREAT LAKES.... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... Low-amplitude, split mid-level flow over much of the central and western CONUS will gradually consolidate and amplify through the forecast period, as a northern-stream shortwave trough merges with strong southwesterly flow from the southern stream. Multiple weak perturbations embedded within the increasingly strong southern-stream flow ahead of the main vort max will aid in deepening a broad surface cyclone along a cold front over the northern Plains. As the surface low and trailing front advance, warm advection will draw limited, but sufficient, moisture northward into the lower OH Valley and Great Lakes. Strong to severe thunderstorms are possible ahead of the low and along the trailing front through early Wednesday. ...Mid MS and Lower OH Valley... Early in the forecast period, isolated to widely scattered thunderstorms may be ongoing within a strong low-level warm advection regime over the lower OH Valley. Ahead of the main surge of deeper surface moisture, these storms are expected to remain primarily elevated through the mid morning. Elevated buoyancy, steep lapse rates and sufficient vertical shear for supercells may support a conditional risk for large hail through mid morning. Continued warm advection should gradually transport upper 50s to low 60s F surface dewpoints northward into parts of southern and central IL, IN and western OH by mid afternoon. A diffuse moisture gradient along a surface pressure trough/weak dryline should become established across western/central IL into far eastern MO by late afternoon. Strong surface heating and confluence along this feature may support isolated convective development by 21-00z across central/northern IL. At the same time, warm advection along an expected differential-heating zone near the nose of the returning surface moisture may allow for scattered thunderstorm development across portions of northern IN, southern lower MI and northwestern OH. Model soundings show moderate MLCAPE (1500-2000 J/kg) and strong effective shear of 40-50 kt favorable for supercells. A prominent EML for February, with lapse rates of 8 C/km, will favor strong updrafts with efficient hail growth and a risk for significant hail. Later in the evening, the approach of the deepening mid-level trough and surface pressure falls ahead of the surface low across northern IL will yield increasing mass response across the warm sector. Model soundings show enlarged low-level hodographs potentially supporting a few tornadoes and damaging gusts. As the cold front and low move eastward, additional storm development is possible along the surface pressure trough and the surging cold front across portions of far eastern MO and southern IL. Uncertainty on storm mode and coverage remains fairly high, with some CAM solutions suggesting more isolated development ahead of the line, while other show mostly linear growth along the front. Regardless, these storms should continue eastward overnight across southern IN, northern KY and into southwestern OH with the potential for hail and damaging gusts. Should more discrete development occur and be maintained ahead of the building squall line, increasingly strong low-level shear (0-1km SRH of 250-400 m2/s2) could support a risk for tornadoes. The severe threat should gradually diminish into Wednesday morning as the frontal squall line pushes eastward into parts of eastern OH and the central Appalachians with decreasing buoyancy. ..Lyons/Darrow.. 02/27/2024 Read more

SPC Feb 27, 2024 0100 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 PM CST Mon Feb 26 2024 Valid 270100Z - 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 parts of the Great Lakes and Ohio Valley. ...01z update... Mid-level moistening is underway this evening as evidenced by 00z RAOBS across the lower OH River Valley and southern Great Lakes. Isolated thunderstorms are possible as moistening and continued isentropic ascent remove elevated inhibition. Confidence remains low on the coverage of storms, but robust elevated buoyancy (1000-2000 J/kg of MUCAPE) rooted about 850mb and 40-50 kt of effective shear would support a conditional risk for elevated supercells. Updated CAM guidance continues to indicate some potential for isolated stronger storms in one or more clusters near the OH River from 8-12z. Given the risk for hail with any stronger storms able to become established, the MRGL risk will be maintained, with no modification, late tonight into early Tuesday. ...Southwest... Evening water-vapor imagery shows a subtle perturbation within the amplified subtropical jet passing over parts of the Southwest. Weak broad-scale ascent from this feature and diurnal heating has resulted in scattered, low-topped convection with occasional lightning. With generally below 250 J/kg of MUCAPE, updrafts are not expected to be particularly strong or long lived. However, a few of these storms may continue into the evening and early overnight hours across eastern AZ and southwestern NM as ascent shifts eastward. General thunder probabilities have been added, given the potential for weak destabilization and continuation of sporadic lightning downstream late this evening. ..Lyons.. 02/27/2024 Read more

SPC Feb 27, 2024 0100 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 PM CST Mon Feb 26 2024 Valid 270100Z - 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 parts of the Great Lakes and Ohio Valley. ...01z update... Mid-level moistening is underway this evening as evidenced by 00z RAOBS across the lower OH River Valley and southern Great Lakes. Isolated thunderstorms are possible as moistening and continued isentropic ascent remove elevated inhibition. Confidence remains low on the coverage of storms, but robust elevated buoyancy (1000-2000 J/kg of MUCAPE) rooted about 850mb and 40-50 kt of effective shear would support a conditional risk for elevated supercells. Updated CAM guidance continues to indicate some potential for isolated stronger storms in one or more clusters near the OH River from 8-12z. Given the risk for hail with any stronger storms able to become established, the MRGL risk will be maintained, with no modification, late tonight into early Tuesday. ...Southwest... Evening water-vapor imagery shows a subtle perturbation within the amplified subtropical jet passing over parts of the Southwest. Weak broad-scale ascent from this feature and diurnal heating has resulted in scattered, low-topped convection with occasional lightning. With generally below 250 J/kg of MUCAPE, updrafts are not expected to be particularly strong or long lived. However, a few of these storms may continue into the evening and early overnight hours across eastern AZ and southwestern NM as ascent shifts eastward. General thunder probabilities have been added, given the potential for weak destabilization and continuation of sporadic lightning downstream late this evening. ..Lyons.. 02/27/2024 Read more

SPC Day 3-8 Fire Weather Outlook

1 year 5 months ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0308 PM CST Mon Feb 26 2024 Valid 281200Z - 051200Z Large-scale ridging aloft will overspread much of the central U.S. during the middle/latter portions of the week. A southern stream shortwave trough is forecast to eject out of northern Mexico into the southern Plains late Wednesday into Thursday. By early Saturday, a potent upper-level trough will dig into the southwestern U.S. and make quick progress through the Southwest into the southern Plains by Sunday. Strong surface cyclones can be expected in the Plains in association with this upper-level system. ...Southern High Plains... The focus for potentially critical fire weather continues to be focused on the southern High Plains as the next trough approaches the region this coming weekend. Models continue general agreement on the timing and structure of this large-scale feature. Confidence in critical fire weather has increased on Saturday and a 40% area has been added. Sunday continues to appear like the peak intensity of the event. Continued model convergence does suggest that higher probabilities may be needed in the coming days. At this time, there is still enough potential for the timing and/or latitudinal position of the trough to change that confidence in properly placing any increased probabilities is limited. Further, a leading southern stream shortwave trough may produce precipitation in parts of the southern High Plains on Thursday. While amounts may remain minimal to light for some areas, given some remaining dry air near the surface, this also adds to the overall uncertainty. ..Wendt.. 02/26/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

1 year 5 months ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0308 PM CST Mon Feb 26 2024 Valid 281200Z - 051200Z Large-scale ridging aloft will overspread much of the central U.S. during the middle/latter portions of the week. A southern stream shortwave trough is forecast to eject out of northern Mexico into the southern Plains late Wednesday into Thursday. By early Saturday, a potent upper-level trough will dig into the southwestern U.S. and make quick progress through the Southwest into the southern Plains by Sunday. Strong surface cyclones can be expected in the Plains in association with this upper-level system. ...Southern High Plains... The focus for potentially critical fire weather continues to be focused on the southern High Plains as the next trough approaches the region this coming weekend. Models continue general agreement on the timing and structure of this large-scale feature. Confidence in critical fire weather has increased on Saturday and a 40% area has been added. Sunday continues to appear like the peak intensity of the event. Continued model convergence does suggest that higher probabilities may be needed in the coming days. At this time, there is still enough potential for the timing and/or latitudinal position of the trough to change that confidence in properly placing any increased probabilities is limited. Further, a leading southern stream shortwave trough may produce precipitation in parts of the southern High Plains on Thursday. While amounts may remain minimal to light for some areas, given some remaining dry air near the surface, this also adds to the overall uncertainty. ..Wendt.. 02/26/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

1 year 5 months ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0308 PM CST Mon Feb 26 2024 Valid 281200Z - 051200Z Large-scale ridging aloft will overspread much of the central U.S. during the middle/latter portions of the week. A southern stream shortwave trough is forecast to eject out of northern Mexico into the southern Plains late Wednesday into Thursday. By early Saturday, a potent upper-level trough will dig into the southwestern U.S. and make quick progress through the Southwest into the southern Plains by Sunday. Strong surface cyclones can be expected in the Plains in association with this upper-level system. ...Southern High Plains... The focus for potentially critical fire weather continues to be focused on the southern High Plains as the next trough approaches the region this coming weekend. Models continue general agreement on the timing and structure of this large-scale feature. Confidence in critical fire weather has increased on Saturday and a 40% area has been added. Sunday continues to appear like the peak intensity of the event. Continued model convergence does suggest that higher probabilities may be needed in the coming days. At this time, there is still enough potential for the timing and/or latitudinal position of the trough to change that confidence in properly placing any increased probabilities is limited. Further, a leading southern stream shortwave trough may produce precipitation in parts of the southern High Plains on Thursday. While amounts may remain minimal to light for some areas, given some remaining dry air near the surface, this also adds to the overall uncertainty. ..Wendt.. 02/26/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

1 year 5 months ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0308 PM CST Mon Feb 26 2024 Valid 281200Z - 051200Z Large-scale ridging aloft will overspread much of the central U.S. during the middle/latter portions of the week. A southern stream shortwave trough is forecast to eject out of northern Mexico into the southern Plains late Wednesday into Thursday. By early Saturday, a potent upper-level trough will dig into the southwestern U.S. and make quick progress through the Southwest into the southern Plains by Sunday. Strong surface cyclones can be expected in the Plains in association with this upper-level system. ...Southern High Plains... The focus for potentially critical fire weather continues to be focused on the southern High Plains as the next trough approaches the region this coming weekend. Models continue general agreement on the timing and structure of this large-scale feature. Confidence in critical fire weather has increased on Saturday and a 40% area has been added. Sunday continues to appear like the peak intensity of the event. Continued model convergence does suggest that higher probabilities may be needed in the coming days. At this time, there is still enough potential for the timing and/or latitudinal position of the trough to change that confidence in properly placing any increased probabilities is limited. Further, a leading southern stream shortwave trough may produce precipitation in parts of the southern High Plains on Thursday. While amounts may remain minimal to light for some areas, given some remaining dry air near the surface, this also adds to the overall uncertainty. ..Wendt.. 02/26/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

1 year 5 months ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0308 PM CST Mon Feb 26 2024 Valid 281200Z - 051200Z Large-scale ridging aloft will overspread much of the central U.S. during the middle/latter portions of the week. A southern stream shortwave trough is forecast to eject out of northern Mexico into the southern Plains late Wednesday into Thursday. By early Saturday, a potent upper-level trough will dig into the southwestern U.S. and make quick progress through the Southwest into the southern Plains by Sunday. Strong surface cyclones can be expected in the Plains in association with this upper-level system. ...Southern High Plains... The focus for potentially critical fire weather continues to be focused on the southern High Plains as the next trough approaches the region this coming weekend. Models continue general agreement on the timing and structure of this large-scale feature. Confidence in critical fire weather has increased on Saturday and a 40% area has been added. Sunday continues to appear like the peak intensity of the event. Continued model convergence does suggest that higher probabilities may be needed in the coming days. At this time, there is still enough potential for the timing and/or latitudinal position of the trough to change that confidence in properly placing any increased probabilities is limited. Further, a leading southern stream shortwave trough may produce precipitation in parts of the southern High Plains on Thursday. While amounts may remain minimal to light for some areas, given some remaining dry air near the surface, this also adds to the overall uncertainty. ..Wendt.. 02/26/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

1 year 5 months ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0308 PM CST Mon Feb 26 2024 Valid 281200Z - 051200Z Large-scale ridging aloft will overspread much of the central U.S. during the middle/latter portions of the week. A southern stream shortwave trough is forecast to eject out of northern Mexico into the southern Plains late Wednesday into Thursday. By early Saturday, a potent upper-level trough will dig into the southwestern U.S. and make quick progress through the Southwest into the southern Plains by Sunday. Strong surface cyclones can be expected in the Plains in association with this upper-level system. ...Southern High Plains... The focus for potentially critical fire weather continues to be focused on the southern High Plains as the next trough approaches the region this coming weekend. Models continue general agreement on the timing and structure of this large-scale feature. Confidence in critical fire weather has increased on Saturday and a 40% area has been added. Sunday continues to appear like the peak intensity of the event. Continued model convergence does suggest that higher probabilities may be needed in the coming days. At this time, there is still enough potential for the timing and/or latitudinal position of the trough to change that confidence in properly placing any increased probabilities is limited. Further, a leading southern stream shortwave trough may produce precipitation in parts of the southern High Plains on Thursday. While amounts may remain minimal to light for some areas, given some remaining dry air near the surface, this also adds to the overall uncertainty. ..Wendt.. 02/26/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

1 year 5 months ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0308 PM CST Mon Feb 26 2024 Valid 281200Z - 051200Z Large-scale ridging aloft will overspread much of the central U.S. during the middle/latter portions of the week. A southern stream shortwave trough is forecast to eject out of northern Mexico into the southern Plains late Wednesday into Thursday. By early Saturday, a potent upper-level trough will dig into the southwestern U.S. and make quick progress through the Southwest into the southern Plains by Sunday. Strong surface cyclones can be expected in the Plains in association with this upper-level system. ...Southern High Plains... The focus for potentially critical fire weather continues to be focused on the southern High Plains as the next trough approaches the region this coming weekend. Models continue general agreement on the timing and structure of this large-scale feature. Confidence in critical fire weather has increased on Saturday and a 40% area has been added. Sunday continues to appear like the peak intensity of the event. Continued model convergence does suggest that higher probabilities may be needed in the coming days. At this time, there is still enough potential for the timing and/or latitudinal position of the trough to change that confidence in properly placing any increased probabilities is limited. Further, a leading southern stream shortwave trough may produce precipitation in parts of the southern High Plains on Thursday. While amounts may remain minimal to light for some areas, given some remaining dry air near the surface, this also adds to the overall uncertainty. ..Wendt.. 02/26/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Feb 26, 2024 2000 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Mon Feb 26 2024 Valid 262000Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT LAKES AND OHIO VALLEY... ...SUMMARY... Isolated late-night hail is possible across parts of the Great Lakes and Ohio Valley. ...20Z Update... ...Midwest into Lower MI... Conditional threat for elevated supercells capable of large hail described in the previous outlook (appended below) remains valid. Additionally, confidence in thunderstorm development has increased enough across bring the 5% hail probability south into northern KY. Environmental conditions in this area are similar to those farther north, and should support isolated hail with any deeper convective cores. Overall storm coverage is still expected to remain isolated, precluding the need to increase probabilities. ..Mosier.. 02/26/2024 .PREV DISCUSSION... /ISSUED 1028 AM CST Mon Feb 26 2024/ ...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. Read more
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