Severe Storms

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0114 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHEAST CO...MUCH OF NE/KS/IA...NORTHERN MO...SOUTHERN MN... CORRECTED FOR HAIL GRAPHIC ...SUMMARY... Severe thunderstorms may develop from parts of the central Plains into parts of the upper Midwest and upper Mississippi Valley on Friday. Large hail, damaging wind, and a couple tornadoes will be possible. ...Central/northern Plains into the upper Midwest/Great Lakes... A mid/upper-level trough will move eastward across the northern Great Plains into the upper Great Lakes region on Friday into Friday night. In conjunction with the shortwave, a surface low will move eastward across the Dakotas into MN, with secondary low development possible across the central Plains. A warm front is forecast to move northward across the mid/upper MS Valley, while a cold front will move through the northern/central Plains into MN through the day and into the evening. Elevated convection may be ongoing at the start of the period, within a warm-advection regime. In the wake of the morning convection, moderate to locally strong destabilization will be possible in the vicinity of the cold front and a possible outflow boundary across parts of NE/IA into northeast KS/northwest MO, with somewhat more modest destabilization along the northward extension of the front into parts of MN. Deep-layer shear will be sufficient for organized convection across the region. Storm evolution during the afternoon/evening remains somewhat uncertain, but development of a few supercells and/or stronger clusters will be possible near the front from eastern NE/northeast KS into southern MN/western IA/northwest MO. Hail and damaging winds will be possible with the strongest storms across the warm sector. In addition, some tornado threat may evolve with any sustained supercell, especially from southeast NE/eastern KS into northwest MO/southwest IA, where buoyancy may be maximized, and low-level shear/SRH will be somewhat enhanced into the evening. Farther west, organized storms may also develop near and north of the front across the central High Plains. Initial supercell development will be possible from northeast CO into southwest NE/northwest KS, with a threat of hail and localized severe gusts. Some upscale growth into multiple clusters or a small MCS may occur with time, which could pose at least a localized threat of significant severe gusts. The Slight Risk has been expanded to cover the scenarios described above, though some uncertainty remains regarding storm evolution through the period. ..Dean.. 06/27/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0114 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHEAST CO...MUCH OF NE/KS/IA...NORTHERN MO...SOUTHERN MN... CORRECTED FOR HAIL GRAPHIC ...SUMMARY... Severe thunderstorms may develop from parts of the central Plains into parts of the upper Midwest and upper Mississippi Valley on Friday. Large hail, damaging wind, and a couple tornadoes will be possible. ...Central/northern Plains into the upper Midwest/Great Lakes... A mid/upper-level trough will move eastward across the northern Great Plains into the upper Great Lakes region on Friday into Friday night. In conjunction with the shortwave, a surface low will move eastward across the Dakotas into MN, with secondary low development possible across the central Plains. A warm front is forecast to move northward across the mid/upper MS Valley, while a cold front will move through the northern/central Plains into MN through the day and into the evening. Elevated convection may be ongoing at the start of the period, within a warm-advection regime. In the wake of the morning convection, moderate to locally strong destabilization will be possible in the vicinity of the cold front and a possible outflow boundary across parts of NE/IA into northeast KS/northwest MO, with somewhat more modest destabilization along the northward extension of the front into parts of MN. Deep-layer shear will be sufficient for organized convection across the region. Storm evolution during the afternoon/evening remains somewhat uncertain, but development of a few supercells and/or stronger clusters will be possible near the front from eastern NE/northeast KS into southern MN/western IA/northwest MO. Hail and damaging winds will be possible with the strongest storms across the warm sector. In addition, some tornado threat may evolve with any sustained supercell, especially from southeast NE/eastern KS into northwest MO/southwest IA, where buoyancy may be maximized, and low-level shear/SRH will be somewhat enhanced into the evening. Farther west, organized storms may also develop near and north of the front across the central High Plains. Initial supercell development will be possible from northeast CO into southwest NE/northwest KS, with a threat of hail and localized severe gusts. Some upscale growth into multiple clusters or a small MCS may occur with time, which could pose at least a localized threat of significant severe gusts. The Slight Risk has been expanded to cover the scenarios described above, though some uncertainty remains regarding storm evolution through the period. ..Dean.. 06/27/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0114 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHEAST CO...MUCH OF NE/KS/IA...NORTHERN MO...SOUTHERN MN... CORRECTED FOR HAIL GRAPHIC ...SUMMARY... Severe thunderstorms may develop from parts of the central Plains into parts of the upper Midwest and upper Mississippi Valley on Friday. Large hail, damaging wind, and a couple tornadoes will be possible. ...Central/northern Plains into the upper Midwest/Great Lakes... A mid/upper-level trough will move eastward across the northern Great Plains into the upper Great Lakes region on Friday into Friday night. In conjunction with the shortwave, a surface low will move eastward across the Dakotas into MN, with secondary low development possible across the central Plains. A warm front is forecast to move northward across the mid/upper MS Valley, while a cold front will move through the northern/central Plains into MN through the day and into the evening. Elevated convection may be ongoing at the start of the period, within a warm-advection regime. In the wake of the morning convection, moderate to locally strong destabilization will be possible in the vicinity of the cold front and a possible outflow boundary across parts of NE/IA into northeast KS/northwest MO, with somewhat more modest destabilization along the northward extension of the front into parts of MN. Deep-layer shear will be sufficient for organized convection across the region. Storm evolution during the afternoon/evening remains somewhat uncertain, but development of a few supercells and/or stronger clusters will be possible near the front from eastern NE/northeast KS into southern MN/western IA/northwest MO. Hail and damaging winds will be possible with the strongest storms across the warm sector. In addition, some tornado threat may evolve with any sustained supercell, especially from southeast NE/eastern KS into northwest MO/southwest IA, where buoyancy may be maximized, and low-level shear/SRH will be somewhat enhanced into the evening. Farther west, organized storms may also develop near and north of the front across the central High Plains. Initial supercell development will be possible from northeast CO into southwest NE/northwest KS, with a threat of hail and localized severe gusts. Some upscale growth into multiple clusters or a small MCS may occur with time, which could pose at least a localized threat of significant severe gusts. The Slight Risk has been expanded to cover the scenarios described above, though some uncertainty remains regarding storm evolution through the period. ..Dean.. 06/27/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0114 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHEAST CO...MUCH OF NE/KS/IA...NORTHERN MO...SOUTHERN MN... CORRECTED FOR HAIL GRAPHIC ...SUMMARY... Severe thunderstorms may develop from parts of the central Plains into parts of the upper Midwest and upper Mississippi Valley on Friday. Large hail, damaging wind, and a couple tornadoes will be possible. ...Central/northern Plains into the upper Midwest/Great Lakes... A mid/upper-level trough will move eastward across the northern Great Plains into the upper Great Lakes region on Friday into Friday night. In conjunction with the shortwave, a surface low will move eastward across the Dakotas into MN, with secondary low development possible across the central Plains. A warm front is forecast to move northward across the mid/upper MS Valley, while a cold front will move through the northern/central Plains into MN through the day and into the evening. Elevated convection may be ongoing at the start of the period, within a warm-advection regime. In the wake of the morning convection, moderate to locally strong destabilization will be possible in the vicinity of the cold front and a possible outflow boundary across parts of NE/IA into northeast KS/northwest MO, with somewhat more modest destabilization along the northward extension of the front into parts of MN. Deep-layer shear will be sufficient for organized convection across the region. Storm evolution during the afternoon/evening remains somewhat uncertain, but development of a few supercells and/or stronger clusters will be possible near the front from eastern NE/northeast KS into southern MN/western IA/northwest MO. Hail and damaging winds will be possible with the strongest storms across the warm sector. In addition, some tornado threat may evolve with any sustained supercell, especially from southeast NE/eastern KS into northwest MO/southwest IA, where buoyancy may be maximized, and low-level shear/SRH will be somewhat enhanced into the evening. Farther west, organized storms may also develop near and north of the front across the central High Plains. Initial supercell development will be possible from northeast CO into southwest NE/northwest KS, with a threat of hail and localized severe gusts. Some upscale growth into multiple clusters or a small MCS may occur with time, which could pose at least a localized threat of significant severe gusts. The Slight Risk has been expanded to cover the scenarios described above, though some uncertainty remains regarding storm evolution through the period. ..Dean.. 06/27/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHEAST CO...MUCH OF NE/KS/IA...NORTHERN MO...SOUTHERN MN... ...SUMMARY... Severe thunderstorms may develop from parts of the central Plains into parts of the upper Midwest and upper Mississippi Valley on Friday. Large hail, damaging wind, and a couple tornadoes will be possible. ...Central/northern Plains into the upper Midwest/Great Lakes... A mid/upper-level trough will move eastward across the northern Great Plains into the upper Great Lakes region on Friday into Friday night. In conjunction with the shortwave, a surface low will move eastward across the Dakotas into MN, with secondary low development possible across the central Plains. A warm front is forecast to move northward across the mid/upper MS Valley, while a cold front will move through the northern/central Plains into MN through the day and into the evening. Elevated convection may be ongoing at the start of the period, within a warm-advection regime. In the wake of the morning convection, moderate to locally strong destabilization will be possible in the vicinity of the cold front and a possible outflow boundary across parts of NE/IA into northeast KS/northwest MO, with somewhat more modest destabilization along the northward extension of the front into parts of MN. Deep-layer shear will be sufficient for organized convection across the region. Storm evolution during the afternoon/evening remains somewhat uncertain, but development of a few supercells and/or stronger clusters will be possible near the front from eastern NE/northeast KS into southern MN/western IA/northwest MO. Hail and damaging winds will be possible with the strongest storms across the warm sector. In addition, some tornado threat may evolve with any sustained supercell, especially from southeast NE/eastern KS into northwest MO/southwest IA, where buoyancy may be maximized, and low-level shear/SRH will be somewhat enhanced into the evening. Farther west, organized storms may also develop near and north of the front across the central High Plains. Initial supercell development will be possible from northeast CO into southwest NE/northwest KS, with a threat of hail and localized severe gusts. Some upscale growth into multiple clusters or a small MCS may occur with time, which could pose at least a localized threat of significant severe gusts. The Slight Risk has been expanded to cover the scenarios described above, though some uncertainty remains regarding storm evolution through the period. ..Dean.. 06/27/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA TO NORTHERN AND CENTRAL HIGH PLAINS.... ...SUMMARY... Severe thunderstorms producing gusts to 80 mph, large hail greater than 2.5 inches, and a few tornadoes are possible across parts of eastern Montana into western portions of the Great Plains this afternoon and evening. Additional severe storms are possible over parts of the western US and the Southeast. ...MT and the Dakotas... An upper ridge centered over the Rockies will weaken under the influence of a deepening mid-level low over the Pacific Northwest. Ascent from the deepening low and strengthening flow aloft will aid in the development of a surface lee cyclone over eastern MT. Surface-pressure falls will increase low-level advection of rich boundary-layer moisture over the central and northern Plains northwest into eastern MT and the western Dakotas by midday. Steepening mid-level lapse rates, increasing large-scale ascent, moist advection, and diurnal heating will rapidly destabilize the air mass, allowing for scattered thunderstorm development. Convective development appears likely over several areas of the northern Rockies/High Plains by early to mid afternoon. A cold front trailing the low in central MT will likely initiate first, followed by the surface low in eastern MT and western ND, and along a trailing dryline into portions of western SD and far northeastern WY. With moderate buoyancy and increasingly strong deep-layer shear of 40-50 kt, convection should rapidly organize into supercells. Steep mid-level lapse rates and the initial discrete mode will favor large to very large hail with these supercells. Backed southeasterly upslope flow and large low-level CAPE near the surface low also suggest the potential for a couple tornadoes, especially with supercells that remain discrete into the early evening. Eventual upscale growth into a cluster or MCS with a threat for damaging gusts is likely later this evening, and could persist overnight with ample buoyancy and a 40-50 kt southerly low-level jet over the northern Plains. ...Central and southern High Plains... Widely scattered storm development is expected late this afternoon along the dryline from western SD into western NE, as temperatures warm and inhibition is removed from upslope flow and the approach of the upper low. Rich moisture (dewpoints in the upper 60s to low 70s F) and steep mid-level lapse rates will support large buoyancy by early afternoon. Albeit weaker, on the southern fringes of the better flow aloft, adequate deep-layer shear will support supercells capable of all hazards, with eventual upscale growth occurring this evening. Farther south, more isolated storm coverage is expected into parts of eastern CO and western KS. Likely higher based, owing to very warm temperatures in the upper 90s to low 100s F, damaging winds and hail will be possible with a mix of mutlicells and transient supercells. Some clustering is expected into the evening hours with the risk for damaging gusts shifting into parts of central KS and northern OK. However, the exact eastward extent remains unclear, given stronger capping and weakening upper-level support to the south and east. ...Eastern UT into Western CO and southern WY... Modest ascent from the approaching trough combined with diurnal orographic circulations will support scattered thunderstorm development across parts of the Intermountain west from mid morning through the afternoon. Relatively high dewpoints in the low 50s F and steep lapse rates will aid in afternoon destabilization, with MLCAPE of 1000-1500 J/kg forecast. Scattered organized storms, including supercells, should form over the higher terrain and along the trailing cold front/wind shift eastern UT into southwest WY and northwest CO. Damaging winds and hail are likely with the more robust storms. While low-level shear is not overly strong, favorable terrain interactions and the supercell mode could also support a tornado or two. ...Southeast... An upper trough over the eastern COUS will phase with a modest subtropical vort max rounding the eastern periphery of the rapidly flattening ridge over the southeastern CONUS. Subtle ascent from the phasing of the two troughs will support scattered afternoon thunderstorms over portions of AL/GA and into the Carolinas along a diffuse surface boundary. A very warm and moist air mass will allow for moderate to large buoyancy supporting strong updrafts despite poor mid-level lapse rates. While effective shear appears to be only modest (generally less than 15-20 kt), heavily water-loaded downdrafts may produce isolated pulse-type damaging gusts. A remnant MCV/weak upper-level support may also allow for the development of a loosely organized cluster of storms with time over portions of eastern GA and southern SC. A localized corridor of more sustained severe potential may develop, though confidence in exactly where remains low. ..Lyons/Wendt.. 06/27/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA TO NORTHERN AND CENTRAL HIGH PLAINS.... ...SUMMARY... Severe thunderstorms producing gusts to 80 mph, large hail greater than 2.5 inches, and a few tornadoes are possible across parts of eastern Montana into western portions of the Great Plains this afternoon and evening. Additional severe storms are possible over parts of the western US and the Southeast. ...MT and the Dakotas... An upper ridge centered over the Rockies will weaken under the influence of a deepening mid-level low over the Pacific Northwest. Ascent from the deepening low and strengthening flow aloft will aid in the development of a surface lee cyclone over eastern MT. Surface-pressure falls will increase low-level advection of rich boundary-layer moisture over the central and northern Plains northwest into eastern MT and the western Dakotas by midday. Steepening mid-level lapse rates, increasing large-scale ascent, moist advection, and diurnal heating will rapidly destabilize the air mass, allowing for scattered thunderstorm development. Convective development appears likely over several areas of the northern Rockies/High Plains by early to mid afternoon. A cold front trailing the low in central MT will likely initiate first, followed by the surface low in eastern MT and western ND, and along a trailing dryline into portions of western SD and far northeastern WY. With moderate buoyancy and increasingly strong deep-layer shear of 40-50 kt, convection should rapidly organize into supercells. Steep mid-level lapse rates and the initial discrete mode will favor large to very large hail with these supercells. Backed southeasterly upslope flow and large low-level CAPE near the surface low also suggest the potential for a couple tornadoes, especially with supercells that remain discrete into the early evening. Eventual upscale growth into a cluster or MCS with a threat for damaging gusts is likely later this evening, and could persist overnight with ample buoyancy and a 40-50 kt southerly low-level jet over the northern Plains. ...Central and southern High Plains... Widely scattered storm development is expected late this afternoon along the dryline from western SD into western NE, as temperatures warm and inhibition is removed from upslope flow and the approach of the upper low. Rich moisture (dewpoints in the upper 60s to low 70s F) and steep mid-level lapse rates will support large buoyancy by early afternoon. Albeit weaker, on the southern fringes of the better flow aloft, adequate deep-layer shear will support supercells capable of all hazards, with eventual upscale growth occurring this evening. Farther south, more isolated storm coverage is expected into parts of eastern CO and western KS. Likely higher based, owing to very warm temperatures in the upper 90s to low 100s F, damaging winds and hail will be possible with a mix of mutlicells and transient supercells. Some clustering is expected into the evening hours with the risk for damaging gusts shifting into parts of central KS and northern OK. However, the exact eastward extent remains unclear, given stronger capping and weakening upper-level support to the south and east. ...Eastern UT into Western CO and southern WY... Modest ascent from the approaching trough combined with diurnal orographic circulations will support scattered thunderstorm development across parts of the Intermountain west from mid morning through the afternoon. Relatively high dewpoints in the low 50s F and steep lapse rates will aid in afternoon destabilization, with MLCAPE of 1000-1500 J/kg forecast. Scattered organized storms, including supercells, should form over the higher terrain and along the trailing cold front/wind shift eastern UT into southwest WY and northwest CO. Damaging winds and hail are likely with the more robust storms. While low-level shear is not overly strong, favorable terrain interactions and the supercell mode could also support a tornado or two. ...Southeast... An upper trough over the eastern COUS will phase with a modest subtropical vort max rounding the eastern periphery of the rapidly flattening ridge over the southeastern CONUS. Subtle ascent from the phasing of the two troughs will support scattered afternoon thunderstorms over portions of AL/GA and into the Carolinas along a diffuse surface boundary. A very warm and moist air mass will allow for moderate to large buoyancy supporting strong updrafts despite poor mid-level lapse rates. While effective shear appears to be only modest (generally less than 15-20 kt), heavily water-loaded downdrafts may produce isolated pulse-type damaging gusts. A remnant MCV/weak upper-level support may also allow for the development of a loosely organized cluster of storms with time over portions of eastern GA and southern SC. A localized corridor of more sustained severe potential may develop, though confidence in exactly where remains low. ..Lyons/Wendt.. 06/27/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA TO NORTHERN AND CENTRAL HIGH PLAINS.... ...SUMMARY... Severe thunderstorms producing gusts to 80 mph, large hail greater than 2.5 inches, and a few tornadoes are possible across parts of eastern Montana into western portions of the Great Plains this afternoon and evening. Additional severe storms are possible over parts of the western US and the Southeast. ...MT and the Dakotas... An upper ridge centered over the Rockies will weaken under the influence of a deepening mid-level low over the Pacific Northwest. Ascent from the deepening low and strengthening flow aloft will aid in the development of a surface lee cyclone over eastern MT. Surface-pressure falls will increase low-level advection of rich boundary-layer moisture over the central and northern Plains northwest into eastern MT and the western Dakotas by midday. Steepening mid-level lapse rates, increasing large-scale ascent, moist advection, and diurnal heating will rapidly destabilize the air mass, allowing for scattered thunderstorm development. Convective development appears likely over several areas of the northern Rockies/High Plains by early to mid afternoon. A cold front trailing the low in central MT will likely initiate first, followed by the surface low in eastern MT and western ND, and along a trailing dryline into portions of western SD and far northeastern WY. With moderate buoyancy and increasingly strong deep-layer shear of 40-50 kt, convection should rapidly organize into supercells. Steep mid-level lapse rates and the initial discrete mode will favor large to very large hail with these supercells. Backed southeasterly upslope flow and large low-level CAPE near the surface low also suggest the potential for a couple tornadoes, especially with supercells that remain discrete into the early evening. Eventual upscale growth into a cluster or MCS with a threat for damaging gusts is likely later this evening, and could persist overnight with ample buoyancy and a 40-50 kt southerly low-level jet over the northern Plains. ...Central and southern High Plains... Widely scattered storm development is expected late this afternoon along the dryline from western SD into western NE, as temperatures warm and inhibition is removed from upslope flow and the approach of the upper low. Rich moisture (dewpoints in the upper 60s to low 70s F) and steep mid-level lapse rates will support large buoyancy by early afternoon. Albeit weaker, on the southern fringes of the better flow aloft, adequate deep-layer shear will support supercells capable of all hazards, with eventual upscale growth occurring this evening. Farther south, more isolated storm coverage is expected into parts of eastern CO and western KS. Likely higher based, owing to very warm temperatures in the upper 90s to low 100s F, damaging winds and hail will be possible with a mix of mutlicells and transient supercells. Some clustering is expected into the evening hours with the risk for damaging gusts shifting into parts of central KS and northern OK. However, the exact eastward extent remains unclear, given stronger capping and weakening upper-level support to the south and east. ...Eastern UT into Western CO and southern WY... Modest ascent from the approaching trough combined with diurnal orographic circulations will support scattered thunderstorm development across parts of the Intermountain west from mid morning through the afternoon. Relatively high dewpoints in the low 50s F and steep lapse rates will aid in afternoon destabilization, with MLCAPE of 1000-1500 J/kg forecast. Scattered organized storms, including supercells, should form over the higher terrain and along the trailing cold front/wind shift eastern UT into southwest WY and northwest CO. Damaging winds and hail are likely with the more robust storms. While low-level shear is not overly strong, favorable terrain interactions and the supercell mode could also support a tornado or two. ...Southeast... An upper trough over the eastern COUS will phase with a modest subtropical vort max rounding the eastern periphery of the rapidly flattening ridge over the southeastern CONUS. Subtle ascent from the phasing of the two troughs will support scattered afternoon thunderstorms over portions of AL/GA and into the Carolinas along a diffuse surface boundary. A very warm and moist air mass will allow for moderate to large buoyancy supporting strong updrafts despite poor mid-level lapse rates. While effective shear appears to be only modest (generally less than 15-20 kt), heavily water-loaded downdrafts may produce isolated pulse-type damaging gusts. A remnant MCV/weak upper-level support may also allow for the development of a loosely organized cluster of storms with time over portions of eastern GA and southern SC. A localized corridor of more sustained severe potential may develop, though confidence in exactly where remains low. ..Lyons/Wendt.. 06/27/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA TO NORTHERN AND CENTRAL HIGH PLAINS.... ...SUMMARY... Severe thunderstorms producing gusts to 80 mph, large hail greater than 2.5 inches, and a few tornadoes are possible across parts of eastern Montana into western portions of the Great Plains this afternoon and evening. Additional severe storms are possible over parts of the western US and the Southeast. ...MT and the Dakotas... An upper ridge centered over the Rockies will weaken under the influence of a deepening mid-level low over the Pacific Northwest. Ascent from the deepening low and strengthening flow aloft will aid in the development of a surface lee cyclone over eastern MT. Surface-pressure falls will increase low-level advection of rich boundary-layer moisture over the central and northern Plains northwest into eastern MT and the western Dakotas by midday. Steepening mid-level lapse rates, increasing large-scale ascent, moist advection, and diurnal heating will rapidly destabilize the air mass, allowing for scattered thunderstorm development. Convective development appears likely over several areas of the northern Rockies/High Plains by early to mid afternoon. A cold front trailing the low in central MT will likely initiate first, followed by the surface low in eastern MT and western ND, and along a trailing dryline into portions of western SD and far northeastern WY. With moderate buoyancy and increasingly strong deep-layer shear of 40-50 kt, convection should rapidly organize into supercells. Steep mid-level lapse rates and the initial discrete mode will favor large to very large hail with these supercells. Backed southeasterly upslope flow and large low-level CAPE near the surface low also suggest the potential for a couple tornadoes, especially with supercells that remain discrete into the early evening. Eventual upscale growth into a cluster or MCS with a threat for damaging gusts is likely later this evening, and could persist overnight with ample buoyancy and a 40-50 kt southerly low-level jet over the northern Plains. ...Central and southern High Plains... Widely scattered storm development is expected late this afternoon along the dryline from western SD into western NE, as temperatures warm and inhibition is removed from upslope flow and the approach of the upper low. Rich moisture (dewpoints in the upper 60s to low 70s F) and steep mid-level lapse rates will support large buoyancy by early afternoon. Albeit weaker, on the southern fringes of the better flow aloft, adequate deep-layer shear will support supercells capable of all hazards, with eventual upscale growth occurring this evening. Farther south, more isolated storm coverage is expected into parts of eastern CO and western KS. Likely higher based, owing to very warm temperatures in the upper 90s to low 100s F, damaging winds and hail will be possible with a mix of mutlicells and transient supercells. Some clustering is expected into the evening hours with the risk for damaging gusts shifting into parts of central KS and northern OK. However, the exact eastward extent remains unclear, given stronger capping and weakening upper-level support to the south and east. ...Eastern UT into Western CO and southern WY... Modest ascent from the approaching trough combined with diurnal orographic circulations will support scattered thunderstorm development across parts of the Intermountain west from mid morning through the afternoon. Relatively high dewpoints in the low 50s F and steep lapse rates will aid in afternoon destabilization, with MLCAPE of 1000-1500 J/kg forecast. Scattered organized storms, including supercells, should form over the higher terrain and along the trailing cold front/wind shift eastern UT into southwest WY and northwest CO. Damaging winds and hail are likely with the more robust storms. While low-level shear is not overly strong, favorable terrain interactions and the supercell mode could also support a tornado or two. ...Southeast... An upper trough over the eastern COUS will phase with a modest subtropical vort max rounding the eastern periphery of the rapidly flattening ridge over the southeastern CONUS. Subtle ascent from the phasing of the two troughs will support scattered afternoon thunderstorms over portions of AL/GA and into the Carolinas along a diffuse surface boundary. A very warm and moist air mass will allow for moderate to large buoyancy supporting strong updrafts despite poor mid-level lapse rates. While effective shear appears to be only modest (generally less than 15-20 kt), heavily water-loaded downdrafts may produce isolated pulse-type damaging gusts. A remnant MCV/weak upper-level support may also allow for the development of a loosely organized cluster of storms with time over portions of eastern GA and southern SC. A localized corridor of more sustained severe potential may develop, though confidence in exactly where remains low. ..Lyons/Wendt.. 06/27/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA TO NORTHERN AND CENTRAL HIGH PLAINS.... ...SUMMARY... Severe thunderstorms producing gusts to 80 mph, large hail greater than 2.5 inches, and a few tornadoes are possible across parts of eastern Montana into western portions of the Great Plains this afternoon and evening. Additional severe storms are possible over parts of the western US and the Southeast. ...MT and the Dakotas... An upper ridge centered over the Rockies will weaken under the influence of a deepening mid-level low over the Pacific Northwest. Ascent from the deepening low and strengthening flow aloft will aid in the development of a surface lee cyclone over eastern MT. Surface-pressure falls will increase low-level advection of rich boundary-layer moisture over the central and northern Plains northwest into eastern MT and the western Dakotas by midday. Steepening mid-level lapse rates, increasing large-scale ascent, moist advection, and diurnal heating will rapidly destabilize the air mass, allowing for scattered thunderstorm development. Convective development appears likely over several areas of the northern Rockies/High Plains by early to mid afternoon. A cold front trailing the low in central MT will likely initiate first, followed by the surface low in eastern MT and western ND, and along a trailing dryline into portions of western SD and far northeastern WY. With moderate buoyancy and increasingly strong deep-layer shear of 40-50 kt, convection should rapidly organize into supercells. Steep mid-level lapse rates and the initial discrete mode will favor large to very large hail with these supercells. Backed southeasterly upslope flow and large low-level CAPE near the surface low also suggest the potential for a couple tornadoes, especially with supercells that remain discrete into the early evening. Eventual upscale growth into a cluster or MCS with a threat for damaging gusts is likely later this evening, and could persist overnight with ample buoyancy and a 40-50 kt southerly low-level jet over the northern Plains. ...Central and southern High Plains... Widely scattered storm development is expected late this afternoon along the dryline from western SD into western NE, as temperatures warm and inhibition is removed from upslope flow and the approach of the upper low. Rich moisture (dewpoints in the upper 60s to low 70s F) and steep mid-level lapse rates will support large buoyancy by early afternoon. Albeit weaker, on the southern fringes of the better flow aloft, adequate deep-layer shear will support supercells capable of all hazards, with eventual upscale growth occurring this evening. Farther south, more isolated storm coverage is expected into parts of eastern CO and western KS. Likely higher based, owing to very warm temperatures in the upper 90s to low 100s F, damaging winds and hail will be possible with a mix of mutlicells and transient supercells. Some clustering is expected into the evening hours with the risk for damaging gusts shifting into parts of central KS and northern OK. However, the exact eastward extent remains unclear, given stronger capping and weakening upper-level support to the south and east. ...Eastern UT into Western CO and southern WY... Modest ascent from the approaching trough combined with diurnal orographic circulations will support scattered thunderstorm development across parts of the Intermountain west from mid morning through the afternoon. Relatively high dewpoints in the low 50s F and steep lapse rates will aid in afternoon destabilization, with MLCAPE of 1000-1500 J/kg forecast. Scattered organized storms, including supercells, should form over the higher terrain and along the trailing cold front/wind shift eastern UT into southwest WY and northwest CO. Damaging winds and hail are likely with the more robust storms. While low-level shear is not overly strong, favorable terrain interactions and the supercell mode could also support a tornado or two. ...Southeast... An upper trough over the eastern COUS will phase with a modest subtropical vort max rounding the eastern periphery of the rapidly flattening ridge over the southeastern CONUS. Subtle ascent from the phasing of the two troughs will support scattered afternoon thunderstorms over portions of AL/GA and into the Carolinas along a diffuse surface boundary. A very warm and moist air mass will allow for moderate to large buoyancy supporting strong updrafts despite poor mid-level lapse rates. While effective shear appears to be only modest (generally less than 15-20 kt), heavily water-loaded downdrafts may produce isolated pulse-type damaging gusts. A remnant MCV/weak upper-level support may also allow for the development of a loosely organized cluster of storms with time over portions of eastern GA and southern SC. A localized corridor of more sustained severe potential may develop, though confidence in exactly where remains low. ..Lyons/Wendt.. 06/27/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA TO NORTHERN AND CENTRAL HIGH PLAINS.... ...SUMMARY... Severe thunderstorms producing gusts to 80 mph, large hail greater than 2.5 inches, and a few tornadoes are possible across parts of eastern Montana into western portions of the Great Plains this afternoon and evening. Additional severe storms are possible over parts of the western US and the Southeast. ...MT and the Dakotas... An upper ridge centered over the Rockies will weaken under the influence of a deepening mid-level low over the Pacific Northwest. Ascent from the deepening low and strengthening flow aloft will aid in the development of a surface lee cyclone over eastern MT. Surface-pressure falls will increase low-level advection of rich boundary-layer moisture over the central and northern Plains northwest into eastern MT and the western Dakotas by midday. Steepening mid-level lapse rates, increasing large-scale ascent, moist advection, and diurnal heating will rapidly destabilize the air mass, allowing for scattered thunderstorm development. Convective development appears likely over several areas of the northern Rockies/High Plains by early to mid afternoon. A cold front trailing the low in central MT will likely initiate first, followed by the surface low in eastern MT and western ND, and along a trailing dryline into portions of western SD and far northeastern WY. With moderate buoyancy and increasingly strong deep-layer shear of 40-50 kt, convection should rapidly organize into supercells. Steep mid-level lapse rates and the initial discrete mode will favor large to very large hail with these supercells. Backed southeasterly upslope flow and large low-level CAPE near the surface low also suggest the potential for a couple tornadoes, especially with supercells that remain discrete into the early evening. Eventual upscale growth into a cluster or MCS with a threat for damaging gusts is likely later this evening, and could persist overnight with ample buoyancy and a 40-50 kt southerly low-level jet over the northern Plains. ...Central and southern High Plains... Widely scattered storm development is expected late this afternoon along the dryline from western SD into western NE, as temperatures warm and inhibition is removed from upslope flow and the approach of the upper low. Rich moisture (dewpoints in the upper 60s to low 70s F) and steep mid-level lapse rates will support large buoyancy by early afternoon. Albeit weaker, on the southern fringes of the better flow aloft, adequate deep-layer shear will support supercells capable of all hazards, with eventual upscale growth occurring this evening. Farther south, more isolated storm coverage is expected into parts of eastern CO and western KS. Likely higher based, owing to very warm temperatures in the upper 90s to low 100s F, damaging winds and hail will be possible with a mix of mutlicells and transient supercells. Some clustering is expected into the evening hours with the risk for damaging gusts shifting into parts of central KS and northern OK. However, the exact eastward extent remains unclear, given stronger capping and weakening upper-level support to the south and east. ...Eastern UT into Western CO and southern WY... Modest ascent from the approaching trough combined with diurnal orographic circulations will support scattered thunderstorm development across parts of the Intermountain west from mid morning through the afternoon. Relatively high dewpoints in the low 50s F and steep lapse rates will aid in afternoon destabilization, with MLCAPE of 1000-1500 J/kg forecast. Scattered organized storms, including supercells, should form over the higher terrain and along the trailing cold front/wind shift eastern UT into southwest WY and northwest CO. Damaging winds and hail are likely with the more robust storms. While low-level shear is not overly strong, favorable terrain interactions and the supercell mode could also support a tornado or two. ...Southeast... An upper trough over the eastern COUS will phase with a modest subtropical vort max rounding the eastern periphery of the rapidly flattening ridge over the southeastern CONUS. Subtle ascent from the phasing of the two troughs will support scattered afternoon thunderstorms over portions of AL/GA and into the Carolinas along a diffuse surface boundary. A very warm and moist air mass will allow for moderate to large buoyancy supporting strong updrafts despite poor mid-level lapse rates. While effective shear appears to be only modest (generally less than 15-20 kt), heavily water-loaded downdrafts may produce isolated pulse-type damaging gusts. A remnant MCV/weak upper-level support may also allow for the development of a loosely organized cluster of storms with time over portions of eastern GA and southern SC. A localized corridor of more sustained severe potential may develop, though confidence in exactly where remains low. ..Lyons/Wendt.. 06/27/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...Synopsis... A potent upper-level trough will move through the Northwest and into the northern Rockies today. At the surface, a low will deepen in the northern High Plains. A cold front will push into the Great Basin from the northwest. ...Northern Nevada into Snake River Plain... Winds ahead of and behind the surface boundary will intensify by the afternoon. RH during the afternoon is less than certain as there is some possibility of some higher-level cloud cover ahead of the trough as well as cumulus buildups within the terrain areas. However, it seems reasonable to expect 15-20% for most areas. Winds through the Snake Plain are likely to be stronger given the proximity to the mid-level jet. There, 20-25 mph will be possible. Into Nevada, 15-20 mph is more likely. With rainfall having occurred across central portions of Nevada, the elevated area has been adjusted to account for temporary fuel moistening. Within the Snake Plain, fuels are not yet critically dry and will not support an addition of critical highlights despite favorable meteorological conditions. ..Wendt.. 06/27/2024 ...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 1251 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...Synopsis... A potent upper-level trough will move through the Northwest and into the northern Rockies today. At the surface, a low will deepen in the northern High Plains. A cold front will push into the Great Basin from the northwest. ...Northern Nevada into Snake River Plain... Winds ahead of and behind the surface boundary will intensify by the afternoon. RH during the afternoon is less than certain as there is some possibility of some higher-level cloud cover ahead of the trough as well as cumulus buildups within the terrain areas. However, it seems reasonable to expect 15-20% for most areas. Winds through the Snake Plain are likely to be stronger given the proximity to the mid-level jet. There, 20-25 mph will be possible. Into Nevada, 15-20 mph is more likely. With rainfall having occurred across central portions of Nevada, the elevated area has been adjusted to account for temporary fuel moistening. Within the Snake Plain, fuels are not yet critically dry and will not support an addition of critical highlights despite favorable meteorological conditions. ..Wendt.. 06/27/2024 ...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 1251 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...Synopsis... A potent upper-level trough will move through the Northwest and into the northern Rockies today. At the surface, a low will deepen in the northern High Plains. A cold front will push into the Great Basin from the northwest. ...Northern Nevada into Snake River Plain... Winds ahead of and behind the surface boundary will intensify by the afternoon. RH during the afternoon is less than certain as there is some possibility of some higher-level cloud cover ahead of the trough as well as cumulus buildups within the terrain areas. However, it seems reasonable to expect 15-20% for most areas. Winds through the Snake Plain are likely to be stronger given the proximity to the mid-level jet. There, 20-25 mph will be possible. Into Nevada, 15-20 mph is more likely. With rainfall having occurred across central portions of Nevada, the elevated area has been adjusted to account for temporary fuel moistening. Within the Snake Plain, fuels are not yet critically dry and will not support an addition of critical highlights despite favorable meteorological conditions. ..Wendt.. 06/27/2024 ...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 1251 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...Synopsis... A potent upper-level trough will move through the Northwest and into the northern Rockies today. At the surface, a low will deepen in the northern High Plains. A cold front will push into the Great Basin from the northwest. ...Northern Nevada into Snake River Plain... Winds ahead of and behind the surface boundary will intensify by the afternoon. RH during the afternoon is less than certain as there is some possibility of some higher-level cloud cover ahead of the trough as well as cumulus buildups within the terrain areas. However, it seems reasonable to expect 15-20% for most areas. Winds through the Snake Plain are likely to be stronger given the proximity to the mid-level jet. There, 20-25 mph will be possible. Into Nevada, 15-20 mph is more likely. With rainfall having occurred across central portions of Nevada, the elevated area has been adjusted to account for temporary fuel moistening. Within the Snake Plain, fuels are not yet critically dry and will not support an addition of critical highlights despite favorable meteorological conditions. ..Wendt.. 06/27/2024 ...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 1251 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...Synopsis... A potent upper-level trough will move through the Northwest and into the northern Rockies today. At the surface, a low will deepen in the northern High Plains. A cold front will push into the Great Basin from the northwest. ...Northern Nevada into Snake River Plain... Winds ahead of and behind the surface boundary will intensify by the afternoon. RH during the afternoon is less than certain as there is some possibility of some higher-level cloud cover ahead of the trough as well as cumulus buildups within the terrain areas. However, it seems reasonable to expect 15-20% for most areas. Winds through the Snake Plain are likely to be stronger given the proximity to the mid-level jet. There, 20-25 mph will be possible. Into Nevada, 15-20 mph is more likely. With rainfall having occurred across central portions of Nevada, the elevated area has been adjusted to account for temporary fuel moistening. Within the Snake Plain, fuels are not yet critically dry and will not support an addition of critical highlights despite favorable meteorological conditions. ..Wendt.. 06/27/2024 ...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 1251 AM CDT Thu Jun 27 2024 Valid 271200Z - 281200Z ...Synopsis... A potent upper-level trough will move through the Northwest and into the northern Rockies today. At the surface, a low will deepen in the northern High Plains. A cold front will push into the Great Basin from the northwest. ...Northern Nevada into Snake River Plain... Winds ahead of and behind the surface boundary will intensify by the afternoon. RH during the afternoon is less than certain as there is some possibility of some higher-level cloud cover ahead of the trough as well as cumulus buildups within the terrain areas. However, it seems reasonable to expect 15-20% for most areas. Winds through the Snake Plain are likely to be stronger given the proximity to the mid-level jet. There, 20-25 mph will be possible. Into Nevada, 15-20 mph is more likely. With rainfall having occurred across central portions of Nevada, the elevated area has been adjusted to account for temporary fuel moistening. Within the Snake Plain, fuels are not yet critically dry and will not support an addition of critical highlights despite favorable meteorological conditions. ..Wendt.. 06/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1443 CONCERNING SEVERE THUNDERSTORM WATCH 472... FOR FAR EASTERN CONNECTICUT/RHODE ISLAND/CENTRAL AND EASTERN MASSACHUSETTS
Mesoscale Discussion 1443 NWS Storm Prediction Center Norman OK 1012 PM CDT Wed Jun 26 2024 Areas affected...far eastern Connecticut/Rhode Island/central and eastern Massachusetts Concerning...Severe Thunderstorm Watch 472... Valid 270312Z - 270415Z The severe weather threat for Severe Thunderstorm Watch 472 continues. SUMMARY...A band of strong/severe storms continues moving eastward across southern New England, where locally damaging wind gusts remain possible over the next couple of hours. DISCUSSION...Latest radar loop shows a north-south band of strong/severe storms moving eastward at around 40 kt in the vicinity of the Connecticut/Rhode Island border. The storms have a history of producing strong/severe wind gusts, including a 67 kt gust at Hartford/Bradley Airport (KBDL) in the past hour. While instability is gradually diminishing nocturnally, and capping correspondingly increasing, storms will likely maintain intensity given the degree of organization. With that said, hints exist in KBOX radar data that outflow is beginning to outpace the main band of storms. This -- and the ongoing nocturnal boundary-layer cooling -- suggests that storms are becoming slightly elevated with time. Still, locally severe/damaging gusts remain possible over the next 1 to 2 hours. ..Goss.. 06/27/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BOX... LAT...LON 41397172 41717175 42507207 42897039 42197004 41966998 41707005 41507075 41397172 Read more

MD 1441 CONCERNING SEVERE THUNDERSTORM WATCH 470... FOR PORTIONS OF NORTH TEXAS
Mesoscale Discussion 1441 NWS Storm Prediction Center Norman OK 0827 PM CDT Wed Jun 26 2024 Areas affected...Portions of North Texas Concerning...Severe Thunderstorm Watch 470... Valid 270127Z - 270300Z The severe weather threat for Severe Thunderstorm Watch 470 continues. SUMMARY...Large hail and severe winds remain possible with a supercell in North Texas. Southern extent of the threat is not clear. Watch extensions will need to be considered if trends warrant. DISCUSSION...A supercell near Denison/Sherman has generally been moving south-southwestward roughly along an outflow boundary. This storm will likely continue into the mid evening. So far, 1 inch hail has been reported with this storm. MLCIN has been increasing to the south over the last hour. However, with an established supercell, it will take time to have a negative impact on the storm. The outflow boundary drapes southward trough western portions of the Metroplex. The observed 00Z FWD showed modest MLCIN along with steep mid-level lapse rates and 34 kts of effective shear. It is not clear whether this storm will persist far enough to impact DFW proper, but it is possible. Trends will need to be monitored for possible watch extensions farther south. ..Wendt.. 06/27/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...OUN... LAT...LON 33199630 32829647 32699678 32689709 32819728 33409735 33759732 33919711 34149670 34049652 33749627 33199630 Read more

WW 0469 Status Updates
STATUS REPORT ON WW 469 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 W ABE TO 20 W GON TO 10 SE BAF. ..GOSS..06/27/24 ATTN...WFO...OKX...BOX...ALY...PHI... STATUS REPORT FOR WS 469 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC001-007-009-011-013-015-270340- CT . CONNECTICUT COUNTIES INCLUDED ARE FAIRFIELD MIDDLESEX NEW HAVEN NEW LONDON TOLLAND WINDHAM NJC003-005-007-013-015-017-019-021-023-025-027-029-031-035-039- 041-270340- NJ . NEW JERSEY COUNTIES INCLUDED ARE BERGEN BURLINGTON CAMDEN ESSEX GLOUCESTER HUDSON HUNTERDON MERCER MIDDLESEX MONMOUTH MORRIS OCEAN PASSAIC SOMERSET UNION WARREN NYC005-047-059-061-081-085-087-103-119-270340- Read more