SPC Sep 21, 2024 1730 UTC Day 2 Convective Outlook

9 months 4 weeks ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS TO SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Synopsis... A filling mid-level low will move toward the central High Plains on Sunday afternoon/evening. Moderate mid-level flow will maintain southeast of this low and overspread the Oklahoma/southern Kansas vicinity. At the surface, a cold front will extend from southern Michigan across Illinois and Missouri and into Oklahoma and Texas. ...Southern Missouri across Oklahoma and into West Texas... Thunderstorms will likely be ongoing along and ahead of the surface front across the TX Panhandle and into Oklahoma and from central Kansas, across Missouri, and to southern Illinois Sunday morning. A seasonally moist airmass featuring upper 60s to perhaps low 70s dewpoints will exist ahead of the surface front Sunday afternoon/evening. Surface heating ahead of the front should result in moderate instability amid a marginally sheared airmass. A few stronger/organized storms are possible with a primary threat of damaging wind gusts, especially where any clustering or line segments can develop. Some large hail is also possible, where a few supercells are possible across northwest Texas and West Texas. The severe threat will be primarily diurnally driven with minimal severe concerns after 1-3 UTC. ..Bentley.. 09/21/2024 Read more

SPC Sep 21, 2024 1730 UTC Day 2 Convective Outlook

9 months 4 weeks ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS TO SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Synopsis... A filling mid-level low will move toward the central High Plains on Sunday afternoon/evening. Moderate mid-level flow will maintain southeast of this low and overspread the Oklahoma/southern Kansas vicinity. At the surface, a cold front will extend from southern Michigan across Illinois and Missouri and into Oklahoma and Texas. ...Southern Missouri across Oklahoma and into West Texas... Thunderstorms will likely be ongoing along and ahead of the surface front across the TX Panhandle and into Oklahoma and from central Kansas, across Missouri, and to southern Illinois Sunday morning. A seasonally moist airmass featuring upper 60s to perhaps low 70s dewpoints will exist ahead of the surface front Sunday afternoon/evening. Surface heating ahead of the front should result in moderate instability amid a marginally sheared airmass. A few stronger/organized storms are possible with a primary threat of damaging wind gusts, especially where any clustering or line segments can develop. Some large hail is also possible, where a few supercells are possible across northwest Texas and West Texas. The severe threat will be primarily diurnally driven with minimal severe concerns after 1-3 UTC. ..Bentley.. 09/21/2024 Read more

SPC Sep 21, 2024 1730 UTC Day 2 Convective Outlook

9 months 4 weeks ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS TO SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Synopsis... A filling mid-level low will move toward the central High Plains on Sunday afternoon/evening. Moderate mid-level flow will maintain southeast of this low and overspread the Oklahoma/southern Kansas vicinity. At the surface, a cold front will extend from southern Michigan across Illinois and Missouri and into Oklahoma and Texas. ...Southern Missouri across Oklahoma and into West Texas... Thunderstorms will likely be ongoing along and ahead of the surface front across the TX Panhandle and into Oklahoma and from central Kansas, across Missouri, and to southern Illinois Sunday morning. A seasonally moist airmass featuring upper 60s to perhaps low 70s dewpoints will exist ahead of the surface front Sunday afternoon/evening. Surface heating ahead of the front should result in moderate instability amid a marginally sheared airmass. A few stronger/organized storms are possible with a primary threat of damaging wind gusts, especially where any clustering or line segments can develop. Some large hail is also possible, where a few supercells are possible across northwest Texas and West Texas. The severe threat will be primarily diurnally driven with minimal severe concerns after 1-3 UTC. ..Bentley.. 09/21/2024 Read more

SPC Sep 21, 2024 1730 UTC Day 2 Convective Outlook

9 months 4 weeks ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS TO SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Synopsis... A filling mid-level low will move toward the central High Plains on Sunday afternoon/evening. Moderate mid-level flow will maintain southeast of this low and overspread the Oklahoma/southern Kansas vicinity. At the surface, a cold front will extend from southern Michigan across Illinois and Missouri and into Oklahoma and Texas. ...Southern Missouri across Oklahoma and into West Texas... Thunderstorms will likely be ongoing along and ahead of the surface front across the TX Panhandle and into Oklahoma and from central Kansas, across Missouri, and to southern Illinois Sunday morning. A seasonally moist airmass featuring upper 60s to perhaps low 70s dewpoints will exist ahead of the surface front Sunday afternoon/evening. Surface heating ahead of the front should result in moderate instability amid a marginally sheared airmass. A few stronger/organized storms are possible with a primary threat of damaging wind gusts, especially where any clustering or line segments can develop. Some large hail is also possible, where a few supercells are possible across northwest Texas and West Texas. The severe threat will be primarily diurnally driven with minimal severe concerns after 1-3 UTC. ..Bentley.. 09/21/2024 Read more

SPC Sep 21, 2024 1730 UTC Day 2 Convective Outlook

9 months 4 weeks ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS TO SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Synopsis... A filling mid-level low will move toward the central High Plains on Sunday afternoon/evening. Moderate mid-level flow will maintain southeast of this low and overspread the Oklahoma/southern Kansas vicinity. At the surface, a cold front will extend from southern Michigan across Illinois and Missouri and into Oklahoma and Texas. ...Southern Missouri across Oklahoma and into West Texas... Thunderstorms will likely be ongoing along and ahead of the surface front across the TX Panhandle and into Oklahoma and from central Kansas, across Missouri, and to southern Illinois Sunday morning. A seasonally moist airmass featuring upper 60s to perhaps low 70s dewpoints will exist ahead of the surface front Sunday afternoon/evening. Surface heating ahead of the front should result in moderate instability amid a marginally sheared airmass. A few stronger/organized storms are possible with a primary threat of damaging wind gusts, especially where any clustering or line segments can develop. Some large hail is also possible, where a few supercells are possible across northwest Texas and West Texas. The severe threat will be primarily diurnally driven with minimal severe concerns after 1-3 UTC. ..Bentley.. 09/21/2024 Read more

SPC Sep 21, 2024 1730 UTC Day 2 Convective Outlook

9 months 4 weeks ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS TO SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Synopsis... A filling mid-level low will move toward the central High Plains on Sunday afternoon/evening. Moderate mid-level flow will maintain southeast of this low and overspread the Oklahoma/southern Kansas vicinity. At the surface, a cold front will extend from southern Michigan across Illinois and Missouri and into Oklahoma and Texas. ...Southern Missouri across Oklahoma and into West Texas... Thunderstorms will likely be ongoing along and ahead of the surface front across the TX Panhandle and into Oklahoma and from central Kansas, across Missouri, and to southern Illinois Sunday morning. A seasonally moist airmass featuring upper 60s to perhaps low 70s dewpoints will exist ahead of the surface front Sunday afternoon/evening. Surface heating ahead of the front should result in moderate instability amid a marginally sheared airmass. A few stronger/organized storms are possible with a primary threat of damaging wind gusts, especially where any clustering or line segments can develop. Some large hail is also possible, where a few supercells are possible across northwest Texas and West Texas. The severe threat will be primarily diurnally driven with minimal severe concerns after 1-3 UTC. ..Bentley.. 09/21/2024 Read more

SPC Sep 21, 2024 1730 UTC Day 2 Convective Outlook

9 months 4 weeks ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS TO SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Synopsis... A filling mid-level low will move toward the central High Plains on Sunday afternoon/evening. Moderate mid-level flow will maintain southeast of this low and overspread the Oklahoma/southern Kansas vicinity. At the surface, a cold front will extend from southern Michigan across Illinois and Missouri and into Oklahoma and Texas. ...Southern Missouri across Oklahoma and into West Texas... Thunderstorms will likely be ongoing along and ahead of the surface front across the TX Panhandle and into Oklahoma and from central Kansas, across Missouri, and to southern Illinois Sunday morning. A seasonally moist airmass featuring upper 60s to perhaps low 70s dewpoints will exist ahead of the surface front Sunday afternoon/evening. Surface heating ahead of the front should result in moderate instability amid a marginally sheared airmass. A few stronger/organized storms are possible with a primary threat of damaging wind gusts, especially where any clustering or line segments can develop. Some large hail is also possible, where a few supercells are possible across northwest Texas and West Texas. The severe threat will be primarily diurnally driven with minimal severe concerns after 1-3 UTC. ..Bentley.. 09/21/2024 Read more

SPC Sep 21, 2024 1730 UTC Day 2 Convective Outlook

9 months 4 weeks ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS TO SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Synopsis... A filling mid-level low will move toward the central High Plains on Sunday afternoon/evening. Moderate mid-level flow will maintain southeast of this low and overspread the Oklahoma/southern Kansas vicinity. At the surface, a cold front will extend from southern Michigan across Illinois and Missouri and into Oklahoma and Texas. ...Southern Missouri across Oklahoma and into West Texas... Thunderstorms will likely be ongoing along and ahead of the surface front across the TX Panhandle and into Oklahoma and from central Kansas, across Missouri, and to southern Illinois Sunday morning. A seasonally moist airmass featuring upper 60s to perhaps low 70s dewpoints will exist ahead of the surface front Sunday afternoon/evening. Surface heating ahead of the front should result in moderate instability amid a marginally sheared airmass. A few stronger/organized storms are possible with a primary threat of damaging wind gusts, especially where any clustering or line segments can develop. Some large hail is also possible, where a few supercells are possible across northwest Texas and West Texas. The severe threat will be primarily diurnally driven with minimal severe concerns after 1-3 UTC. ..Bentley.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more

SPC Sep 21, 2024 1630 UTC Day 1 Convective Outlook

9 months 4 weeks ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Sat Sep 21 2024 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.... ...SUMMARY... Scattered severe storms capable of all hazards are possible this afternoon and evening across portions of the southern High Plains. ...Southern High Plains... A potent upper low and associated 65-75 kt mid-level jet max centered over AZ are expected to quickly move eastward, overspreading the southern Rockies/High Plains this afternoon and evening. At the surface, sustained southerly flow ahead of a deepening surface low and trailing cold front over western NM will support moderate destabilization (MLCAPE 1500-2000 J/kg) with afternoon heating and continued low-level upslope. As the mid-level system approaches, mid-level height falls and flow aloft will intensify, elongating low and mid-level hodographs, allowing for convective development/organization in the form of supercells. One source of continued uncertainty is the ongoing elevated convection and cloud debris centered north of a diffuse surface boundary stretching from central NM to the western TX Panhandle. So far, this boundary has been slowly lifting north with pronounced low-level theta-e advection taking place to the south. As deep-layer ascent intensifies through the late morning, continued convective development to the north may support reinforcement and stalling of the boundary. The northward extent of destabilization remains unclear, though this boundary could serve as a focus for renewed development of more robust convection expected later this afternoon. Most CAM guidance shows scattered thunderstorms initiating off the higher terrain of eastern NM, or ahead of the cold front farther west by early this afternoon. These storms should quickly mature with supportive thermodynamics and kinematics, eventually spreading eastward into the TX Panhandle. The risk for large to very large hail/severe gusts will likely accompany the stronger supercells, and a threat for a couple tornadoes may be realized later this afternoon/early evening from eastern NM into parts of adjacent west TX, especially near the boundary where low-level shear may be locally enhanced. ...Upper Midwest and MO Valley... A second upper low near the international border is forecast to quickly move eastward reaching the western Great Lakes by early this evening. Weak ascent is expected ahead of a surging cold front and diffuse wave cyclone across the northern MO valley and southern MN. Surface moistening with a warm front lifting north near the IA/MN border may act as a focus for more robust convective development along the cold front late this afternoon. Increasingly orthogonal deep-layer flow and steeping low/mid-level lapse rates could support a mix of supercells and multi-cell clusters. A few of the stronger storms may pose some hail/wind threat, which should peak in intensity during the early evening. However, somewhat limited heating and the lack of broader forcing for ascent suggests storm coverage should remain isolated. ...Western PA into the Mid Atlantic... Short-wave troughing across the upper OH Valley within mid-level northwesterly flow is expected to support isolated to widely scattered thunderstorms across western PA/VA later this afternoon. Model forecast soundings with moderate buoyancy and modest deep-layer shear would imply some of the stronger storms being capable of an isolated risk for wind damage (50-60 mph) and perhaps some hail. This activity will likely diminish by early evening coincident with nocturnal cooling. ..Lyons/Goss.. 09/21/2024 Read more