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SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue May 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND NORTHERN FLORIDA INTO EXTREME SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms will be possible today over parts of central and northern Florida into extreme southern Georgia, with damaging gusts and a tornado or two the main threats. Isolated severe storms will also be possible across portions of the Ohio and Tennessee Valleys into the Carolina Piedmont, as well as the central Rockies/High Plains and parts of western Texas. ...Synopsis... A mid-level trough will slowly progress across the Southeast as a second, low amplitude trough traverses the central Rockies today. Multiple embedded impulses should pivot around the Southeast mid-level trough and eject into the Atlantic, providing multiple rounds of deep-layer ascent to support a few rounds of thunderstorms over northern into central FL. Accompanying the southeast mid-level trough is a weak surface low over the OH/TN Valleys, which will aid in the northward transport of low-level moisture and associated buoyancy. Given modest vertical wind shear in place, adequate buoyancy will support the organization of at least isolated strong to severe thunderstorms over the OH/TN Valleys, with a more concentrated severe risk possible in northern FL along a residual baroclinic boundary. Elsewhere across the central Rockies/High Plains, enough deep-layer ascent will support scattered thunderstorms atop a well-mixed, heated boundary layer to support an isolated severe threat. ...Central and northern FL into extreme southern GA... A baroclinic boundary will become reinforced somewhere over northern FL with the passage of an MCS at the start of the period. Along this boundary, the MCS should intensify as a 500 mb jet streak overspreads the moist, destabilizing boundary layer. 7+ C/km mid-level lapse rates overspreading 70+ F surface dewpoints will boost MLCAPE to the 2000-3000 J/kg range. Modest low-level hodograph curvature and some elongation suggests that embedded bowing structures and mesovortices could develop, accompanied by a damaging gust and tornado risk. After the first round of storms diminish by the afternoon, a second round of strong to potentially severe thunderstorms could develop over northern FL as a second mid-level impulse embedded in the upper trough overspreads the region. Severe coverage with this second round of storms will be more conditional on how much airmass recovery can occur between both rounds of storms. ...OH and TN Valleys into the Carolina Piedmont... Deep-layer moisture will advect northward ahead of the meandering surface low, beneath a nearly uncapped troposphere. As such, diurnal heating needs only to boost surface temperatures into the lower 70s F to initiate convection. These temperatures, along with low to mid 60s F dewpoints, will support around 1000 J/kg SBCAPE by afternoon. Flow aloft is not expected to be overly strong, with slightly curved and short hodographs likely resulting in mainly pulse cellular and multicellular storms. Damaging gusts and hail will be the main threats, though a brief tornado or two cannot be ruled out. ...Central Rockies into the Central High Plains... The approach of a low-amplitude mid-level trough, and diurnal heating of an uncapped boundary layer, will support scattered to numerous thunderstorms during the afternoon and evening hours. A deep and dry boundary layer should become established by afternoon peak heating, resulting in high-based pulse- and multicell storms capable of producing isolated severe gusts (given 7-9 C/km low and mid-level lapse rates). A couple instances of severe hail may also accompany storms over the central High Plains, where low-level moisture is slightly more favorable. ...Portions of western Texas... A narrow corridor of thunderstorm potential exists ahead of a diffuse dryline over western TX by afternoon peak heating, where the dryline circulation may be strong enough to assist in the initiation of isolated thunderstorms amid minimal CINH. Low-level moisture will be meager, with mid 80s F surface temperatures and low 50s F dewpoints contributing to over 30 F spreads, so any storms that develop will be high based. Somewhat elongated hodographs suggest that supercells would be the dominant mode of convection, accompanied by an isolated severe wind/hail risk. ..Squitieri.. 05/14/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue May 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND NORTHERN FLORIDA INTO EXTREME SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms will be possible today over parts of central and northern Florida into extreme southern Georgia, with damaging gusts and a tornado or two the main threats. Isolated severe storms will also be possible across portions of the Ohio and Tennessee Valleys into the Carolina Piedmont, as well as the central Rockies/High Plains and parts of western Texas. ...Synopsis... A mid-level trough will slowly progress across the Southeast as a second, low amplitude trough traverses the central Rockies today. Multiple embedded impulses should pivot around the Southeast mid-level trough and eject into the Atlantic, providing multiple rounds of deep-layer ascent to support a few rounds of thunderstorms over northern into central FL. Accompanying the southeast mid-level trough is a weak surface low over the OH/TN Valleys, which will aid in the northward transport of low-level moisture and associated buoyancy. Given modest vertical wind shear in place, adequate buoyancy will support the organization of at least isolated strong to severe thunderstorms over the OH/TN Valleys, with a more concentrated severe risk possible in northern FL along a residual baroclinic boundary. Elsewhere across the central Rockies/High Plains, enough deep-layer ascent will support scattered thunderstorms atop a well-mixed, heated boundary layer to support an isolated severe threat. ...Central and northern FL into extreme southern GA... A baroclinic boundary will become reinforced somewhere over northern FL with the passage of an MCS at the start of the period. Along this boundary, the MCS should intensify as a 500 mb jet streak overspreads the moist, destabilizing boundary layer. 7+ C/km mid-level lapse rates overspreading 70+ F surface dewpoints will boost MLCAPE to the 2000-3000 J/kg range. Modest low-level hodograph curvature and some elongation suggests that embedded bowing structures and mesovortices could develop, accompanied by a damaging gust and tornado risk. After the first round of storms diminish by the afternoon, a second round of strong to potentially severe thunderstorms could develop over northern FL as a second mid-level impulse embedded in the upper trough overspreads the region. Severe coverage with this second round of storms will be more conditional on how much airmass recovery can occur between both rounds of storms. ...OH and TN Valleys into the Carolina Piedmont... Deep-layer moisture will advect northward ahead of the meandering surface low, beneath a nearly uncapped troposphere. As such, diurnal heating needs only to boost surface temperatures into the lower 70s F to initiate convection. These temperatures, along with low to mid 60s F dewpoints, will support around 1000 J/kg SBCAPE by afternoon. Flow aloft is not expected to be overly strong, with slightly curved and short hodographs likely resulting in mainly pulse cellular and multicellular storms. Damaging gusts and hail will be the main threats, though a brief tornado or two cannot be ruled out. ...Central Rockies into the Central High Plains... The approach of a low-amplitude mid-level trough, and diurnal heating of an uncapped boundary layer, will support scattered to numerous thunderstorms during the afternoon and evening hours. A deep and dry boundary layer should become established by afternoon peak heating, resulting in high-based pulse- and multicell storms capable of producing isolated severe gusts (given 7-9 C/km low and mid-level lapse rates). A couple instances of severe hail may also accompany storms over the central High Plains, where low-level moisture is slightly more favorable. ...Portions of western Texas... A narrow corridor of thunderstorm potential exists ahead of a diffuse dryline over western TX by afternoon peak heating, where the dryline circulation may be strong enough to assist in the initiation of isolated thunderstorms amid minimal CINH. Low-level moisture will be meager, with mid 80s F surface temperatures and low 50s F dewpoints contributing to over 30 F spreads, so any storms that develop will be high based. Somewhat elongated hodographs suggest that supercells would be the dominant mode of convection, accompanied by an isolated severe wind/hail risk. ..Squitieri.. 05/14/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue May 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND NORTHERN FLORIDA INTO EXTREME SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms will be possible today over parts of central and northern Florida into extreme southern Georgia, with damaging gusts and a tornado or two the main threats. Isolated severe storms will also be possible across portions of the Ohio and Tennessee Valleys into the Carolina Piedmont, as well as the central Rockies/High Plains and parts of western Texas. ...Synopsis... A mid-level trough will slowly progress across the Southeast as a second, low amplitude trough traverses the central Rockies today. Multiple embedded impulses should pivot around the Southeast mid-level trough and eject into the Atlantic, providing multiple rounds of deep-layer ascent to support a few rounds of thunderstorms over northern into central FL. Accompanying the southeast mid-level trough is a weak surface low over the OH/TN Valleys, which will aid in the northward transport of low-level moisture and associated buoyancy. Given modest vertical wind shear in place, adequate buoyancy will support the organization of at least isolated strong to severe thunderstorms over the OH/TN Valleys, with a more concentrated severe risk possible in northern FL along a residual baroclinic boundary. Elsewhere across the central Rockies/High Plains, enough deep-layer ascent will support scattered thunderstorms atop a well-mixed, heated boundary layer to support an isolated severe threat. ...Central and northern FL into extreme southern GA... A baroclinic boundary will become reinforced somewhere over northern FL with the passage of an MCS at the start of the period. Along this boundary, the MCS should intensify as a 500 mb jet streak overspreads the moist, destabilizing boundary layer. 7+ C/km mid-level lapse rates overspreading 70+ F surface dewpoints will boost MLCAPE to the 2000-3000 J/kg range. Modest low-level hodograph curvature and some elongation suggests that embedded bowing structures and mesovortices could develop, accompanied by a damaging gust and tornado risk. After the first round of storms diminish by the afternoon, a second round of strong to potentially severe thunderstorms could develop over northern FL as a second mid-level impulse embedded in the upper trough overspreads the region. Severe coverage with this second round of storms will be more conditional on how much airmass recovery can occur between both rounds of storms. ...OH and TN Valleys into the Carolina Piedmont... Deep-layer moisture will advect northward ahead of the meandering surface low, beneath a nearly uncapped troposphere. As such, diurnal heating needs only to boost surface temperatures into the lower 70s F to initiate convection. These temperatures, along with low to mid 60s F dewpoints, will support around 1000 J/kg SBCAPE by afternoon. Flow aloft is not expected to be overly strong, with slightly curved and short hodographs likely resulting in mainly pulse cellular and multicellular storms. Damaging gusts and hail will be the main threats, though a brief tornado or two cannot be ruled out. ...Central Rockies into the Central High Plains... The approach of a low-amplitude mid-level trough, and diurnal heating of an uncapped boundary layer, will support scattered to numerous thunderstorms during the afternoon and evening hours. A deep and dry boundary layer should become established by afternoon peak heating, resulting in high-based pulse- and multicell storms capable of producing isolated severe gusts (given 7-9 C/km low and mid-level lapse rates). A couple instances of severe hail may also accompany storms over the central High Plains, where low-level moisture is slightly more favorable. ...Portions of western Texas... A narrow corridor of thunderstorm potential exists ahead of a diffuse dryline over western TX by afternoon peak heating, where the dryline circulation may be strong enough to assist in the initiation of isolated thunderstorms amid minimal CINH. Low-level moisture will be meager, with mid 80s F surface temperatures and low 50s F dewpoints contributing to over 30 F spreads, so any storms that develop will be high based. Somewhat elongated hodographs suggest that supercells would be the dominant mode of convection, accompanied by an isolated severe wind/hail risk. ..Squitieri.. 05/14/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue May 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND NORTHERN FLORIDA INTO EXTREME SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms will be possible today over parts of central and northern Florida into extreme southern Georgia, with damaging gusts and a tornado or two the main threats. Isolated severe storms will also be possible across portions of the Ohio and Tennessee Valleys into the Carolina Piedmont, as well as the central Rockies/High Plains and parts of western Texas. ...Synopsis... A mid-level trough will slowly progress across the Southeast as a second, low amplitude trough traverses the central Rockies today. Multiple embedded impulses should pivot around the Southeast mid-level trough and eject into the Atlantic, providing multiple rounds of deep-layer ascent to support a few rounds of thunderstorms over northern into central FL. Accompanying the southeast mid-level trough is a weak surface low over the OH/TN Valleys, which will aid in the northward transport of low-level moisture and associated buoyancy. Given modest vertical wind shear in place, adequate buoyancy will support the organization of at least isolated strong to severe thunderstorms over the OH/TN Valleys, with a more concentrated severe risk possible in northern FL along a residual baroclinic boundary. Elsewhere across the central Rockies/High Plains, enough deep-layer ascent will support scattered thunderstorms atop a well-mixed, heated boundary layer to support an isolated severe threat. ...Central and northern FL into extreme southern GA... A baroclinic boundary will become reinforced somewhere over northern FL with the passage of an MCS at the start of the period. Along this boundary, the MCS should intensify as a 500 mb jet streak overspreads the moist, destabilizing boundary layer. 7+ C/km mid-level lapse rates overspreading 70+ F surface dewpoints will boost MLCAPE to the 2000-3000 J/kg range. Modest low-level hodograph curvature and some elongation suggests that embedded bowing structures and mesovortices could develop, accompanied by a damaging gust and tornado risk. After the first round of storms diminish by the afternoon, a second round of strong to potentially severe thunderstorms could develop over northern FL as a second mid-level impulse embedded in the upper trough overspreads the region. Severe coverage with this second round of storms will be more conditional on how much airmass recovery can occur between both rounds of storms. ...OH and TN Valleys into the Carolina Piedmont... Deep-layer moisture will advect northward ahead of the meandering surface low, beneath a nearly uncapped troposphere. As such, diurnal heating needs only to boost surface temperatures into the lower 70s F to initiate convection. These temperatures, along with low to mid 60s F dewpoints, will support around 1000 J/kg SBCAPE by afternoon. Flow aloft is not expected to be overly strong, with slightly curved and short hodographs likely resulting in mainly pulse cellular and multicellular storms. Damaging gusts and hail will be the main threats, though a brief tornado or two cannot be ruled out. ...Central Rockies into the Central High Plains... The approach of a low-amplitude mid-level trough, and diurnal heating of an uncapped boundary layer, will support scattered to numerous thunderstorms during the afternoon and evening hours. A deep and dry boundary layer should become established by afternoon peak heating, resulting in high-based pulse- and multicell storms capable of producing isolated severe gusts (given 7-9 C/km low and mid-level lapse rates). A couple instances of severe hail may also accompany storms over the central High Plains, where low-level moisture is slightly more favorable. ...Portions of western Texas... A narrow corridor of thunderstorm potential exists ahead of a diffuse dryline over western TX by afternoon peak heating, where the dryline circulation may be strong enough to assist in the initiation of isolated thunderstorms amid minimal CINH. Low-level moisture will be meager, with mid 80s F surface temperatures and low 50s F dewpoints contributing to over 30 F spreads, so any storms that develop will be high based. Somewhat elongated hodographs suggest that supercells would be the dominant mode of convection, accompanied by an isolated severe wind/hail risk. ..Squitieri.. 05/14/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue May 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND NORTHERN FLORIDA INTO EXTREME SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms will be possible today over parts of central and northern Florida into extreme southern Georgia, with damaging gusts and a tornado or two the main threats. Isolated severe storms will also be possible across portions of the Ohio and Tennessee Valleys into the Carolina Piedmont, as well as the central Rockies/High Plains and parts of western Texas. ...Synopsis... A mid-level trough will slowly progress across the Southeast as a second, low amplitude trough traverses the central Rockies today. Multiple embedded impulses should pivot around the Southeast mid-level trough and eject into the Atlantic, providing multiple rounds of deep-layer ascent to support a few rounds of thunderstorms over northern into central FL. Accompanying the southeast mid-level trough is a weak surface low over the OH/TN Valleys, which will aid in the northward transport of low-level moisture and associated buoyancy. Given modest vertical wind shear in place, adequate buoyancy will support the organization of at least isolated strong to severe thunderstorms over the OH/TN Valleys, with a more concentrated severe risk possible in northern FL along a residual baroclinic boundary. Elsewhere across the central Rockies/High Plains, enough deep-layer ascent will support scattered thunderstorms atop a well-mixed, heated boundary layer to support an isolated severe threat. ...Central and northern FL into extreme southern GA... A baroclinic boundary will become reinforced somewhere over northern FL with the passage of an MCS at the start of the period. Along this boundary, the MCS should intensify as a 500 mb jet streak overspreads the moist, destabilizing boundary layer. 7+ C/km mid-level lapse rates overspreading 70+ F surface dewpoints will boost MLCAPE to the 2000-3000 J/kg range. Modest low-level hodograph curvature and some elongation suggests that embedded bowing structures and mesovortices could develop, accompanied by a damaging gust and tornado risk. After the first round of storms diminish by the afternoon, a second round of strong to potentially severe thunderstorms could develop over northern FL as a second mid-level impulse embedded in the upper trough overspreads the region. Severe coverage with this second round of storms will be more conditional on how much airmass recovery can occur between both rounds of storms. ...OH and TN Valleys into the Carolina Piedmont... Deep-layer moisture will advect northward ahead of the meandering surface low, beneath a nearly uncapped troposphere. As such, diurnal heating needs only to boost surface temperatures into the lower 70s F to initiate convection. These temperatures, along with low to mid 60s F dewpoints, will support around 1000 J/kg SBCAPE by afternoon. Flow aloft is not expected to be overly strong, with slightly curved and short hodographs likely resulting in mainly pulse cellular and multicellular storms. Damaging gusts and hail will be the main threats, though a brief tornado or two cannot be ruled out. ...Central Rockies into the Central High Plains... The approach of a low-amplitude mid-level trough, and diurnal heating of an uncapped boundary layer, will support scattered to numerous thunderstorms during the afternoon and evening hours. A deep and dry boundary layer should become established by afternoon peak heating, resulting in high-based pulse- and multicell storms capable of producing isolated severe gusts (given 7-9 C/km low and mid-level lapse rates). A couple instances of severe hail may also accompany storms over the central High Plains, where low-level moisture is slightly more favorable. ...Portions of western Texas... A narrow corridor of thunderstorm potential exists ahead of a diffuse dryline over western TX by afternoon peak heating, where the dryline circulation may be strong enough to assist in the initiation of isolated thunderstorms amid minimal CINH. Low-level moisture will be meager, with mid 80s F surface temperatures and low 50s F dewpoints contributing to over 30 F spreads, so any storms that develop will be high based. Somewhat elongated hodographs suggest that supercells would be the dominant mode of convection, accompanied by an isolated severe wind/hail risk. ..Squitieri.. 05/14/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue May 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND NORTHERN FLORIDA INTO EXTREME SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms will be possible today over parts of central and northern Florida into extreme southern Georgia, with damaging gusts and a tornado or two the main threats. Isolated severe storms will also be possible across portions of the Ohio and Tennessee Valleys into the Carolina Piedmont, as well as the central Rockies/High Plains and parts of western Texas. ...Synopsis... A mid-level trough will slowly progress across the Southeast as a second, low amplitude trough traverses the central Rockies today. Multiple embedded impulses should pivot around the Southeast mid-level trough and eject into the Atlantic, providing multiple rounds of deep-layer ascent to support a few rounds of thunderstorms over northern into central FL. Accompanying the southeast mid-level trough is a weak surface low over the OH/TN Valleys, which will aid in the northward transport of low-level moisture and associated buoyancy. Given modest vertical wind shear in place, adequate buoyancy will support the organization of at least isolated strong to severe thunderstorms over the OH/TN Valleys, with a more concentrated severe risk possible in northern FL along a residual baroclinic boundary. Elsewhere across the central Rockies/High Plains, enough deep-layer ascent will support scattered thunderstorms atop a well-mixed, heated boundary layer to support an isolated severe threat. ...Central and northern FL into extreme southern GA... A baroclinic boundary will become reinforced somewhere over northern FL with the passage of an MCS at the start of the period. Along this boundary, the MCS should intensify as a 500 mb jet streak overspreads the moist, destabilizing boundary layer. 7+ C/km mid-level lapse rates overspreading 70+ F surface dewpoints will boost MLCAPE to the 2000-3000 J/kg range. Modest low-level hodograph curvature and some elongation suggests that embedded bowing structures and mesovortices could develop, accompanied by a damaging gust and tornado risk. After the first round of storms diminish by the afternoon, a second round of strong to potentially severe thunderstorms could develop over northern FL as a second mid-level impulse embedded in the upper trough overspreads the region. Severe coverage with this second round of storms will be more conditional on how much airmass recovery can occur between both rounds of storms. ...OH and TN Valleys into the Carolina Piedmont... Deep-layer moisture will advect northward ahead of the meandering surface low, beneath a nearly uncapped troposphere. As such, diurnal heating needs only to boost surface temperatures into the lower 70s F to initiate convection. These temperatures, along with low to mid 60s F dewpoints, will support around 1000 J/kg SBCAPE by afternoon. Flow aloft is not expected to be overly strong, with slightly curved and short hodographs likely resulting in mainly pulse cellular and multicellular storms. Damaging gusts and hail will be the main threats, though a brief tornado or two cannot be ruled out. ...Central Rockies into the Central High Plains... The approach of a low-amplitude mid-level trough, and diurnal heating of an uncapped boundary layer, will support scattered to numerous thunderstorms during the afternoon and evening hours. A deep and dry boundary layer should become established by afternoon peak heating, resulting in high-based pulse- and multicell storms capable of producing isolated severe gusts (given 7-9 C/km low and mid-level lapse rates). A couple instances of severe hail may also accompany storms over the central High Plains, where low-level moisture is slightly more favorable. ...Portions of western Texas... A narrow corridor of thunderstorm potential exists ahead of a diffuse dryline over western TX by afternoon peak heating, where the dryline circulation may be strong enough to assist in the initiation of isolated thunderstorms amid minimal CINH. Low-level moisture will be meager, with mid 80s F surface temperatures and low 50s F dewpoints contributing to over 30 F spreads, so any storms that develop will be high based. Somewhat elongated hodographs suggest that supercells would be the dominant mode of convection, accompanied by an isolated severe wind/hail risk. ..Squitieri.. 05/14/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue May 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND NORTHERN FLORIDA INTO EXTREME SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms will be possible today over parts of central and northern Florida into extreme southern Georgia, with damaging gusts and a tornado or two the main threats. Isolated severe storms will also be possible across portions of the Ohio and Tennessee Valleys into the Carolina Piedmont, as well as the central Rockies/High Plains and parts of western Texas. ...Synopsis... A mid-level trough will slowly progress across the Southeast as a second, low amplitude trough traverses the central Rockies today. Multiple embedded impulses should pivot around the Southeast mid-level trough and eject into the Atlantic, providing multiple rounds of deep-layer ascent to support a few rounds of thunderstorms over northern into central FL. Accompanying the southeast mid-level trough is a weak surface low over the OH/TN Valleys, which will aid in the northward transport of low-level moisture and associated buoyancy. Given modest vertical wind shear in place, adequate buoyancy will support the organization of at least isolated strong to severe thunderstorms over the OH/TN Valleys, with a more concentrated severe risk possible in northern FL along a residual baroclinic boundary. Elsewhere across the central Rockies/High Plains, enough deep-layer ascent will support scattered thunderstorms atop a well-mixed, heated boundary layer to support an isolated severe threat. ...Central and northern FL into extreme southern GA... A baroclinic boundary will become reinforced somewhere over northern FL with the passage of an MCS at the start of the period. Along this boundary, the MCS should intensify as a 500 mb jet streak overspreads the moist, destabilizing boundary layer. 7+ C/km mid-level lapse rates overspreading 70+ F surface dewpoints will boost MLCAPE to the 2000-3000 J/kg range. Modest low-level hodograph curvature and some elongation suggests that embedded bowing structures and mesovortices could develop, accompanied by a damaging gust and tornado risk. After the first round of storms diminish by the afternoon, a second round of strong to potentially severe thunderstorms could develop over northern FL as a second mid-level impulse embedded in the upper trough overspreads the region. Severe coverage with this second round of storms will be more conditional on how much airmass recovery can occur between both rounds of storms. ...OH and TN Valleys into the Carolina Piedmont... Deep-layer moisture will advect northward ahead of the meandering surface low, beneath a nearly uncapped troposphere. As such, diurnal heating needs only to boost surface temperatures into the lower 70s F to initiate convection. These temperatures, along with low to mid 60s F dewpoints, will support around 1000 J/kg SBCAPE by afternoon. Flow aloft is not expected to be overly strong, with slightly curved and short hodographs likely resulting in mainly pulse cellular and multicellular storms. Damaging gusts and hail will be the main threats, though a brief tornado or two cannot be ruled out. ...Central Rockies into the Central High Plains... The approach of a low-amplitude mid-level trough, and diurnal heating of an uncapped boundary layer, will support scattered to numerous thunderstorms during the afternoon and evening hours. A deep and dry boundary layer should become established by afternoon peak heating, resulting in high-based pulse- and multicell storms capable of producing isolated severe gusts (given 7-9 C/km low and mid-level lapse rates). A couple instances of severe hail may also accompany storms over the central High Plains, where low-level moisture is slightly more favorable. ...Portions of western Texas... A narrow corridor of thunderstorm potential exists ahead of a diffuse dryline over western TX by afternoon peak heating, where the dryline circulation may be strong enough to assist in the initiation of isolated thunderstorms amid minimal CINH. Low-level moisture will be meager, with mid 80s F surface temperatures and low 50s F dewpoints contributing to over 30 F spreads, so any storms that develop will be high based. Somewhat elongated hodographs suggest that supercells would be the dominant mode of convection, accompanied by an isolated severe wind/hail risk. ..Squitieri.. 05/14/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue May 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND NORTHERN FLORIDA INTO EXTREME SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms will be possible today over parts of central and northern Florida into extreme southern Georgia, with damaging gusts and a tornado or two the main threats. Isolated severe storms will also be possible across portions of the Ohio and Tennessee Valleys into the Carolina Piedmont, as well as the central Rockies/High Plains and parts of western Texas. ...Synopsis... A mid-level trough will slowly progress across the Southeast as a second, low amplitude trough traverses the central Rockies today. Multiple embedded impulses should pivot around the Southeast mid-level trough and eject into the Atlantic, providing multiple rounds of deep-layer ascent to support a few rounds of thunderstorms over northern into central FL. Accompanying the southeast mid-level trough is a weak surface low over the OH/TN Valleys, which will aid in the northward transport of low-level moisture and associated buoyancy. Given modest vertical wind shear in place, adequate buoyancy will support the organization of at least isolated strong to severe thunderstorms over the OH/TN Valleys, with a more concentrated severe risk possible in northern FL along a residual baroclinic boundary. Elsewhere across the central Rockies/High Plains, enough deep-layer ascent will support scattered thunderstorms atop a well-mixed, heated boundary layer to support an isolated severe threat. ...Central and northern FL into extreme southern GA... A baroclinic boundary will become reinforced somewhere over northern FL with the passage of an MCS at the start of the period. Along this boundary, the MCS should intensify as a 500 mb jet streak overspreads the moist, destabilizing boundary layer. 7+ C/km mid-level lapse rates overspreading 70+ F surface dewpoints will boost MLCAPE to the 2000-3000 J/kg range. Modest low-level hodograph curvature and some elongation suggests that embedded bowing structures and mesovortices could develop, accompanied by a damaging gust and tornado risk. After the first round of storms diminish by the afternoon, a second round of strong to potentially severe thunderstorms could develop over northern FL as a second mid-level impulse embedded in the upper trough overspreads the region. Severe coverage with this second round of storms will be more conditional on how much airmass recovery can occur between both rounds of storms. ...OH and TN Valleys into the Carolina Piedmont... Deep-layer moisture will advect northward ahead of the meandering surface low, beneath a nearly uncapped troposphere. As such, diurnal heating needs only to boost surface temperatures into the lower 70s F to initiate convection. These temperatures, along with low to mid 60s F dewpoints, will support around 1000 J/kg SBCAPE by afternoon. Flow aloft is not expected to be overly strong, with slightly curved and short hodographs likely resulting in mainly pulse cellular and multicellular storms. Damaging gusts and hail will be the main threats, though a brief tornado or two cannot be ruled out. ...Central Rockies into the Central High Plains... The approach of a low-amplitude mid-level trough, and diurnal heating of an uncapped boundary layer, will support scattered to numerous thunderstorms during the afternoon and evening hours. A deep and dry boundary layer should become established by afternoon peak heating, resulting in high-based pulse- and multicell storms capable of producing isolated severe gusts (given 7-9 C/km low and mid-level lapse rates). A couple instances of severe hail may also accompany storms over the central High Plains, where low-level moisture is slightly more favorable. ...Portions of western Texas... A narrow corridor of thunderstorm potential exists ahead of a diffuse dryline over western TX by afternoon peak heating, where the dryline circulation may be strong enough to assist in the initiation of isolated thunderstorms amid minimal CINH. Low-level moisture will be meager, with mid 80s F surface temperatures and low 50s F dewpoints contributing to over 30 F spreads, so any storms that develop will be high based. Somewhat elongated hodographs suggest that supercells would be the dominant mode of convection, accompanied by an isolated severe wind/hail risk. ..Squitieri.. 05/14/2024 Read more

Nitrogen fertilizer can accumulate in farm fields during years of drought and can wash into streams in large amounts when rain returns and brings an end to drought. Such an event is occurring in Iowa’s large rivers, including the Boone, Cedar, Iowa and Turkey rivers, where concentrations have hit four-year highs. Stream flows are much higher than usual, and concentrations are extremely high, so the total nitrate load is also very high. “This is one of the biggest nitrate leaching events in 11 years,” according to David Cwiertny, director of the Center for Health Effects of Environmental Contamination at the University of Iowa. Water quality experts anticipated such a spike in pollution after significant rain fell after years of drought. More than twice the normal rain has fallen in recent weeks in Iowa, providing this wave of moisture to wash the nitrate out of the soil and into streams and rivers. Des Moines Water Works started its nitrate removal system on May 13 as the nitrate concentration in the Raccoon River, one of the main water sources, exceeded 15 parts per million. In March, the concentration was about 1 part per million, per DMWW data. Nitrate levels were extraordinarily high in other rivers, according to the Iowa Water Quality Information System. The Turkey River near Garber had a nitrate level of 18 parts per million. The Cedar River near Janesville reached 24 parts per million. And the Boone River near Webster City hit 25 parts per million. Iowa Capital Dispatch (Des Moines), May 12, 2024

MD 0775 CONCERNING SEVERE THUNDERSTORM WATCH 239... FOR CENTRAL GULF COAST VICINITY
Mesoscale Discussion 0775 NWS Storm Prediction Center Norman OK 0825 PM CDT Mon May 13 2024 Areas affected...Central Gulf Coast Vicinity Concerning...Severe Thunderstorm Watch 239... Valid 140125Z - 140330Z The severe weather threat for Severe Thunderstorm Watch 239 continues. SUMMARY...Severe threat will shift east along the central Gulf Coast this evening. Damaging winds are the primary risk. DISCUSSION...Well-organized MCS has matured along the central Gulf Coast early this evening. MCV appears to be embedded within the larger precip shield near the LA/MS border south of Natchez. Early-day thunderstorm complex that spread along the northeast Gulf Coast has advanced into the northern FL Peninsula and weakened, but trailing outflow and rain-cooled boundary layer has stabilized much of the FL Panhandle into southern AL. As the leading edge of the MCS surges east into this air mass there should be some propensity for weakening as it encounters a less favorable environment. Until then, damaging winds can be expected with the surging squall line. Given the expected weakening, current thinking is a new watch may not be warranted. ..Darrow.. 05/14/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MOB...JAN...LIX...LCH... LAT...LON 31129258 30778841 28898841 29249260 31129258 Read more

WW 0239 Status Updates
STATUS REPORT ON WW 239 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 S HUM TO 40 NNE ASD. ..SPC..05/14/24 ATTN...WFO...LCH...LIX... STATUS REPORT FOR WS 239 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS LAC051-057-071-075-087-140340- LA . LOUISIANA PARISHES INCLUDED ARE JEFFERSON LAFOURCHE ORLEANS PLAQUEMINES ST. BERNARD MSC045-047-059-109-140340- MS . MISSISSIPPI COUNTIES INCLUDED ARE HANCOCK HARRISON JACKSON PEARL RIVER GMZ532-534-536-538-550-552-555-557-140340- CW . ADJACENT COASTAL WATERS INCLUDED ARE MISSISSIPPI SOUND Read more

WW 0239 Status Updates
STATUS REPORT ON WW 239 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 S HUM TO 40 NNE ASD. ..SPC..05/14/24 ATTN...WFO...LCH...LIX... STATUS REPORT FOR WS 239 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS LAC051-057-071-075-087-140340- LA . LOUISIANA PARISHES INCLUDED ARE JEFFERSON LAFOURCHE ORLEANS PLAQUEMINES ST. BERNARD MSC045-047-059-109-140340- MS . MISSISSIPPI COUNTIES INCLUDED ARE HANCOCK HARRISON JACKSON PEARL RIVER GMZ532-534-536-538-550-552-555-557-140340- CW . ADJACENT COASTAL WATERS INCLUDED ARE MISSISSIPPI SOUND Read more

WW 0239 Status Updates
STATUS REPORT ON WW 239 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 S HUM TO 40 NNE ASD. ..SPC..05/14/24 ATTN...WFO...LCH...LIX... STATUS REPORT FOR WS 239 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS LAC051-057-071-075-087-140340- LA . LOUISIANA PARISHES INCLUDED ARE JEFFERSON LAFOURCHE ORLEANS PLAQUEMINES ST. BERNARD MSC045-047-059-109-140340- MS . MISSISSIPPI COUNTIES INCLUDED ARE HANCOCK HARRISON JACKSON PEARL RIVER GMZ532-534-536-538-550-552-555-557-140340- CW . ADJACENT COASTAL WATERS INCLUDED ARE MISSISSIPPI SOUND Read more

WW 0239 Status Updates
STATUS REPORT ON WW 239 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 S HUM TO 40 NNE ASD. ..SPC..05/14/24 ATTN...WFO...LCH...LIX... STATUS REPORT FOR WS 239 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS LAC051-057-071-075-087-140340- LA . LOUISIANA PARISHES INCLUDED ARE JEFFERSON LAFOURCHE ORLEANS PLAQUEMINES ST. BERNARD MSC045-047-059-109-140340- MS . MISSISSIPPI COUNTIES INCLUDED ARE HANCOCK HARRISON JACKSON PEARL RIVER GMZ532-534-536-538-550-552-555-557-140340- CW . ADJACENT COASTAL WATERS INCLUDED ARE MISSISSIPPI SOUND Read more

WW 0239 Status Updates
STATUS REPORT ON WW 239 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 S HUM TO 40 NNE ASD. ..SPC..05/14/24 ATTN...WFO...LCH...LIX... STATUS REPORT FOR WS 239 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS LAC051-057-071-075-087-140340- LA . LOUISIANA PARISHES INCLUDED ARE JEFFERSON LAFOURCHE ORLEANS PLAQUEMINES ST. BERNARD MSC045-047-059-109-140340- MS . MISSISSIPPI COUNTIES INCLUDED ARE HANCOCK HARRISON JACKSON PEARL RIVER GMZ532-534-536-538-550-552-555-557-140340- CW . ADJACENT COASTAL WATERS INCLUDED ARE MISSISSIPPI SOUND Read more

WW 239 SEVERE TSTM LA MS CW 132225Z - 140500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 239 NWS Storm Prediction Center Norman OK 525 PM CDT Mon May 13 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central and Southeast Louisiana Southern Mississippi Coastal Waters * Effective this Monday afternoon from 525 PM until Midnight CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph likely Scattered large hail and isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...A fast moving line of thunderstorms over southwest Louisiana will track across the watch area during the evening. Damaging winds are the main threat with these storms, along with a possible tornado or two along the leading edge of activity. The severe thunderstorm watch area is approximately along and 65 statute miles north and south of a line from 40 miles northwest of Intracoastal City LA to 55 miles southeast of Gulfport MS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 236...WW 237...WW 238... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27035. ...Hart Read more

WW 0239 Status Updates
STATUS REPORT ON WW 239 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 SSE 7R4 TO 20 SSE MCB. ..SPC..05/14/24 ATTN...WFO...LCH...LIX... STATUS REPORT FOR WS 239 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS LAC005-007-051-057-063-071-075-087-089-091-093-095-101-103-105- 109-117-140240- LA . LOUISIANA PARISHES INCLUDED ARE ASCENSION ASSUMPTION JEFFERSON LAFOURCHE LIVINGSTON ORLEANS PLAQUEMINES ST. BERNARD ST. CHARLES ST. HELENA ST. JAMES ST. JOHN THE BAPTIST ST. MARY ST. TAMMANY TANGIPAHOA TERREBONNE WASHINGTON MSC045-047-059-109-147-140240- MS . MISSISSIPPI COUNTIES INCLUDED ARE HANCOCK HARRISON JACKSON PEARL RIVER WALTHALL GMZ436-455-530-532-534-536-538-550-552-555-557-140240- Read more

MD 0773 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR MO OZARKS TO OUACHITA MOUNTAINS
Mesoscale Discussion 0773 NWS Storm Prediction Center Norman OK 0616 PM CDT Mon May 13 2024 Areas affected...MO Ozarks to Ouachita Mountains Concerning...Severe potential...Watch unlikely Valid 132316Z - 140115Z Probability of Watch Issuance...20 percent SUMMARY...Some risk for marginally severe hail and gusty winds exists with convection into the early evening. At this time a severe thunderstorm watch is not anticipated. DISCUSSION...Water-vapor imagery depicts a well-defined upper trough advancing east across eastern KS/OK into MO/AR. Cool mid-levels and modest deep-layer lapse rates are contributing to adequate buoyancy immediately ahead of this trough from southern MO into southeast OK. Scattered robust thunderstorms have evolved within an air mass characterized by roughly 1000 J/kg MLCAPE and strong surface-6km bulk shear. A few storms have exhibited some weak rotation and isolated supercells may linger through mid evening until buoyancy begins to wane with loss of heating. Until then, gusty winds and some risk for marginally severe hail can be expected with this activity. ..Darrow/Hart.. 05/13/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...SGF...SHV...TSA... LAT...LON 34539322 34289503 34799511 35579360 36899232 36519146 34539322 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0755 PM CDT Mon May 13 2024 Valid 140100Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN LOUISIANA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF DEEP SOUTH TEXAS AND PARTS OF EXTREME SOUTHEAST MISSISSIPPI INTO THE FLORIDA PANHANDLE... ...SUMMARY... Severe-hail-producing storms should continue across deep south Texas for a few more hours. Severe gusts may also continue into the evening with storms in Louisiana as they move along the Gulf Coast. Finally, isolated instances of hail and damaging gusts are still possible this evening across the Florida Peninsula. ...01Z Update... A mid-level trough continues to traverse the southern U.S., with a moist and unstable airmass fueling strong to severe thunderstorms along immediate portions of the Gulf Coast. A trailing outflow boundary continues to progress across Deep South Texas, where hail-producing supercells continue to move offshore into the Gulf of Mexico. Large hail remains possible over the next couple of hours while storms remain onshore. Meanwhile, an organized bow-echo MCS continues to move across LA, where multiple severe gusts (some over 65 kts) have been reported. This MCS is beginning to move toward a cooler, more stable airmass, which should dampen the severe wind threat to a degree. Nonetheless, at least a few more severe gusts may continue along the immediate Gulf Coast, where at least Slight risk probabilities have been maintained. Finally, a few supercells continue to move across the central FL peninsula, while additional storms continue to approach the peninsula from the Gulf. Here, the severe threat should also subside with nocturnal cooling. In the meantime, an isolated instance of severe hail or wind cannot be ruled out. A couple of strong storms remain possible over the southern Plains into the Ozarks closer to a weak surface low. Before nocturnal cooling, one of the stronger storms could produce a marginally severe gust or instance of hail. ..Squitieri.. 05/14/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0755 PM CDT Mon May 13 2024 Valid 140100Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN LOUISIANA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF DEEP SOUTH TEXAS AND PARTS OF EXTREME SOUTHEAST MISSISSIPPI INTO THE FLORIDA PANHANDLE... ...SUMMARY... Severe-hail-producing storms should continue across deep south Texas for a few more hours. Severe gusts may also continue into the evening with storms in Louisiana as they move along the Gulf Coast. Finally, isolated instances of hail and damaging gusts are still possible this evening across the Florida Peninsula. ...01Z Update... A mid-level trough continues to traverse the southern U.S., with a moist and unstable airmass fueling strong to severe thunderstorms along immediate portions of the Gulf Coast. A trailing outflow boundary continues to progress across Deep South Texas, where hail-producing supercells continue to move offshore into the Gulf of Mexico. Large hail remains possible over the next couple of hours while storms remain onshore. Meanwhile, an organized bow-echo MCS continues to move across LA, where multiple severe gusts (some over 65 kts) have been reported. This MCS is beginning to move toward a cooler, more stable airmass, which should dampen the severe wind threat to a degree. Nonetheless, at least a few more severe gusts may continue along the immediate Gulf Coast, where at least Slight risk probabilities have been maintained. Finally, a few supercells continue to move across the central FL peninsula, while additional storms continue to approach the peninsula from the Gulf. Here, the severe threat should also subside with nocturnal cooling. In the meantime, an isolated instance of severe hail or wind cannot be ruled out. A couple of strong storms remain possible over the southern Plains into the Ozarks closer to a weak surface low. Before nocturnal cooling, one of the stronger storms could produce a marginally severe gust or instance of hail. ..Squitieri.. 05/14/2024 Read more