Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z Primary change to the Day 2 (Sunday) Fire Weather Outlook update was to expand isolated dry thunderstorm highlights southeastward into central and southeastern Montana, as well as northern and eastern Wyoming. Fuels are critically receptive to fire spread in these areas, driven in part by drought conditions. While recent rainfall has occurred in the past week, and a few storms may produce locally wetting rainfall on Day 1 (today), this precipitation will not likely dampen fuels enough to eliminate wildfire-growth potential for tomorrow. The latest guidance consensus shows fast-moving, high-based thunderstorms moving across the central and northern Rockies atop a well-mixed boundary layer, characterized by inverted-v soundings extending above 700 mb. Some of these storms may produce strong, erratic wind gusts that can exacerbate wildfire growth, and severe gusts cannot be ruled out (see the Day 2 Convective Outlook for more details on severe thunderstorms). The combination of critically receptive fuels, and at least a few dry thunderstorms with strong to severe wind gusts, warrants the expansion of isolated dry thunderstorm highlights, even if some preceding fuels dampening takes place. ..Squitieri.. 07/27/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Sat Jul 27 2024/ ...Synopsis... Broad west-southwesterly mid-level flow will continue to bring dry and windy conditions to portions of southern Nevada and southwestern Utah, into northwestern Colorado and southern Wyoming. Additionally, a mid-level shortwave trough moving across northern Idaho and Montana will bring chances for isolated dry thunderstorms to western Montana and into far northwestern Wyoming. ...Dry Thunder... Cold temperatures aloft and forcing for ascent from a mid-level trough moving across northern Montana will bring chances for isolated dry thunder to much of western Montana, where fuels are receptive to lightning-based ignitions and wildfire spread. ...Dry and Windy... Dry and windy conditions will persist across the Great Basin on Sunday, where meteorological conditions will locally reach Critical criteria. Current fuel guidance suggests less than ideal conditions for wildfire ignitions, precluding the introduction of Critical highlights at this time. However, the dry and windy conditions of the previous day could result in some fuel recovery and will continue to be monitored. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z Primary change to the Day 2 (Sunday) Fire Weather Outlook update was to expand isolated dry thunderstorm highlights southeastward into central and southeastern Montana, as well as northern and eastern Wyoming. Fuels are critically receptive to fire spread in these areas, driven in part by drought conditions. While recent rainfall has occurred in the past week, and a few storms may produce locally wetting rainfall on Day 1 (today), this precipitation will not likely dampen fuels enough to eliminate wildfire-growth potential for tomorrow. The latest guidance consensus shows fast-moving, high-based thunderstorms moving across the central and northern Rockies atop a well-mixed boundary layer, characterized by inverted-v soundings extending above 700 mb. Some of these storms may produce strong, erratic wind gusts that can exacerbate wildfire growth, and severe gusts cannot be ruled out (see the Day 2 Convective Outlook for more details on severe thunderstorms). The combination of critically receptive fuels, and at least a few dry thunderstorms with strong to severe wind gusts, warrants the expansion of isolated dry thunderstorm highlights, even if some preceding fuels dampening takes place. ..Squitieri.. 07/27/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Sat Jul 27 2024/ ...Synopsis... Broad west-southwesterly mid-level flow will continue to bring dry and windy conditions to portions of southern Nevada and southwestern Utah, into northwestern Colorado and southern Wyoming. Additionally, a mid-level shortwave trough moving across northern Idaho and Montana will bring chances for isolated dry thunderstorms to western Montana and into far northwestern Wyoming. ...Dry Thunder... Cold temperatures aloft and forcing for ascent from a mid-level trough moving across northern Montana will bring chances for isolated dry thunder to much of western Montana, where fuels are receptive to lightning-based ignitions and wildfire spread. ...Dry and Windy... Dry and windy conditions will persist across the Great Basin on Sunday, where meteorological conditions will locally reach Critical criteria. Current fuel guidance suggests less than ideal conditions for wildfire ignitions, precluding the introduction of Critical highlights at this time. However, the dry and windy conditions of the previous day could result in some fuel recovery and will continue to be monitored. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z Primary change to the Day 2 (Sunday) Fire Weather Outlook update was to expand isolated dry thunderstorm highlights southeastward into central and southeastern Montana, as well as northern and eastern Wyoming. Fuels are critically receptive to fire spread in these areas, driven in part by drought conditions. While recent rainfall has occurred in the past week, and a few storms may produce locally wetting rainfall on Day 1 (today), this precipitation will not likely dampen fuels enough to eliminate wildfire-growth potential for tomorrow. The latest guidance consensus shows fast-moving, high-based thunderstorms moving across the central and northern Rockies atop a well-mixed boundary layer, characterized by inverted-v soundings extending above 700 mb. Some of these storms may produce strong, erratic wind gusts that can exacerbate wildfire growth, and severe gusts cannot be ruled out (see the Day 2 Convective Outlook for more details on severe thunderstorms). The combination of critically receptive fuels, and at least a few dry thunderstorms with strong to severe wind gusts, warrants the expansion of isolated dry thunderstorm highlights, even if some preceding fuels dampening takes place. ..Squitieri.. 07/27/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Sat Jul 27 2024/ ...Synopsis... Broad west-southwesterly mid-level flow will continue to bring dry and windy conditions to portions of southern Nevada and southwestern Utah, into northwestern Colorado and southern Wyoming. Additionally, a mid-level shortwave trough moving across northern Idaho and Montana will bring chances for isolated dry thunderstorms to western Montana and into far northwestern Wyoming. ...Dry Thunder... Cold temperatures aloft and forcing for ascent from a mid-level trough moving across northern Montana will bring chances for isolated dry thunder to much of western Montana, where fuels are receptive to lightning-based ignitions and wildfire spread. ...Dry and Windy... Dry and windy conditions will persist across the Great Basin on Sunday, where meteorological conditions will locally reach Critical criteria. Current fuel guidance suggests less than ideal conditions for wildfire ignitions, precluding the introduction of Critical highlights at this time. However, the dry and windy conditions of the previous day could result in some fuel recovery and will continue to be monitored. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z Primary change to the Day 2 (Sunday) Fire Weather Outlook update was to expand isolated dry thunderstorm highlights southeastward into central and southeastern Montana, as well as northern and eastern Wyoming. Fuels are critically receptive to fire spread in these areas, driven in part by drought conditions. While recent rainfall has occurred in the past week, and a few storms may produce locally wetting rainfall on Day 1 (today), this precipitation will not likely dampen fuels enough to eliminate wildfire-growth potential for tomorrow. The latest guidance consensus shows fast-moving, high-based thunderstorms moving across the central and northern Rockies atop a well-mixed boundary layer, characterized by inverted-v soundings extending above 700 mb. Some of these storms may produce strong, erratic wind gusts that can exacerbate wildfire growth, and severe gusts cannot be ruled out (see the Day 2 Convective Outlook for more details on severe thunderstorms). The combination of critically receptive fuels, and at least a few dry thunderstorms with strong to severe wind gusts, warrants the expansion of isolated dry thunderstorm highlights, even if some preceding fuels dampening takes place. ..Squitieri.. 07/27/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Sat Jul 27 2024/ ...Synopsis... Broad west-southwesterly mid-level flow will continue to bring dry and windy conditions to portions of southern Nevada and southwestern Utah, into northwestern Colorado and southern Wyoming. Additionally, a mid-level shortwave trough moving across northern Idaho and Montana will bring chances for isolated dry thunderstorms to western Montana and into far northwestern Wyoming. ...Dry Thunder... Cold temperatures aloft and forcing for ascent from a mid-level trough moving across northern Montana will bring chances for isolated dry thunder to much of western Montana, where fuels are receptive to lightning-based ignitions and wildfire spread. ...Dry and Windy... Dry and windy conditions will persist across the Great Basin on Sunday, where meteorological conditions will locally reach Critical criteria. Current fuel guidance suggests less than ideal conditions for wildfire ignitions, precluding the introduction of Critical highlights at this time. However, the dry and windy conditions of the previous day could result in some fuel recovery and will continue to be monitored. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z Primary change to the Day 2 (Sunday) Fire Weather Outlook update was to expand isolated dry thunderstorm highlights southeastward into central and southeastern Montana, as well as northern and eastern Wyoming. Fuels are critically receptive to fire spread in these areas, driven in part by drought conditions. While recent rainfall has occurred in the past week, and a few storms may produce locally wetting rainfall on Day 1 (today), this precipitation will not likely dampen fuels enough to eliminate wildfire-growth potential for tomorrow. The latest guidance consensus shows fast-moving, high-based thunderstorms moving across the central and northern Rockies atop a well-mixed boundary layer, characterized by inverted-v soundings extending above 700 mb. Some of these storms may produce strong, erratic wind gusts that can exacerbate wildfire growth, and severe gusts cannot be ruled out (see the Day 2 Convective Outlook for more details on severe thunderstorms). The combination of critically receptive fuels, and at least a few dry thunderstorms with strong to severe wind gusts, warrants the expansion of isolated dry thunderstorm highlights, even if some preceding fuels dampening takes place. ..Squitieri.. 07/27/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Sat Jul 27 2024/ ...Synopsis... Broad west-southwesterly mid-level flow will continue to bring dry and windy conditions to portions of southern Nevada and southwestern Utah, into northwestern Colorado and southern Wyoming. Additionally, a mid-level shortwave trough moving across northern Idaho and Montana will bring chances for isolated dry thunderstorms to western Montana and into far northwestern Wyoming. ...Dry Thunder... Cold temperatures aloft and forcing for ascent from a mid-level trough moving across northern Montana will bring chances for isolated dry thunder to much of western Montana, where fuels are receptive to lightning-based ignitions and wildfire spread. ...Dry and Windy... Dry and windy conditions will persist across the Great Basin on Sunday, where meteorological conditions will locally reach Critical criteria. Current fuel guidance suggests less than ideal conditions for wildfire ignitions, precluding the introduction of Critical highlights at this time. However, the dry and windy conditions of the previous day could result in some fuel recovery and will continue to be monitored. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Sat Jul 27 17:48:01 UTC 2024.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected across portions of the central/northern Plains on Sunday. ...Synopsis... The overall synoptic regime is forecast to largely remain stagnant over the next 24-48 hours with persistent mean west to southwesterly upper-level flow across much of the central and western CONUS. Multiple mid-level impulses are noted in early-afternoon water-vapor imagery across the western U.S., but the most influential feature for Sunday's severe weather potential appears to be a weakening shortwave trough migrating across the northern Great Basin. This feature should phase with a second shortwave trough entering the Pacific Northwest as they eject into the central and northern Plains by Sunday afternoon. As this occurs, strengthening flow aloft combined with modest broad scale ascent ahead of the mean mid-level trough axis should result in a deepening lee surface trough along the High Plains, with the potential for two surface cyclones across western SD and western NE. The surface trough will likely act as a dryline by late afternoon as it shifts east and impinges on the western periphery of a plume of 60-70 F dewpoints currently in place over the Plains. Thunderstorm development will likely be focused along this boundary as well as in the vicinity of the surface lows and along a residual cold front across the upper MS River Valley region. ...South Dakota into Minnesota... Consensus among latest model solutions suggests that confidence remains relatively high in the development of an organized surface low across western SD by tomorrow afternoon. A trailing cold front will likely stall by late morning with some northward advancement as a warm front by mid/late afternoon across central to northern SD. Initially high-based thunderstorms developing in the vicinity of the deepening low or along the sharpening surface trough/dryline will likely pose a severe wind threat as they develop within a relatively dry/well-mixed environment. Intensification appears probable as they migrate east into the higher theta-e air mass where MLCAPE is forecast to be upwards of 2000-3000 J/kg. While mid-level flow will not be overly strong (around 30 knots), east/southeasterly low-level flow will likely result in effective bulk shear values between 30-40 knots. Consequently, a few supercells appear possible with an attendant risk for large hail. Low-level veering within the warm frontal zone appears sufficient to support a tornado concern, but this potential may be highly conditional on realizing a relatively discrete storm mode without undercutting outflow. Additional thunderstorm development is anticipated along the residual frontal boundary across southeast ND into northern MN, but displacement from better flow aloft should limit the potential for long-lived organized convection. Some solutions - most notable the 12 UTC HRRR - hint at the development of a mature MCS along the warm front that propagates into the upper MS River Valley by early morning Monday. This scenario appears plausible given an adequate environmental parameter space and a favorable deep-layer flow orientation with the warm front; however, forcing for ascent is expected to be relatively weak given the low-amplitude nature of the upper wave with low confidence in convective coverage. Furthermore, the potential MCS should be relatively displaced from the low-level jet axis further to the southeast. Ensemble guidance also suggests this is a low-probability scenario with only weak/non-coherent signals in QPF, UH, and updraft probability fields. ...Nebraska into Kansas... A similar convective environment is expected to be in place further south into NE and KS by Sunday afternoon. Forcing along the surface trough and in the vicinity of a secondary surface low over west/southwest NE should support a few initially discrete, high-based cells with the potential for upscale growth into one or more organized clusters by early evening. Ensemble consensus shows a similar signal for convective coverage and severe wind potential across portions of southern NE into far northern KS as compared to portions of SD. As such, 15% wind probabilities have been extended south to the general vicinity of the secondary surface low to account for this potential. ..Moore.. 07/27/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected across portions of the central/northern Plains on Sunday. ...Synopsis... The overall synoptic regime is forecast to largely remain stagnant over the next 24-48 hours with persistent mean west to southwesterly upper-level flow across much of the central and western CONUS. Multiple mid-level impulses are noted in early-afternoon water-vapor imagery across the western U.S., but the most influential feature for Sunday's severe weather potential appears to be a weakening shortwave trough migrating across the northern Great Basin. This feature should phase with a second shortwave trough entering the Pacific Northwest as they eject into the central and northern Plains by Sunday afternoon. As this occurs, strengthening flow aloft combined with modest broad scale ascent ahead of the mean mid-level trough axis should result in a deepening lee surface trough along the High Plains, with the potential for two surface cyclones across western SD and western NE. The surface trough will likely act as a dryline by late afternoon as it shifts east and impinges on the western periphery of a plume of 60-70 F dewpoints currently in place over the Plains. Thunderstorm development will likely be focused along this boundary as well as in the vicinity of the surface lows and along a residual cold front across the upper MS River Valley region. ...South Dakota into Minnesota... Consensus among latest model solutions suggests that confidence remains relatively high in the development of an organized surface low across western SD by tomorrow afternoon. A trailing cold front will likely stall by late morning with some northward advancement as a warm front by mid/late afternoon across central to northern SD. Initially high-based thunderstorms developing in the vicinity of the deepening low or along the sharpening surface trough/dryline will likely pose a severe wind threat as they develop within a relatively dry/well-mixed environment. Intensification appears probable as they migrate east into the higher theta-e air mass where MLCAPE is forecast to be upwards of 2000-3000 J/kg. While mid-level flow will not be overly strong (around 30 knots), east/southeasterly low-level flow will likely result in effective bulk shear values between 30-40 knots. Consequently, a few supercells appear possible with an attendant risk for large hail. Low-level veering within the warm frontal zone appears sufficient to support a tornado concern, but this potential may be highly conditional on realizing a relatively discrete storm mode without undercutting outflow. Additional thunderstorm development is anticipated along the residual frontal boundary across southeast ND into northern MN, but displacement from better flow aloft should limit the potential for long-lived organized convection. Some solutions - most notable the 12 UTC HRRR - hint at the development of a mature MCS along the warm front that propagates into the upper MS River Valley by early morning Monday. This scenario appears plausible given an adequate environmental parameter space and a favorable deep-layer flow orientation with the warm front; however, forcing for ascent is expected to be relatively weak given the low-amplitude nature of the upper wave with low confidence in convective coverage. Furthermore, the potential MCS should be relatively displaced from the low-level jet axis further to the southeast. Ensemble guidance also suggests this is a low-probability scenario with only weak/non-coherent signals in QPF, UH, and updraft probability fields. ...Nebraska into Kansas... A similar convective environment is expected to be in place further south into NE and KS by Sunday afternoon. Forcing along the surface trough and in the vicinity of a secondary surface low over west/southwest NE should support a few initially discrete, high-based cells with the potential for upscale growth into one or more organized clusters by early evening. Ensemble consensus shows a similar signal for convective coverage and severe wind potential across portions of southern NE into far northern KS as compared to portions of SD. As such, 15% wind probabilities have been extended south to the general vicinity of the secondary surface low to account for this potential. ..Moore.. 07/27/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected across portions of the central/northern Plains on Sunday. ...Synopsis... The overall synoptic regime is forecast to largely remain stagnant over the next 24-48 hours with persistent mean west to southwesterly upper-level flow across much of the central and western CONUS. Multiple mid-level impulses are noted in early-afternoon water-vapor imagery across the western U.S., but the most influential feature for Sunday's severe weather potential appears to be a weakening shortwave trough migrating across the northern Great Basin. This feature should phase with a second shortwave trough entering the Pacific Northwest as they eject into the central and northern Plains by Sunday afternoon. As this occurs, strengthening flow aloft combined with modest broad scale ascent ahead of the mean mid-level trough axis should result in a deepening lee surface trough along the High Plains, with the potential for two surface cyclones across western SD and western NE. The surface trough will likely act as a dryline by late afternoon as it shifts east and impinges on the western periphery of a plume of 60-70 F dewpoints currently in place over the Plains. Thunderstorm development will likely be focused along this boundary as well as in the vicinity of the surface lows and along a residual cold front across the upper MS River Valley region. ...South Dakota into Minnesota... Consensus among latest model solutions suggests that confidence remains relatively high in the development of an organized surface low across western SD by tomorrow afternoon. A trailing cold front will likely stall by late morning with some northward advancement as a warm front by mid/late afternoon across central to northern SD. Initially high-based thunderstorms developing in the vicinity of the deepening low or along the sharpening surface trough/dryline will likely pose a severe wind threat as they develop within a relatively dry/well-mixed environment. Intensification appears probable as they migrate east into the higher theta-e air mass where MLCAPE is forecast to be upwards of 2000-3000 J/kg. While mid-level flow will not be overly strong (around 30 knots), east/southeasterly low-level flow will likely result in effective bulk shear values between 30-40 knots. Consequently, a few supercells appear possible with an attendant risk for large hail. Low-level veering within the warm frontal zone appears sufficient to support a tornado concern, but this potential may be highly conditional on realizing a relatively discrete storm mode without undercutting outflow. Additional thunderstorm development is anticipated along the residual frontal boundary across southeast ND into northern MN, but displacement from better flow aloft should limit the potential for long-lived organized convection. Some solutions - most notable the 12 UTC HRRR - hint at the development of a mature MCS along the warm front that propagates into the upper MS River Valley by early morning Monday. This scenario appears plausible given an adequate environmental parameter space and a favorable deep-layer flow orientation with the warm front; however, forcing for ascent is expected to be relatively weak given the low-amplitude nature of the upper wave with low confidence in convective coverage. Furthermore, the potential MCS should be relatively displaced from the low-level jet axis further to the southeast. Ensemble guidance also suggests this is a low-probability scenario with only weak/non-coherent signals in QPF, UH, and updraft probability fields. ...Nebraska into Kansas... A similar convective environment is expected to be in place further south into NE and KS by Sunday afternoon. Forcing along the surface trough and in the vicinity of a secondary surface low over west/southwest NE should support a few initially discrete, high-based cells with the potential for upscale growth into one or more organized clusters by early evening. Ensemble consensus shows a similar signal for convective coverage and severe wind potential across portions of southern NE into far northern KS as compared to portions of SD. As such, 15% wind probabilities have been extended south to the general vicinity of the secondary surface low to account for this potential. ..Moore.. 07/27/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected across portions of the central/northern Plains on Sunday. ...Synopsis... The overall synoptic regime is forecast to largely remain stagnant over the next 24-48 hours with persistent mean west to southwesterly upper-level flow across much of the central and western CONUS. Multiple mid-level impulses are noted in early-afternoon water-vapor imagery across the western U.S., but the most influential feature for Sunday's severe weather potential appears to be a weakening shortwave trough migrating across the northern Great Basin. This feature should phase with a second shortwave trough entering the Pacific Northwest as they eject into the central and northern Plains by Sunday afternoon. As this occurs, strengthening flow aloft combined with modest broad scale ascent ahead of the mean mid-level trough axis should result in a deepening lee surface trough along the High Plains, with the potential for two surface cyclones across western SD and western NE. The surface trough will likely act as a dryline by late afternoon as it shifts east and impinges on the western periphery of a plume of 60-70 F dewpoints currently in place over the Plains. Thunderstorm development will likely be focused along this boundary as well as in the vicinity of the surface lows and along a residual cold front across the upper MS River Valley region. ...South Dakota into Minnesota... Consensus among latest model solutions suggests that confidence remains relatively high in the development of an organized surface low across western SD by tomorrow afternoon. A trailing cold front will likely stall by late morning with some northward advancement as a warm front by mid/late afternoon across central to northern SD. Initially high-based thunderstorms developing in the vicinity of the deepening low or along the sharpening surface trough/dryline will likely pose a severe wind threat as they develop within a relatively dry/well-mixed environment. Intensification appears probable as they migrate east into the higher theta-e air mass where MLCAPE is forecast to be upwards of 2000-3000 J/kg. While mid-level flow will not be overly strong (around 30 knots), east/southeasterly low-level flow will likely result in effective bulk shear values between 30-40 knots. Consequently, a few supercells appear possible with an attendant risk for large hail. Low-level veering within the warm frontal zone appears sufficient to support a tornado concern, but this potential may be highly conditional on realizing a relatively discrete storm mode without undercutting outflow. Additional thunderstorm development is anticipated along the residual frontal boundary across southeast ND into northern MN, but displacement from better flow aloft should limit the potential for long-lived organized convection. Some solutions - most notable the 12 UTC HRRR - hint at the development of a mature MCS along the warm front that propagates into the upper MS River Valley by early morning Monday. This scenario appears plausible given an adequate environmental parameter space and a favorable deep-layer flow orientation with the warm front; however, forcing for ascent is expected to be relatively weak given the low-amplitude nature of the upper wave with low confidence in convective coverage. Furthermore, the potential MCS should be relatively displaced from the low-level jet axis further to the southeast. Ensemble guidance also suggests this is a low-probability scenario with only weak/non-coherent signals in QPF, UH, and updraft probability fields. ...Nebraska into Kansas... A similar convective environment is expected to be in place further south into NE and KS by Sunday afternoon. Forcing along the surface trough and in the vicinity of a secondary surface low over west/southwest NE should support a few initially discrete, high-based cells with the potential for upscale growth into one or more organized clusters by early evening. Ensemble consensus shows a similar signal for convective coverage and severe wind potential across portions of southern NE into far northern KS as compared to portions of SD. As such, 15% wind probabilities have been extended south to the general vicinity of the secondary surface low to account for this potential. ..Moore.. 07/27/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected across portions of the central/northern Plains on Sunday. ...Synopsis... The overall synoptic regime is forecast to largely remain stagnant over the next 24-48 hours with persistent mean west to southwesterly upper-level flow across much of the central and western CONUS. Multiple mid-level impulses are noted in early-afternoon water-vapor imagery across the western U.S., but the most influential feature for Sunday's severe weather potential appears to be a weakening shortwave trough migrating across the northern Great Basin. This feature should phase with a second shortwave trough entering the Pacific Northwest as they eject into the central and northern Plains by Sunday afternoon. As this occurs, strengthening flow aloft combined with modest broad scale ascent ahead of the mean mid-level trough axis should result in a deepening lee surface trough along the High Plains, with the potential for two surface cyclones across western SD and western NE. The surface trough will likely act as a dryline by late afternoon as it shifts east and impinges on the western periphery of a plume of 60-70 F dewpoints currently in place over the Plains. Thunderstorm development will likely be focused along this boundary as well as in the vicinity of the surface lows and along a residual cold front across the upper MS River Valley region. ...South Dakota into Minnesota... Consensus among latest model solutions suggests that confidence remains relatively high in the development of an organized surface low across western SD by tomorrow afternoon. A trailing cold front will likely stall by late morning with some northward advancement as a warm front by mid/late afternoon across central to northern SD. Initially high-based thunderstorms developing in the vicinity of the deepening low or along the sharpening surface trough/dryline will likely pose a severe wind threat as they develop within a relatively dry/well-mixed environment. Intensification appears probable as they migrate east into the higher theta-e air mass where MLCAPE is forecast to be upwards of 2000-3000 J/kg. While mid-level flow will not be overly strong (around 30 knots), east/southeasterly low-level flow will likely result in effective bulk shear values between 30-40 knots. Consequently, a few supercells appear possible with an attendant risk for large hail. Low-level veering within the warm frontal zone appears sufficient to support a tornado concern, but this potential may be highly conditional on realizing a relatively discrete storm mode without undercutting outflow. Additional thunderstorm development is anticipated along the residual frontal boundary across southeast ND into northern MN, but displacement from better flow aloft should limit the potential for long-lived organized convection. Some solutions - most notable the 12 UTC HRRR - hint at the development of a mature MCS along the warm front that propagates into the upper MS River Valley by early morning Monday. This scenario appears plausible given an adequate environmental parameter space and a favorable deep-layer flow orientation with the warm front; however, forcing for ascent is expected to be relatively weak given the low-amplitude nature of the upper wave with low confidence in convective coverage. Furthermore, the potential MCS should be relatively displaced from the low-level jet axis further to the southeast. Ensemble guidance also suggests this is a low-probability scenario with only weak/non-coherent signals in QPF, UH, and updraft probability fields. ...Nebraska into Kansas... A similar convective environment is expected to be in place further south into NE and KS by Sunday afternoon. Forcing along the surface trough and in the vicinity of a secondary surface low over west/southwest NE should support a few initially discrete, high-based cells with the potential for upscale growth into one or more organized clusters by early evening. Ensemble consensus shows a similar signal for convective coverage and severe wind potential across portions of southern NE into far northern KS as compared to portions of SD. As such, 15% wind probabilities have been extended south to the general vicinity of the secondary surface low to account for this potential. ..Moore.. 07/27/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected across portions of the central/northern Plains on Sunday. ...Synopsis... The overall synoptic regime is forecast to largely remain stagnant over the next 24-48 hours with persistent mean west to southwesterly upper-level flow across much of the central and western CONUS. Multiple mid-level impulses are noted in early-afternoon water-vapor imagery across the western U.S., but the most influential feature for Sunday's severe weather potential appears to be a weakening shortwave trough migrating across the northern Great Basin. This feature should phase with a second shortwave trough entering the Pacific Northwest as they eject into the central and northern Plains by Sunday afternoon. As this occurs, strengthening flow aloft combined with modest broad scale ascent ahead of the mean mid-level trough axis should result in a deepening lee surface trough along the High Plains, with the potential for two surface cyclones across western SD and western NE. The surface trough will likely act as a dryline by late afternoon as it shifts east and impinges on the western periphery of a plume of 60-70 F dewpoints currently in place over the Plains. Thunderstorm development will likely be focused along this boundary as well as in the vicinity of the surface lows and along a residual cold front across the upper MS River Valley region. ...South Dakota into Minnesota... Consensus among latest model solutions suggests that confidence remains relatively high in the development of an organized surface low across western SD by tomorrow afternoon. A trailing cold front will likely stall by late morning with some northward advancement as a warm front by mid/late afternoon across central to northern SD. Initially high-based thunderstorms developing in the vicinity of the deepening low or along the sharpening surface trough/dryline will likely pose a severe wind threat as they develop within a relatively dry/well-mixed environment. Intensification appears probable as they migrate east into the higher theta-e air mass where MLCAPE is forecast to be upwards of 2000-3000 J/kg. While mid-level flow will not be overly strong (around 30 knots), east/southeasterly low-level flow will likely result in effective bulk shear values between 30-40 knots. Consequently, a few supercells appear possible with an attendant risk for large hail. Low-level veering within the warm frontal zone appears sufficient to support a tornado concern, but this potential may be highly conditional on realizing a relatively discrete storm mode without undercutting outflow. Additional thunderstorm development is anticipated along the residual frontal boundary across southeast ND into northern MN, but displacement from better flow aloft should limit the potential for long-lived organized convection. Some solutions - most notable the 12 UTC HRRR - hint at the development of a mature MCS along the warm front that propagates into the upper MS River Valley by early morning Monday. This scenario appears plausible given an adequate environmental parameter space and a favorable deep-layer flow orientation with the warm front; however, forcing for ascent is expected to be relatively weak given the low-amplitude nature of the upper wave with low confidence in convective coverage. Furthermore, the potential MCS should be relatively displaced from the low-level jet axis further to the southeast. Ensemble guidance also suggests this is a low-probability scenario with only weak/non-coherent signals in QPF, UH, and updraft probability fields. ...Nebraska into Kansas... A similar convective environment is expected to be in place further south into NE and KS by Sunday afternoon. Forcing along the surface trough and in the vicinity of a secondary surface low over west/southwest NE should support a few initially discrete, high-based cells with the potential for upscale growth into one or more organized clusters by early evening. Ensemble consensus shows a similar signal for convective coverage and severe wind potential across portions of southern NE into far northern KS as compared to portions of SD. As such, 15% wind probabilities have been extended south to the general vicinity of the secondary surface low to account for this potential. ..Moore.. 07/27/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected across portions of the central/northern Plains on Sunday. ...Synopsis... The overall synoptic regime is forecast to largely remain stagnant over the next 24-48 hours with persistent mean west to southwesterly upper-level flow across much of the central and western CONUS. Multiple mid-level impulses are noted in early-afternoon water-vapor imagery across the western U.S., but the most influential feature for Sunday's severe weather potential appears to be a weakening shortwave trough migrating across the northern Great Basin. This feature should phase with a second shortwave trough entering the Pacific Northwest as they eject into the central and northern Plains by Sunday afternoon. As this occurs, strengthening flow aloft combined with modest broad scale ascent ahead of the mean mid-level trough axis should result in a deepening lee surface trough along the High Plains, with the potential for two surface cyclones across western SD and western NE. The surface trough will likely act as a dryline by late afternoon as it shifts east and impinges on the western periphery of a plume of 60-70 F dewpoints currently in place over the Plains. Thunderstorm development will likely be focused along this boundary as well as in the vicinity of the surface lows and along a residual cold front across the upper MS River Valley region. ...South Dakota into Minnesota... Consensus among latest model solutions suggests that confidence remains relatively high in the development of an organized surface low across western SD by tomorrow afternoon. A trailing cold front will likely stall by late morning with some northward advancement as a warm front by mid/late afternoon across central to northern SD. Initially high-based thunderstorms developing in the vicinity of the deepening low or along the sharpening surface trough/dryline will likely pose a severe wind threat as they develop within a relatively dry/well-mixed environment. Intensification appears probable as they migrate east into the higher theta-e air mass where MLCAPE is forecast to be upwards of 2000-3000 J/kg. While mid-level flow will not be overly strong (around 30 knots), east/southeasterly low-level flow will likely result in effective bulk shear values between 30-40 knots. Consequently, a few supercells appear possible with an attendant risk for large hail. Low-level veering within the warm frontal zone appears sufficient to support a tornado concern, but this potential may be highly conditional on realizing a relatively discrete storm mode without undercutting outflow. Additional thunderstorm development is anticipated along the residual frontal boundary across southeast ND into northern MN, but displacement from better flow aloft should limit the potential for long-lived organized convection. Some solutions - most notable the 12 UTC HRRR - hint at the development of a mature MCS along the warm front that propagates into the upper MS River Valley by early morning Monday. This scenario appears plausible given an adequate environmental parameter space and a favorable deep-layer flow orientation with the warm front; however, forcing for ascent is expected to be relatively weak given the low-amplitude nature of the upper wave with low confidence in convective coverage. Furthermore, the potential MCS should be relatively displaced from the low-level jet axis further to the southeast. Ensemble guidance also suggests this is a low-probability scenario with only weak/non-coherent signals in QPF, UH, and updraft probability fields. ...Nebraska into Kansas... A similar convective environment is expected to be in place further south into NE and KS by Sunday afternoon. Forcing along the surface trough and in the vicinity of a secondary surface low over west/southwest NE should support a few initially discrete, high-based cells with the potential for upscale growth into one or more organized clusters by early evening. Ensemble consensus shows a similar signal for convective coverage and severe wind potential across portions of southern NE into far northern KS as compared to portions of SD. As such, 15% wind probabilities have been extended south to the general vicinity of the secondary surface low to account for this potential. ..Moore.. 07/27/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected across portions of the central/northern Plains on Sunday. ...Synopsis... The overall synoptic regime is forecast to largely remain stagnant over the next 24-48 hours with persistent mean west to southwesterly upper-level flow across much of the central and western CONUS. Multiple mid-level impulses are noted in early-afternoon water-vapor imagery across the western U.S., but the most influential feature for Sunday's severe weather potential appears to be a weakening shortwave trough migrating across the northern Great Basin. This feature should phase with a second shortwave trough entering the Pacific Northwest as they eject into the central and northern Plains by Sunday afternoon. As this occurs, strengthening flow aloft combined with modest broad scale ascent ahead of the mean mid-level trough axis should result in a deepening lee surface trough along the High Plains, with the potential for two surface cyclones across western SD and western NE. The surface trough will likely act as a dryline by late afternoon as it shifts east and impinges on the western periphery of a plume of 60-70 F dewpoints currently in place over the Plains. Thunderstorm development will likely be focused along this boundary as well as in the vicinity of the surface lows and along a residual cold front across the upper MS River Valley region. ...South Dakota into Minnesota... Consensus among latest model solutions suggests that confidence remains relatively high in the development of an organized surface low across western SD by tomorrow afternoon. A trailing cold front will likely stall by late morning with some northward advancement as a warm front by mid/late afternoon across central to northern SD. Initially high-based thunderstorms developing in the vicinity of the deepening low or along the sharpening surface trough/dryline will likely pose a severe wind threat as they develop within a relatively dry/well-mixed environment. Intensification appears probable as they migrate east into the higher theta-e air mass where MLCAPE is forecast to be upwards of 2000-3000 J/kg. While mid-level flow will not be overly strong (around 30 knots), east/southeasterly low-level flow will likely result in effective bulk shear values between 30-40 knots. Consequently, a few supercells appear possible with an attendant risk for large hail. Low-level veering within the warm frontal zone appears sufficient to support a tornado concern, but this potential may be highly conditional on realizing a relatively discrete storm mode without undercutting outflow. Additional thunderstorm development is anticipated along the residual frontal boundary across southeast ND into northern MN, but displacement from better flow aloft should limit the potential for long-lived organized convection. Some solutions - most notable the 12 UTC HRRR - hint at the development of a mature MCS along the warm front that propagates into the upper MS River Valley by early morning Monday. This scenario appears plausible given an adequate environmental parameter space and a favorable deep-layer flow orientation with the warm front; however, forcing for ascent is expected to be relatively weak given the low-amplitude nature of the upper wave with low confidence in convective coverage. Furthermore, the potential MCS should be relatively displaced from the low-level jet axis further to the southeast. Ensemble guidance also suggests this is a low-probability scenario with only weak/non-coherent signals in QPF, UH, and updraft probability fields. ...Nebraska into Kansas... A similar convective environment is expected to be in place further south into NE and KS by Sunday afternoon. Forcing along the surface trough and in the vicinity of a secondary surface low over west/southwest NE should support a few initially discrete, high-based cells with the potential for upscale growth into one or more organized clusters by early evening. Ensemble consensus shows a similar signal for convective coverage and severe wind potential across portions of southern NE into far northern KS as compared to portions of SD. As such, 15% wind probabilities have been extended south to the general vicinity of the secondary surface low to account for this potential. ..Moore.. 07/27/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Jul 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected across portions of the central/northern Plains on Sunday. ...Synopsis... The overall synoptic regime is forecast to largely remain stagnant over the next 24-48 hours with persistent mean west to southwesterly upper-level flow across much of the central and western CONUS. Multiple mid-level impulses are noted in early-afternoon water-vapor imagery across the western U.S., but the most influential feature for Sunday's severe weather potential appears to be a weakening shortwave trough migrating across the northern Great Basin. This feature should phase with a second shortwave trough entering the Pacific Northwest as they eject into the central and northern Plains by Sunday afternoon. As this occurs, strengthening flow aloft combined with modest broad scale ascent ahead of the mean mid-level trough axis should result in a deepening lee surface trough along the High Plains, with the potential for two surface cyclones across western SD and western NE. The surface trough will likely act as a dryline by late afternoon as it shifts east and impinges on the western periphery of a plume of 60-70 F dewpoints currently in place over the Plains. Thunderstorm development will likely be focused along this boundary as well as in the vicinity of the surface lows and along a residual cold front across the upper MS River Valley region. ...South Dakota into Minnesota... Consensus among latest model solutions suggests that confidence remains relatively high in the development of an organized surface low across western SD by tomorrow afternoon. A trailing cold front will likely stall by late morning with some northward advancement as a warm front by mid/late afternoon across central to northern SD. Initially high-based thunderstorms developing in the vicinity of the deepening low or along the sharpening surface trough/dryline will likely pose a severe wind threat as they develop within a relatively dry/well-mixed environment. Intensification appears probable as they migrate east into the higher theta-e air mass where MLCAPE is forecast to be upwards of 2000-3000 J/kg. While mid-level flow will not be overly strong (around 30 knots), east/southeasterly low-level flow will likely result in effective bulk shear values between 30-40 knots. Consequently, a few supercells appear possible with an attendant risk for large hail. Low-level veering within the warm frontal zone appears sufficient to support a tornado concern, but this potential may be highly conditional on realizing a relatively discrete storm mode without undercutting outflow. Additional thunderstorm development is anticipated along the residual frontal boundary across southeast ND into northern MN, but displacement from better flow aloft should limit the potential for long-lived organized convection. Some solutions - most notable the 12 UTC HRRR - hint at the development of a mature MCS along the warm front that propagates into the upper MS River Valley by early morning Monday. This scenario appears plausible given an adequate environmental parameter space and a favorable deep-layer flow orientation with the warm front; however, forcing for ascent is expected to be relatively weak given the low-amplitude nature of the upper wave with low confidence in convective coverage. Furthermore, the potential MCS should be relatively displaced from the low-level jet axis further to the southeast. Ensemble guidance also suggests this is a low-probability scenario with only weak/non-coherent signals in QPF, UH, and updraft probability fields. ...Nebraska into Kansas... A similar convective environment is expected to be in place further south into NE and KS by Sunday afternoon. Forcing along the surface trough and in the vicinity of a secondary surface low over west/southwest NE should support a few initially discrete, high-based cells with the potential for upscale growth into one or more organized clusters by early evening. Ensemble consensus shows a similar signal for convective coverage and severe wind potential across portions of southern NE into far northern KS as compared to portions of SD. As such, 15% wind probabilities have been extended south to the general vicinity of the secondary surface low to account for this potential. ..Moore.. 07/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sat Jul 27 2024 Valid 271630Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH DAKOTA AND NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms capable of producing both large hail and damaging winds appear possible across portions of the northern Plains vicinity, including parts of the Dakotas and northern Minnesota, mainly this afternoon and evening. ...Northern Plains/Upper Midwest... A closed upper low centered over northern Saskatchewan/Manitoba this morning will move slowly eastward towards Hudson Bay through the period. Across the northern Plains, a low-amplitude shortwave trough over the Dakotas is forecast to advance northeastward into eastern ND and northern MN through this evening. This feature should aid in renewed convective development across this area later today. A cold front/surface trough arcs southward from the primary surface low in northern Saskatchewan/Manitoba into parts of eastern MT. Low-level moisture remains more limited with westward extent across the northern High Plains, with greater surface dewpoints (mid/upper 60s to low 70s) present farther east in the Dakotas and northern MN. Scattered thunderstorms should develop this afternoon along an instability/moisture gradient across parts of northern MN as the previously mentioned shortwave trough overspreads this region. Ongoing weak/elevated thunderstorms in northeast SD may also persist and gradually strengthen as they move northeastward into greater instability this afternoon. Around 1500-2500 J/kg of MLCAPE is forecast to be in place in a narrow corridor across northern MN and vicinity by late afternoon, as daytime heating of the moist low-level airmass continues to occur, and as modestly steepened mid-level lapse rates overspread the warm sector. Around 35-50 kt of southwesterly mid-level flow associated with the shortwave trough should aid in similar values of deep-layer shear, which will promote organized severe thunderstorm potential, including supercells. Large hail and severe/damaging winds will be a threat with any robust convection that can remain at least semi-discrete. Enough low-level shear should also be present to support some threat for a tornado or two. This activity will spread northeastward towards the international border through the evening, before eventually moving into Canada. Additional convection may also develop along the weak cold front/surface trough in the western/central Dakotas vicinity late this afternoon and early evening. This potential still appears somewhat more uncertain in the wake of the lead shortwave trough. Even so, any thunderstorm clusters that can be sustained will be capable of producing both large hail and damaging winds, given a favorable thermodynamic environment and sufficient deep-layer shear. This convection should eventually weaken by late evening into the eastern Dakotas with the loss of daytime heating. ...Northern Great Basin into the Central Rockies/High Plains... Multiple mid-level vorticity maxima will move east-northeastward across the northern Great Basin and central Rockies/High Plains today. Scattered to numerous thunderstorms should develop across these regions this afternoon and evening while spreading generally eastward. Even though low-level moisture will tend to remain fairly limited, steepened low/mid-level lapse rates and modestly enhanced mid-level flow should support an isolated threat for strong to severe wind gusts with the more robust cores. Convection may have a tendency to form into one or more loosely organized clusters through this evening, especially across the central High Plains of eastern WY/northeast CO into the NE Panhandle vicinity. Still, with generally modest deep-layer shear, confidence in a more concentrated corridor of severe winds remains too low to include a Slight Risk across the central High Plains with this update. ..Gleason/Mosier.. 07/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sat Jul 27 2024 Valid 271630Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH DAKOTA AND NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms capable of producing both large hail and damaging winds appear possible across portions of the northern Plains vicinity, including parts of the Dakotas and northern Minnesota, mainly this afternoon and evening. ...Northern Plains/Upper Midwest... A closed upper low centered over northern Saskatchewan/Manitoba this morning will move slowly eastward towards Hudson Bay through the period. Across the northern Plains, a low-amplitude shortwave trough over the Dakotas is forecast to advance northeastward into eastern ND and northern MN through this evening. This feature should aid in renewed convective development across this area later today. A cold front/surface trough arcs southward from the primary surface low in northern Saskatchewan/Manitoba into parts of eastern MT. Low-level moisture remains more limited with westward extent across the northern High Plains, with greater surface dewpoints (mid/upper 60s to low 70s) present farther east in the Dakotas and northern MN. Scattered thunderstorms should develop this afternoon along an instability/moisture gradient across parts of northern MN as the previously mentioned shortwave trough overspreads this region. Ongoing weak/elevated thunderstorms in northeast SD may also persist and gradually strengthen as they move northeastward into greater instability this afternoon. Around 1500-2500 J/kg of MLCAPE is forecast to be in place in a narrow corridor across northern MN and vicinity by late afternoon, as daytime heating of the moist low-level airmass continues to occur, and as modestly steepened mid-level lapse rates overspread the warm sector. Around 35-50 kt of southwesterly mid-level flow associated with the shortwave trough should aid in similar values of deep-layer shear, which will promote organized severe thunderstorm potential, including supercells. Large hail and severe/damaging winds will be a threat with any robust convection that can remain at least semi-discrete. Enough low-level shear should also be present to support some threat for a tornado or two. This activity will spread northeastward towards the international border through the evening, before eventually moving into Canada. Additional convection may also develop along the weak cold front/surface trough in the western/central Dakotas vicinity late this afternoon and early evening. This potential still appears somewhat more uncertain in the wake of the lead shortwave trough. Even so, any thunderstorm clusters that can be sustained will be capable of producing both large hail and damaging winds, given a favorable thermodynamic environment and sufficient deep-layer shear. This convection should eventually weaken by late evening into the eastern Dakotas with the loss of daytime heating. ...Northern Great Basin into the Central Rockies/High Plains... Multiple mid-level vorticity maxima will move east-northeastward across the northern Great Basin and central Rockies/High Plains today. Scattered to numerous thunderstorms should develop across these regions this afternoon and evening while spreading generally eastward. Even though low-level moisture will tend to remain fairly limited, steepened low/mid-level lapse rates and modestly enhanced mid-level flow should support an isolated threat for strong to severe wind gusts with the more robust cores. Convection may have a tendency to form into one or more loosely organized clusters through this evening, especially across the central High Plains of eastern WY/northeast CO into the NE Panhandle vicinity. Still, with generally modest deep-layer shear, confidence in a more concentrated corridor of severe winds remains too low to include a Slight Risk across the central High Plains with this update. ..Gleason/Mosier.. 07/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sat Jul 27 2024 Valid 271630Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH DAKOTA AND NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms capable of producing both large hail and damaging winds appear possible across portions of the northern Plains vicinity, including parts of the Dakotas and northern Minnesota, mainly this afternoon and evening. ...Northern Plains/Upper Midwest... A closed upper low centered over northern Saskatchewan/Manitoba this morning will move slowly eastward towards Hudson Bay through the period. Across the northern Plains, a low-amplitude shortwave trough over the Dakotas is forecast to advance northeastward into eastern ND and northern MN through this evening. This feature should aid in renewed convective development across this area later today. A cold front/surface trough arcs southward from the primary surface low in northern Saskatchewan/Manitoba into parts of eastern MT. Low-level moisture remains more limited with westward extent across the northern High Plains, with greater surface dewpoints (mid/upper 60s to low 70s) present farther east in the Dakotas and northern MN. Scattered thunderstorms should develop this afternoon along an instability/moisture gradient across parts of northern MN as the previously mentioned shortwave trough overspreads this region. Ongoing weak/elevated thunderstorms in northeast SD may also persist and gradually strengthen as they move northeastward into greater instability this afternoon. Around 1500-2500 J/kg of MLCAPE is forecast to be in place in a narrow corridor across northern MN and vicinity by late afternoon, as daytime heating of the moist low-level airmass continues to occur, and as modestly steepened mid-level lapse rates overspread the warm sector. Around 35-50 kt of southwesterly mid-level flow associated with the shortwave trough should aid in similar values of deep-layer shear, which will promote organized severe thunderstorm potential, including supercells. Large hail and severe/damaging winds will be a threat with any robust convection that can remain at least semi-discrete. Enough low-level shear should also be present to support some threat for a tornado or two. This activity will spread northeastward towards the international border through the evening, before eventually moving into Canada. Additional convection may also develop along the weak cold front/surface trough in the western/central Dakotas vicinity late this afternoon and early evening. This potential still appears somewhat more uncertain in the wake of the lead shortwave trough. Even so, any thunderstorm clusters that can be sustained will be capable of producing both large hail and damaging winds, given a favorable thermodynamic environment and sufficient deep-layer shear. This convection should eventually weaken by late evening into the eastern Dakotas with the loss of daytime heating. ...Northern Great Basin into the Central Rockies/High Plains... Multiple mid-level vorticity maxima will move east-northeastward across the northern Great Basin and central Rockies/High Plains today. Scattered to numerous thunderstorms should develop across these regions this afternoon and evening while spreading generally eastward. Even though low-level moisture will tend to remain fairly limited, steepened low/mid-level lapse rates and modestly enhanced mid-level flow should support an isolated threat for strong to severe wind gusts with the more robust cores. Convection may have a tendency to form into one or more loosely organized clusters through this evening, especially across the central High Plains of eastern WY/northeast CO into the NE Panhandle vicinity. Still, with generally modest deep-layer shear, confidence in a more concentrated corridor of severe winds remains too low to include a Slight Risk across the central High Plains with this update. ..Gleason/Mosier.. 07/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sat Jul 27 2024 Valid 271630Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH DAKOTA AND NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms capable of producing both large hail and damaging winds appear possible across portions of the northern Plains vicinity, including parts of the Dakotas and northern Minnesota, mainly this afternoon and evening. ...Northern Plains/Upper Midwest... A closed upper low centered over northern Saskatchewan/Manitoba this morning will move slowly eastward towards Hudson Bay through the period. Across the northern Plains, a low-amplitude shortwave trough over the Dakotas is forecast to advance northeastward into eastern ND and northern MN through this evening. This feature should aid in renewed convective development across this area later today. A cold front/surface trough arcs southward from the primary surface low in northern Saskatchewan/Manitoba into parts of eastern MT. Low-level moisture remains more limited with westward extent across the northern High Plains, with greater surface dewpoints (mid/upper 60s to low 70s) present farther east in the Dakotas and northern MN. Scattered thunderstorms should develop this afternoon along an instability/moisture gradient across parts of northern MN as the previously mentioned shortwave trough overspreads this region. Ongoing weak/elevated thunderstorms in northeast SD may also persist and gradually strengthen as they move northeastward into greater instability this afternoon. Around 1500-2500 J/kg of MLCAPE is forecast to be in place in a narrow corridor across northern MN and vicinity by late afternoon, as daytime heating of the moist low-level airmass continues to occur, and as modestly steepened mid-level lapse rates overspread the warm sector. Around 35-50 kt of southwesterly mid-level flow associated with the shortwave trough should aid in similar values of deep-layer shear, which will promote organized severe thunderstorm potential, including supercells. Large hail and severe/damaging winds will be a threat with any robust convection that can remain at least semi-discrete. Enough low-level shear should also be present to support some threat for a tornado or two. This activity will spread northeastward towards the international border through the evening, before eventually moving into Canada. Additional convection may also develop along the weak cold front/surface trough in the western/central Dakotas vicinity late this afternoon and early evening. This potential still appears somewhat more uncertain in the wake of the lead shortwave trough. Even so, any thunderstorm clusters that can be sustained will be capable of producing both large hail and damaging winds, given a favorable thermodynamic environment and sufficient deep-layer shear. This convection should eventually weaken by late evening into the eastern Dakotas with the loss of daytime heating. ...Northern Great Basin into the Central Rockies/High Plains... Multiple mid-level vorticity maxima will move east-northeastward across the northern Great Basin and central Rockies/High Plains today. Scattered to numerous thunderstorms should develop across these regions this afternoon and evening while spreading generally eastward. Even though low-level moisture will tend to remain fairly limited, steepened low/mid-level lapse rates and modestly enhanced mid-level flow should support an isolated threat for strong to severe wind gusts with the more robust cores. Convection may have a tendency to form into one or more loosely organized clusters through this evening, especially across the central High Plains of eastern WY/northeast CO into the NE Panhandle vicinity. Still, with generally modest deep-layer shear, confidence in a more concentrated corridor of severe winds remains too low to include a Slight Risk across the central High Plains with this update. ..Gleason/Mosier.. 07/27/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sat Jul 27 2024 Valid 271630Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH DAKOTA AND NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms capable of producing both large hail and damaging winds appear possible across portions of the northern Plains vicinity, including parts of the Dakotas and northern Minnesota, mainly this afternoon and evening. ...Northern Plains/Upper Midwest... A closed upper low centered over northern Saskatchewan/Manitoba this morning will move slowly eastward towards Hudson Bay through the period. Across the northern Plains, a low-amplitude shortwave trough over the Dakotas is forecast to advance northeastward into eastern ND and northern MN through this evening. This feature should aid in renewed convective development across this area later today. A cold front/surface trough arcs southward from the primary surface low in northern Saskatchewan/Manitoba into parts of eastern MT. Low-level moisture remains more limited with westward extent across the northern High Plains, with greater surface dewpoints (mid/upper 60s to low 70s) present farther east in the Dakotas and northern MN. Scattered thunderstorms should develop this afternoon along an instability/moisture gradient across parts of northern MN as the previously mentioned shortwave trough overspreads this region. Ongoing weak/elevated thunderstorms in northeast SD may also persist and gradually strengthen as they move northeastward into greater instability this afternoon. Around 1500-2500 J/kg of MLCAPE is forecast to be in place in a narrow corridor across northern MN and vicinity by late afternoon, as daytime heating of the moist low-level airmass continues to occur, and as modestly steepened mid-level lapse rates overspread the warm sector. Around 35-50 kt of southwesterly mid-level flow associated with the shortwave trough should aid in similar values of deep-layer shear, which will promote organized severe thunderstorm potential, including supercells. Large hail and severe/damaging winds will be a threat with any robust convection that can remain at least semi-discrete. Enough low-level shear should also be present to support some threat for a tornado or two. This activity will spread northeastward towards the international border through the evening, before eventually moving into Canada. Additional convection may also develop along the weak cold front/surface trough in the western/central Dakotas vicinity late this afternoon and early evening. This potential still appears somewhat more uncertain in the wake of the lead shortwave trough. Even so, any thunderstorm clusters that can be sustained will be capable of producing both large hail and damaging winds, given a favorable thermodynamic environment and sufficient deep-layer shear. This convection should eventually weaken by late evening into the eastern Dakotas with the loss of daytime heating. ...Northern Great Basin into the Central Rockies/High Plains... Multiple mid-level vorticity maxima will move east-northeastward across the northern Great Basin and central Rockies/High Plains today. Scattered to numerous thunderstorms should develop across these regions this afternoon and evening while spreading generally eastward. Even though low-level moisture will tend to remain fairly limited, steepened low/mid-level lapse rates and modestly enhanced mid-level flow should support an isolated threat for strong to severe wind gusts with the more robust cores. Convection may have a tendency to form into one or more loosely organized clusters through this evening, especially across the central High Plains of eastern WY/northeast CO into the NE Panhandle vicinity. Still, with generally modest deep-layer shear, confidence in a more concentrated corridor of severe winds remains too low to include a Slight Risk across the central High Plains with this update. ..Gleason/Mosier.. 07/27/2024 Read more