Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1030 AM CST Sun Dec 15 2024 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated severe hail, strong/gusty winds, and perhaps a tornado may occur tonight through early Monday morning from parts of north Texas to the Ozarks. ...Synopsis... Gradual amplification and consolidation of upper troughing will occur through the period across parts of the northern Plains and Upper Midwest. The southern fringe of this upper trough will begin to influence and overspread portions of the central/southern Plains late this evening and overnight. The primary surface low will develop towards the international border region of northern MN/southern Canada, while partially modified Gulf moisture continues to gradually stream northward over portions of the southern Plains into the Ozarks ahead of a cold front. ...Eastern Oklahoma into Western Arkansas and Southwest Missouri... Convective initiation will likely be delayed until 03Z or later this evening across eastern OK/western AR vicinity, as low-level warm/moist advection aids in the northward transport of a moist low-level airmass. Once convection develops as glancing ascent from the approaching upper trough overspreads the warm sector, convective mode may quickly become messy, as generally southwesterly low/mid-level flow encourages updraft interactions and mergers. Even so, around 1000-2000 J/kg of MUCAPE, aided by modestly steepened mid-level lapse rates, should support robust updrafts. Coupled with sufficient (around 30-40 kt) deep-layer shear, some of this initial development could produce marginally severe hail on an isolated basis. Based on latest guidance trends showing convective initiation farther north across parts of northern OK into southwest MO, the Marginal Risk has been expanded northward to account for this initial hail threat. Poor/neutral low-level lapse rates and a generally saturated boundary-layer shown in various NAM/RAP forecast soundings limit confidence to some extent in the potential for truly surface-based thunderstorms tonight across the warm sector. Still, the presence of a 35-45 kt southwesterly low-level jet, with associated 0-1 km SRH sufficient for low-level updraft rotation, suggests a non-zero threat for a tornado along with some potential for occasional strong/gusty winds as convection spreads eastward across eastern OK into western AR and the Ozarks through early Monday morning. The potential for sustained supercells appears limited by a weakness in the flow/hodograph forecast around 700 mb, with the southward-moving cold front also encouraging a more linear/cluster mode with time. Overall, the severe threat with any convection that develops should remain rather isolated, but within a conditionally somewhat favorable environment. ..Gleason/Squitieri.. 12/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1030 AM CST Sun Dec 15 2024 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated severe hail, strong/gusty winds, and perhaps a tornado may occur tonight through early Monday morning from parts of north Texas to the Ozarks. ...Synopsis... Gradual amplification and consolidation of upper troughing will occur through the period across parts of the northern Plains and Upper Midwest. The southern fringe of this upper trough will begin to influence and overspread portions of the central/southern Plains late this evening and overnight. The primary surface low will develop towards the international border region of northern MN/southern Canada, while partially modified Gulf moisture continues to gradually stream northward over portions of the southern Plains into the Ozarks ahead of a cold front. ...Eastern Oklahoma into Western Arkansas and Southwest Missouri... Convective initiation will likely be delayed until 03Z or later this evening across eastern OK/western AR vicinity, as low-level warm/moist advection aids in the northward transport of a moist low-level airmass. Once convection develops as glancing ascent from the approaching upper trough overspreads the warm sector, convective mode may quickly become messy, as generally southwesterly low/mid-level flow encourages updraft interactions and mergers. Even so, around 1000-2000 J/kg of MUCAPE, aided by modestly steepened mid-level lapse rates, should support robust updrafts. Coupled with sufficient (around 30-40 kt) deep-layer shear, some of this initial development could produce marginally severe hail on an isolated basis. Based on latest guidance trends showing convective initiation farther north across parts of northern OK into southwest MO, the Marginal Risk has been expanded northward to account for this initial hail threat. Poor/neutral low-level lapse rates and a generally saturated boundary-layer shown in various NAM/RAP forecast soundings limit confidence to some extent in the potential for truly surface-based thunderstorms tonight across the warm sector. Still, the presence of a 35-45 kt southwesterly low-level jet, with associated 0-1 km SRH sufficient for low-level updraft rotation, suggests a non-zero threat for a tornado along with some potential for occasional strong/gusty winds as convection spreads eastward across eastern OK into western AR and the Ozarks through early Monday morning. The potential for sustained supercells appears limited by a weakness in the flow/hodograph forecast around 700 mb, with the southward-moving cold front also encouraging a more linear/cluster mode with time. Overall, the severe threat with any convection that develops should remain rather isolated, but within a conditionally somewhat favorable environment. ..Gleason/Squitieri.. 12/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1030 AM CST Sun Dec 15 2024 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated severe hail, strong/gusty winds, and perhaps a tornado may occur tonight through early Monday morning from parts of north Texas to the Ozarks. ...Synopsis... Gradual amplification and consolidation of upper troughing will occur through the period across parts of the northern Plains and Upper Midwest. The southern fringe of this upper trough will begin to influence and overspread portions of the central/southern Plains late this evening and overnight. The primary surface low will develop towards the international border region of northern MN/southern Canada, while partially modified Gulf moisture continues to gradually stream northward over portions of the southern Plains into the Ozarks ahead of a cold front. ...Eastern Oklahoma into Western Arkansas and Southwest Missouri... Convective initiation will likely be delayed until 03Z or later this evening across eastern OK/western AR vicinity, as low-level warm/moist advection aids in the northward transport of a moist low-level airmass. Once convection develops as glancing ascent from the approaching upper trough overspreads the warm sector, convective mode may quickly become messy, as generally southwesterly low/mid-level flow encourages updraft interactions and mergers. Even so, around 1000-2000 J/kg of MUCAPE, aided by modestly steepened mid-level lapse rates, should support robust updrafts. Coupled with sufficient (around 30-40 kt) deep-layer shear, some of this initial development could produce marginally severe hail on an isolated basis. Based on latest guidance trends showing convective initiation farther north across parts of northern OK into southwest MO, the Marginal Risk has been expanded northward to account for this initial hail threat. Poor/neutral low-level lapse rates and a generally saturated boundary-layer shown in various NAM/RAP forecast soundings limit confidence to some extent in the potential for truly surface-based thunderstorms tonight across the warm sector. Still, the presence of a 35-45 kt southwesterly low-level jet, with associated 0-1 km SRH sufficient for low-level updraft rotation, suggests a non-zero threat for a tornado along with some potential for occasional strong/gusty winds as convection spreads eastward across eastern OK into western AR and the Ozarks through early Monday morning. The potential for sustained supercells appears limited by a weakness in the flow/hodograph forecast around 700 mb, with the southward-moving cold front also encouraging a more linear/cluster mode with time. Overall, the severe threat with any convection that develops should remain rather isolated, but within a conditionally somewhat favorable environment. ..Gleason/Squitieri.. 12/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1030 AM CST Sun Dec 15 2024 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated severe hail, strong/gusty winds, and perhaps a tornado may occur tonight through early Monday morning from parts of north Texas to the Ozarks. ...Synopsis... Gradual amplification and consolidation of upper troughing will occur through the period across parts of the northern Plains and Upper Midwest. The southern fringe of this upper trough will begin to influence and overspread portions of the central/southern Plains late this evening and overnight. The primary surface low will develop towards the international border region of northern MN/southern Canada, while partially modified Gulf moisture continues to gradually stream northward over portions of the southern Plains into the Ozarks ahead of a cold front. ...Eastern Oklahoma into Western Arkansas and Southwest Missouri... Convective initiation will likely be delayed until 03Z or later this evening across eastern OK/western AR vicinity, as low-level warm/moist advection aids in the northward transport of a moist low-level airmass. Once convection develops as glancing ascent from the approaching upper trough overspreads the warm sector, convective mode may quickly become messy, as generally southwesterly low/mid-level flow encourages updraft interactions and mergers. Even so, around 1000-2000 J/kg of MUCAPE, aided by modestly steepened mid-level lapse rates, should support robust updrafts. Coupled with sufficient (around 30-40 kt) deep-layer shear, some of this initial development could produce marginally severe hail on an isolated basis. Based on latest guidance trends showing convective initiation farther north across parts of northern OK into southwest MO, the Marginal Risk has been expanded northward to account for this initial hail threat. Poor/neutral low-level lapse rates and a generally saturated boundary-layer shown in various NAM/RAP forecast soundings limit confidence to some extent in the potential for truly surface-based thunderstorms tonight across the warm sector. Still, the presence of a 35-45 kt southwesterly low-level jet, with associated 0-1 km SRH sufficient for low-level updraft rotation, suggests a non-zero threat for a tornado along with some potential for occasional strong/gusty winds as convection spreads eastward across eastern OK into western AR and the Ozarks through early Monday morning. The potential for sustained supercells appears limited by a weakness in the flow/hodograph forecast around 700 mb, with the southward-moving cold front also encouraging a more linear/cluster mode with time. Overall, the severe threat with any convection that develops should remain rather isolated, but within a conditionally somewhat favorable environment. ..Gleason/Squitieri.. 12/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1030 AM CST Sun Dec 15 2024 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated severe hail, strong/gusty winds, and perhaps a tornado may occur tonight through early Monday morning from parts of north Texas to the Ozarks. ...Synopsis... Gradual amplification and consolidation of upper troughing will occur through the period across parts of the northern Plains and Upper Midwest. The southern fringe of this upper trough will begin to influence and overspread portions of the central/southern Plains late this evening and overnight. The primary surface low will develop towards the international border region of northern MN/southern Canada, while partially modified Gulf moisture continues to gradually stream northward over portions of the southern Plains into the Ozarks ahead of a cold front. ...Eastern Oklahoma into Western Arkansas and Southwest Missouri... Convective initiation will likely be delayed until 03Z or later this evening across eastern OK/western AR vicinity, as low-level warm/moist advection aids in the northward transport of a moist low-level airmass. Once convection develops as glancing ascent from the approaching upper trough overspreads the warm sector, convective mode may quickly become messy, as generally southwesterly low/mid-level flow encourages updraft interactions and mergers. Even so, around 1000-2000 J/kg of MUCAPE, aided by modestly steepened mid-level lapse rates, should support robust updrafts. Coupled with sufficient (around 30-40 kt) deep-layer shear, some of this initial development could produce marginally severe hail on an isolated basis. Based on latest guidance trends showing convective initiation farther north across parts of northern OK into southwest MO, the Marginal Risk has been expanded northward to account for this initial hail threat. Poor/neutral low-level lapse rates and a generally saturated boundary-layer shown in various NAM/RAP forecast soundings limit confidence to some extent in the potential for truly surface-based thunderstorms tonight across the warm sector. Still, the presence of a 35-45 kt southwesterly low-level jet, with associated 0-1 km SRH sufficient for low-level updraft rotation, suggests a non-zero threat for a tornado along with some potential for occasional strong/gusty winds as convection spreads eastward across eastern OK into western AR and the Ozarks through early Monday morning. The potential for sustained supercells appears limited by a weakness in the flow/hodograph forecast around 700 mb, with the southward-moving cold front also encouraging a more linear/cluster mode with time. Overall, the severe threat with any convection that develops should remain rather isolated, but within a conditionally somewhat favorable environment. ..Gleason/Squitieri.. 12/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1030 AM CST Sun Dec 15 2024 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated severe hail, strong/gusty winds, and perhaps a tornado may occur tonight through early Monday morning from parts of north Texas to the Ozarks. ...Synopsis... Gradual amplification and consolidation of upper troughing will occur through the period across parts of the northern Plains and Upper Midwest. The southern fringe of this upper trough will begin to influence and overspread portions of the central/southern Plains late this evening and overnight. The primary surface low will develop towards the international border region of northern MN/southern Canada, while partially modified Gulf moisture continues to gradually stream northward over portions of the southern Plains into the Ozarks ahead of a cold front. ...Eastern Oklahoma into Western Arkansas and Southwest Missouri... Convective initiation will likely be delayed until 03Z or later this evening across eastern OK/western AR vicinity, as low-level warm/moist advection aids in the northward transport of a moist low-level airmass. Once convection develops as glancing ascent from the approaching upper trough overspreads the warm sector, convective mode may quickly become messy, as generally southwesterly low/mid-level flow encourages updraft interactions and mergers. Even so, around 1000-2000 J/kg of MUCAPE, aided by modestly steepened mid-level lapse rates, should support robust updrafts. Coupled with sufficient (around 30-40 kt) deep-layer shear, some of this initial development could produce marginally severe hail on an isolated basis. Based on latest guidance trends showing convective initiation farther north across parts of northern OK into southwest MO, the Marginal Risk has been expanded northward to account for this initial hail threat. Poor/neutral low-level lapse rates and a generally saturated boundary-layer shown in various NAM/RAP forecast soundings limit confidence to some extent in the potential for truly surface-based thunderstorms tonight across the warm sector. Still, the presence of a 35-45 kt southwesterly low-level jet, with associated 0-1 km SRH sufficient for low-level updraft rotation, suggests a non-zero threat for a tornado along with some potential for occasional strong/gusty winds as convection spreads eastward across eastern OK into western AR and the Ozarks through early Monday morning. The potential for sustained supercells appears limited by a weakness in the flow/hodograph forecast around 700 mb, with the southward-moving cold front also encouraging a more linear/cluster mode with time. Overall, the severe threat with any convection that develops should remain rather isolated, but within a conditionally somewhat favorable environment. ..Gleason/Squitieri.. 12/15/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1032 AM CST Sun Dec 15 2024 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... Embedded within stronger quasi-zonal flow aloft, a shortwave trough is forecast to rapidly eject eastward from the Intermoutnain West across the central and northern Rockies early this morning. As lift from the trough shifts east, a lee low and trailing surface trough will quickly deepen across parts of the High Plains, while a cold front will approach from the interior West. The strong mid-level flow and lee low will support downslope winds across portions of the central High Plains, and to a lesser degree across eastern NM and far West TX. These strong winds of 20-30 mph may briefly overlap with areas of moderately low RH this afternoon. While there is some risk, fire-weather concerns are not expected to be widespread, given the brief nature of the strong winds and lower RH, as well as the passage of the cold front later this afternoon and into the evening. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1032 AM CST Sun Dec 15 2024 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... Embedded within stronger quasi-zonal flow aloft, a shortwave trough is forecast to rapidly eject eastward from the Intermoutnain West across the central and northern Rockies early this morning. As lift from the trough shifts east, a lee low and trailing surface trough will quickly deepen across parts of the High Plains, while a cold front will approach from the interior West. The strong mid-level flow and lee low will support downslope winds across portions of the central High Plains, and to a lesser degree across eastern NM and far West TX. These strong winds of 20-30 mph may briefly overlap with areas of moderately low RH this afternoon. While there is some risk, fire-weather concerns are not expected to be widespread, given the brief nature of the strong winds and lower RH, as well as the passage of the cold front later this afternoon and into the evening. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1032 AM CST Sun Dec 15 2024 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... Embedded within stronger quasi-zonal flow aloft, a shortwave trough is forecast to rapidly eject eastward from the Intermoutnain West across the central and northern Rockies early this morning. As lift from the trough shifts east, a lee low and trailing surface trough will quickly deepen across parts of the High Plains, while a cold front will approach from the interior West. The strong mid-level flow and lee low will support downslope winds across portions of the central High Plains, and to a lesser degree across eastern NM and far West TX. These strong winds of 20-30 mph may briefly overlap with areas of moderately low RH this afternoon. While there is some risk, fire-weather concerns are not expected to be widespread, given the brief nature of the strong winds and lower RH, as well as the passage of the cold front later this afternoon and into the evening. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1032 AM CST Sun Dec 15 2024 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... Embedded within stronger quasi-zonal flow aloft, a shortwave trough is forecast to rapidly eject eastward from the Intermoutnain West across the central and northern Rockies early this morning. As lift from the trough shifts east, a lee low and trailing surface trough will quickly deepen across parts of the High Plains, while a cold front will approach from the interior West. The strong mid-level flow and lee low will support downslope winds across portions of the central High Plains, and to a lesser degree across eastern NM and far West TX. These strong winds of 20-30 mph may briefly overlap with areas of moderately low RH this afternoon. While there is some risk, fire-weather concerns are not expected to be widespread, given the brief nature of the strong winds and lower RH, as well as the passage of the cold front later this afternoon and into the evening. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1032 AM CST Sun Dec 15 2024 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... Embedded within stronger quasi-zonal flow aloft, a shortwave trough is forecast to rapidly eject eastward from the Intermoutnain West across the central and northern Rockies early this morning. As lift from the trough shifts east, a lee low and trailing surface trough will quickly deepen across parts of the High Plains, while a cold front will approach from the interior West. The strong mid-level flow and lee low will support downslope winds across portions of the central High Plains, and to a lesser degree across eastern NM and far West TX. These strong winds of 20-30 mph may briefly overlap with areas of moderately low RH this afternoon. While there is some risk, fire-weather concerns are not expected to be widespread, given the brief nature of the strong winds and lower RH, as well as the passage of the cold front later this afternoon and into the evening. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1032 AM CST Sun Dec 15 2024 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... Embedded within stronger quasi-zonal flow aloft, a shortwave trough is forecast to rapidly eject eastward from the Intermoutnain West across the central and northern Rockies early this morning. As lift from the trough shifts east, a lee low and trailing surface trough will quickly deepen across parts of the High Plains, while a cold front will approach from the interior West. The strong mid-level flow and lee low will support downslope winds across portions of the central High Plains, and to a lesser degree across eastern NM and far West TX. These strong winds of 20-30 mph may briefly overlap with areas of moderately low RH this afternoon. While there is some risk, fire-weather concerns are not expected to be widespread, given the brief nature of the strong winds and lower RH, as well as the passage of the cold front later this afternoon and into the evening. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1032 AM CST Sun Dec 15 2024 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... Embedded within stronger quasi-zonal flow aloft, a shortwave trough is forecast to rapidly eject eastward from the Intermoutnain West across the central and northern Rockies early this morning. As lift from the trough shifts east, a lee low and trailing surface trough will quickly deepen across parts of the High Plains, while a cold front will approach from the interior West. The strong mid-level flow and lee low will support downslope winds across portions of the central High Plains, and to a lesser degree across eastern NM and far West TX. These strong winds of 20-30 mph may briefly overlap with areas of moderately low RH this afternoon. While there is some risk, fire-weather concerns are not expected to be widespread, given the brief nature of the strong winds and lower RH, as well as the passage of the cold front later this afternoon and into the evening. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1032 AM CST Sun Dec 15 2024 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... Embedded within stronger quasi-zonal flow aloft, a shortwave trough is forecast to rapidly eject eastward from the Intermoutnain West across the central and northern Rockies early this morning. As lift from the trough shifts east, a lee low and trailing surface trough will quickly deepen across parts of the High Plains, while a cold front will approach from the interior West. The strong mid-level flow and lee low will support downslope winds across portions of the central High Plains, and to a lesser degree across eastern NM and far West TX. These strong winds of 20-30 mph may briefly overlap with areas of moderately low RH this afternoon. While there is some risk, fire-weather concerns are not expected to be widespread, given the brief nature of the strong winds and lower RH, as well as the passage of the cold front later this afternoon and into the evening. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0624 AM CST Sun Dec 15 2024 Valid 151300Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated hail near severe limits is possible tonight from portions of north Texas to the Ozarks. ...Synopsis... In mid/upper levels, a low-amplitude longwave pattern will remain in place over the CONUS, with progressive shortwave to synoptic troughs traversing the prevailing westerlies. The leading trough -- currently anchored by a closed low near the northern IL/IN border -- should devolve to an open wave and move to the northern Mid-Atlantic region by 12Z tomorrow. Meanwhile, a series of shortwaves and vorticity lobes -- occupying broadly cyclonic flow over much of the western CONUS -- will consolidate/phase somewhat through the period while shifting eastward. By 00Z, a loosely organized synoptic trough will extend from the Dakotas across the central High Plains to AZ. Overnight, a closed 500-mb low should develop over southern MB, with the trough extending across central NE/KS to southern NM and northwestern MX by 12Z. At the surface, 11Z analysis showed a decaying cold to stationary front from eastern IL across southern AR, north-central and west- central TX. This boundary will move slowly northward through the day and continue to weaken. Meanwhile, cold frontogenesis is forecast today ahead of the mid/upper trough, and over parts of the central/northern Plains. This Plains front should reach western parts of MN/IA, northeastern to south-central KS, and the TX Panhandle by 00Z. By 12Z, the cold front should reach central/ southern IL, the Ozarks, eastern/southern OK, and the TX South Plains region. ...North TX to the Lower OH Valley... Episodic, isolated to scattered thunderstorms are expected throughout the period, embedded in a plume of low-level warm/moist advection and moisture transport extending from central/east TX to the lower Ohio Valley. Through the day, this activity will occur in weak midlevel lapse rates and modest deep shear, with most or all of it elevated over a relatively stable, near-surface layer, and accordingly minimal severe potential. Meanwhile, surface dewpoints in the 60s F will spread northward into and across much of the outlook area, as the older boundary becomes diffuse ahead of the Plains cold front. Concurrent with height falls aloft and increasing deep shear, the warm conveyor and accompanying isentropic ascent to LFC should intensify this evening amid mass response to the consolidation/ approach of the mid/upper trough, and related 45-55-kt LLJ. Greatest thunderstorm coverage in the plume is expected after about 03Z from near the Red River Valley to the Ozarks, spreading into the lower Ohio Valley from around 09Z onward. During phases when convection is still relatively discrete, and around the southern part of denser/later convective coverage, the most vigorous cells may produce severe hail. Forecast soundings show a nearly saturated, near-neutral stability profile in the boundary layer over north TX to eastern OK, and perhaps into some of northwestern AR, depending on outflow timing/intensity. This renders profiles that may be effectively surface-based, with MLCAPE in the 1000-1500 J/kg rage and slightly greater MUCAPE, but still often containing weak, near-surface static stability. At this time, severe-gust/tornado potential appears too conditional and low to draw even marginal categorical probabilities for those hazards, and the previous outlook area still appears to capture the consensus of most probable, favorably positioned convection in the plume as well. ..Edwards/Goss.. 12/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0624 AM CST Sun Dec 15 2024 Valid 151300Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated hail near severe limits is possible tonight from portions of north Texas to the Ozarks. ...Synopsis... In mid/upper levels, a low-amplitude longwave pattern will remain in place over the CONUS, with progressive shortwave to synoptic troughs traversing the prevailing westerlies. The leading trough -- currently anchored by a closed low near the northern IL/IN border -- should devolve to an open wave and move to the northern Mid-Atlantic region by 12Z tomorrow. Meanwhile, a series of shortwaves and vorticity lobes -- occupying broadly cyclonic flow over much of the western CONUS -- will consolidate/phase somewhat through the period while shifting eastward. By 00Z, a loosely organized synoptic trough will extend from the Dakotas across the central High Plains to AZ. Overnight, a closed 500-mb low should develop over southern MB, with the trough extending across central NE/KS to southern NM and northwestern MX by 12Z. At the surface, 11Z analysis showed a decaying cold to stationary front from eastern IL across southern AR, north-central and west- central TX. This boundary will move slowly northward through the day and continue to weaken. Meanwhile, cold frontogenesis is forecast today ahead of the mid/upper trough, and over parts of the central/northern Plains. This Plains front should reach western parts of MN/IA, northeastern to south-central KS, and the TX Panhandle by 00Z. By 12Z, the cold front should reach central/ southern IL, the Ozarks, eastern/southern OK, and the TX South Plains region. ...North TX to the Lower OH Valley... Episodic, isolated to scattered thunderstorms are expected throughout the period, embedded in a plume of low-level warm/moist advection and moisture transport extending from central/east TX to the lower Ohio Valley. Through the day, this activity will occur in weak midlevel lapse rates and modest deep shear, with most or all of it elevated over a relatively stable, near-surface layer, and accordingly minimal severe potential. Meanwhile, surface dewpoints in the 60s F will spread northward into and across much of the outlook area, as the older boundary becomes diffuse ahead of the Plains cold front. Concurrent with height falls aloft and increasing deep shear, the warm conveyor and accompanying isentropic ascent to LFC should intensify this evening amid mass response to the consolidation/ approach of the mid/upper trough, and related 45-55-kt LLJ. Greatest thunderstorm coverage in the plume is expected after about 03Z from near the Red River Valley to the Ozarks, spreading into the lower Ohio Valley from around 09Z onward. During phases when convection is still relatively discrete, and around the southern part of denser/later convective coverage, the most vigorous cells may produce severe hail. Forecast soundings show a nearly saturated, near-neutral stability profile in the boundary layer over north TX to eastern OK, and perhaps into some of northwestern AR, depending on outflow timing/intensity. This renders profiles that may be effectively surface-based, with MLCAPE in the 1000-1500 J/kg rage and slightly greater MUCAPE, but still often containing weak, near-surface static stability. At this time, severe-gust/tornado potential appears too conditional and low to draw even marginal categorical probabilities for those hazards, and the previous outlook area still appears to capture the consensus of most probable, favorably positioned convection in the plume as well. ..Edwards/Goss.. 12/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0624 AM CST Sun Dec 15 2024 Valid 151300Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated hail near severe limits is possible tonight from portions of north Texas to the Ozarks. ...Synopsis... In mid/upper levels, a low-amplitude longwave pattern will remain in place over the CONUS, with progressive shortwave to synoptic troughs traversing the prevailing westerlies. The leading trough -- currently anchored by a closed low near the northern IL/IN border -- should devolve to an open wave and move to the northern Mid-Atlantic region by 12Z tomorrow. Meanwhile, a series of shortwaves and vorticity lobes -- occupying broadly cyclonic flow over much of the western CONUS -- will consolidate/phase somewhat through the period while shifting eastward. By 00Z, a loosely organized synoptic trough will extend from the Dakotas across the central High Plains to AZ. Overnight, a closed 500-mb low should develop over southern MB, with the trough extending across central NE/KS to southern NM and northwestern MX by 12Z. At the surface, 11Z analysis showed a decaying cold to stationary front from eastern IL across southern AR, north-central and west- central TX. This boundary will move slowly northward through the day and continue to weaken. Meanwhile, cold frontogenesis is forecast today ahead of the mid/upper trough, and over parts of the central/northern Plains. This Plains front should reach western parts of MN/IA, northeastern to south-central KS, and the TX Panhandle by 00Z. By 12Z, the cold front should reach central/ southern IL, the Ozarks, eastern/southern OK, and the TX South Plains region. ...North TX to the Lower OH Valley... Episodic, isolated to scattered thunderstorms are expected throughout the period, embedded in a plume of low-level warm/moist advection and moisture transport extending from central/east TX to the lower Ohio Valley. Through the day, this activity will occur in weak midlevel lapse rates and modest deep shear, with most or all of it elevated over a relatively stable, near-surface layer, and accordingly minimal severe potential. Meanwhile, surface dewpoints in the 60s F will spread northward into and across much of the outlook area, as the older boundary becomes diffuse ahead of the Plains cold front. Concurrent with height falls aloft and increasing deep shear, the warm conveyor and accompanying isentropic ascent to LFC should intensify this evening amid mass response to the consolidation/ approach of the mid/upper trough, and related 45-55-kt LLJ. Greatest thunderstorm coverage in the plume is expected after about 03Z from near the Red River Valley to the Ozarks, spreading into the lower Ohio Valley from around 09Z onward. During phases when convection is still relatively discrete, and around the southern part of denser/later convective coverage, the most vigorous cells may produce severe hail. Forecast soundings show a nearly saturated, near-neutral stability profile in the boundary layer over north TX to eastern OK, and perhaps into some of northwestern AR, depending on outflow timing/intensity. This renders profiles that may be effectively surface-based, with MLCAPE in the 1000-1500 J/kg rage and slightly greater MUCAPE, but still often containing weak, near-surface static stability. At this time, severe-gust/tornado potential appears too conditional and low to draw even marginal categorical probabilities for those hazards, and the previous outlook area still appears to capture the consensus of most probable, favorably positioned convection in the plume as well. ..Edwards/Goss.. 12/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0624 AM CST Sun Dec 15 2024 Valid 151300Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated hail near severe limits is possible tonight from portions of north Texas to the Ozarks. ...Synopsis... In mid/upper levels, a low-amplitude longwave pattern will remain in place over the CONUS, with progressive shortwave to synoptic troughs traversing the prevailing westerlies. The leading trough -- currently anchored by a closed low near the northern IL/IN border -- should devolve to an open wave and move to the northern Mid-Atlantic region by 12Z tomorrow. Meanwhile, a series of shortwaves and vorticity lobes -- occupying broadly cyclonic flow over much of the western CONUS -- will consolidate/phase somewhat through the period while shifting eastward. By 00Z, a loosely organized synoptic trough will extend from the Dakotas across the central High Plains to AZ. Overnight, a closed 500-mb low should develop over southern MB, with the trough extending across central NE/KS to southern NM and northwestern MX by 12Z. At the surface, 11Z analysis showed a decaying cold to stationary front from eastern IL across southern AR, north-central and west- central TX. This boundary will move slowly northward through the day and continue to weaken. Meanwhile, cold frontogenesis is forecast today ahead of the mid/upper trough, and over parts of the central/northern Plains. This Plains front should reach western parts of MN/IA, northeastern to south-central KS, and the TX Panhandle by 00Z. By 12Z, the cold front should reach central/ southern IL, the Ozarks, eastern/southern OK, and the TX South Plains region. ...North TX to the Lower OH Valley... Episodic, isolated to scattered thunderstorms are expected throughout the period, embedded in a plume of low-level warm/moist advection and moisture transport extending from central/east TX to the lower Ohio Valley. Through the day, this activity will occur in weak midlevel lapse rates and modest deep shear, with most or all of it elevated over a relatively stable, near-surface layer, and accordingly minimal severe potential. Meanwhile, surface dewpoints in the 60s F will spread northward into and across much of the outlook area, as the older boundary becomes diffuse ahead of the Plains cold front. Concurrent with height falls aloft and increasing deep shear, the warm conveyor and accompanying isentropic ascent to LFC should intensify this evening amid mass response to the consolidation/ approach of the mid/upper trough, and related 45-55-kt LLJ. Greatest thunderstorm coverage in the plume is expected after about 03Z from near the Red River Valley to the Ozarks, spreading into the lower Ohio Valley from around 09Z onward. During phases when convection is still relatively discrete, and around the southern part of denser/later convective coverage, the most vigorous cells may produce severe hail. Forecast soundings show a nearly saturated, near-neutral stability profile in the boundary layer over north TX to eastern OK, and perhaps into some of northwestern AR, depending on outflow timing/intensity. This renders profiles that may be effectively surface-based, with MLCAPE in the 1000-1500 J/kg rage and slightly greater MUCAPE, but still often containing weak, near-surface static stability. At this time, severe-gust/tornado potential appears too conditional and low to draw even marginal categorical probabilities for those hazards, and the previous outlook area still appears to capture the consensus of most probable, favorably positioned convection in the plume as well. ..Edwards/Goss.. 12/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0624 AM CST Sun Dec 15 2024 Valid 151300Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated hail near severe limits is possible tonight from portions of north Texas to the Ozarks. ...Synopsis... In mid/upper levels, a low-amplitude longwave pattern will remain in place over the CONUS, with progressive shortwave to synoptic troughs traversing the prevailing westerlies. The leading trough -- currently anchored by a closed low near the northern IL/IN border -- should devolve to an open wave and move to the northern Mid-Atlantic region by 12Z tomorrow. Meanwhile, a series of shortwaves and vorticity lobes -- occupying broadly cyclonic flow over much of the western CONUS -- will consolidate/phase somewhat through the period while shifting eastward. By 00Z, a loosely organized synoptic trough will extend from the Dakotas across the central High Plains to AZ. Overnight, a closed 500-mb low should develop over southern MB, with the trough extending across central NE/KS to southern NM and northwestern MX by 12Z. At the surface, 11Z analysis showed a decaying cold to stationary front from eastern IL across southern AR, north-central and west- central TX. This boundary will move slowly northward through the day and continue to weaken. Meanwhile, cold frontogenesis is forecast today ahead of the mid/upper trough, and over parts of the central/northern Plains. This Plains front should reach western parts of MN/IA, northeastern to south-central KS, and the TX Panhandle by 00Z. By 12Z, the cold front should reach central/ southern IL, the Ozarks, eastern/southern OK, and the TX South Plains region. ...North TX to the Lower OH Valley... Episodic, isolated to scattered thunderstorms are expected throughout the period, embedded in a plume of low-level warm/moist advection and moisture transport extending from central/east TX to the lower Ohio Valley. Through the day, this activity will occur in weak midlevel lapse rates and modest deep shear, with most or all of it elevated over a relatively stable, near-surface layer, and accordingly minimal severe potential. Meanwhile, surface dewpoints in the 60s F will spread northward into and across much of the outlook area, as the older boundary becomes diffuse ahead of the Plains cold front. Concurrent with height falls aloft and increasing deep shear, the warm conveyor and accompanying isentropic ascent to LFC should intensify this evening amid mass response to the consolidation/ approach of the mid/upper trough, and related 45-55-kt LLJ. Greatest thunderstorm coverage in the plume is expected after about 03Z from near the Red River Valley to the Ozarks, spreading into the lower Ohio Valley from around 09Z onward. During phases when convection is still relatively discrete, and around the southern part of denser/later convective coverage, the most vigorous cells may produce severe hail. Forecast soundings show a nearly saturated, near-neutral stability profile in the boundary layer over north TX to eastern OK, and perhaps into some of northwestern AR, depending on outflow timing/intensity. This renders profiles that may be effectively surface-based, with MLCAPE in the 1000-1500 J/kg rage and slightly greater MUCAPE, but still often containing weak, near-surface static stability. At this time, severe-gust/tornado potential appears too conditional and low to draw even marginal categorical probabilities for those hazards, and the previous outlook area still appears to capture the consensus of most probable, favorably positioned convection in the plume as well. ..Edwards/Goss.. 12/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0624 AM CST Sun Dec 15 2024 Valid 151300Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated hail near severe limits is possible tonight from portions of north Texas to the Ozarks. ...Synopsis... In mid/upper levels, a low-amplitude longwave pattern will remain in place over the CONUS, with progressive shortwave to synoptic troughs traversing the prevailing westerlies. The leading trough -- currently anchored by a closed low near the northern IL/IN border -- should devolve to an open wave and move to the northern Mid-Atlantic region by 12Z tomorrow. Meanwhile, a series of shortwaves and vorticity lobes -- occupying broadly cyclonic flow over much of the western CONUS -- will consolidate/phase somewhat through the period while shifting eastward. By 00Z, a loosely organized synoptic trough will extend from the Dakotas across the central High Plains to AZ. Overnight, a closed 500-mb low should develop over southern MB, with the trough extending across central NE/KS to southern NM and northwestern MX by 12Z. At the surface, 11Z analysis showed a decaying cold to stationary front from eastern IL across southern AR, north-central and west- central TX. This boundary will move slowly northward through the day and continue to weaken. Meanwhile, cold frontogenesis is forecast today ahead of the mid/upper trough, and over parts of the central/northern Plains. This Plains front should reach western parts of MN/IA, northeastern to south-central KS, and the TX Panhandle by 00Z. By 12Z, the cold front should reach central/ southern IL, the Ozarks, eastern/southern OK, and the TX South Plains region. ...North TX to the Lower OH Valley... Episodic, isolated to scattered thunderstorms are expected throughout the period, embedded in a plume of low-level warm/moist advection and moisture transport extending from central/east TX to the lower Ohio Valley. Through the day, this activity will occur in weak midlevel lapse rates and modest deep shear, with most or all of it elevated over a relatively stable, near-surface layer, and accordingly minimal severe potential. Meanwhile, surface dewpoints in the 60s F will spread northward into and across much of the outlook area, as the older boundary becomes diffuse ahead of the Plains cold front. Concurrent with height falls aloft and increasing deep shear, the warm conveyor and accompanying isentropic ascent to LFC should intensify this evening amid mass response to the consolidation/ approach of the mid/upper trough, and related 45-55-kt LLJ. Greatest thunderstorm coverage in the plume is expected after about 03Z from near the Red River Valley to the Ozarks, spreading into the lower Ohio Valley from around 09Z onward. During phases when convection is still relatively discrete, and around the southern part of denser/later convective coverage, the most vigorous cells may produce severe hail. Forecast soundings show a nearly saturated, near-neutral stability profile in the boundary layer over north TX to eastern OK, and perhaps into some of northwestern AR, depending on outflow timing/intensity. This renders profiles that may be effectively surface-based, with MLCAPE in the 1000-1500 J/kg rage and slightly greater MUCAPE, but still often containing weak, near-surface static stability. At this time, severe-gust/tornado potential appears too conditional and low to draw even marginal categorical probabilities for those hazards, and the previous outlook area still appears to capture the consensus of most probable, favorably positioned convection in the plume as well. ..Edwards/Goss.. 12/15/2024 Read more