Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Dec 15 2024 Valid 152000Z - 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. ...20Z Update... The previous forecast (see below) remains on track, and no changes were needed with this update. The latest guidance indicates some potential for embedded/loosely organized cells tracking northeastward across southeast MO during the early morning hours -- mainly capable of producing small hail and/or locally strong gusts. It is unclear if this activity will be surface-based, and given marginal midlevel lapse rates/instability, severe potential appears too low to expand probabilities. ..Weinman.. 12/15/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Sun Dec 15 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Dec 15 2024 Valid 152000Z - 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. ...20Z Update... The previous forecast (see below) remains on track, and no changes were needed with this update. The latest guidance indicates some potential for embedded/loosely organized cells tracking northeastward across southeast MO during the early morning hours -- mainly capable of producing small hail and/or locally strong gusts. It is unclear if this activity will be surface-based, and given marginal midlevel lapse rates/instability, severe potential appears too low to expand probabilities. ..Weinman.. 12/15/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Sun Dec 15 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Dec 15 2024 Valid 152000Z - 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. ...20Z Update... The previous forecast (see below) remains on track, and no changes were needed with this update. The latest guidance indicates some potential for embedded/loosely organized cells tracking northeastward across southeast MO during the early morning hours -- mainly capable of producing small hail and/or locally strong gusts. It is unclear if this activity will be surface-based, and given marginal midlevel lapse rates/instability, severe potential appears too low to expand probabilities. ..Weinman.. 12/15/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Sun Dec 15 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Dec 15 2024 Valid 152000Z - 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. ...20Z Update... The previous forecast (see below) remains on track, and no changes were needed with this update. The latest guidance indicates some potential for embedded/loosely organized cells tracking northeastward across southeast MO during the early morning hours -- mainly capable of producing small hail and/or locally strong gusts. It is unclear if this activity will be surface-based, and given marginal midlevel lapse rates/instability, severe potential appears too low to expand probabilities. ..Weinman.. 12/15/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Sun Dec 15 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Dec 15 2024 Valid 152000Z - 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. ...20Z Update... The previous forecast (see below) remains on track, and no changes were needed with this update. The latest guidance indicates some potential for embedded/loosely organized cells tracking northeastward across southeast MO during the early morning hours -- mainly capable of producing small hail and/or locally strong gusts. It is unclear if this activity will be surface-based, and given marginal midlevel lapse rates/instability, severe potential appears too low to expand probabilities. ..Weinman.. 12/15/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Sun Dec 15 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Dec 15 2024 Valid 152000Z - 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. ...20Z Update... The previous forecast (see below) remains on track, and no changes were needed with this update. The latest guidance indicates some potential for embedded/loosely organized cells tracking northeastward across southeast MO during the early morning hours -- mainly capable of producing small hail and/or locally strong gusts. It is unclear if this activity will be surface-based, and given marginal midlevel lapse rates/instability, severe potential appears too low to expand probabilities. ..Weinman.. 12/15/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Sun Dec 15 2024/ ...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. Read more

MD 2268 CONCERNING WINTER MIXED PRECIPITATION FOR PORTIONS OF WEST VIRGINIA INTO WESTERN MARYLAND AND SOUTHWESTERN PENNSYLVANIA
Mesoscale Discussion 2268 NWS Storm Prediction Center Norman OK 0930 AM CST Sun Dec 15 2024 Areas affected...portions of West Virginia into western Maryland and southwestern Pennsylvania Concerning...Winter mixed precipitation Valid 151530Z - 152030Z SUMMARY...Freezing rain should gradually increase into the late morning and early afternoon hours, with some sleet or snow also possible. Up to .06/3 hr ice accretion rates cannot be ruled out, especially in higher-terrain areas. DISCUSSION...A pronounced mid-level trough is progressing eastward across the OH Valley, encouraging low-level warm air/moisture advection over portions of the Appalachians. Here, QG ascent is supporting a broad shield of precipitation, which is beginning to approach a wedge of sub-freezing low-level temperatures over higher-terrain areas. Surface observations from Hardy County, WV to Cambria County, PA show temperatures around or below freezing, with wet bulb temperatures well below freezing over several locales. 15Z mesoanalysis continues to show 925-850 mb CAA over the higher terrain, which will further support freezing rain potential, perhaps with some sleet or snow mixed in. The best chance for .06/3hr ice accretion rates, as well as some sleet or snow, will be late this morning into the afternoon hours, as also shown by the latest HRRR and HREF probabilistic guidance. ..Squitieri.. 12/15/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CTP...LWX...PBZ...RLX... LAT...LON 38687964 39297928 39857927 40527896 40647851 40497812 40037806 39357826 38937852 38677891 38547926 38687964 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... A progressive and mostly zonal mid-level flow pattern is expected over the CONUS D2/Mon. A pronounced shortwave trough within the stronger westerly flow will move quickly eastward over the northern third of the CONUS. At the surface, cyclone associated with the mid-level trough will move along the US/Canadian border, trailing a cold front over the central US. In the wake of the front, a much colder air mass and modest high pressure are likely over the western 2/3rds of the US. This should keep winds relatively light and RH values elevated. Additionally precipitation ahead of the front and from the prior day will augment fuels, such that little or no fire-weather risk is expected. ...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 0134 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... A progressive and mostly zonal mid-level flow pattern is expected over the CONUS D2/Mon. A pronounced shortwave trough within the stronger westerly flow will move quickly eastward over the northern third of the CONUS. At the surface, cyclone associated with the mid-level trough will move along the US/Canadian border, trailing a cold front over the central US. In the wake of the front, a much colder air mass and modest high pressure are likely over the western 2/3rds of the US. This should keep winds relatively light and RH values elevated. Additionally precipitation ahead of the front and from the prior day will augment fuels, such that little or no fire-weather risk is expected. ...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 0134 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... A progressive and mostly zonal mid-level flow pattern is expected over the CONUS D2/Mon. A pronounced shortwave trough within the stronger westerly flow will move quickly eastward over the northern third of the CONUS. At the surface, cyclone associated with the mid-level trough will move along the US/Canadian border, trailing a cold front over the central US. In the wake of the front, a much colder air mass and modest high pressure are likely over the western 2/3rds of the US. This should keep winds relatively light and RH values elevated. Additionally precipitation ahead of the front and from the prior day will augment fuels, such that little or no fire-weather risk is expected. ...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 0134 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... A progressive and mostly zonal mid-level flow pattern is expected over the CONUS D2/Mon. A pronounced shortwave trough within the stronger westerly flow will move quickly eastward over the northern third of the CONUS. At the surface, cyclone associated with the mid-level trough will move along the US/Canadian border, trailing a cold front over the central US. In the wake of the front, a much colder air mass and modest high pressure are likely over the western 2/3rds of the US. This should keep winds relatively light and RH values elevated. Additionally precipitation ahead of the front and from the prior day will augment fuels, such that little or no fire-weather risk is expected. ...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 0134 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... A progressive and mostly zonal mid-level flow pattern is expected over the CONUS D2/Mon. A pronounced shortwave trough within the stronger westerly flow will move quickly eastward over the northern third of the CONUS. At the surface, cyclone associated with the mid-level trough will move along the US/Canadian border, trailing a cold front over the central US. In the wake of the front, a much colder air mass and modest high pressure are likely over the western 2/3rds of the US. This should keep winds relatively light and RH values elevated. Additionally precipitation ahead of the front and from the prior day will augment fuels, such that little or no fire-weather risk is expected. ...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 0134 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/15/2024 .PREV DISCUSSION... /ISSUED 0155 AM CST Sun Dec 15 2024/ ...Synopsis... A progressive and mostly zonal mid-level flow pattern is expected over the CONUS D2/Mon. A pronounced shortwave trough within the stronger westerly flow will move quickly eastward over the northern third of the CONUS. At the surface, cyclone associated with the mid-level trough will move along the US/Canadian border, trailing a cold front over the central US. In the wake of the front, a much colder air mass and modest high pressure are likely over the western 2/3rds of the US. This should keep winds relatively light and RH values elevated. Additionally precipitation ahead of the front and from the prior day will augment fuels, such that little or no fire-weather risk is expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Sun Dec 15 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Mid-Mississippi Valley and across Florida on Tuesday. Severe thunderstorms appear unlikely at this time. ...Synopsis... On Tuesday, a fast moving jet streak will move from the Inter Mountain West to the central Plains. This will lead to some weak lee cyclogenesis with this surface low drifting south along the Front Range through the day. The positively tilted upper trough will sharpen by Tuesday evening, and a surface low will start to develop into the Plains and eventually move somewhere near the Mid-Mississippi Valley by the end of the period. A reservoir of moderate instability will be present across the southern half of Texas on Tuesday morning with slow northward movement toward the Red River through the day. Neutral to slightly rising heights aloft will likely keep thunderstorm activity limited during the day. However, during the evening and overnight hours as the upper trough sharpens and ejects into the Plains, height falls and increasing vorticity advection combined with increasing isentropic ascent should provide ample lift for scattered thunderstorm activity Tuesday night. Forecast soundings show weak to moderate elevated instability and moderate mid-level lapse rates. As mid-level flow strengthens with the approaching jet streak, 30 to 35 knots of effective shear will likely be present along and to the north of the front. Isolated large hail may be possible in this zone after 03Z. The better chance for surface based thunderstorms will be farther south near the ArkLaTex. However, forecast soundings show weak shear that far south which would likely limit storm intensity even if surface-based convection can develop within a more unstable environment. A marginal risk may be needed for portions of the southern Plains/Ozarks in later outlooks if overlap between forcing, instability and shear becomes more clear. ..Bentley.. 12/15/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Sun Dec 15 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Mid-Mississippi Valley and across Florida on Tuesday. Severe thunderstorms appear unlikely at this time. ...Synopsis... On Tuesday, a fast moving jet streak will move from the Inter Mountain West to the central Plains. This will lead to some weak lee cyclogenesis with this surface low drifting south along the Front Range through the day. The positively tilted upper trough will sharpen by Tuesday evening, and a surface low will start to develop into the Plains and eventually move somewhere near the Mid-Mississippi Valley by the end of the period. A reservoir of moderate instability will be present across the southern half of Texas on Tuesday morning with slow northward movement toward the Red River through the day. Neutral to slightly rising heights aloft will likely keep thunderstorm activity limited during the day. However, during the evening and overnight hours as the upper trough sharpens and ejects into the Plains, height falls and increasing vorticity advection combined with increasing isentropic ascent should provide ample lift for scattered thunderstorm activity Tuesday night. Forecast soundings show weak to moderate elevated instability and moderate mid-level lapse rates. As mid-level flow strengthens with the approaching jet streak, 30 to 35 knots of effective shear will likely be present along and to the north of the front. Isolated large hail may be possible in this zone after 03Z. The better chance for surface based thunderstorms will be farther south near the ArkLaTex. However, forecast soundings show weak shear that far south which would likely limit storm intensity even if surface-based convection can develop within a more unstable environment. A marginal risk may be needed for portions of the southern Plains/Ozarks in later outlooks if overlap between forcing, instability and shear becomes more clear. ..Bentley.. 12/15/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Sun Dec 15 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Mid-Mississippi Valley and across Florida on Tuesday. Severe thunderstorms appear unlikely at this time. ...Synopsis... On Tuesday, a fast moving jet streak will move from the Inter Mountain West to the central Plains. This will lead to some weak lee cyclogenesis with this surface low drifting south along the Front Range through the day. The positively tilted upper trough will sharpen by Tuesday evening, and a surface low will start to develop into the Plains and eventually move somewhere near the Mid-Mississippi Valley by the end of the period. A reservoir of moderate instability will be present across the southern half of Texas on Tuesday morning with slow northward movement toward the Red River through the day. Neutral to slightly rising heights aloft will likely keep thunderstorm activity limited during the day. However, during the evening and overnight hours as the upper trough sharpens and ejects into the Plains, height falls and increasing vorticity advection combined with increasing isentropic ascent should provide ample lift for scattered thunderstorm activity Tuesday night. Forecast soundings show weak to moderate elevated instability and moderate mid-level lapse rates. As mid-level flow strengthens with the approaching jet streak, 30 to 35 knots of effective shear will likely be present along and to the north of the front. Isolated large hail may be possible in this zone after 03Z. The better chance for surface based thunderstorms will be farther south near the ArkLaTex. However, forecast soundings show weak shear that far south which would likely limit storm intensity even if surface-based convection can develop within a more unstable environment. A marginal risk may be needed for portions of the southern Plains/Ozarks in later outlooks if overlap between forcing, instability and shear becomes more clear. ..Bentley.. 12/15/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Sun Dec 15 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Mid-Mississippi Valley and across Florida on Tuesday. Severe thunderstorms appear unlikely at this time. ...Synopsis... On Tuesday, a fast moving jet streak will move from the Inter Mountain West to the central Plains. This will lead to some weak lee cyclogenesis with this surface low drifting south along the Front Range through the day. The positively tilted upper trough will sharpen by Tuesday evening, and a surface low will start to develop into the Plains and eventually move somewhere near the Mid-Mississippi Valley by the end of the period. A reservoir of moderate instability will be present across the southern half of Texas on Tuesday morning with slow northward movement toward the Red River through the day. Neutral to slightly rising heights aloft will likely keep thunderstorm activity limited during the day. However, during the evening and overnight hours as the upper trough sharpens and ejects into the Plains, height falls and increasing vorticity advection combined with increasing isentropic ascent should provide ample lift for scattered thunderstorm activity Tuesday night. Forecast soundings show weak to moderate elevated instability and moderate mid-level lapse rates. As mid-level flow strengthens with the approaching jet streak, 30 to 35 knots of effective shear will likely be present along and to the north of the front. Isolated large hail may be possible in this zone after 03Z. The better chance for surface based thunderstorms will be farther south near the ArkLaTex. However, forecast soundings show weak shear that far south which would likely limit storm intensity even if surface-based convection can develop within a more unstable environment. A marginal risk may be needed for portions of the southern Plains/Ozarks in later outlooks if overlap between forcing, instability and shear becomes more clear. ..Bentley.. 12/15/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Sun Dec 15 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Mid-Mississippi Valley and across Florida on Tuesday. Severe thunderstorms appear unlikely at this time. ...Synopsis... On Tuesday, a fast moving jet streak will move from the Inter Mountain West to the central Plains. This will lead to some weak lee cyclogenesis with this surface low drifting south along the Front Range through the day. The positively tilted upper trough will sharpen by Tuesday evening, and a surface low will start to develop into the Plains and eventually move somewhere near the Mid-Mississippi Valley by the end of the period. A reservoir of moderate instability will be present across the southern half of Texas on Tuesday morning with slow northward movement toward the Red River through the day. Neutral to slightly rising heights aloft will likely keep thunderstorm activity limited during the day. However, during the evening and overnight hours as the upper trough sharpens and ejects into the Plains, height falls and increasing vorticity advection combined with increasing isentropic ascent should provide ample lift for scattered thunderstorm activity Tuesday night. Forecast soundings show weak to moderate elevated instability and moderate mid-level lapse rates. As mid-level flow strengthens with the approaching jet streak, 30 to 35 knots of effective shear will likely be present along and to the north of the front. Isolated large hail may be possible in this zone after 03Z. The better chance for surface based thunderstorms will be farther south near the ArkLaTex. However, forecast soundings show weak shear that far south which would likely limit storm intensity even if surface-based convection can develop within a more unstable environment. A marginal risk may be needed for portions of the southern Plains/Ozarks in later outlooks if overlap between forcing, instability and shear becomes more clear. ..Bentley.. 12/15/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Sun Dec 15 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Mid-Mississippi Valley and across Florida on Tuesday. Severe thunderstorms appear unlikely at this time. ...Synopsis... On Tuesday, a fast moving jet streak will move from the Inter Mountain West to the central Plains. This will lead to some weak lee cyclogenesis with this surface low drifting south along the Front Range through the day. The positively tilted upper trough will sharpen by Tuesday evening, and a surface low will start to develop into the Plains and eventually move somewhere near the Mid-Mississippi Valley by the end of the period. A reservoir of moderate instability will be present across the southern half of Texas on Tuesday morning with slow northward movement toward the Red River through the day. Neutral to slightly rising heights aloft will likely keep thunderstorm activity limited during the day. However, during the evening and overnight hours as the upper trough sharpens and ejects into the Plains, height falls and increasing vorticity advection combined with increasing isentropic ascent should provide ample lift for scattered thunderstorm activity Tuesday night. Forecast soundings show weak to moderate elevated instability and moderate mid-level lapse rates. As mid-level flow strengthens with the approaching jet streak, 30 to 35 knots of effective shear will likely be present along and to the north of the front. Isolated large hail may be possible in this zone after 03Z. The better chance for surface based thunderstorms will be farther south near the ArkLaTex. However, forecast soundings show weak shear that far south which would likely limit storm intensity even if surface-based convection can develop within a more unstable environment. A marginal risk may be needed for portions of the southern Plains/Ozarks in later outlooks if overlap between forcing, instability and shear becomes more clear. ..Bentley.. 12/15/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Sun Dec 15 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Mid-Mississippi Valley and across Florida on Tuesday. Severe thunderstorms appear unlikely at this time. ...Synopsis... On Tuesday, a fast moving jet streak will move from the Inter Mountain West to the central Plains. This will lead to some weak lee cyclogenesis with this surface low drifting south along the Front Range through the day. The positively tilted upper trough will sharpen by Tuesday evening, and a surface low will start to develop into the Plains and eventually move somewhere near the Mid-Mississippi Valley by the end of the period. A reservoir of moderate instability will be present across the southern half of Texas on Tuesday morning with slow northward movement toward the Red River through the day. Neutral to slightly rising heights aloft will likely keep thunderstorm activity limited during the day. However, during the evening and overnight hours as the upper trough sharpens and ejects into the Plains, height falls and increasing vorticity advection combined with increasing isentropic ascent should provide ample lift for scattered thunderstorm activity Tuesday night. Forecast soundings show weak to moderate elevated instability and moderate mid-level lapse rates. As mid-level flow strengthens with the approaching jet streak, 30 to 35 knots of effective shear will likely be present along and to the north of the front. Isolated large hail may be possible in this zone after 03Z. The better chance for surface based thunderstorms will be farther south near the ArkLaTex. However, forecast soundings show weak shear that far south which would likely limit storm intensity even if surface-based convection can develop within a more unstable environment. A marginal risk may be needed for portions of the southern Plains/Ozarks in later outlooks if overlap between forcing, instability and shear becomes more clear. ..Bentley.. 12/15/2024 Read more