Aggregator

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Thu Dec 12 2024 Valid 121630Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Lightning is possible this evening and tonight along the eastern shores of Lake Ontario in association with lake-effect snow bands. ...NY... Cool/dry and stable conditions will prevail over the most of the CONUS today, with no organized thunderstorm activity expected. One exception will be in the vicinity of the eastern shores of Lake Ontario (Jefferson/Lewis/Oswego counties). A long-fetch lake-effect snow band is forecast to develop later this evening and tonight. Forecast soundings suggest a sufficiently deep convective layer to promote charge separation and a few lightning strikes - mainly after 02z. ..Hart.. 12/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Thu Dec 12 2024 Valid 121630Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Lightning is possible this evening and tonight along the eastern shores of Lake Ontario in association with lake-effect snow bands. ...NY... Cool/dry and stable conditions will prevail over the most of the CONUS today, with no organized thunderstorm activity expected. One exception will be in the vicinity of the eastern shores of Lake Ontario (Jefferson/Lewis/Oswego counties). A long-fetch lake-effect snow band is forecast to develop later this evening and tonight. Forecast soundings suggest a sufficiently deep convective layer to promote charge separation and a few lightning strikes - mainly after 02z. ..Hart.. 12/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Thu Dec 12 2024 Valid 121630Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Lightning is possible this evening and tonight along the eastern shores of Lake Ontario in association with lake-effect snow bands. ...NY... Cool/dry and stable conditions will prevail over the most of the CONUS today, with no organized thunderstorm activity expected. One exception will be in the vicinity of the eastern shores of Lake Ontario (Jefferson/Lewis/Oswego counties). A long-fetch lake-effect snow band is forecast to develop later this evening and tonight. Forecast soundings suggest a sufficiently deep convective layer to promote charge separation and a few lightning strikes - mainly after 02z. ..Hart.. 12/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Thu Dec 12 2024 Valid 121630Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Lightning is possible this evening and tonight along the eastern shores of Lake Ontario in association with lake-effect snow bands. ...NY... Cool/dry and stable conditions will prevail over the most of the CONUS today, with no organized thunderstorm activity expected. One exception will be in the vicinity of the eastern shores of Lake Ontario (Jefferson/Lewis/Oswego counties). A long-fetch lake-effect snow band is forecast to develop later this evening and tonight. Forecast soundings suggest a sufficiently deep convective layer to promote charge separation and a few lightning strikes - mainly after 02z. ..Hart.. 12/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Thu Dec 12 2024 Valid 121630Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Lightning is possible this evening and tonight along the eastern shores of Lake Ontario in association with lake-effect snow bands. ...NY... Cool/dry and stable conditions will prevail over the most of the CONUS today, with no organized thunderstorm activity expected. One exception will be in the vicinity of the eastern shores of Lake Ontario (Jefferson/Lewis/Oswego counties). A long-fetch lake-effect snow band is forecast to develop later this evening and tonight. Forecast soundings suggest a sufficiently deep convective layer to promote charge separation and a few lightning strikes - mainly after 02z. ..Hart.. 12/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0617 AM CST Thu Dec 12 2024 Valid 121300Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms appear unlikely through tonight. ...Synopsis/Discussion... A mid/upper-level cyclone -- initially over northern ON -- will break down as another develops across central QC today, within the same larger-scale troughing regime. As the resulting low ejects northeastward over northern QC, and synoptic ridging moves from the Rockies to the Plains States, heights will rise over most of the central/eastern CONUS. The air mass east of the Rockies mostly will remain too dry and/or stable for thunderstorms, behind the cold frontal passage related to the departing eastern trough. One exception may be in the lake-effect regimes east of the lower Great Lakes, where steep low/middle-level lapse rates will support plumes of heavy convective snow. However, shallowness of buoyancy/ELs precludes more than very brief/isolated lightning potential at most, and the threat appears too conditional and limited for outlook areas. A cyclone now located off the coast of OR and northwestern CA will move inland and devolve slightly to a strong shortwave trough, reaching northern CA and western/southern NV by 00Z. By 12Z, the trough will reach southern ID, UT and AZ. Strong DCVA/cooling aloft is expected immediately to its east today and tonight, from the Great Basin to the Colorado Plateau and UT/southwestern WY. However, with dry air in low levels over most of the region, midlevel moisture/buoyancy should remain too weak and isolated for enough lightning to justify an outlook area. ..Edwards/Jewell.. 12/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0617 AM CST Thu Dec 12 2024 Valid 121300Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms appear unlikely through tonight. ...Synopsis/Discussion... A mid/upper-level cyclone -- initially over northern ON -- will break down as another develops across central QC today, within the same larger-scale troughing regime. As the resulting low ejects northeastward over northern QC, and synoptic ridging moves from the Rockies to the Plains States, heights will rise over most of the central/eastern CONUS. The air mass east of the Rockies mostly will remain too dry and/or stable for thunderstorms, behind the cold frontal passage related to the departing eastern trough. One exception may be in the lake-effect regimes east of the lower Great Lakes, where steep low/middle-level lapse rates will support plumes of heavy convective snow. However, shallowness of buoyancy/ELs precludes more than very brief/isolated lightning potential at most, and the threat appears too conditional and limited for outlook areas. A cyclone now located off the coast of OR and northwestern CA will move inland and devolve slightly to a strong shortwave trough, reaching northern CA and western/southern NV by 00Z. By 12Z, the trough will reach southern ID, UT and AZ. Strong DCVA/cooling aloft is expected immediately to its east today and tonight, from the Great Basin to the Colorado Plateau and UT/southwestern WY. However, with dry air in low levels over most of the region, midlevel moisture/buoyancy should remain too weak and isolated for enough lightning to justify an outlook area. ..Edwards/Jewell.. 12/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0617 AM CST Thu Dec 12 2024 Valid 121300Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms appear unlikely through tonight. ...Synopsis/Discussion... A mid/upper-level cyclone -- initially over northern ON -- will break down as another develops across central QC today, within the same larger-scale troughing regime. As the resulting low ejects northeastward over northern QC, and synoptic ridging moves from the Rockies to the Plains States, heights will rise over most of the central/eastern CONUS. The air mass east of the Rockies mostly will remain too dry and/or stable for thunderstorms, behind the cold frontal passage related to the departing eastern trough. One exception may be in the lake-effect regimes east of the lower Great Lakes, where steep low/middle-level lapse rates will support plumes of heavy convective snow. However, shallowness of buoyancy/ELs precludes more than very brief/isolated lightning potential at most, and the threat appears too conditional and limited for outlook areas. A cyclone now located off the coast of OR and northwestern CA will move inland and devolve slightly to a strong shortwave trough, reaching northern CA and western/southern NV by 00Z. By 12Z, the trough will reach southern ID, UT and AZ. Strong DCVA/cooling aloft is expected immediately to its east today and tonight, from the Great Basin to the Colorado Plateau and UT/southwestern WY. However, with dry air in low levels over most of the region, midlevel moisture/buoyancy should remain too weak and isolated for enough lightning to justify an outlook area. ..Edwards/Jewell.. 12/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0617 AM CST Thu Dec 12 2024 Valid 121300Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms appear unlikely through tonight. ...Synopsis/Discussion... A mid/upper-level cyclone -- initially over northern ON -- will break down as another develops across central QC today, within the same larger-scale troughing regime. As the resulting low ejects northeastward over northern QC, and synoptic ridging moves from the Rockies to the Plains States, heights will rise over most of the central/eastern CONUS. The air mass east of the Rockies mostly will remain too dry and/or stable for thunderstorms, behind the cold frontal passage related to the departing eastern trough. One exception may be in the lake-effect regimes east of the lower Great Lakes, where steep low/middle-level lapse rates will support plumes of heavy convective snow. However, shallowness of buoyancy/ELs precludes more than very brief/isolated lightning potential at most, and the threat appears too conditional and limited for outlook areas. A cyclone now located off the coast of OR and northwestern CA will move inland and devolve slightly to a strong shortwave trough, reaching northern CA and western/southern NV by 00Z. By 12Z, the trough will reach southern ID, UT and AZ. Strong DCVA/cooling aloft is expected immediately to its east today and tonight, from the Great Basin to the Colorado Plateau and UT/southwestern WY. However, with dry air in low levels over most of the region, midlevel moisture/buoyancy should remain too weak and isolated for enough lightning to justify an outlook area. ..Edwards/Jewell.. 12/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0617 AM CST Thu Dec 12 2024 Valid 121300Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms appear unlikely through tonight. ...Synopsis/Discussion... A mid/upper-level cyclone -- initially over northern ON -- will break down as another develops across central QC today, within the same larger-scale troughing regime. As the resulting low ejects northeastward over northern QC, and synoptic ridging moves from the Rockies to the Plains States, heights will rise over most of the central/eastern CONUS. The air mass east of the Rockies mostly will remain too dry and/or stable for thunderstorms, behind the cold frontal passage related to the departing eastern trough. One exception may be in the lake-effect regimes east of the lower Great Lakes, where steep low/middle-level lapse rates will support plumes of heavy convective snow. However, shallowness of buoyancy/ELs precludes more than very brief/isolated lightning potential at most, and the threat appears too conditional and limited for outlook areas. A cyclone now located off the coast of OR and northwestern CA will move inland and devolve slightly to a strong shortwave trough, reaching northern CA and western/southern NV by 00Z. By 12Z, the trough will reach southern ID, UT and AZ. Strong DCVA/cooling aloft is expected immediately to its east today and tonight, from the Great Basin to the Colorado Plateau and UT/southwestern WY. However, with dry air in low levels over most of the region, midlevel moisture/buoyancy should remain too weak and isolated for enough lightning to justify an outlook area. ..Edwards/Jewell.. 12/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0617 AM CST Thu Dec 12 2024 Valid 121300Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms appear unlikely through tonight. ...Synopsis/Discussion... A mid/upper-level cyclone -- initially over northern ON -- will break down as another develops across central QC today, within the same larger-scale troughing regime. As the resulting low ejects northeastward over northern QC, and synoptic ridging moves from the Rockies to the Plains States, heights will rise over most of the central/eastern CONUS. The air mass east of the Rockies mostly will remain too dry and/or stable for thunderstorms, behind the cold frontal passage related to the departing eastern trough. One exception may be in the lake-effect regimes east of the lower Great Lakes, where steep low/middle-level lapse rates will support plumes of heavy convective snow. However, shallowness of buoyancy/ELs precludes more than very brief/isolated lightning potential at most, and the threat appears too conditional and limited for outlook areas. A cyclone now located off the coast of OR and northwestern CA will move inland and devolve slightly to a strong shortwave trough, reaching northern CA and western/southern NV by 00Z. By 12Z, the trough will reach southern ID, UT and AZ. Strong DCVA/cooling aloft is expected immediately to its east today and tonight, from the Great Basin to the Colorado Plateau and UT/southwestern WY. However, with dry air in low levels over most of the region, midlevel moisture/buoyancy should remain too weak and isolated for enough lightning to justify an outlook area. ..Edwards/Jewell.. 12/12/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Dec 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... Most of the medium-range guidance has trend faster and less amplified with the shortwave trough expected to move from the Four Corners region through the central Plains on D4/Sunday. This more northerly progression will limit the interaction between this wave and any returning low-level moisture, which should limit thunderstorm potential throughout most of the day. Another shortwave trough is expected to follow in the wake of this lead wave, but with a more southerly track across the Southwest and into the southern Plains. Guidance is in relatively good agreement that this wave will move over the southern High Plains late D4/Sunday into early D5/Monday. This wave is expected to interact with the returning low-level moisture, with thunderstorm development along and ahead of its associated front from central OK/north TX into the Ozarks early Monday morning. Thunderstorms are expected to gradually shift eastward throughout the day D5/Monday, expanding into more of east/southeast TX and the Mid/Lower MS Valley. Seasonally warm and moist conditions are anticipated, and enough buoyancy and shear could be in place for severe thunderstorms. However, overall buoyancy will likely be mitigated by poor lapse rates, and warm mid-level temperatures could contribute to some inhibition. There is also some potential for a more front-parallel orientation, which could result in a more anafrontal character to the storms. These factors, combined with the notable variability within the guidance, introduce enough uncertainty to merit withholding any severe probabilities for D4/Sunday or D5/Monday with this outlook. Another shortwave trough may progress into the Plains on D7/Wednesday, with preceding moisture return across the southern Plains setting up the potential for thunderstorms as this wave and its associated cold front push eastward/southeastward across the southern Plains. However, GEFS members show large differences on how this wave progresses, with notable differences within the ECMWF members too. Some members within both of these ensemble systems suggest the development of a closed low over the Southwest instead of progressive wave into the Plains. Consequently, as with the earlier wave, predictability issues limit forecast confidence. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Dec 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... Most of the medium-range guidance has trend faster and less amplified with the shortwave trough expected to move from the Four Corners region through the central Plains on D4/Sunday. This more northerly progression will limit the interaction between this wave and any returning low-level moisture, which should limit thunderstorm potential throughout most of the day. Another shortwave trough is expected to follow in the wake of this lead wave, but with a more southerly track across the Southwest and into the southern Plains. Guidance is in relatively good agreement that this wave will move over the southern High Plains late D4/Sunday into early D5/Monday. This wave is expected to interact with the returning low-level moisture, with thunderstorm development along and ahead of its associated front from central OK/north TX into the Ozarks early Monday morning. Thunderstorms are expected to gradually shift eastward throughout the day D5/Monday, expanding into more of east/southeast TX and the Mid/Lower MS Valley. Seasonally warm and moist conditions are anticipated, and enough buoyancy and shear could be in place for severe thunderstorms. However, overall buoyancy will likely be mitigated by poor lapse rates, and warm mid-level temperatures could contribute to some inhibition. There is also some potential for a more front-parallel orientation, which could result in a more anafrontal character to the storms. These factors, combined with the notable variability within the guidance, introduce enough uncertainty to merit withholding any severe probabilities for D4/Sunday or D5/Monday with this outlook. Another shortwave trough may progress into the Plains on D7/Wednesday, with preceding moisture return across the southern Plains setting up the potential for thunderstorms as this wave and its associated cold front push eastward/southeastward across the southern Plains. However, GEFS members show large differences on how this wave progresses, with notable differences within the ECMWF members too. Some members within both of these ensemble systems suggest the development of a closed low over the Southwest instead of progressive wave into the Plains. Consequently, as with the earlier wave, predictability issues limit forecast confidence. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Dec 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... Most of the medium-range guidance has trend faster and less amplified with the shortwave trough expected to move from the Four Corners region through the central Plains on D4/Sunday. This more northerly progression will limit the interaction between this wave and any returning low-level moisture, which should limit thunderstorm potential throughout most of the day. Another shortwave trough is expected to follow in the wake of this lead wave, but with a more southerly track across the Southwest and into the southern Plains. Guidance is in relatively good agreement that this wave will move over the southern High Plains late D4/Sunday into early D5/Monday. This wave is expected to interact with the returning low-level moisture, with thunderstorm development along and ahead of its associated front from central OK/north TX into the Ozarks early Monday morning. Thunderstorms are expected to gradually shift eastward throughout the day D5/Monday, expanding into more of east/southeast TX and the Mid/Lower MS Valley. Seasonally warm and moist conditions are anticipated, and enough buoyancy and shear could be in place for severe thunderstorms. However, overall buoyancy will likely be mitigated by poor lapse rates, and warm mid-level temperatures could contribute to some inhibition. There is also some potential for a more front-parallel orientation, which could result in a more anafrontal character to the storms. These factors, combined with the notable variability within the guidance, introduce enough uncertainty to merit withholding any severe probabilities for D4/Sunday or D5/Monday with this outlook. Another shortwave trough may progress into the Plains on D7/Wednesday, with preceding moisture return across the southern Plains setting up the potential for thunderstorms as this wave and its associated cold front push eastward/southeastward across the southern Plains. However, GEFS members show large differences on how this wave progresses, with notable differences within the ECMWF members too. Some members within both of these ensemble systems suggest the development of a closed low over the Southwest instead of progressive wave into the Plains. Consequently, as with the earlier wave, predictability issues limit forecast confidence. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Dec 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... Most of the medium-range guidance has trend faster and less amplified with the shortwave trough expected to move from the Four Corners region through the central Plains on D4/Sunday. This more northerly progression will limit the interaction between this wave and any returning low-level moisture, which should limit thunderstorm potential throughout most of the day. Another shortwave trough is expected to follow in the wake of this lead wave, but with a more southerly track across the Southwest and into the southern Plains. Guidance is in relatively good agreement that this wave will move over the southern High Plains late D4/Sunday into early D5/Monday. This wave is expected to interact with the returning low-level moisture, with thunderstorm development along and ahead of its associated front from central OK/north TX into the Ozarks early Monday morning. Thunderstorms are expected to gradually shift eastward throughout the day D5/Monday, expanding into more of east/southeast TX and the Mid/Lower MS Valley. Seasonally warm and moist conditions are anticipated, and enough buoyancy and shear could be in place for severe thunderstorms. However, overall buoyancy will likely be mitigated by poor lapse rates, and warm mid-level temperatures could contribute to some inhibition. There is also some potential for a more front-parallel orientation, which could result in a more anafrontal character to the storms. These factors, combined with the notable variability within the guidance, introduce enough uncertainty to merit withholding any severe probabilities for D4/Sunday or D5/Monday with this outlook. Another shortwave trough may progress into the Plains on D7/Wednesday, with preceding moisture return across the southern Plains setting up the potential for thunderstorms as this wave and its associated cold front push eastward/southeastward across the southern Plains. However, GEFS members show large differences on how this wave progresses, with notable differences within the ECMWF members too. Some members within both of these ensemble systems suggest the development of a closed low over the Southwest instead of progressive wave into the Plains. Consequently, as with the earlier wave, predictability issues limit forecast confidence. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Dec 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... Most of the medium-range guidance has trend faster and less amplified with the shortwave trough expected to move from the Four Corners region through the central Plains on D4/Sunday. This more northerly progression will limit the interaction between this wave and any returning low-level moisture, which should limit thunderstorm potential throughout most of the day. Another shortwave trough is expected to follow in the wake of this lead wave, but with a more southerly track across the Southwest and into the southern Plains. Guidance is in relatively good agreement that this wave will move over the southern High Plains late D4/Sunday into early D5/Monday. This wave is expected to interact with the returning low-level moisture, with thunderstorm development along and ahead of its associated front from central OK/north TX into the Ozarks early Monday morning. Thunderstorms are expected to gradually shift eastward throughout the day D5/Monday, expanding into more of east/southeast TX and the Mid/Lower MS Valley. Seasonally warm and moist conditions are anticipated, and enough buoyancy and shear could be in place for severe thunderstorms. However, overall buoyancy will likely be mitigated by poor lapse rates, and warm mid-level temperatures could contribute to some inhibition. There is also some potential for a more front-parallel orientation, which could result in a more anafrontal character to the storms. These factors, combined with the notable variability within the guidance, introduce enough uncertainty to merit withholding any severe probabilities for D4/Sunday or D5/Monday with this outlook. Another shortwave trough may progress into the Plains on D7/Wednesday, with preceding moisture return across the southern Plains setting up the potential for thunderstorms as this wave and its associated cold front push eastward/southeastward across the southern Plains. However, GEFS members show large differences on how this wave progresses, with notable differences within the ECMWF members too. Some members within both of these ensemble systems suggest the development of a closed low over the Southwest instead of progressive wave into the Plains. Consequently, as with the earlier wave, predictability issues limit forecast confidence. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Dec 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... Most of the medium-range guidance has trend faster and less amplified with the shortwave trough expected to move from the Four Corners region through the central Plains on D4/Sunday. This more northerly progression will limit the interaction between this wave and any returning low-level moisture, which should limit thunderstorm potential throughout most of the day. Another shortwave trough is expected to follow in the wake of this lead wave, but with a more southerly track across the Southwest and into the southern Plains. Guidance is in relatively good agreement that this wave will move over the southern High Plains late D4/Sunday into early D5/Monday. This wave is expected to interact with the returning low-level moisture, with thunderstorm development along and ahead of its associated front from central OK/north TX into the Ozarks early Monday morning. Thunderstorms are expected to gradually shift eastward throughout the day D5/Monday, expanding into more of east/southeast TX and the Mid/Lower MS Valley. Seasonally warm and moist conditions are anticipated, and enough buoyancy and shear could be in place for severe thunderstorms. However, overall buoyancy will likely be mitigated by poor lapse rates, and warm mid-level temperatures could contribute to some inhibition. There is also some potential for a more front-parallel orientation, which could result in a more anafrontal character to the storms. These factors, combined with the notable variability within the guidance, introduce enough uncertainty to merit withholding any severe probabilities for D4/Sunday or D5/Monday with this outlook. Another shortwave trough may progress into the Plains on D7/Wednesday, with preceding moisture return across the southern Plains setting up the potential for thunderstorms as this wave and its associated cold front push eastward/southeastward across the southern Plains. However, GEFS members show large differences on how this wave progresses, with notable differences within the ECMWF members too. Some members within both of these ensemble systems suggest the development of a closed low over the Southwest instead of progressive wave into the Plains. Consequently, as with the earlier wave, predictability issues limit forecast confidence. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0219 AM CST Thu Dec 12 2024 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible from the Texas Hill Country into the Middle/Lower Mississippi Valley on Saturday. ...Synopsis and Discussion... A stacked mid-latitude cyclone is forecast to be over the central Plains early Saturday morning before progressing northeastward throughout the day and ending the period over the Mid MS Valley. This cyclone will be accompanied by strong mid-level jet throughout its base, which will spread from OK northeastward across MO and into the Lower OH Valley as the cyclone moves northeastward. This overall evolution will displace this cyclone and associated ascent well north of the better low-level moisture, which is expected to remain confined largely to the TX and LA coasts throughout the day. Even so, a strong low-level jet is anticipated throughout the warm sector of this cyclone, and the associated warm-air advection will likely result in elevated showers and thunderstorms. Elevated thunderstorms will likely be ongoing at the beginning of the period from east TX into the Lower MO Valley. This is area expected is shift eastward throughout the day with gradually diminishing storm coverage. Limited buoyancy should temper updraft strength, but vertical shear is strong enough to support small-hail production within the deepest, most persistent updrafts. An additional northwestward push of greater low-level moisture into more of the TX Hill Country is possible late Saturday/early Sunday ahead of another shortwave trough approaching the Four Corners. A few isolated thunderstorms may occur over the TX Hill Country as this returning moisture interacts with increasing low-level flow. ..Mosier.. 12/12/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0219 AM CST Thu Dec 12 2024 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible from the Texas Hill Country into the Middle/Lower Mississippi Valley on Saturday. ...Synopsis and Discussion... A stacked mid-latitude cyclone is forecast to be over the central Plains early Saturday morning before progressing northeastward throughout the day and ending the period over the Mid MS Valley. This cyclone will be accompanied by strong mid-level jet throughout its base, which will spread from OK northeastward across MO and into the Lower OH Valley as the cyclone moves northeastward. This overall evolution will displace this cyclone and associated ascent well north of the better low-level moisture, which is expected to remain confined largely to the TX and LA coasts throughout the day. Even so, a strong low-level jet is anticipated throughout the warm sector of this cyclone, and the associated warm-air advection will likely result in elevated showers and thunderstorms. Elevated thunderstorms will likely be ongoing at the beginning of the period from east TX into the Lower MO Valley. This is area expected is shift eastward throughout the day with gradually diminishing storm coverage. Limited buoyancy should temper updraft strength, but vertical shear is strong enough to support small-hail production within the deepest, most persistent updrafts. An additional northwestward push of greater low-level moisture into more of the TX Hill Country is possible late Saturday/early Sunday ahead of another shortwave trough approaching the Four Corners. A few isolated thunderstorms may occur over the TX Hill Country as this returning moisture interacts with increasing low-level flow. ..Mosier.. 12/12/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0219 AM CST Thu Dec 12 2024 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible from the Texas Hill Country into the Middle/Lower Mississippi Valley on Saturday. ...Synopsis and Discussion... A stacked mid-latitude cyclone is forecast to be over the central Plains early Saturday morning before progressing northeastward throughout the day and ending the period over the Mid MS Valley. This cyclone will be accompanied by strong mid-level jet throughout its base, which will spread from OK northeastward across MO and into the Lower OH Valley as the cyclone moves northeastward. This overall evolution will displace this cyclone and associated ascent well north of the better low-level moisture, which is expected to remain confined largely to the TX and LA coasts throughout the day. Even so, a strong low-level jet is anticipated throughout the warm sector of this cyclone, and the associated warm-air advection will likely result in elevated showers and thunderstorms. Elevated thunderstorms will likely be ongoing at the beginning of the period from east TX into the Lower MO Valley. This is area expected is shift eastward throughout the day with gradually diminishing storm coverage. Limited buoyancy should temper updraft strength, but vertical shear is strong enough to support small-hail production within the deepest, most persistent updrafts. An additional northwestward push of greater low-level moisture into more of the TX Hill Country is possible late Saturday/early Sunday ahead of another shortwave trough approaching the Four Corners. A few isolated thunderstorms may occur over the TX Hill Country as this returning moisture interacts with increasing low-level flow. ..Mosier.. 12/12/2024 Read more