Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0142 PM CST Fri Dec 13 2024 Valid 132000Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely through tonight. ...20Z Update... The previous forecast reasoning (see below) remains the same, and only minor changes were made with this update. ..Weinman.. 12/13/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Fri Dec 13 2024/ ...Southern/Central Plains into the Ozarks/ArkLaTex... A compact shortwave trough over the Great Basin this morning will move eastward across the southern/central Plains through tonight while gradually amplifying. Related low-level mass response will encourage the northward advance of modified Gulf moisture across parts of the southern/central Plains ahead of a weak surface low and cold front forecast to track from the central High Plains to eastern KS/OK by early Saturday morning. Given the limited/shallow nature of the low-level moisture return, current expectations are for any convection that develops late tonight in the warm advection regime to remain elevated. MUCAPE is generally forecast to remain less than 1000 J/kg, which should tend to limit the prospect for large hail with these elevated thunderstorms. Even so, cold mid-level temperatures associated with the ejecting shortwave trough and sufficient shear through the cloud-bearing layer may support some risk for small hail with the strongest cores. This activity is expected to spread eastward from the southern/central Plains into the Ozarks/ArkLaTex vicinity through the end of the period. ...Northern California... An upper trough will approach the West Coast late tonight into early Saturday morning. Associated low-level warm/moist advection will occur ahead of a weak surface front, with a broad area of precipitation forecast across parts of northern CA and the Pacific Northwest. Gradual cooling of mid-level temperatures will occur as the upper trough approaches, which may support meager MUCAPE across parts of northern CA for the last few hours of the period (early Saturday morning). Isolated lightning flashes may occur with low-topped convection along/near the front, with overall thunderstorm probabilities around 10 percent. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0142 PM CST Fri Dec 13 2024 Valid 132000Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely through tonight. ...20Z Update... The previous forecast reasoning (see below) remains the same, and only minor changes were made with this update. ..Weinman.. 12/13/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Fri Dec 13 2024/ ...Southern/Central Plains into the Ozarks/ArkLaTex... A compact shortwave trough over the Great Basin this morning will move eastward across the southern/central Plains through tonight while gradually amplifying. Related low-level mass response will encourage the northward advance of modified Gulf moisture across parts of the southern/central Plains ahead of a weak surface low and cold front forecast to track from the central High Plains to eastern KS/OK by early Saturday morning. Given the limited/shallow nature of the low-level moisture return, current expectations are for any convection that develops late tonight in the warm advection regime to remain elevated. MUCAPE is generally forecast to remain less than 1000 J/kg, which should tend to limit the prospect for large hail with these elevated thunderstorms. Even so, cold mid-level temperatures associated with the ejecting shortwave trough and sufficient shear through the cloud-bearing layer may support some risk for small hail with the strongest cores. This activity is expected to spread eastward from the southern/central Plains into the Ozarks/ArkLaTex vicinity through the end of the period. ...Northern California... An upper trough will approach the West Coast late tonight into early Saturday morning. Associated low-level warm/moist advection will occur ahead of a weak surface front, with a broad area of precipitation forecast across parts of northern CA and the Pacific Northwest. Gradual cooling of mid-level temperatures will occur as the upper trough approaches, which may support meager MUCAPE across parts of northern CA for the last few hours of the period (early Saturday morning). Isolated lightning flashes may occur with low-topped convection along/near the front, with overall thunderstorm probabilities around 10 percent. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0142 PM CST Fri Dec 13 2024 Valid 132000Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely through tonight. ...20Z Update... The previous forecast reasoning (see below) remains the same, and only minor changes were made with this update. ..Weinman.. 12/13/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Fri Dec 13 2024/ ...Southern/Central Plains into the Ozarks/ArkLaTex... A compact shortwave trough over the Great Basin this morning will move eastward across the southern/central Plains through tonight while gradually amplifying. Related low-level mass response will encourage the northward advance of modified Gulf moisture across parts of the southern/central Plains ahead of a weak surface low and cold front forecast to track from the central High Plains to eastern KS/OK by early Saturday morning. Given the limited/shallow nature of the low-level moisture return, current expectations are for any convection that develops late tonight in the warm advection regime to remain elevated. MUCAPE is generally forecast to remain less than 1000 J/kg, which should tend to limit the prospect for large hail with these elevated thunderstorms. Even so, cold mid-level temperatures associated with the ejecting shortwave trough and sufficient shear through the cloud-bearing layer may support some risk for small hail with the strongest cores. This activity is expected to spread eastward from the southern/central Plains into the Ozarks/ArkLaTex vicinity through the end of the period. ...Northern California... An upper trough will approach the West Coast late tonight into early Saturday morning. Associated low-level warm/moist advection will occur ahead of a weak surface front, with a broad area of precipitation forecast across parts of northern CA and the Pacific Northwest. Gradual cooling of mid-level temperatures will occur as the upper trough approaches, which may support meager MUCAPE across parts of northern CA for the last few hours of the period (early Saturday morning). Isolated lightning flashes may occur with low-topped convection along/near the front, with overall thunderstorm probabilities around 10 percent. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0138 PM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/13/2024 .PREV DISCUSSION... /ISSUED 0154 AM CST Fri Dec 13 2024/ ...Synopsis... In the wake of the progressive mid-level trough moving over the South Plains D1/Fri, shortwave ridging will rapidly develop over the western High Plains ahead of a second deepening trough farther west. The ridging will favor weak winds and relatively mild temperatures through much of the day. The ridge will break down ahead of the strengthening mid-level trough late in the day into early D3/Sun. Strong westerly winds aloft may support downslope flow west of a surface lee trough over parts of the Rockies and High Plains. However, the trough aloft is expected to be poorly timed with the diurnal cycle, supporting only modest surface winds and relatively poor overlap with critically low RH values. This should largely negate fire-weather concerns across the CONUS. ...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 0138 PM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/13/2024 .PREV DISCUSSION... /ISSUED 0154 AM CST Fri Dec 13 2024/ ...Synopsis... In the wake of the progressive mid-level trough moving over the South Plains D1/Fri, shortwave ridging will rapidly develop over the western High Plains ahead of a second deepening trough farther west. The ridging will favor weak winds and relatively mild temperatures through much of the day. The ridge will break down ahead of the strengthening mid-level trough late in the day into early D3/Sun. Strong westerly winds aloft may support downslope flow west of a surface lee trough over parts of the Rockies and High Plains. However, the trough aloft is expected to be poorly timed with the diurnal cycle, supporting only modest surface winds and relatively poor overlap with critically low RH values. This should largely negate fire-weather concerns across the CONUS. ...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 0138 PM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/13/2024 .PREV DISCUSSION... /ISSUED 0154 AM CST Fri Dec 13 2024/ ...Synopsis... In the wake of the progressive mid-level trough moving over the South Plains D1/Fri, shortwave ridging will rapidly develop over the western High Plains ahead of a second deepening trough farther west. The ridging will favor weak winds and relatively mild temperatures through much of the day. The ridge will break down ahead of the strengthening mid-level trough late in the day into early D3/Sun. Strong westerly winds aloft may support downslope flow west of a surface lee trough over parts of the Rockies and High Plains. However, the trough aloft is expected to be poorly timed with the diurnal cycle, supporting only modest surface winds and relatively poor overlap with critically low RH values. This should largely negate fire-weather concerns across the CONUS. ...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 0138 PM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/13/2024 .PREV DISCUSSION... /ISSUED 0154 AM CST Fri Dec 13 2024/ ...Synopsis... In the wake of the progressive mid-level trough moving over the South Plains D1/Fri, shortwave ridging will rapidly develop over the western High Plains ahead of a second deepening trough farther west. The ridging will favor weak winds and relatively mild temperatures through much of the day. The ridge will break down ahead of the strengthening mid-level trough late in the day into early D3/Sun. Strong westerly winds aloft may support downslope flow west of a surface lee trough over parts of the Rockies and High Plains. However, the trough aloft is expected to be poorly timed with the diurnal cycle, supporting only modest surface winds and relatively poor overlap with critically low RH values. This should largely negate fire-weather concerns across the CONUS. ...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 0138 PM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/13/2024 .PREV DISCUSSION... /ISSUED 0154 AM CST Fri Dec 13 2024/ ...Synopsis... In the wake of the progressive mid-level trough moving over the South Plains D1/Fri, shortwave ridging will rapidly develop over the western High Plains ahead of a second deepening trough farther west. The ridging will favor weak winds and relatively mild temperatures through much of the day. The ridge will break down ahead of the strengthening mid-level trough late in the day into early D3/Sun. Strong westerly winds aloft may support downslope flow west of a surface lee trough over parts of the Rockies and High Plains. However, the trough aloft is expected to be poorly timed with the diurnal cycle, supporting only modest surface winds and relatively poor overlap with critically low RH values. This should largely negate fire-weather concerns across the CONUS. ...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 Fri Dec 13 2024 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is expected to remain limited on Sunday. ...Synopsis... A broad mid-level trough will move from the Great Basin on Sunday morning to the central Plains by Monday morning, amplifying early Monday morning. Lee troughing will persist through the period across the Plains which will strengthen the low-level jet and increase moisture advection into the Plains and Ozarks. Weak isentropic ascent could lead to isolated thunderstorm development from East Texas into southeast Oklahoma during the day Sunday. However, surface based instability will likely not develop until after 04Z as mid-level temperatures start to cool. During this late overnight period is also when ascent increases with the sharpening mid-level trough. Therefore, moderate instability amid a sheared environment with increasing ascent could lead to some severe weather potential across eastern Oklahoma into southeast Kansas, southwest Missouri and far northwest Arkansas between 06Z and 12Z Monday. However, a limited time window for severe late in the outlook period, and questions regarding storm mode and timing preclude a marginal risk at this time. ..Bentley.. 12/13/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Fri Dec 13 2024 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is expected to remain limited on Sunday. ...Synopsis... A broad mid-level trough will move from the Great Basin on Sunday morning to the central Plains by Monday morning, amplifying early Monday morning. Lee troughing will persist through the period across the Plains which will strengthen the low-level jet and increase moisture advection into the Plains and Ozarks. Weak isentropic ascent could lead to isolated thunderstorm development from East Texas into southeast Oklahoma during the day Sunday. However, surface based instability will likely not develop until after 04Z as mid-level temperatures start to cool. During this late overnight period is also when ascent increases with the sharpening mid-level trough. Therefore, moderate instability amid a sheared environment with increasing ascent could lead to some severe weather potential across eastern Oklahoma into southeast Kansas, southwest Missouri and far northwest Arkansas between 06Z and 12Z Monday. However, a limited time window for severe late in the outlook period, and questions regarding storm mode and timing preclude a marginal risk at this time. ..Bentley.. 12/13/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Fri Dec 13 2024 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is expected to remain limited on Sunday. ...Synopsis... A broad mid-level trough will move from the Great Basin on Sunday morning to the central Plains by Monday morning, amplifying early Monday morning. Lee troughing will persist through the period across the Plains which will strengthen the low-level jet and increase moisture advection into the Plains and Ozarks. Weak isentropic ascent could lead to isolated thunderstorm development from East Texas into southeast Oklahoma during the day Sunday. However, surface based instability will likely not develop until after 04Z as mid-level temperatures start to cool. During this late overnight period is also when ascent increases with the sharpening mid-level trough. Therefore, moderate instability amid a sheared environment with increasing ascent could lead to some severe weather potential across eastern Oklahoma into southeast Kansas, southwest Missouri and far northwest Arkansas between 06Z and 12Z Monday. However, a limited time window for severe late in the outlook period, and questions regarding storm mode and timing preclude a marginal risk at this time. ..Bentley.. 12/13/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Fri Dec 13 2024 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is expected to remain limited on Sunday. ...Synopsis... A broad mid-level trough will move from the Great Basin on Sunday morning to the central Plains by Monday morning, amplifying early Monday morning. Lee troughing will persist through the period across the Plains which will strengthen the low-level jet and increase moisture advection into the Plains and Ozarks. Weak isentropic ascent could lead to isolated thunderstorm development from East Texas into southeast Oklahoma during the day Sunday. However, surface based instability will likely not develop until after 04Z as mid-level temperatures start to cool. During this late overnight period is also when ascent increases with the sharpening mid-level trough. Therefore, moderate instability amid a sheared environment with increasing ascent could lead to some severe weather potential across eastern Oklahoma into southeast Kansas, southwest Missouri and far northwest Arkansas between 06Z and 12Z Monday. However, a limited time window for severe late in the outlook period, and questions regarding storm mode and timing preclude a marginal risk at this time. ..Bentley.. 12/13/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Fri Dec 13 2024 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is expected to remain limited on Sunday. ...Synopsis... A broad mid-level trough will move from the Great Basin on Sunday morning to the central Plains by Monday morning, amplifying early Monday morning. Lee troughing will persist through the period across the Plains which will strengthen the low-level jet and increase moisture advection into the Plains and Ozarks. Weak isentropic ascent could lead to isolated thunderstorm development from East Texas into southeast Oklahoma during the day Sunday. However, surface based instability will likely not develop until after 04Z as mid-level temperatures start to cool. During this late overnight period is also when ascent increases with the sharpening mid-level trough. Therefore, moderate instability amid a sheared environment with increasing ascent could lead to some severe weather potential across eastern Oklahoma into southeast Kansas, southwest Missouri and far northwest Arkansas between 06Z and 12Z Monday. However, a limited time window for severe late in the outlook period, and questions regarding storm mode and timing preclude a marginal risk at this time. ..Bentley.. 12/13/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Fri Dec 13 2024 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is expected to remain limited on Sunday. ...Synopsis... A broad mid-level trough will move from the Great Basin on Sunday morning to the central Plains by Monday morning, amplifying early Monday morning. Lee troughing will persist through the period across the Plains which will strengthen the low-level jet and increase moisture advection into the Plains and Ozarks. Weak isentropic ascent could lead to isolated thunderstorm development from East Texas into southeast Oklahoma during the day Sunday. However, surface based instability will likely not develop until after 04Z as mid-level temperatures start to cool. During this late overnight period is also when ascent increases with the sharpening mid-level trough. Therefore, moderate instability amid a sheared environment with increasing ascent could lead to some severe weather potential across eastern Oklahoma into southeast Kansas, southwest Missouri and far northwest Arkansas between 06Z and 12Z Monday. However, a limited time window for severe late in the outlook period, and questions regarding storm mode and timing preclude a marginal risk at this time. ..Bentley.. 12/13/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday. ...Central/Southern Plains to the Lower Ohio Valley... An upper low will move from the central Plains to the Great Lakes on Saturday. A surface low will weaken through the day as this trough advances northeast. A sustained low-level jet will advance from the Ozarks to the Ohio Valley and provide ample ascent and elevated instability for thunderstorm activity through the day. Instability should remain too limited for any severe weather threat from this elevated convection. Weak surface heating across the ArkLaTex may be sufficient for a few surface-based storms. However, instability will be weak and ascent will mostly be focused north of this area. Therefore, no severe storms are anticipated. ...California to the Pacific Northwest... A trough approaching the Pacific coast on Saturday will result in scattered thunderstorm activity from southwest Washington to central California as cooler air aloft steepens lapse rates across the region. Overall, weak instability combined with relatively weak low-level flow should preclude any severe weather threat. A more focused low-level jet will result in stronger low-level flow across the central California Coast late Saturday morning into the early afternoon. However, during this period, forecast soundings indicate minimal to no instability which should preclude any severe weather concern. ..Bentley.. 12/13/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday. ...Central/Southern Plains to the Lower Ohio Valley... An upper low will move from the central Plains to the Great Lakes on Saturday. A surface low will weaken through the day as this trough advances northeast. A sustained low-level jet will advance from the Ozarks to the Ohio Valley and provide ample ascent and elevated instability for thunderstorm activity through the day. Instability should remain too limited for any severe weather threat from this elevated convection. Weak surface heating across the ArkLaTex may be sufficient for a few surface-based storms. However, instability will be weak and ascent will mostly be focused north of this area. Therefore, no severe storms are anticipated. ...California to the Pacific Northwest... A trough approaching the Pacific coast on Saturday will result in scattered thunderstorm activity from southwest Washington to central California as cooler air aloft steepens lapse rates across the region. Overall, weak instability combined with relatively weak low-level flow should preclude any severe weather threat. A more focused low-level jet will result in stronger low-level flow across the central California Coast late Saturday morning into the early afternoon. However, during this period, forecast soundings indicate minimal to no instability which should preclude any severe weather concern. ..Bentley.. 12/13/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday. ...Central/Southern Plains to the Lower Ohio Valley... An upper low will move from the central Plains to the Great Lakes on Saturday. A surface low will weaken through the day as this trough advances northeast. A sustained low-level jet will advance from the Ozarks to the Ohio Valley and provide ample ascent and elevated instability for thunderstorm activity through the day. Instability should remain too limited for any severe weather threat from this elevated convection. Weak surface heating across the ArkLaTex may be sufficient for a few surface-based storms. However, instability will be weak and ascent will mostly be focused north of this area. Therefore, no severe storms are anticipated. ...California to the Pacific Northwest... A trough approaching the Pacific coast on Saturday will result in scattered thunderstorm activity from southwest Washington to central California as cooler air aloft steepens lapse rates across the region. Overall, weak instability combined with relatively weak low-level flow should preclude any severe weather threat. A more focused low-level jet will result in stronger low-level flow across the central California Coast late Saturday morning into the early afternoon. However, during this period, forecast soundings indicate minimal to no instability which should preclude any severe weather concern. ..Bentley.. 12/13/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday. ...Central/Southern Plains to the Lower Ohio Valley... An upper low will move from the central Plains to the Great Lakes on Saturday. A surface low will weaken through the day as this trough advances northeast. A sustained low-level jet will advance from the Ozarks to the Ohio Valley and provide ample ascent and elevated instability for thunderstorm activity through the day. Instability should remain too limited for any severe weather threat from this elevated convection. Weak surface heating across the ArkLaTex may be sufficient for a few surface-based storms. However, instability will be weak and ascent will mostly be focused north of this area. Therefore, no severe storms are anticipated. ...California to the Pacific Northwest... A trough approaching the Pacific coast on Saturday will result in scattered thunderstorm activity from southwest Washington to central California as cooler air aloft steepens lapse rates across the region. Overall, weak instability combined with relatively weak low-level flow should preclude any severe weather threat. A more focused low-level jet will result in stronger low-level flow across the central California Coast late Saturday morning into the early afternoon. However, during this period, forecast soundings indicate minimal to no instability which should preclude any severe weather concern. ..Bentley.. 12/13/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday. ...Central/Southern Plains to the Lower Ohio Valley... An upper low will move from the central Plains to the Great Lakes on Saturday. A surface low will weaken through the day as this trough advances northeast. A sustained low-level jet will advance from the Ozarks to the Ohio Valley and provide ample ascent and elevated instability for thunderstorm activity through the day. Instability should remain too limited for any severe weather threat from this elevated convection. Weak surface heating across the ArkLaTex may be sufficient for a few surface-based storms. However, instability will be weak and ascent will mostly be focused north of this area. Therefore, no severe storms are anticipated. ...California to the Pacific Northwest... A trough approaching the Pacific coast on Saturday will result in scattered thunderstorm activity from southwest Washington to central California as cooler air aloft steepens lapse rates across the region. Overall, weak instability combined with relatively weak low-level flow should preclude any severe weather threat. A more focused low-level jet will result in stronger low-level flow across the central California Coast late Saturday morning into the early afternoon. However, during this period, forecast soundings indicate minimal to no instability which should preclude any severe weather concern. ..Bentley.. 12/13/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Fri Dec 13 2024 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday. ...Central/Southern Plains to the Lower Ohio Valley... An upper low will move from the central Plains to the Great Lakes on Saturday. A surface low will weaken through the day as this trough advances northeast. A sustained low-level jet will advance from the Ozarks to the Ohio Valley and provide ample ascent and elevated instability for thunderstorm activity through the day. Instability should remain too limited for any severe weather threat from this elevated convection. Weak surface heating across the ArkLaTex may be sufficient for a few surface-based storms. However, instability will be weak and ascent will mostly be focused north of this area. Therefore, no severe storms are anticipated. ...California to the Pacific Northwest... A trough approaching the Pacific coast on Saturday will result in scattered thunderstorm activity from southwest Washington to central California as cooler air aloft steepens lapse rates across the region. Overall, weak instability combined with relatively weak low-level flow should preclude any severe weather threat. A more focused low-level jet will result in stronger low-level flow across the central California Coast late Saturday morning into the early afternoon. However, during this period, forecast soundings indicate minimal to no instability which should preclude any severe weather concern. ..Bentley.. 12/13/2024 Read more