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SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CST Wed Nov 29 2023 Valid 301200Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A SMALL PART OF SOUTHEAST TEXAS... ...SUMMARY... Scattered storms, some severe, will be possible during the day on Thursday, mainly over southeast Texas. A couple tornadoes will be possible during the day. Otherwise, marginal hail will be possible extending northward into parts of Oklahoma. ...Synopsis... An upper trough will move across the southern Plains on Thursday, with the primary speed max moving from southwest TX toward the Red River through evening, and across the mid MS Valley by 12Z Friday. Relatively cool midlevel temperatures will exist over the southern Plains early in the day, but rapid warming aloft is forecast over the southern half of TX and into LA to the south of the jet core. Low pressure will develop over northwest TX into OK by late afternoon, near the track of the upper wave. Low-level lapse rates will steepen in the veering flow over western TX, but the eastward extent of boundary-layer mixing will be impeded by the moistening air mass to the east which will be a bit cool, and contain scattered showers and thunderstorms. Still, a plume of upper 60s F dewpoints will surge north across the middle TX Coast, with a warm front traversing southeast TX and then southwest LA overnight. Aiding moisture advection and shear will be a 50+ kt low-level jet. ...Much of southeast TX into southwest LA... A conditional setup for supercells and a few tornadoes is forecast on Thursday, as low-level moisture increases well ahead of the upper wave, with a warm front pushing north through the period. Impressive SRH values will exist near the warm front, and effective-layer SRH of 300-400 m2/s2 will overlap the instability axis to the west. The primary negative factors for a more substantial severe weather event include the overall nebulous warm advection/forcing mechanism and early-day storms, and warming temperatures aloft south of the midlevel jet. The ability of storms to fully ingest the saturated boundary-layer air mass and utilize the lower portions of the hodograph is also in question. That said, there may be a focused area where storms developing within the warm advection regime can gain access to the instability plume and utilize the stronger shear. Given the strength of the shear, have opted to introduce a 10% tornado area for portions of southeast TX mainly from late morning through mid afternoon. Other storms may persist overnight into LA, with veering low-level winds and overall weaker instability. ...North TX into OK... Lapse rates will be steepest north of the speed max from northwest TX into OK late in the afternoon and through evening. A prominent midlevel dry slot will push across all of central TX and into south-central OK by 00Z as deep-layer shear increases. Scattered storms are expected during the afternoon over northern TX and OK, in the low-level warm advection regime. Forecast soundings show sufficient elevated instability to support hail in the stronger cells. ..Jewell.. 11/29/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CST Wed Nov 29 2023 Valid 301200Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A SMALL PART OF SOUTHEAST TEXAS... ...SUMMARY... Scattered storms, some severe, will be possible during the day on Thursday, mainly over southeast Texas. A couple tornadoes will be possible during the day. Otherwise, marginal hail will be possible extending northward into parts of Oklahoma. ...Synopsis... An upper trough will move across the southern Plains on Thursday, with the primary speed max moving from southwest TX toward the Red River through evening, and across the mid MS Valley by 12Z Friday. Relatively cool midlevel temperatures will exist over the southern Plains early in the day, but rapid warming aloft is forecast over the southern half of TX and into LA to the south of the jet core. Low pressure will develop over northwest TX into OK by late afternoon, near the track of the upper wave. Low-level lapse rates will steepen in the veering flow over western TX, but the eastward extent of boundary-layer mixing will be impeded by the moistening air mass to the east which will be a bit cool, and contain scattered showers and thunderstorms. Still, a plume of upper 60s F dewpoints will surge north across the middle TX Coast, with a warm front traversing southeast TX and then southwest LA overnight. Aiding moisture advection and shear will be a 50+ kt low-level jet. ...Much of southeast TX into southwest LA... A conditional setup for supercells and a few tornadoes is forecast on Thursday, as low-level moisture increases well ahead of the upper wave, with a warm front pushing north through the period. Impressive SRH values will exist near the warm front, and effective-layer SRH of 300-400 m2/s2 will overlap the instability axis to the west. The primary negative factors for a more substantial severe weather event include the overall nebulous warm advection/forcing mechanism and early-day storms, and warming temperatures aloft south of the midlevel jet. The ability of storms to fully ingest the saturated boundary-layer air mass and utilize the lower portions of the hodograph is also in question. That said, there may be a focused area where storms developing within the warm advection regime can gain access to the instability plume and utilize the stronger shear. Given the strength of the shear, have opted to introduce a 10% tornado area for portions of southeast TX mainly from late morning through mid afternoon. Other storms may persist overnight into LA, with veering low-level winds and overall weaker instability. ...North TX into OK... Lapse rates will be steepest north of the speed max from northwest TX into OK late in the afternoon and through evening. A prominent midlevel dry slot will push across all of central TX and into south-central OK by 00Z as deep-layer shear increases. Scattered storms are expected during the afternoon over northern TX and OK, in the low-level warm advection regime. Forecast soundings show sufficient elevated instability to support hail in the stronger cells. ..Jewell.. 11/29/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CST Wed Nov 29 2023 Valid 301200Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A SMALL PART OF SOUTHEAST TEXAS... ...SUMMARY... Scattered storms, some severe, will be possible during the day on Thursday, mainly over southeast Texas. A couple tornadoes will be possible during the day. Otherwise, marginal hail will be possible extending northward into parts of Oklahoma. ...Synopsis... An upper trough will move across the southern Plains on Thursday, with the primary speed max moving from southwest TX toward the Red River through evening, and across the mid MS Valley by 12Z Friday. Relatively cool midlevel temperatures will exist over the southern Plains early in the day, but rapid warming aloft is forecast over the southern half of TX and into LA to the south of the jet core. Low pressure will develop over northwest TX into OK by late afternoon, near the track of the upper wave. Low-level lapse rates will steepen in the veering flow over western TX, but the eastward extent of boundary-layer mixing will be impeded by the moistening air mass to the east which will be a bit cool, and contain scattered showers and thunderstorms. Still, a plume of upper 60s F dewpoints will surge north across the middle TX Coast, with a warm front traversing southeast TX and then southwest LA overnight. Aiding moisture advection and shear will be a 50+ kt low-level jet. ...Much of southeast TX into southwest LA... A conditional setup for supercells and a few tornadoes is forecast on Thursday, as low-level moisture increases well ahead of the upper wave, with a warm front pushing north through the period. Impressive SRH values will exist near the warm front, and effective-layer SRH of 300-400 m2/s2 will overlap the instability axis to the west. The primary negative factors for a more substantial severe weather event include the overall nebulous warm advection/forcing mechanism and early-day storms, and warming temperatures aloft south of the midlevel jet. The ability of storms to fully ingest the saturated boundary-layer air mass and utilize the lower portions of the hodograph is also in question. That said, there may be a focused area where storms developing within the warm advection regime can gain access to the instability plume and utilize the stronger shear. Given the strength of the shear, have opted to introduce a 10% tornado area for portions of southeast TX mainly from late morning through mid afternoon. Other storms may persist overnight into LA, with veering low-level winds and overall weaker instability. ...North TX into OK... Lapse rates will be steepest north of the speed max from northwest TX into OK late in the afternoon and through evening. A prominent midlevel dry slot will push across all of central TX and into south-central OK by 00Z as deep-layer shear increases. Scattered storms are expected during the afternoon over northern TX and OK, in the low-level warm advection regime. Forecast soundings show sufficient elevated instability to support hail in the stronger cells. ..Jewell.. 11/29/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CST Wed Nov 29 2023 Valid 301200Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A SMALL PART OF SOUTHEAST TEXAS... ...SUMMARY... Scattered storms, some severe, will be possible during the day on Thursday, mainly over southeast Texas. A couple tornadoes will be possible during the day. Otherwise, marginal hail will be possible extending northward into parts of Oklahoma. ...Synopsis... An upper trough will move across the southern Plains on Thursday, with the primary speed max moving from southwest TX toward the Red River through evening, and across the mid MS Valley by 12Z Friday. Relatively cool midlevel temperatures will exist over the southern Plains early in the day, but rapid warming aloft is forecast over the southern half of TX and into LA to the south of the jet core. Low pressure will develop over northwest TX into OK by late afternoon, near the track of the upper wave. Low-level lapse rates will steepen in the veering flow over western TX, but the eastward extent of boundary-layer mixing will be impeded by the moistening air mass to the east which will be a bit cool, and contain scattered showers and thunderstorms. Still, a plume of upper 60s F dewpoints will surge north across the middle TX Coast, with a warm front traversing southeast TX and then southwest LA overnight. Aiding moisture advection and shear will be a 50+ kt low-level jet. ...Much of southeast TX into southwest LA... A conditional setup for supercells and a few tornadoes is forecast on Thursday, as low-level moisture increases well ahead of the upper wave, with a warm front pushing north through the period. Impressive SRH values will exist near the warm front, and effective-layer SRH of 300-400 m2/s2 will overlap the instability axis to the west. The primary negative factors for a more substantial severe weather event include the overall nebulous warm advection/forcing mechanism and early-day storms, and warming temperatures aloft south of the midlevel jet. The ability of storms to fully ingest the saturated boundary-layer air mass and utilize the lower portions of the hodograph is also in question. That said, there may be a focused area where storms developing within the warm advection regime can gain access to the instability plume and utilize the stronger shear. Given the strength of the shear, have opted to introduce a 10% tornado area for portions of southeast TX mainly from late morning through mid afternoon. Other storms may persist overnight into LA, with veering low-level winds and overall weaker instability. ...North TX into OK... Lapse rates will be steepest north of the speed max from northwest TX into OK late in the afternoon and through evening. A prominent midlevel dry slot will push across all of central TX and into south-central OK by 00Z as deep-layer shear increases. Scattered storms are expected during the afternoon over northern TX and OK, in the low-level warm advection regime. Forecast soundings show sufficient elevated instability to support hail in the stronger cells. ..Jewell.. 11/29/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CST Wed Nov 29 2023 Valid 301200Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A SMALL PART OF SOUTHEAST TEXAS... ...SUMMARY... Scattered storms, some severe, will be possible during the day on Thursday, mainly over southeast Texas. A couple tornadoes will be possible during the day. Otherwise, marginal hail will be possible extending northward into parts of Oklahoma. ...Synopsis... An upper trough will move across the southern Plains on Thursday, with the primary speed max moving from southwest TX toward the Red River through evening, and across the mid MS Valley by 12Z Friday. Relatively cool midlevel temperatures will exist over the southern Plains early in the day, but rapid warming aloft is forecast over the southern half of TX and into LA to the south of the jet core. Low pressure will develop over northwest TX into OK by late afternoon, near the track of the upper wave. Low-level lapse rates will steepen in the veering flow over western TX, but the eastward extent of boundary-layer mixing will be impeded by the moistening air mass to the east which will be a bit cool, and contain scattered showers and thunderstorms. Still, a plume of upper 60s F dewpoints will surge north across the middle TX Coast, with a warm front traversing southeast TX and then southwest LA overnight. Aiding moisture advection and shear will be a 50+ kt low-level jet. ...Much of southeast TX into southwest LA... A conditional setup for supercells and a few tornadoes is forecast on Thursday, as low-level moisture increases well ahead of the upper wave, with a warm front pushing north through the period. Impressive SRH values will exist near the warm front, and effective-layer SRH of 300-400 m2/s2 will overlap the instability axis to the west. The primary negative factors for a more substantial severe weather event include the overall nebulous warm advection/forcing mechanism and early-day storms, and warming temperatures aloft south of the midlevel jet. The ability of storms to fully ingest the saturated boundary-layer air mass and utilize the lower portions of the hodograph is also in question. That said, there may be a focused area where storms developing within the warm advection regime can gain access to the instability plume and utilize the stronger shear. Given the strength of the shear, have opted to introduce a 10% tornado area for portions of southeast TX mainly from late morning through mid afternoon. Other storms may persist overnight into LA, with veering low-level winds and overall weaker instability. ...North TX into OK... Lapse rates will be steepest north of the speed max from northwest TX into OK late in the afternoon and through evening. A prominent midlevel dry slot will push across all of central TX and into south-central OK by 00Z as deep-layer shear increases. Scattered storms are expected during the afternoon over northern TX and OK, in the low-level warm advection regime. Forecast soundings show sufficient elevated instability to support hail in the stronger cells. ..Jewell.. 11/29/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Tue Nov 28 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorm development is possible by this evening across parts of the Colorado Plateau into the southern Rockies, and across parts of the southern Great Plains overnight. The risk for severe storms still appears negligible until after daybreak Thursday. ...Synopsis... While an initially deep and elongated mid-level low over Hudson Bay may become more axisymmetric and deepen further through this period, troughing to its southeast is forecast to continue to pivot away and northeast of the Atlantic Seaboard. As it does, mid-level flow appears likely trend more zonal across and east of the Mississippi Valley, but cool to cold, dry and stable conditions across much of the East will be slow to modify. The center of the cold surface ridging is forecast to begin redeveloping across and offshore of the southern Atlantic coast, leading to a strengthening southerly return flow from the western Gulf of Mexico into southern Great Plains. Models indicate that this will be enhanced by deepening surface troughing to the lee of the southern Rockies, as a short wave trough (within a branch of westerlies emanating from the southern mid-latitude Pacific) digs inland of the central/southern California coast, through the Southwest by 12Z Thursday. While the mid-level cold core is forecast to pivot inland of the California coast during the day, low-level moistening and any potential destabilization will remain confined to areas near and offshore of southern California into northern Baja California coastal areas. However, farther inland, across parts of the Colorado Plateau into the southern Rockies, low-level warming and steepening lapse rates aided by daytime heating, may contribute to destabilization. As stronger forcing for ascent and mid-level cooling overspreads this region, in the exit region of a 70-80 kt 500 mb jet streak nosing across northern Mexico, scattered weak thunderstorm development is possible during the evening into the overnight hours. Farther downstream, models indicate that rapid low-level moisture return from the southwestern Gulf of Mexico is possible, particularly tonight as a southerly low-level jet (30-40+ kt around 850 mb) strengthens across the lower Rio Grande Valley into the southern Great Plains. North and inland of the lower Texas coast, associated destabilization will likely be rooted above at least a shallow stable surface-based layer. Across the Hill Country into northwest Texas, most unstable CAPE might increase to 500-1000 J/kg by late tonight, beneath a generally capping plume of elevated mixed-layer air. On the leading edge and northeast/east of this plume, lift associated with warm advection may support increasing thunderstorm development toward daybreak Thursday. However, weaker and weakening lapse rates within this elevated convective regime seems likely to minimize the risk for severe hail. ..Kerr/Weinman.. 11/29/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Tue Nov 28 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorm development is possible by this evening across parts of the Colorado Plateau into the southern Rockies, and across parts of the southern Great Plains overnight. The risk for severe storms still appears negligible until after daybreak Thursday. ...Synopsis... While an initially deep and elongated mid-level low over Hudson Bay may become more axisymmetric and deepen further through this period, troughing to its southeast is forecast to continue to pivot away and northeast of the Atlantic Seaboard. As it does, mid-level flow appears likely trend more zonal across and east of the Mississippi Valley, but cool to cold, dry and stable conditions across much of the East will be slow to modify. The center of the cold surface ridging is forecast to begin redeveloping across and offshore of the southern Atlantic coast, leading to a strengthening southerly return flow from the western Gulf of Mexico into southern Great Plains. Models indicate that this will be enhanced by deepening surface troughing to the lee of the southern Rockies, as a short wave trough (within a branch of westerlies emanating from the southern mid-latitude Pacific) digs inland of the central/southern California coast, through the Southwest by 12Z Thursday. While the mid-level cold core is forecast to pivot inland of the California coast during the day, low-level moistening and any potential destabilization will remain confined to areas near and offshore of southern California into northern Baja California coastal areas. However, farther inland, across parts of the Colorado Plateau into the southern Rockies, low-level warming and steepening lapse rates aided by daytime heating, may contribute to destabilization. As stronger forcing for ascent and mid-level cooling overspreads this region, in the exit region of a 70-80 kt 500 mb jet streak nosing across northern Mexico, scattered weak thunderstorm development is possible during the evening into the overnight hours. Farther downstream, models indicate that rapid low-level moisture return from the southwestern Gulf of Mexico is possible, particularly tonight as a southerly low-level jet (30-40+ kt around 850 mb) strengthens across the lower Rio Grande Valley into the southern Great Plains. North and inland of the lower Texas coast, associated destabilization will likely be rooted above at least a shallow stable surface-based layer. Across the Hill Country into northwest Texas, most unstable CAPE might increase to 500-1000 J/kg by late tonight, beneath a generally capping plume of elevated mixed-layer air. On the leading edge and northeast/east of this plume, lift associated with warm advection may support increasing thunderstorm development toward daybreak Thursday. However, weaker and weakening lapse rates within this elevated convective regime seems likely to minimize the risk for severe hail. ..Kerr/Weinman.. 11/29/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Tue Nov 28 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorm development is possible by this evening across parts of the Colorado Plateau into the southern Rockies, and across parts of the southern Great Plains overnight. The risk for severe storms still appears negligible until after daybreak Thursday. ...Synopsis... While an initially deep and elongated mid-level low over Hudson Bay may become more axisymmetric and deepen further through this period, troughing to its southeast is forecast to continue to pivot away and northeast of the Atlantic Seaboard. As it does, mid-level flow appears likely trend more zonal across and east of the Mississippi Valley, but cool to cold, dry and stable conditions across much of the East will be slow to modify. The center of the cold surface ridging is forecast to begin redeveloping across and offshore of the southern Atlantic coast, leading to a strengthening southerly return flow from the western Gulf of Mexico into southern Great Plains. Models indicate that this will be enhanced by deepening surface troughing to the lee of the southern Rockies, as a short wave trough (within a branch of westerlies emanating from the southern mid-latitude Pacific) digs inland of the central/southern California coast, through the Southwest by 12Z Thursday. While the mid-level cold core is forecast to pivot inland of the California coast during the day, low-level moistening and any potential destabilization will remain confined to areas near and offshore of southern California into northern Baja California coastal areas. However, farther inland, across parts of the Colorado Plateau into the southern Rockies, low-level warming and steepening lapse rates aided by daytime heating, may contribute to destabilization. As stronger forcing for ascent and mid-level cooling overspreads this region, in the exit region of a 70-80 kt 500 mb jet streak nosing across northern Mexico, scattered weak thunderstorm development is possible during the evening into the overnight hours. Farther downstream, models indicate that rapid low-level moisture return from the southwestern Gulf of Mexico is possible, particularly tonight as a southerly low-level jet (30-40+ kt around 850 mb) strengthens across the lower Rio Grande Valley into the southern Great Plains. North and inland of the lower Texas coast, associated destabilization will likely be rooted above at least a shallow stable surface-based layer. Across the Hill Country into northwest Texas, most unstable CAPE might increase to 500-1000 J/kg by late tonight, beneath a generally capping plume of elevated mixed-layer air. On the leading edge and northeast/east of this plume, lift associated with warm advection may support increasing thunderstorm development toward daybreak Thursday. However, weaker and weakening lapse rates within this elevated convective regime seems likely to minimize the risk for severe hail. ..Kerr/Weinman.. 11/29/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Tue Nov 28 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorm development is possible by this evening across parts of the Colorado Plateau into the southern Rockies, and across parts of the southern Great Plains overnight. The risk for severe storms still appears negligible until after daybreak Thursday. ...Synopsis... While an initially deep and elongated mid-level low over Hudson Bay may become more axisymmetric and deepen further through this period, troughing to its southeast is forecast to continue to pivot away and northeast of the Atlantic Seaboard. As it does, mid-level flow appears likely trend more zonal across and east of the Mississippi Valley, but cool to cold, dry and stable conditions across much of the East will be slow to modify. The center of the cold surface ridging is forecast to begin redeveloping across and offshore of the southern Atlantic coast, leading to a strengthening southerly return flow from the western Gulf of Mexico into southern Great Plains. Models indicate that this will be enhanced by deepening surface troughing to the lee of the southern Rockies, as a short wave trough (within a branch of westerlies emanating from the southern mid-latitude Pacific) digs inland of the central/southern California coast, through the Southwest by 12Z Thursday. While the mid-level cold core is forecast to pivot inland of the California coast during the day, low-level moistening and any potential destabilization will remain confined to areas near and offshore of southern California into northern Baja California coastal areas. However, farther inland, across parts of the Colorado Plateau into the southern Rockies, low-level warming and steepening lapse rates aided by daytime heating, may contribute to destabilization. As stronger forcing for ascent and mid-level cooling overspreads this region, in the exit region of a 70-80 kt 500 mb jet streak nosing across northern Mexico, scattered weak thunderstorm development is possible during the evening into the overnight hours. Farther downstream, models indicate that rapid low-level moisture return from the southwestern Gulf of Mexico is possible, particularly tonight as a southerly low-level jet (30-40+ kt around 850 mb) strengthens across the lower Rio Grande Valley into the southern Great Plains. North and inland of the lower Texas coast, associated destabilization will likely be rooted above at least a shallow stable surface-based layer. Across the Hill Country into northwest Texas, most unstable CAPE might increase to 500-1000 J/kg by late tonight, beneath a generally capping plume of elevated mixed-layer air. On the leading edge and northeast/east of this plume, lift associated with warm advection may support increasing thunderstorm development toward daybreak Thursday. However, weaker and weakening lapse rates within this elevated convective regime seems likely to minimize the risk for severe hail. ..Kerr/Weinman.. 11/29/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Tue Nov 28 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorm development is possible by this evening across parts of the Colorado Plateau into the southern Rockies, and across parts of the southern Great Plains overnight. The risk for severe storms still appears negligible until after daybreak Thursday. ...Synopsis... While an initially deep and elongated mid-level low over Hudson Bay may become more axisymmetric and deepen further through this period, troughing to its southeast is forecast to continue to pivot away and northeast of the Atlantic Seaboard. As it does, mid-level flow appears likely trend more zonal across and east of the Mississippi Valley, but cool to cold, dry and stable conditions across much of the East will be slow to modify. The center of the cold surface ridging is forecast to begin redeveloping across and offshore of the southern Atlantic coast, leading to a strengthening southerly return flow from the western Gulf of Mexico into southern Great Plains. Models indicate that this will be enhanced by deepening surface troughing to the lee of the southern Rockies, as a short wave trough (within a branch of westerlies emanating from the southern mid-latitude Pacific) digs inland of the central/southern California coast, through the Southwest by 12Z Thursday. While the mid-level cold core is forecast to pivot inland of the California coast during the day, low-level moistening and any potential destabilization will remain confined to areas near and offshore of southern California into northern Baja California coastal areas. However, farther inland, across parts of the Colorado Plateau into the southern Rockies, low-level warming and steepening lapse rates aided by daytime heating, may contribute to destabilization. As stronger forcing for ascent and mid-level cooling overspreads this region, in the exit region of a 70-80 kt 500 mb jet streak nosing across northern Mexico, scattered weak thunderstorm development is possible during the evening into the overnight hours. Farther downstream, models indicate that rapid low-level moisture return from the southwestern Gulf of Mexico is possible, particularly tonight as a southerly low-level jet (30-40+ kt around 850 mb) strengthens across the lower Rio Grande Valley into the southern Great Plains. North and inland of the lower Texas coast, associated destabilization will likely be rooted above at least a shallow stable surface-based layer. Across the Hill Country into northwest Texas, most unstable CAPE might increase to 500-1000 J/kg by late tonight, beneath a generally capping plume of elevated mixed-layer air. On the leading edge and northeast/east of this plume, lift associated with warm advection may support increasing thunderstorm development toward daybreak Thursday. However, weaker and weakening lapse rates within this elevated convective regime seems likely to minimize the risk for severe hail. ..Kerr/Weinman.. 11/29/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 PM CST Tue Nov 28 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered thunderstorm development is possible by this evening across parts of the Colorado Plateau into the southern Rockies, and across parts of the southern Great Plains overnight. The risk for severe storms still appears negligible until after daybreak Thursday. ...Synopsis... While an initially deep and elongated mid-level low over Hudson Bay may become more axisymmetric and deepen further through this period, troughing to its southeast is forecast to continue to pivot away and northeast of the Atlantic Seaboard. As it does, mid-level flow appears likely trend more zonal across and east of the Mississippi Valley, but cool to cold, dry and stable conditions across much of the East will be slow to modify. The center of the cold surface ridging is forecast to begin redeveloping across and offshore of the southern Atlantic coast, leading to a strengthening southerly return flow from the western Gulf of Mexico into southern Great Plains. Models indicate that this will be enhanced by deepening surface troughing to the lee of the southern Rockies, as a short wave trough (within a branch of westerlies emanating from the southern mid-latitude Pacific) digs inland of the central/southern California coast, through the Southwest by 12Z Thursday. While the mid-level cold core is forecast to pivot inland of the California coast during the day, low-level moistening and any potential destabilization will remain confined to areas near and offshore of southern California into northern Baja California coastal areas. However, farther inland, across parts of the Colorado Plateau into the southern Rockies, low-level warming and steepening lapse rates aided by daytime heating, may contribute to destabilization. As stronger forcing for ascent and mid-level cooling overspreads this region, in the exit region of a 70-80 kt 500 mb jet streak nosing across northern Mexico, scattered weak thunderstorm development is possible during the evening into the overnight hours. Farther downstream, models indicate that rapid low-level moisture return from the southwestern Gulf of Mexico is possible, particularly tonight as a southerly low-level jet (30-40+ kt around 850 mb) strengthens across the lower Rio Grande Valley into the southern Great Plains. North and inland of the lower Texas coast, associated destabilization will likely be rooted above at least a shallow stable surface-based layer. Across the Hill Country into northwest Texas, most unstable CAPE might increase to 500-1000 J/kg by late tonight, beneath a generally capping plume of elevated mixed-layer air. On the leading edge and northeast/east of this plume, lift associated with warm advection may support increasing thunderstorm development toward daybreak Thursday. However, weaker and weakening lapse rates within this elevated convective regime seems likely to minimize the risk for severe hail. ..Kerr/Weinman.. 11/29/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0640 PM CST Tue Nov 28 2023 Valid 290100Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. through tonight. ...01Z Update... Some lightning was noted earlier today with convection beneath the cold core of a weakening mid-level low, which is now a couple hundred miles west-southwest of the northern California coast. The remnant mid-level circulation may shift into coastal areas near Eureka by late tonight, but the associated weakening, occluded surface low and front are forecast to remain offshore of the California coast. Stronger mid-level forcing for ascent and cooling, within the exit region of a digging jet streak (to the west of the mid-level trough axis), may approach coastal areas south of San Francisco Bay overnight, possibly supporting a developing band of frontal convection with some lightning. ..Kerr.. 11/29/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0640 PM CST Tue Nov 28 2023 Valid 290100Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. through tonight. ...01Z Update... Some lightning was noted earlier today with convection beneath the cold core of a weakening mid-level low, which is now a couple hundred miles west-southwest of the northern California coast. The remnant mid-level circulation may shift into coastal areas near Eureka by late tonight, but the associated weakening, occluded surface low and front are forecast to remain offshore of the California coast. Stronger mid-level forcing for ascent and cooling, within the exit region of a digging jet streak (to the west of the mid-level trough axis), may approach coastal areas south of San Francisco Bay overnight, possibly supporting a developing band of frontal convection with some lightning. ..Kerr.. 11/29/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0640 PM CST Tue Nov 28 2023 Valid 290100Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of thunderstorms appears negligible across much of the U.S. through tonight. ...01Z Update... Some lightning was noted earlier today with convection beneath the cold core of a weakening mid-level low, which is now a couple hundred miles west-southwest of the northern California coast. The remnant mid-level circulation may shift into coastal areas near Eureka by late tonight, but the associated weakening, occluded surface low and front are forecast to remain offshore of the California coast. Stronger mid-level forcing for ascent and cooling, within the exit region of a digging jet streak (to the west of the mid-level trough axis), may approach coastal areas south of San Francisco Bay overnight, possibly supporting a developing band of frontal convection with some lightning. ..Kerr.. 11/29/2023 Read more

No watches are valid as of Tue Nov 28 22:06:02 UTC 2023.

No Mesoscale Discussions are in effect as of Tue Nov 28 22:06:02 UTC 2023.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0320 PM CST Tue Nov 28 2023 Valid 301200Z - 061200Z A progressive upper-air pattern is expected through the extended period, with a series of mid-level troughs traversing the U.S. and corresponding surface lee troughs/surface cyclones developing over the central Plains. While cool or moist surface conditions will limit wildfire-spread potential over most locales, prolonged dry and breezy conditions are expected across the central and southern High Plains most days. At the moment, the main reasons for not adding Critical probabilities this outlook are 1) uncertainty in fuel receptiveness, and 2) strength of the larger-scale surface wind field. Widespread, appreciable precipitation accumulations may not occur across the central/southern High Plains into early next week, suggesting that some continued drying of fuels should take place. If guidance agreement in overlapping Elevated conditions can persist over the next few days, lower-end Critical probabilities may be introduced in future outlooks. ..Squitieri.. 11/28/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0320 PM CST Tue Nov 28 2023 Valid 301200Z - 061200Z A progressive upper-air pattern is expected through the extended period, with a series of mid-level troughs traversing the U.S. and corresponding surface lee troughs/surface cyclones developing over the central Plains. While cool or moist surface conditions will limit wildfire-spread potential over most locales, prolonged dry and breezy conditions are expected across the central and southern High Plains most days. At the moment, the main reasons for not adding Critical probabilities this outlook are 1) uncertainty in fuel receptiveness, and 2) strength of the larger-scale surface wind field. Widespread, appreciable precipitation accumulations may not occur across the central/southern High Plains into early next week, suggesting that some continued drying of fuels should take place. If guidance agreement in overlapping Elevated conditions can persist over the next few days, lower-end Critical probabilities may be introduced in future outlooks. ..Squitieri.. 11/28/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0320 PM CST Tue Nov 28 2023 Valid 301200Z - 061200Z A progressive upper-air pattern is expected through the extended period, with a series of mid-level troughs traversing the U.S. and corresponding surface lee troughs/surface cyclones developing over the central Plains. While cool or moist surface conditions will limit wildfire-spread potential over most locales, prolonged dry and breezy conditions are expected across the central and southern High Plains most days. At the moment, the main reasons for not adding Critical probabilities this outlook are 1) uncertainty in fuel receptiveness, and 2) strength of the larger-scale surface wind field. Widespread, appreciable precipitation accumulations may not occur across the central/southern High Plains into early next week, suggesting that some continued drying of fuels should take place. If guidance agreement in overlapping Elevated conditions can persist over the next few days, lower-end Critical probabilities may be introduced in future outlooks. ..Squitieri.. 11/28/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0320 PM CST Tue Nov 28 2023 Valid 301200Z - 061200Z A progressive upper-air pattern is expected through the extended period, with a series of mid-level troughs traversing the U.S. and corresponding surface lee troughs/surface cyclones developing over the central Plains. While cool or moist surface conditions will limit wildfire-spread potential over most locales, prolonged dry and breezy conditions are expected across the central and southern High Plains most days. At the moment, the main reasons for not adding Critical probabilities this outlook are 1) uncertainty in fuel receptiveness, and 2) strength of the larger-scale surface wind field. Widespread, appreciable precipitation accumulations may not occur across the central/southern High Plains into early next week, suggesting that some continued drying of fuels should take place. If guidance agreement in overlapping Elevated conditions can persist over the next few days, lower-end Critical probabilities may be introduced in future outlooks. ..Squitieri.. 11/28/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more