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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Wed Nov 15 2023 Valid 151300Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast. ...Synopsis/Discussion... The synoptic/upper-air pattern over the CONUS will be dominated by three troughs (and related smaller-scale features): 1. A northern-stream perturbation, splitting eastward out of mean troughing over the northeast Pacific, across BC and the Canadian Rockies. This feature should extend across much of SK and northern/western MT by 12Z tomorrow, remaining too removed from sufficient low-level theta-e to support thunderstorm potential despite cold air aloft. 2. A Pacific cutoff low, centered around 500-550 nm off the central CA coast, forecast to drift erratically southward/southwestward through the period. A basal shortwave trough is apparent in moisture-channel imagery approaching 130W, south of the main mid/ upper low, with sporadic lightning detected. This feature should eject northeastward across parts of the central/southern CA coastline between 00-03Z, while deamplifying. An associated band of enhanced large-scale DCVA/lift should precede the trough across the region and inland, steepening mid/upper-level lapse rates over a cool, moist, stable low-level profile. Elevated MUCAPE to around 500 J/kg is possible (rooted between 700-800 mb), amidst 35-40 kt effective-shear magnitudes. This indicates that the most vigorous cells may produce small hail or locally gusty winds through the stable low-level profiles. Organized severe appears unlikely. 3. A southern-stream trough -- initially apparent from central/ southern MS to a prominent low/middle-level vorticity max near the Mississippi River mouth, then across the central Gulf toward the Yucatan Peninsula. The low-level circulation should drift erratically near its present position today, then shift farther offshore and weaken tonight, as the trough aloft starts to eject away from the low-level vortex. A low-level baroclinic zone -- extending from the low east-southeastward over parts of south FL -- should remain quasistationary through the period. Mesobeta-scale oscillations of the diffuse surface boundary are possible in response to areas of precip (including embedded thunderstorms) to its north. Lapse rates, lift and deep shear each should remain too weak for overland severe. A few weak/shallow supercells may occur around the Keys, with slightly enlarged hodographs in deep low-level eaterlies, but weak flow aloft. The greatest convective coverage/intensity should remain over the open Gulf, where marine moisture/heat fluxes are maximized into the boundary layer near the Loop Current. ..Edwards/Gleason.. 11/15/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Wed Nov 15 2023 Valid 151300Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast. ...Synopsis/Discussion... The synoptic/upper-air pattern over the CONUS will be dominated by three troughs (and related smaller-scale features): 1. A northern-stream perturbation, splitting eastward out of mean troughing over the northeast Pacific, across BC and the Canadian Rockies. This feature should extend across much of SK and northern/western MT by 12Z tomorrow, remaining too removed from sufficient low-level theta-e to support thunderstorm potential despite cold air aloft. 2. A Pacific cutoff low, centered around 500-550 nm off the central CA coast, forecast to drift erratically southward/southwestward through the period. A basal shortwave trough is apparent in moisture-channel imagery approaching 130W, south of the main mid/ upper low, with sporadic lightning detected. This feature should eject northeastward across parts of the central/southern CA coastline between 00-03Z, while deamplifying. An associated band of enhanced large-scale DCVA/lift should precede the trough across the region and inland, steepening mid/upper-level lapse rates over a cool, moist, stable low-level profile. Elevated MUCAPE to around 500 J/kg is possible (rooted between 700-800 mb), amidst 35-40 kt effective-shear magnitudes. This indicates that the most vigorous cells may produce small hail or locally gusty winds through the stable low-level profiles. Organized severe appears unlikely. 3. A southern-stream trough -- initially apparent from central/ southern MS to a prominent low/middle-level vorticity max near the Mississippi River mouth, then across the central Gulf toward the Yucatan Peninsula. The low-level circulation should drift erratically near its present position today, then shift farther offshore and weaken tonight, as the trough aloft starts to eject away from the low-level vortex. A low-level baroclinic zone -- extending from the low east-southeastward over parts of south FL -- should remain quasistationary through the period. Mesobeta-scale oscillations of the diffuse surface boundary are possible in response to areas of precip (including embedded thunderstorms) to its north. Lapse rates, lift and deep shear each should remain too weak for overland severe. A few weak/shallow supercells may occur around the Keys, with slightly enlarged hodographs in deep low-level eaterlies, but weak flow aloft. The greatest convective coverage/intensity should remain over the open Gulf, where marine moisture/heat fluxes are maximized into the boundary layer near the Loop Current. ..Edwards/Gleason.. 11/15/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Wed Nov 15 2023 Valid 151300Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast. ...Synopsis/Discussion... The synoptic/upper-air pattern over the CONUS will be dominated by three troughs (and related smaller-scale features): 1. A northern-stream perturbation, splitting eastward out of mean troughing over the northeast Pacific, across BC and the Canadian Rockies. This feature should extend across much of SK and northern/western MT by 12Z tomorrow, remaining too removed from sufficient low-level theta-e to support thunderstorm potential despite cold air aloft. 2. A Pacific cutoff low, centered around 500-550 nm off the central CA coast, forecast to drift erratically southward/southwestward through the period. A basal shortwave trough is apparent in moisture-channel imagery approaching 130W, south of the main mid/ upper low, with sporadic lightning detected. This feature should eject northeastward across parts of the central/southern CA coastline between 00-03Z, while deamplifying. An associated band of enhanced large-scale DCVA/lift should precede the trough across the region and inland, steepening mid/upper-level lapse rates over a cool, moist, stable low-level profile. Elevated MUCAPE to around 500 J/kg is possible (rooted between 700-800 mb), amidst 35-40 kt effective-shear magnitudes. This indicates that the most vigorous cells may produce small hail or locally gusty winds through the stable low-level profiles. Organized severe appears unlikely. 3. A southern-stream trough -- initially apparent from central/ southern MS to a prominent low/middle-level vorticity max near the Mississippi River mouth, then across the central Gulf toward the Yucatan Peninsula. The low-level circulation should drift erratically near its present position today, then shift farther offshore and weaken tonight, as the trough aloft starts to eject away from the low-level vortex. A low-level baroclinic zone -- extending from the low east-southeastward over parts of south FL -- should remain quasistationary through the period. Mesobeta-scale oscillations of the diffuse surface boundary are possible in response to areas of precip (including embedded thunderstorms) to its north. Lapse rates, lift and deep shear each should remain too weak for overland severe. A few weak/shallow supercells may occur around the Keys, with slightly enlarged hodographs in deep low-level eaterlies, but weak flow aloft. The greatest convective coverage/intensity should remain over the open Gulf, where marine moisture/heat fluxes are maximized into the boundary layer near the Loop Current. ..Edwards/Gleason.. 11/15/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Wed Nov 15 2023 Valid 151300Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast. ...Synopsis/Discussion... The synoptic/upper-air pattern over the CONUS will be dominated by three troughs (and related smaller-scale features): 1. A northern-stream perturbation, splitting eastward out of mean troughing over the northeast Pacific, across BC and the Canadian Rockies. This feature should extend across much of SK and northern/western MT by 12Z tomorrow, remaining too removed from sufficient low-level theta-e to support thunderstorm potential despite cold air aloft. 2. A Pacific cutoff low, centered around 500-550 nm off the central CA coast, forecast to drift erratically southward/southwestward through the period. A basal shortwave trough is apparent in moisture-channel imagery approaching 130W, south of the main mid/ upper low, with sporadic lightning detected. This feature should eject northeastward across parts of the central/southern CA coastline between 00-03Z, while deamplifying. An associated band of enhanced large-scale DCVA/lift should precede the trough across the region and inland, steepening mid/upper-level lapse rates over a cool, moist, stable low-level profile. Elevated MUCAPE to around 500 J/kg is possible (rooted between 700-800 mb), amidst 35-40 kt effective-shear magnitudes. This indicates that the most vigorous cells may produce small hail or locally gusty winds through the stable low-level profiles. Organized severe appears unlikely. 3. A southern-stream trough -- initially apparent from central/ southern MS to a prominent low/middle-level vorticity max near the Mississippi River mouth, then across the central Gulf toward the Yucatan Peninsula. The low-level circulation should drift erratically near its present position today, then shift farther offshore and weaken tonight, as the trough aloft starts to eject away from the low-level vortex. A low-level baroclinic zone -- extending from the low east-southeastward over parts of south FL -- should remain quasistationary through the period. Mesobeta-scale oscillations of the diffuse surface boundary are possible in response to areas of precip (including embedded thunderstorms) to its north. Lapse rates, lift and deep shear each should remain too weak for overland severe. A few weak/shallow supercells may occur around the Keys, with slightly enlarged hodographs in deep low-level eaterlies, but weak flow aloft. The greatest convective coverage/intensity should remain over the open Gulf, where marine moisture/heat fluxes are maximized into the boundary layer near the Loop Current. ..Edwards/Gleason.. 11/15/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Wed Nov 15 2023 Valid 151300Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast. ...Synopsis/Discussion... The synoptic/upper-air pattern over the CONUS will be dominated by three troughs (and related smaller-scale features): 1. A northern-stream perturbation, splitting eastward out of mean troughing over the northeast Pacific, across BC and the Canadian Rockies. This feature should extend across much of SK and northern/western MT by 12Z tomorrow, remaining too removed from sufficient low-level theta-e to support thunderstorm potential despite cold air aloft. 2. A Pacific cutoff low, centered around 500-550 nm off the central CA coast, forecast to drift erratically southward/southwestward through the period. A basal shortwave trough is apparent in moisture-channel imagery approaching 130W, south of the main mid/ upper low, with sporadic lightning detected. This feature should eject northeastward across parts of the central/southern CA coastline between 00-03Z, while deamplifying. An associated band of enhanced large-scale DCVA/lift should precede the trough across the region and inland, steepening mid/upper-level lapse rates over a cool, moist, stable low-level profile. Elevated MUCAPE to around 500 J/kg is possible (rooted between 700-800 mb), amidst 35-40 kt effective-shear magnitudes. This indicates that the most vigorous cells may produce small hail or locally gusty winds through the stable low-level profiles. Organized severe appears unlikely. 3. A southern-stream trough -- initially apparent from central/ southern MS to a prominent low/middle-level vorticity max near the Mississippi River mouth, then across the central Gulf toward the Yucatan Peninsula. The low-level circulation should drift erratically near its present position today, then shift farther offshore and weaken tonight, as the trough aloft starts to eject away from the low-level vortex. A low-level baroclinic zone -- extending from the low east-southeastward over parts of south FL -- should remain quasistationary through the period. Mesobeta-scale oscillations of the diffuse surface boundary are possible in response to areas of precip (including embedded thunderstorms) to its north. Lapse rates, lift and deep shear each should remain too weak for overland severe. A few weak/shallow supercells may occur around the Keys, with slightly enlarged hodographs in deep low-level eaterlies, but weak flow aloft. The greatest convective coverage/intensity should remain over the open Gulf, where marine moisture/heat fluxes are maximized into the boundary layer near the Loop Current. ..Edwards/Gleason.. 11/15/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Wed Nov 15 2023 Valid 151300Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast. ...Synopsis/Discussion... The synoptic/upper-air pattern over the CONUS will be dominated by three troughs (and related smaller-scale features): 1. A northern-stream perturbation, splitting eastward out of mean troughing over the northeast Pacific, across BC and the Canadian Rockies. This feature should extend across much of SK and northern/western MT by 12Z tomorrow, remaining too removed from sufficient low-level theta-e to support thunderstorm potential despite cold air aloft. 2. A Pacific cutoff low, centered around 500-550 nm off the central CA coast, forecast to drift erratically southward/southwestward through the period. A basal shortwave trough is apparent in moisture-channel imagery approaching 130W, south of the main mid/ upper low, with sporadic lightning detected. This feature should eject northeastward across parts of the central/southern CA coastline between 00-03Z, while deamplifying. An associated band of enhanced large-scale DCVA/lift should precede the trough across the region and inland, steepening mid/upper-level lapse rates over a cool, moist, stable low-level profile. Elevated MUCAPE to around 500 J/kg is possible (rooted between 700-800 mb), amidst 35-40 kt effective-shear magnitudes. This indicates that the most vigorous cells may produce small hail or locally gusty winds through the stable low-level profiles. Organized severe appears unlikely. 3. A southern-stream trough -- initially apparent from central/ southern MS to a prominent low/middle-level vorticity max near the Mississippi River mouth, then across the central Gulf toward the Yucatan Peninsula. The low-level circulation should drift erratically near its present position today, then shift farther offshore and weaken tonight, as the trough aloft starts to eject away from the low-level vortex. A low-level baroclinic zone -- extending from the low east-southeastward over parts of south FL -- should remain quasistationary through the period. Mesobeta-scale oscillations of the diffuse surface boundary are possible in response to areas of precip (including embedded thunderstorms) to its north. Lapse rates, lift and deep shear each should remain too weak for overland severe. A few weak/shallow supercells may occur around the Keys, with slightly enlarged hodographs in deep low-level eaterlies, but weak flow aloft. The greatest convective coverage/intensity should remain over the open Gulf, where marine moisture/heat fluxes are maximized into the boundary layer near the Loop Current. ..Edwards/Gleason.. 11/15/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Wed Nov 15 2023 Valid 151300Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast. ...Synopsis/Discussion... The synoptic/upper-air pattern over the CONUS will be dominated by three troughs (and related smaller-scale features): 1. A northern-stream perturbation, splitting eastward out of mean troughing over the northeast Pacific, across BC and the Canadian Rockies. This feature should extend across much of SK and northern/western MT by 12Z tomorrow, remaining too removed from sufficient low-level theta-e to support thunderstorm potential despite cold air aloft. 2. A Pacific cutoff low, centered around 500-550 nm off the central CA coast, forecast to drift erratically southward/southwestward through the period. A basal shortwave trough is apparent in moisture-channel imagery approaching 130W, south of the main mid/ upper low, with sporadic lightning detected. This feature should eject northeastward across parts of the central/southern CA coastline between 00-03Z, while deamplifying. An associated band of enhanced large-scale DCVA/lift should precede the trough across the region and inland, steepening mid/upper-level lapse rates over a cool, moist, stable low-level profile. Elevated MUCAPE to around 500 J/kg is possible (rooted between 700-800 mb), amidst 35-40 kt effective-shear magnitudes. This indicates that the most vigorous cells may produce small hail or locally gusty winds through the stable low-level profiles. Organized severe appears unlikely. 3. A southern-stream trough -- initially apparent from central/ southern MS to a prominent low/middle-level vorticity max near the Mississippi River mouth, then across the central Gulf toward the Yucatan Peninsula. The low-level circulation should drift erratically near its present position today, then shift farther offshore and weaken tonight, as the trough aloft starts to eject away from the low-level vortex. A low-level baroclinic zone -- extending from the low east-southeastward over parts of south FL -- should remain quasistationary through the period. Mesobeta-scale oscillations of the diffuse surface boundary are possible in response to areas of precip (including embedded thunderstorms) to its north. Lapse rates, lift and deep shear each should remain too weak for overland severe. A few weak/shallow supercells may occur around the Keys, with slightly enlarged hodographs in deep low-level eaterlies, but weak flow aloft. The greatest convective coverage/intensity should remain over the open Gulf, where marine moisture/heat fluxes are maximized into the boundary layer near the Loop Current. ..Edwards/Gleason.. 11/15/2023 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CST Wed Nov 15 2023 Valid 181200Z - 231200Z ...DISCUSSION... ....Saturday/Day 4 to Monday/Day 6... An upper-level trough is forecast to move eastward from the Eastern Seaboard into the western Atlantic on Saturday and Saturday night. Further west, an upper-level trough is forecast to move across the Desert Southwest on Saturday. Low-level moisture will return northward ahead of the system on Sunday, with surface dewpoints possibly reaching the 60s F across the southeastern third of Texas. The airmass should be slow to destabilize during the day due to widespread cloud cover. As a band of large-scale ascent moves into the southern Plains, scattered thunderstorms appear likely to develop during the afternoon and evening from east Texas northward into the Ark-La-Tex. An isolated severe threat will be possible with these storms but weak instability could minimize any severe potential. An associated cold front is forecast to move eastward into the Southeast on Monday. Ahead of the front, weak instability is forecast to develop across the lower Mississippi Valley. The higher quality moisture, with surface dewpoints in the mid 60s F, is expected to remain confined to the central Gulf Coast. There could be an isolated severe threat in the central Gulf Coast states during the day. At this time, the severe potential is not expected to be great enough for the addition of a threat area. ...Tuesday/Day 7 and Wednesday/Day 8... The upper-level trough is forecast to move across the eastern U.S. on Tuesday and Wednesday. Ahead of the trough, thunderstorm development will be possible on Tuesday from Florida northward into the Carolinas. Although a moist airmass should be in place ahead of the system on Tuesday, instability is forecast to remain weak across the Southeast. This is expected to minimize the severe potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CST Wed Nov 15 2023 Valid 181200Z - 231200Z ...DISCUSSION... ....Saturday/Day 4 to Monday/Day 6... An upper-level trough is forecast to move eastward from the Eastern Seaboard into the western Atlantic on Saturday and Saturday night. Further west, an upper-level trough is forecast to move across the Desert Southwest on Saturday. Low-level moisture will return northward ahead of the system on Sunday, with surface dewpoints possibly reaching the 60s F across the southeastern third of Texas. The airmass should be slow to destabilize during the day due to widespread cloud cover. As a band of large-scale ascent moves into the southern Plains, scattered thunderstorms appear likely to develop during the afternoon and evening from east Texas northward into the Ark-La-Tex. An isolated severe threat will be possible with these storms but weak instability could minimize any severe potential. An associated cold front is forecast to move eastward into the Southeast on Monday. Ahead of the front, weak instability is forecast to develop across the lower Mississippi Valley. The higher quality moisture, with surface dewpoints in the mid 60s F, is expected to remain confined to the central Gulf Coast. There could be an isolated severe threat in the central Gulf Coast states during the day. At this time, the severe potential is not expected to be great enough for the addition of a threat area. ...Tuesday/Day 7 and Wednesday/Day 8... The upper-level trough is forecast to move across the eastern U.S. on Tuesday and Wednesday. Ahead of the trough, thunderstorm development will be possible on Tuesday from Florida northward into the Carolinas. Although a moist airmass should be in place ahead of the system on Tuesday, instability is forecast to remain weak across the Southeast. This is expected to minimize the severe potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CST Wed Nov 15 2023 Valid 181200Z - 231200Z ...DISCUSSION... ....Saturday/Day 4 to Monday/Day 6... An upper-level trough is forecast to move eastward from the Eastern Seaboard into the western Atlantic on Saturday and Saturday night. Further west, an upper-level trough is forecast to move across the Desert Southwest on Saturday. Low-level moisture will return northward ahead of the system on Sunday, with surface dewpoints possibly reaching the 60s F across the southeastern third of Texas. The airmass should be slow to destabilize during the day due to widespread cloud cover. As a band of large-scale ascent moves into the southern Plains, scattered thunderstorms appear likely to develop during the afternoon and evening from east Texas northward into the Ark-La-Tex. An isolated severe threat will be possible with these storms but weak instability could minimize any severe potential. An associated cold front is forecast to move eastward into the Southeast on Monday. Ahead of the front, weak instability is forecast to develop across the lower Mississippi Valley. The higher quality moisture, with surface dewpoints in the mid 60s F, is expected to remain confined to the central Gulf Coast. There could be an isolated severe threat in the central Gulf Coast states during the day. At this time, the severe potential is not expected to be great enough for the addition of a threat area. ...Tuesday/Day 7 and Wednesday/Day 8... The upper-level trough is forecast to move across the eastern U.S. on Tuesday and Wednesday. Ahead of the trough, thunderstorm development will be possible on Tuesday from Florida northward into the Carolinas. Although a moist airmass should be in place ahead of the system on Tuesday, instability is forecast to remain weak across the Southeast. This is expected to minimize the severe potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CST Wed Nov 15 2023 Valid 181200Z - 231200Z ...DISCUSSION... ....Saturday/Day 4 to Monday/Day 6... An upper-level trough is forecast to move eastward from the Eastern Seaboard into the western Atlantic on Saturday and Saturday night. Further west, an upper-level trough is forecast to move across the Desert Southwest on Saturday. Low-level moisture will return northward ahead of the system on Sunday, with surface dewpoints possibly reaching the 60s F across the southeastern third of Texas. The airmass should be slow to destabilize during the day due to widespread cloud cover. As a band of large-scale ascent moves into the southern Plains, scattered thunderstorms appear likely to develop during the afternoon and evening from east Texas northward into the Ark-La-Tex. An isolated severe threat will be possible with these storms but weak instability could minimize any severe potential. An associated cold front is forecast to move eastward into the Southeast on Monday. Ahead of the front, weak instability is forecast to develop across the lower Mississippi Valley. The higher quality moisture, with surface dewpoints in the mid 60s F, is expected to remain confined to the central Gulf Coast. There could be an isolated severe threat in the central Gulf Coast states during the day. At this time, the severe potential is not expected to be great enough for the addition of a threat area. ...Tuesday/Day 7 and Wednesday/Day 8... The upper-level trough is forecast to move across the eastern U.S. on Tuesday and Wednesday. Ahead of the trough, thunderstorm development will be possible on Tuesday from Florida northward into the Carolinas. Although a moist airmass should be in place ahead of the system on Tuesday, instability is forecast to remain weak across the Southeast. This is expected to minimize the severe potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CST Wed Nov 15 2023 Valid 181200Z - 231200Z ...DISCUSSION... ....Saturday/Day 4 to Monday/Day 6... An upper-level trough is forecast to move eastward from the Eastern Seaboard into the western Atlantic on Saturday and Saturday night. Further west, an upper-level trough is forecast to move across the Desert Southwest on Saturday. Low-level moisture will return northward ahead of the system on Sunday, with surface dewpoints possibly reaching the 60s F across the southeastern third of Texas. The airmass should be slow to destabilize during the day due to widespread cloud cover. As a band of large-scale ascent moves into the southern Plains, scattered thunderstorms appear likely to develop during the afternoon and evening from east Texas northward into the Ark-La-Tex. An isolated severe threat will be possible with these storms but weak instability could minimize any severe potential. An associated cold front is forecast to move eastward into the Southeast on Monday. Ahead of the front, weak instability is forecast to develop across the lower Mississippi Valley. The higher quality moisture, with surface dewpoints in the mid 60s F, is expected to remain confined to the central Gulf Coast. There could be an isolated severe threat in the central Gulf Coast states during the day. At this time, the severe potential is not expected to be great enough for the addition of a threat area. ...Tuesday/Day 7 and Wednesday/Day 8... The upper-level trough is forecast to move across the eastern U.S. on Tuesday and Wednesday. Ahead of the trough, thunderstorm development will be possible on Tuesday from Florida northward into the Carolinas. Although a moist airmass should be in place ahead of the system on Tuesday, instability is forecast to remain weak across the Southeast. This is expected to minimize the severe potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CST Wed Nov 15 2023 Valid 181200Z - 231200Z ...DISCUSSION... ....Saturday/Day 4 to Monday/Day 6... An upper-level trough is forecast to move eastward from the Eastern Seaboard into the western Atlantic on Saturday and Saturday night. Further west, an upper-level trough is forecast to move across the Desert Southwest on Saturday. Low-level moisture will return northward ahead of the system on Sunday, with surface dewpoints possibly reaching the 60s F across the southeastern third of Texas. The airmass should be slow to destabilize during the day due to widespread cloud cover. As a band of large-scale ascent moves into the southern Plains, scattered thunderstorms appear likely to develop during the afternoon and evening from east Texas northward into the Ark-La-Tex. An isolated severe threat will be possible with these storms but weak instability could minimize any severe potential. An associated cold front is forecast to move eastward into the Southeast on Monday. Ahead of the front, weak instability is forecast to develop across the lower Mississippi Valley. The higher quality moisture, with surface dewpoints in the mid 60s F, is expected to remain confined to the central Gulf Coast. There could be an isolated severe threat in the central Gulf Coast states during the day. At this time, the severe potential is not expected to be great enough for the addition of a threat area. ...Tuesday/Day 7 and Wednesday/Day 8... The upper-level trough is forecast to move across the eastern U.S. on Tuesday and Wednesday. Ahead of the trough, thunderstorm development will be possible on Tuesday from Florida northward into the Carolinas. Although a moist airmass should be in place ahead of the system on Tuesday, instability is forecast to remain weak across the Southeast. This is expected to minimize the severe potential. Read more