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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0737 AM CDT Mon Sep 30 2024 Valid 301300Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today, though a few strong storms may affect central/eastern North Carolina. ...Synopsis/Discussion... The main belt of mid/upper-level, midlatitude westerlies will continue to traverse the northwestern/north-central CONUS and central/southwestern Canada, buckled cyclonically around a prominent synoptic trough now located from eastern SK to central MT and western WY. This trough should phase with another now over central mainland Arctic Canada by the end of the period, resulting in a 500-mb low over southeastern Nunavut, with trough trailing over western Hudson Bay, northwesternmost ON, MN, and IA. Strongly difluent flow aloft will take shape southeast of the trough, across the Mississippi Valley, the Great Lakes from Michigan/Huron on down, the Ohio Valley, and much of the Appalachians. As that occurs, a longstanding, filling, weakening low now over southwestern WV will devolve today to an open-wave trough, losing amplitude rapidly and drifting eastward over the central Appalachians through the period. Part of a basal shortwave trough/vorticity lobe -- now apparent in moisture-channel imagery over eastern TN -- will eject eastward across northern NC and southern VA from this afternoon through tonight. At the surface, 11Z analysis showed a quasistationary front across northern SC to just south of the southern Outer Banks, extending from a triple-point low near CAE. This boundary should shift northward over central/eastern NC through the day. Meanwhile, a cold front -- related to the strong northern-stream trough -- was drawn from central/southern MB across southern ND, central SD, northwestern NE, and southern WY. This front should sweep across most of the Great Plains and upper Mississippi Valley through the period, reaching northern Lower MI, IL, southwestern MO, southern OK, and the TX South Plains by 12Z. ...Central/eastern NC... Widely scattered showers and thunderstorms are expected to develop this afternoon over the Piedmont and coastal plain, in an environment characterized by rich boundary-layer moisture (surface dewpoints commonly in upper 60 to mid 70s F) very weak ambient MLCINH easily removed by diurnal heating, but weak mid/upper-level lapse rates. This will result in 500-1200 J/kg MLCAPE over most of the area from he Piedmont to the Sounds, beneath a belt of sufficiently strong mid/upper flow to yield around 35-45-kt effective-shear magnitudes. Low-level hodographs over central/eastern NC this afternoon, from model forecast soundings, reasonably show curvature near the frontal zone, but with weak speeds in the lowest couple km that substantially limit SRH and vector shear. However, above 1 km, hodographs are somewhat long and straight, suggesting the potential for low-end supercells amidst the mode common multicellular modes. At this time, forecast shear appears too weak to support an unconditional tornado-threat area, but the scenario will be monitored for any mesoscale enhancement to shear (especially along boundaries) that may introduce such a risk. The gust threat appears subsevere at this time, though localized gusts approaching severe limits cannot be ruled out. ..Edwards/Broyles.. 09/30/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0737 AM CDT Mon Sep 30 2024 Valid 301300Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today, though a few strong storms may affect central/eastern North Carolina. ...Synopsis/Discussion... The main belt of mid/upper-level, midlatitude westerlies will continue to traverse the northwestern/north-central CONUS and central/southwestern Canada, buckled cyclonically around a prominent synoptic trough now located from eastern SK to central MT and western WY. This trough should phase with another now over central mainland Arctic Canada by the end of the period, resulting in a 500-mb low over southeastern Nunavut, with trough trailing over western Hudson Bay, northwesternmost ON, MN, and IA. Strongly difluent flow aloft will take shape southeast of the trough, across the Mississippi Valley, the Great Lakes from Michigan/Huron on down, the Ohio Valley, and much of the Appalachians. As that occurs, a longstanding, filling, weakening low now over southwestern WV will devolve today to an open-wave trough, losing amplitude rapidly and drifting eastward over the central Appalachians through the period. Part of a basal shortwave trough/vorticity lobe -- now apparent in moisture-channel imagery over eastern TN -- will eject eastward across northern NC and southern VA from this afternoon through tonight. At the surface, 11Z analysis showed a quasistationary front across northern SC to just south of the southern Outer Banks, extending from a triple-point low near CAE. This boundary should shift northward over central/eastern NC through the day. Meanwhile, a cold front -- related to the strong northern-stream trough -- was drawn from central/southern MB across southern ND, central SD, northwestern NE, and southern WY. This front should sweep across most of the Great Plains and upper Mississippi Valley through the period, reaching northern Lower MI, IL, southwestern MO, southern OK, and the TX South Plains by 12Z. ...Central/eastern NC... Widely scattered showers and thunderstorms are expected to develop this afternoon over the Piedmont and coastal plain, in an environment characterized by rich boundary-layer moisture (surface dewpoints commonly in upper 60 to mid 70s F) very weak ambient MLCINH easily removed by diurnal heating, but weak mid/upper-level lapse rates. This will result in 500-1200 J/kg MLCAPE over most of the area from he Piedmont to the Sounds, beneath a belt of sufficiently strong mid/upper flow to yield around 35-45-kt effective-shear magnitudes. Low-level hodographs over central/eastern NC this afternoon, from model forecast soundings, reasonably show curvature near the frontal zone, but with weak speeds in the lowest couple km that substantially limit SRH and vector shear. However, above 1 km, hodographs are somewhat long and straight, suggesting the potential for low-end supercells amidst the mode common multicellular modes. At this time, forecast shear appears too weak to support an unconditional tornado-threat area, but the scenario will be monitored for any mesoscale enhancement to shear (especially along boundaries) that may introduce such a risk. The gust threat appears subsevere at this time, though localized gusts approaching severe limits cannot be ruled out. ..Edwards/Broyles.. 09/30/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0737 AM CDT Mon Sep 30 2024 Valid 301300Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today, though a few strong storms may affect central/eastern North Carolina. ...Synopsis/Discussion... The main belt of mid/upper-level, midlatitude westerlies will continue to traverse the northwestern/north-central CONUS and central/southwestern Canada, buckled cyclonically around a prominent synoptic trough now located from eastern SK to central MT and western WY. This trough should phase with another now over central mainland Arctic Canada by the end of the period, resulting in a 500-mb low over southeastern Nunavut, with trough trailing over western Hudson Bay, northwesternmost ON, MN, and IA. Strongly difluent flow aloft will take shape southeast of the trough, across the Mississippi Valley, the Great Lakes from Michigan/Huron on down, the Ohio Valley, and much of the Appalachians. As that occurs, a longstanding, filling, weakening low now over southwestern WV will devolve today to an open-wave trough, losing amplitude rapidly and drifting eastward over the central Appalachians through the period. Part of a basal shortwave trough/vorticity lobe -- now apparent in moisture-channel imagery over eastern TN -- will eject eastward across northern NC and southern VA from this afternoon through tonight. At the surface, 11Z analysis showed a quasistationary front across northern SC to just south of the southern Outer Banks, extending from a triple-point low near CAE. This boundary should shift northward over central/eastern NC through the day. Meanwhile, a cold front -- related to the strong northern-stream trough -- was drawn from central/southern MB across southern ND, central SD, northwestern NE, and southern WY. This front should sweep across most of the Great Plains and upper Mississippi Valley through the period, reaching northern Lower MI, IL, southwestern MO, southern OK, and the TX South Plains by 12Z. ...Central/eastern NC... Widely scattered showers and thunderstorms are expected to develop this afternoon over the Piedmont and coastal plain, in an environment characterized by rich boundary-layer moisture (surface dewpoints commonly in upper 60 to mid 70s F) very weak ambient MLCINH easily removed by diurnal heating, but weak mid/upper-level lapse rates. This will result in 500-1200 J/kg MLCAPE over most of the area from he Piedmont to the Sounds, beneath a belt of sufficiently strong mid/upper flow to yield around 35-45-kt effective-shear magnitudes. Low-level hodographs over central/eastern NC this afternoon, from model forecast soundings, reasonably show curvature near the frontal zone, but with weak speeds in the lowest couple km that substantially limit SRH and vector shear. However, above 1 km, hodographs are somewhat long and straight, suggesting the potential for low-end supercells amidst the mode common multicellular modes. At this time, forecast shear appears too weak to support an unconditional tornado-threat area, but the scenario will be monitored for any mesoscale enhancement to shear (especially along boundaries) that may introduce such a risk. The gust threat appears subsevere at this time, though localized gusts approaching severe limits cannot be ruled out. ..Edwards/Broyles.. 09/30/2024 Read more

000
ABPZ20 KNHC 301153
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Mon Sep 30 2024

For the eastern North Pacific...east of 140 degrees west longitude:

Offshore of Southwestern Mexico:
An area of low pressure is expected to develop off the coast of
southwestern Mexico during the next day or so. After that time,
environmental conditions are expected to be generally conducive for
additional development, and a tropical depression is likely to form
by the middle or latter portions of this week. The disturbance is
forecast to meander near or just offshore the coast for much of the
week, and then begin moving slowly west-northwestward, parallel to
the coast of Mexico by this weekend. Regardless of development, this
system is expected to contribute to additional heavy rainfall across
portions of the southwestern coast of Mexico already adversely
affected by substantial rainfall last week, and interests there
should monitor the progress of this disturbance.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...high...70 percent.

South of the Gulf of Tehuantepec:
Another area of low pressure has developed in the Gulf of
Tehuantepec and is producing disorganized showers and thunderstorms
primarily offshore of southern Mexico. The system is forecast to
move erratically through mid-week before drifting northward towards
the southern Mexican coast, and some additional development of the
system is possible while it remains offshore. Regardless of
formation, heavy rain is possible along most of the coast of
southern Mexico and northern Central America throughout this week.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Papin

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Mon Sep 30 2024 Valid 031200Z - 081200Z ...DISCUSSION... Potential for severe weather continues to appear limited on Thursday and Friday as upper-level flow will remain primarily zonal across the CONUS along with a surface pattern that will not promote northward advection of moisture. By the weekend, the predictability of the upper-level pattern begins to decrease quickly. Both the GFS and ECMWF show flow trying to amplify in the northern half of the CONUS. However, the wave pattern between the two models is out of phase. The ECMWF would suggest at least some low potential for severe weather, given a greater southward advancement of an upper trough this weekend into early next week. Even if this evolution is to verify, this severe potential would be conditional on the magnitude and quality of moisture return after another front moves into the Gulf Coast region late next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Mon Sep 30 2024 Valid 031200Z - 081200Z ...DISCUSSION... Potential for severe weather continues to appear limited on Thursday and Friday as upper-level flow will remain primarily zonal across the CONUS along with a surface pattern that will not promote northward advection of moisture. By the weekend, the predictability of the upper-level pattern begins to decrease quickly. Both the GFS and ECMWF show flow trying to amplify in the northern half of the CONUS. However, the wave pattern between the two models is out of phase. The ECMWF would suggest at least some low potential for severe weather, given a greater southward advancement of an upper trough this weekend into early next week. Even if this evolution is to verify, this severe potential would be conditional on the magnitude and quality of moisture return after another front moves into the Gulf Coast region late next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Mon Sep 30 2024 Valid 031200Z - 081200Z ...DISCUSSION... Potential for severe weather continues to appear limited on Thursday and Friday as upper-level flow will remain primarily zonal across the CONUS along with a surface pattern that will not promote northward advection of moisture. By the weekend, the predictability of the upper-level pattern begins to decrease quickly. Both the GFS and ECMWF show flow trying to amplify in the northern half of the CONUS. However, the wave pattern between the two models is out of phase. The ECMWF would suggest at least some low potential for severe weather, given a greater southward advancement of an upper trough this weekend into early next week. Even if this evolution is to verify, this severe potential would be conditional on the magnitude and quality of moisture return after another front moves into the Gulf Coast region late next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Mon Sep 30 2024 Valid 031200Z - 081200Z ...DISCUSSION... Potential for severe weather continues to appear limited on Thursday and Friday as upper-level flow will remain primarily zonal across the CONUS along with a surface pattern that will not promote northward advection of moisture. By the weekend, the predictability of the upper-level pattern begins to decrease quickly. Both the GFS and ECMWF show flow trying to amplify in the northern half of the CONUS. However, the wave pattern between the two models is out of phase. The ECMWF would suggest at least some low potential for severe weather, given a greater southward advancement of an upper trough this weekend into early next week. Even if this evolution is to verify, this severe potential would be conditional on the magnitude and quality of moisture return after another front moves into the Gulf Coast region late next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Mon Sep 30 2024 Valid 031200Z - 081200Z ...DISCUSSION... Potential for severe weather continues to appear limited on Thursday and Friday as upper-level flow will remain primarily zonal across the CONUS along with a surface pattern that will not promote northward advection of moisture. By the weekend, the predictability of the upper-level pattern begins to decrease quickly. Both the GFS and ECMWF show flow trying to amplify in the northern half of the CONUS. However, the wave pattern between the two models is out of phase. The ECMWF would suggest at least some low potential for severe weather, given a greater southward advancement of an upper trough this weekend into early next week. Even if this evolution is to verify, this severe potential would be conditional on the magnitude and quality of moisture return after another front moves into the Gulf Coast region late next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Mon Sep 30 2024 Valid 031200Z - 081200Z ...DISCUSSION... Potential for severe weather continues to appear limited on Thursday and Friday as upper-level flow will remain primarily zonal across the CONUS along with a surface pattern that will not promote northward advection of moisture. By the weekend, the predictability of the upper-level pattern begins to decrease quickly. Both the GFS and ECMWF show flow trying to amplify in the northern half of the CONUS. However, the wave pattern between the two models is out of phase. The ECMWF would suggest at least some low potential for severe weather, given a greater southward advancement of an upper trough this weekend into early next week. Even if this evolution is to verify, this severe potential would be conditional on the magnitude and quality of moisture return after another front moves into the Gulf Coast region late next week. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Mon Sep 30 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Synopsis... A zonal flow pattern aloft is expected to develop by Wednesday morning across the CONUS. The jet stream will be positioned along the Canadian border. Stable conditions in the northern tier of states should generally preclude thunderstorm development with any embedded shortwave troughs. Farther south, upper-level ridging will also minimize thunderstorm potential. Two exceptions are within the Florida Peninsula where the sea breeze will provide sufficient lift for storms during the afternoon. Isolated thunderstorms are also possible within a portion of the Mogollon Rim where mid-level moisture still remains. ..Wendt.. 09/30/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Mon Sep 30 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Synopsis... A zonal flow pattern aloft is expected to develop by Wednesday morning across the CONUS. The jet stream will be positioned along the Canadian border. Stable conditions in the northern tier of states should generally preclude thunderstorm development with any embedded shortwave troughs. Farther south, upper-level ridging will also minimize thunderstorm potential. Two exceptions are within the Florida Peninsula where the sea breeze will provide sufficient lift for storms during the afternoon. Isolated thunderstorms are also possible within a portion of the Mogollon Rim where mid-level moisture still remains. ..Wendt.. 09/30/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Mon Sep 30 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Synopsis... A zonal flow pattern aloft is expected to develop by Wednesday morning across the CONUS. The jet stream will be positioned along the Canadian border. Stable conditions in the northern tier of states should generally preclude thunderstorm development with any embedded shortwave troughs. Farther south, upper-level ridging will also minimize thunderstorm potential. Two exceptions are within the Florida Peninsula where the sea breeze will provide sufficient lift for storms during the afternoon. Isolated thunderstorms are also possible within a portion of the Mogollon Rim where mid-level moisture still remains. ..Wendt.. 09/30/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Mon Sep 30 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Synopsis... A zonal flow pattern aloft is expected to develop by Wednesday morning across the CONUS. The jet stream will be positioned along the Canadian border. Stable conditions in the northern tier of states should generally preclude thunderstorm development with any embedded shortwave troughs. Farther south, upper-level ridging will also minimize thunderstorm potential. Two exceptions are within the Florida Peninsula where the sea breeze will provide sufficient lift for storms during the afternoon. Isolated thunderstorms are also possible within a portion of the Mogollon Rim where mid-level moisture still remains. ..Wendt.. 09/30/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Mon Sep 30 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Synopsis... A zonal flow pattern aloft is expected to develop by Wednesday morning across the CONUS. The jet stream will be positioned along the Canadian border. Stable conditions in the northern tier of states should generally preclude thunderstorm development with any embedded shortwave troughs. Farther south, upper-level ridging will also minimize thunderstorm potential. Two exceptions are within the Florida Peninsula where the sea breeze will provide sufficient lift for storms during the afternoon. Isolated thunderstorms are also possible within a portion of the Mogollon Rim where mid-level moisture still remains. ..Wendt.. 09/30/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0117 AM CDT Mon Sep 30 2024 Valid 011200Z - 021200Z ...Synopsis... On Tuesday, lee troughing will resume across Alberta, which will result in a strengthening pressure gradient and another cold front moving across the northern Rockies/northern Plains. Some dry and breezy conditions are possible ahead of and behind this cold front. Some drier/windier conditions are possible within the broader Elevated area which extends from north-central Montana to far northeast Colorado. However, confidence in where this may occur is too low at this time to add a Critical delineation. In addition, dry and breezy conditions are possible in terrain-favored regions of southern Wyoming. Fuels are also critically dry in this region and will dry further with dry and breezy conditions Monday. An Elevated area has been added to address this threat. ..Bentley.. 09/30/2024 ...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 0117 AM CDT Mon Sep 30 2024 Valid 011200Z - 021200Z ...Synopsis... On Tuesday, lee troughing will resume across Alberta, which will result in a strengthening pressure gradient and another cold front moving across the northern Rockies/northern Plains. Some dry and breezy conditions are possible ahead of and behind this cold front. Some drier/windier conditions are possible within the broader Elevated area which extends from north-central Montana to far northeast Colorado. However, confidence in where this may occur is too low at this time to add a Critical delineation. In addition, dry and breezy conditions are possible in terrain-favored regions of southern Wyoming. Fuels are also critically dry in this region and will dry further with dry and breezy conditions Monday. An Elevated area has been added to address this threat. ..Bentley.. 09/30/2024 ...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 0117 AM CDT Mon Sep 30 2024 Valid 011200Z - 021200Z ...Synopsis... On Tuesday, lee troughing will resume across Alberta, which will result in a strengthening pressure gradient and another cold front moving across the northern Rockies/northern Plains. Some dry and breezy conditions are possible ahead of and behind this cold front. Some drier/windier conditions are possible within the broader Elevated area which extends from north-central Montana to far northeast Colorado. However, confidence in where this may occur is too low at this time to add a Critical delineation. In addition, dry and breezy conditions are possible in terrain-favored regions of southern Wyoming. Fuels are also critically dry in this region and will dry further with dry and breezy conditions Monday. An Elevated area has been added to address this threat. ..Bentley.. 09/30/2024 ...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 0117 AM CDT Mon Sep 30 2024 Valid 011200Z - 021200Z ...Synopsis... On Tuesday, lee troughing will resume across Alberta, which will result in a strengthening pressure gradient and another cold front moving across the northern Rockies/northern Plains. Some dry and breezy conditions are possible ahead of and behind this cold front. Some drier/windier conditions are possible within the broader Elevated area which extends from north-central Montana to far northeast Colorado. However, confidence in where this may occur is too low at this time to add a Critical delineation. In addition, dry and breezy conditions are possible in terrain-favored regions of southern Wyoming. Fuels are also critically dry in this region and will dry further with dry and breezy conditions Monday. An Elevated area has been added to address this threat. ..Bentley.. 09/30/2024 ...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 0117 AM CDT Mon Sep 30 2024 Valid 011200Z - 021200Z ...Synopsis... On Tuesday, lee troughing will resume across Alberta, which will result in a strengthening pressure gradient and another cold front moving across the northern Rockies/northern Plains. Some dry and breezy conditions are possible ahead of and behind this cold front. Some drier/windier conditions are possible within the broader Elevated area which extends from north-central Montana to far northeast Colorado. However, confidence in where this may occur is too low at this time to add a Critical delineation. In addition, dry and breezy conditions are possible in terrain-favored regions of southern Wyoming. Fuels are also critically dry in this region and will dry further with dry and breezy conditions Monday. An Elevated area has been added to address this threat. ..Bentley.. 09/30/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more