Aggregator

804
ABPZ20 KNHC 291133
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Sun Sep 29 2024

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

Offshore of Southern and Southwestern Mexico:
An area of low pressure is forecast to develop off the coast of
southern or southwestern Mexico in a day or two. Thereafter,
environmental conditions appear generally favorable for additional
development, and a tropical depression could form by the middle to
latter part of this week while the system drifts slowly westward or
northwestward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...40 percent.

$$
Forecaster Papin

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Sun Sep 29 2024 Valid 021200Z - 071200Z ...DISCUSSION... Zonal flow aloft is expected to persist into late next week across the CONUS. The upper-level jet will be displaced northward to near and along the Canadian border. As successive shortwave troughs move through that zone of stronger flow, cooler/drier air will move southward into much of the Plains and parts of the Midwest/Northeast. By next weekend, there is some potential for some upper-level flow amplification with a ridge developing in the West and shortwave troughs moving into the eastern third of the CONUS. However, models remain rather divergent in their exact depiction of this evolution (the ECMWF deterministic/ensemble is more amplified than its GFS counterparts). Further increasing uncertainty, the degree of moisture return ahead of any potential shortwave trough is questionable given the expected frontal progression to along/near the Gulf Coast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Sun Sep 29 2024 Valid 021200Z - 071200Z ...DISCUSSION... Zonal flow aloft is expected to persist into late next week across the CONUS. The upper-level jet will be displaced northward to near and along the Canadian border. As successive shortwave troughs move through that zone of stronger flow, cooler/drier air will move southward into much of the Plains and parts of the Midwest/Northeast. By next weekend, there is some potential for some upper-level flow amplification with a ridge developing in the West and shortwave troughs moving into the eastern third of the CONUS. However, models remain rather divergent in their exact depiction of this evolution (the ECMWF deterministic/ensemble is more amplified than its GFS counterparts). Further increasing uncertainty, the degree of moisture return ahead of any potential shortwave trough is questionable given the expected frontal progression to along/near the Gulf Coast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Sun Sep 29 2024 Valid 021200Z - 071200Z ...DISCUSSION... Zonal flow aloft is expected to persist into late next week across the CONUS. The upper-level jet will be displaced northward to near and along the Canadian border. As successive shortwave troughs move through that zone of stronger flow, cooler/drier air will move southward into much of the Plains and parts of the Midwest/Northeast. By next weekend, there is some potential for some upper-level flow amplification with a ridge developing in the West and shortwave troughs moving into the eastern third of the CONUS. However, models remain rather divergent in their exact depiction of this evolution (the ECMWF deterministic/ensemble is more amplified than its GFS counterparts). Further increasing uncertainty, the degree of moisture return ahead of any potential shortwave trough is questionable given the expected frontal progression to along/near the Gulf Coast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Sun Sep 29 2024 Valid 021200Z - 071200Z ...DISCUSSION... Zonal flow aloft is expected to persist into late next week across the CONUS. The upper-level jet will be displaced northward to near and along the Canadian border. As successive shortwave troughs move through that zone of stronger flow, cooler/drier air will move southward into much of the Plains and parts of the Midwest/Northeast. By next weekend, there is some potential for some upper-level flow amplification with a ridge developing in the West and shortwave troughs moving into the eastern third of the CONUS. However, models remain rather divergent in their exact depiction of this evolution (the ECMWF deterministic/ensemble is more amplified than its GFS counterparts). Further increasing uncertainty, the degree of moisture return ahead of any potential shortwave trough is questionable given the expected frontal progression to along/near the Gulf Coast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Sun Sep 29 2024 Valid 021200Z - 071200Z ...DISCUSSION... Zonal flow aloft is expected to persist into late next week across the CONUS. The upper-level jet will be displaced northward to near and along the Canadian border. As successive shortwave troughs move through that zone of stronger flow, cooler/drier air will move southward into much of the Plains and parts of the Midwest/Northeast. By next weekend, there is some potential for some upper-level flow amplification with a ridge developing in the West and shortwave troughs moving into the eastern third of the CONUS. However, models remain rather divergent in their exact depiction of this evolution (the ECMWF deterministic/ensemble is more amplified than its GFS counterparts). Further increasing uncertainty, the degree of moisture return ahead of any potential shortwave trough is questionable given the expected frontal progression to along/near the Gulf Coast. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CDT Sun Sep 29 2024 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... A weak mid-level shortwave trough will move offshore in the Mid-Atlantic on Tuesday. Isolated thunderstorms may occur in far eastern North Carolina during the afternoon before the trough departs. A more substantial upper-level trough will move through the upper Great Lakes region by early/mid afternoon. This trough will push a surface cold front through much of the Midwest and Ohio Valley regions. Dewpoints ahead of the cold front are forecast to be in the low 60s F. Lingering effects of ridging aloft are evident in forecast soundings. However, where mid-level ascent is greatest, some thunderstorm activity is possible along the front in eastern Lower Michigan into parts of northern/central Ohio. Some gusty winds could occur with this activity, but weak low-level winds and the mentioned thermodynamic weaknesses should preclude severe weather potential. The highest coverage of thunderstorms is most likely within the Florida Peninsula as the moist airmass heats during the day and sea breeze boundaries provide lift. ..Wendt.. 09/29/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CDT Sun Sep 29 2024 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... A weak mid-level shortwave trough will move offshore in the Mid-Atlantic on Tuesday. Isolated thunderstorms may occur in far eastern North Carolina during the afternoon before the trough departs. A more substantial upper-level trough will move through the upper Great Lakes region by early/mid afternoon. This trough will push a surface cold front through much of the Midwest and Ohio Valley regions. Dewpoints ahead of the cold front are forecast to be in the low 60s F. Lingering effects of ridging aloft are evident in forecast soundings. However, where mid-level ascent is greatest, some thunderstorm activity is possible along the front in eastern Lower Michigan into parts of northern/central Ohio. Some gusty winds could occur with this activity, but weak low-level winds and the mentioned thermodynamic weaknesses should preclude severe weather potential. The highest coverage of thunderstorms is most likely within the Florida Peninsula as the moist airmass heats during the day and sea breeze boundaries provide lift. ..Wendt.. 09/29/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CDT Sun Sep 29 2024 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... A weak mid-level shortwave trough will move offshore in the Mid-Atlantic on Tuesday. Isolated thunderstorms may occur in far eastern North Carolina during the afternoon before the trough departs. A more substantial upper-level trough will move through the upper Great Lakes region by early/mid afternoon. This trough will push a surface cold front through much of the Midwest and Ohio Valley regions. Dewpoints ahead of the cold front are forecast to be in the low 60s F. Lingering effects of ridging aloft are evident in forecast soundings. However, where mid-level ascent is greatest, some thunderstorm activity is possible along the front in eastern Lower Michigan into parts of northern/central Ohio. Some gusty winds could occur with this activity, but weak low-level winds and the mentioned thermodynamic weaknesses should preclude severe weather potential. The highest coverage of thunderstorms is most likely within the Florida Peninsula as the moist airmass heats during the day and sea breeze boundaries provide lift. ..Wendt.. 09/29/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CDT Sun Sep 29 2024 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... A weak mid-level shortwave trough will move offshore in the Mid-Atlantic on Tuesday. Isolated thunderstorms may occur in far eastern North Carolina during the afternoon before the trough departs. A more substantial upper-level trough will move through the upper Great Lakes region by early/mid afternoon. This trough will push a surface cold front through much of the Midwest and Ohio Valley regions. Dewpoints ahead of the cold front are forecast to be in the low 60s F. Lingering effects of ridging aloft are evident in forecast soundings. However, where mid-level ascent is greatest, some thunderstorm activity is possible along the front in eastern Lower Michigan into parts of northern/central Ohio. Some gusty winds could occur with this activity, but weak low-level winds and the mentioned thermodynamic weaknesses should preclude severe weather potential. The highest coverage of thunderstorms is most likely within the Florida Peninsula as the moist airmass heats during the day and sea breeze boundaries provide lift. ..Wendt.. 09/29/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CDT Sun Sep 29 2024 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... A weak mid-level shortwave trough will move offshore in the Mid-Atlantic on Tuesday. Isolated thunderstorms may occur in far eastern North Carolina during the afternoon before the trough departs. A more substantial upper-level trough will move through the upper Great Lakes region by early/mid afternoon. This trough will push a surface cold front through much of the Midwest and Ohio Valley regions. Dewpoints ahead of the cold front are forecast to be in the low 60s F. Lingering effects of ridging aloft are evident in forecast soundings. However, where mid-level ascent is greatest, some thunderstorm activity is possible along the front in eastern Lower Michigan into parts of northern/central Ohio. Some gusty winds could occur with this activity, but weak low-level winds and the mentioned thermodynamic weaknesses should preclude severe weather potential. The highest coverage of thunderstorms is most likely within the Florida Peninsula as the moist airmass heats during the day and sea breeze boundaries provide lift. ..Wendt.. 09/29/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR CENTRAL AND NORTHERN NEBRASKA... ...Synopsis... A southeastward-moving cold front will bring elevated to critical fire-weather conditions to the central and northern Great Plains. Gusty winds of 20-25 MPH will coincide with post-frontal boundary-layer relative humidity values of 10-15% across much of South Dakota into Nebraska and northern Kansas. These conditions will overlap with ERC fuels that exceed the 98th annual percentile, and warm/dry conditions expected the preceding day. A Critical highlight area was introduced where the greatest confidence in persistent dry and windy conditions will occur, though additional adjustments and expansions may be needed as frontal timing and speed come into clearer focus. ..Halbert.. 09/29/2024 ...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 1244 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR CENTRAL AND NORTHERN NEBRASKA... ...Synopsis... A southeastward-moving cold front will bring elevated to critical fire-weather conditions to the central and northern Great Plains. Gusty winds of 20-25 MPH will coincide with post-frontal boundary-layer relative humidity values of 10-15% across much of South Dakota into Nebraska and northern Kansas. These conditions will overlap with ERC fuels that exceed the 98th annual percentile, and warm/dry conditions expected the preceding day. A Critical highlight area was introduced where the greatest confidence in persistent dry and windy conditions will occur, though additional adjustments and expansions may be needed as frontal timing and speed come into clearer focus. ..Halbert.. 09/29/2024 ...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 1244 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR CENTRAL AND NORTHERN NEBRASKA... ...Synopsis... A southeastward-moving cold front will bring elevated to critical fire-weather conditions to the central and northern Great Plains. Gusty winds of 20-25 MPH will coincide with post-frontal boundary-layer relative humidity values of 10-15% across much of South Dakota into Nebraska and northern Kansas. These conditions will overlap with ERC fuels that exceed the 98th annual percentile, and warm/dry conditions expected the preceding day. A Critical highlight area was introduced where the greatest confidence in persistent dry and windy conditions will occur, though additional adjustments and expansions may be needed as frontal timing and speed come into clearer focus. ..Halbert.. 09/29/2024 ...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 1244 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR CENTRAL AND NORTHERN NEBRASKA... ...Synopsis... A southeastward-moving cold front will bring elevated to critical fire-weather conditions to the central and northern Great Plains. Gusty winds of 20-25 MPH will coincide with post-frontal boundary-layer relative humidity values of 10-15% across much of South Dakota into Nebraska and northern Kansas. These conditions will overlap with ERC fuels that exceed the 98th annual percentile, and warm/dry conditions expected the preceding day. A Critical highlight area was introduced where the greatest confidence in persistent dry and windy conditions will occur, though additional adjustments and expansions may be needed as frontal timing and speed come into clearer focus. ..Halbert.. 09/29/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Sun Sep 29 2024 Valid 291200Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN NEBRASKA...WEST-CENTRAL SOUTH DAKOTA...AND SOUTHERN NORTH DAKOTA... ...Synopsis... Elevated to critical fire-weather conditions are expected across much of the Intermountain West into the northern Great Plains as a progressive mid-level trough traverses the Canadian prairies. The deepening surface cyclone and tightening surface pressure gradients associated with this trough will result in widespread dry and windy conditions over receptive fuels. A narrow Critical area has been maintained where the highest confidence in 20-25 MPH winds and relative humidity values below 15% are expected to overlap with ERC fuels exceeding the 95th annual percentiles. Portions of central and eastern Wyoming may also experience locally critical conditions, though confidence in the magnitude and spatial extent of surface winds precludes Critical highlights at this time. Further west, elevated fire-weather conditions are expected across central and eastern Nevada into western Utah, as well as portions of Columbia River Basin in Washington. Winds in the Columbia River Basin could be as high as 20-25 MPH, but forecast guidance shows significant spread in the forecast boundary-layer relative humidity values (15-25%). Across the Great Basin, winds will generally remain in the 15-20 MPH range with relative humidity values of 10-15%. ..Halbert.. 09/29/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Sun Sep 29 2024 Valid 291200Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN NEBRASKA...WEST-CENTRAL SOUTH DAKOTA...AND SOUTHERN NORTH DAKOTA... ...Synopsis... Elevated to critical fire-weather conditions are expected across much of the Intermountain West into the northern Great Plains as a progressive mid-level trough traverses the Canadian prairies. The deepening surface cyclone and tightening surface pressure gradients associated with this trough will result in widespread dry and windy conditions over receptive fuels. A narrow Critical area has been maintained where the highest confidence in 20-25 MPH winds and relative humidity values below 15% are expected to overlap with ERC fuels exceeding the 95th annual percentiles. Portions of central and eastern Wyoming may also experience locally critical conditions, though confidence in the magnitude and spatial extent of surface winds precludes Critical highlights at this time. Further west, elevated fire-weather conditions are expected across central and eastern Nevada into western Utah, as well as portions of Columbia River Basin in Washington. Winds in the Columbia River Basin could be as high as 20-25 MPH, but forecast guidance shows significant spread in the forecast boundary-layer relative humidity values (15-25%). Across the Great Basin, winds will generally remain in the 15-20 MPH range with relative humidity values of 10-15%. ..Halbert.. 09/29/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Sun Sep 29 2024 Valid 291200Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN NEBRASKA...WEST-CENTRAL SOUTH DAKOTA...AND SOUTHERN NORTH DAKOTA... ...Synopsis... Elevated to critical fire-weather conditions are expected across much of the Intermountain West into the northern Great Plains as a progressive mid-level trough traverses the Canadian prairies. The deepening surface cyclone and tightening surface pressure gradients associated with this trough will result in widespread dry and windy conditions over receptive fuels. A narrow Critical area has been maintained where the highest confidence in 20-25 MPH winds and relative humidity values below 15% are expected to overlap with ERC fuels exceeding the 95th annual percentiles. Portions of central and eastern Wyoming may also experience locally critical conditions, though confidence in the magnitude and spatial extent of surface winds precludes Critical highlights at this time. Further west, elevated fire-weather conditions are expected across central and eastern Nevada into western Utah, as well as portions of Columbia River Basin in Washington. Winds in the Columbia River Basin could be as high as 20-25 MPH, but forecast guidance shows significant spread in the forecast boundary-layer relative humidity values (15-25%). Across the Great Basin, winds will generally remain in the 15-20 MPH range with relative humidity values of 10-15%. ..Halbert.. 09/29/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Sun Sep 29 2024 Valid 291200Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN NEBRASKA...WEST-CENTRAL SOUTH DAKOTA...AND SOUTHERN NORTH DAKOTA... ...Synopsis... Elevated to critical fire-weather conditions are expected across much of the Intermountain West into the northern Great Plains as a progressive mid-level trough traverses the Canadian prairies. The deepening surface cyclone and tightening surface pressure gradients associated with this trough will result in widespread dry and windy conditions over receptive fuels. A narrow Critical area has been maintained where the highest confidence in 20-25 MPH winds and relative humidity values below 15% are expected to overlap with ERC fuels exceeding the 95th annual percentiles. Portions of central and eastern Wyoming may also experience locally critical conditions, though confidence in the magnitude and spatial extent of surface winds precludes Critical highlights at this time. Further west, elevated fire-weather conditions are expected across central and eastern Nevada into western Utah, as well as portions of Columbia River Basin in Washington. Winds in the Columbia River Basin could be as high as 20-25 MPH, but forecast guidance shows significant spread in the forecast boundary-layer relative humidity values (15-25%). Across the Great Basin, winds will generally remain in the 15-20 MPH range with relative humidity values of 10-15%. ..Halbert.. 09/29/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Sun Sep 29 2024 Valid 291200Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN NEBRASKA...WEST-CENTRAL SOUTH DAKOTA...AND SOUTHERN NORTH DAKOTA... ...Synopsis... Elevated to critical fire-weather conditions are expected across much of the Intermountain West into the northern Great Plains as a progressive mid-level trough traverses the Canadian prairies. The deepening surface cyclone and tightening surface pressure gradients associated with this trough will result in widespread dry and windy conditions over receptive fuels. A narrow Critical area has been maintained where the highest confidence in 20-25 MPH winds and relative humidity values below 15% are expected to overlap with ERC fuels exceeding the 95th annual percentiles. Portions of central and eastern Wyoming may also experience locally critical conditions, though confidence in the magnitude and spatial extent of surface winds precludes Critical highlights at this time. Further west, elevated fire-weather conditions are expected across central and eastern Nevada into western Utah, as well as portions of Columbia River Basin in Washington. Winds in the Columbia River Basin could be as high as 20-25 MPH, but forecast guidance shows significant spread in the forecast boundary-layer relative humidity values (15-25%). Across the Great Basin, winds will generally remain in the 15-20 MPH range with relative humidity values of 10-15%. ..Halbert.. 09/29/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more