Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1156 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Southern VA and the Carolinas... A weakening, positive-tilt mid/upper trough will slowly move eastward over the central/southern Appalachians on Monday. Thermodynamic profiles across the region suggest convection should remain shallow due to relatively warm temperatures at mid/upper levels, especially along/south of the quasi-stationary front arcing from central/southern NC to southern WV. Overall thunderstorm coverage should be quite isolated. On the southeast flank of the trough, mid-level southwesterlies will remain enhanced from GA to southern NC. Adequate deep-layer shear with moderate straight-line hodograph elongation should be present near the southeast NC vicinity of the front. But poor mid-level lapse rates (around 4-5 C/km) will temper hail growth. ...FL Peninsula... Rich low-level moisture combined with ascent along the sea breeze should promote isolated to widely scattered thunderstorms during the afternoon. Weak shear will limit organized severe potential. ...Southwest... Limited mid-level moisture within the upper-level ridge may be adequate for very isolated thunderstorms from the southern Rockies to the Mogollon Rim. Consensus of model soundings suggest buoyancy should be scant at most, with high-based, low-topped convection. Gusty, erratic surface winds are possible within dry microbursts. ..Grams.. 09/29/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1156 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Southern VA and the Carolinas... A weakening, positive-tilt mid/upper trough will slowly move eastward over the central/southern Appalachians on Monday. Thermodynamic profiles across the region suggest convection should remain shallow due to relatively warm temperatures at mid/upper levels, especially along/south of the quasi-stationary front arcing from central/southern NC to southern WV. Overall thunderstorm coverage should be quite isolated. On the southeast flank of the trough, mid-level southwesterlies will remain enhanced from GA to southern NC. Adequate deep-layer shear with moderate straight-line hodograph elongation should be present near the southeast NC vicinity of the front. But poor mid-level lapse rates (around 4-5 C/km) will temper hail growth. ...FL Peninsula... Rich low-level moisture combined with ascent along the sea breeze should promote isolated to widely scattered thunderstorms during the afternoon. Weak shear will limit organized severe potential. ...Southwest... Limited mid-level moisture within the upper-level ridge may be adequate for very isolated thunderstorms from the southern Rockies to the Mogollon Rim. Consensus of model soundings suggest buoyancy should be scant at most, with high-based, low-topped convection. Gusty, erratic surface winds are possible within dry microbursts. ..Grams.. 09/29/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1156 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Southern VA and the Carolinas... A weakening, positive-tilt mid/upper trough will slowly move eastward over the central/southern Appalachians on Monday. Thermodynamic profiles across the region suggest convection should remain shallow due to relatively warm temperatures at mid/upper levels, especially along/south of the quasi-stationary front arcing from central/southern NC to southern WV. Overall thunderstorm coverage should be quite isolated. On the southeast flank of the trough, mid-level southwesterlies will remain enhanced from GA to southern NC. Adequate deep-layer shear with moderate straight-line hodograph elongation should be present near the southeast NC vicinity of the front. But poor mid-level lapse rates (around 4-5 C/km) will temper hail growth. ...FL Peninsula... Rich low-level moisture combined with ascent along the sea breeze should promote isolated to widely scattered thunderstorms during the afternoon. Weak shear will limit organized severe potential. ...Southwest... Limited mid-level moisture within the upper-level ridge may be adequate for very isolated thunderstorms from the southern Rockies to the Mogollon Rim. Consensus of model soundings suggest buoyancy should be scant at most, with high-based, low-topped convection. Gusty, erratic surface winds are possible within dry microbursts. ..Grams.. 09/29/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1156 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Southern VA and the Carolinas... A weakening, positive-tilt mid/upper trough will slowly move eastward over the central/southern Appalachians on Monday. Thermodynamic profiles across the region suggest convection should remain shallow due to relatively warm temperatures at mid/upper levels, especially along/south of the quasi-stationary front arcing from central/southern NC to southern WV. Overall thunderstorm coverage should be quite isolated. On the southeast flank of the trough, mid-level southwesterlies will remain enhanced from GA to southern NC. Adequate deep-layer shear with moderate straight-line hodograph elongation should be present near the southeast NC vicinity of the front. But poor mid-level lapse rates (around 4-5 C/km) will temper hail growth. ...FL Peninsula... Rich low-level moisture combined with ascent along the sea breeze should promote isolated to widely scattered thunderstorms during the afternoon. Weak shear will limit organized severe potential. ...Southwest... Limited mid-level moisture within the upper-level ridge may be adequate for very isolated thunderstorms from the southern Rockies to the Mogollon Rim. Consensus of model soundings suggest buoyancy should be scant at most, with high-based, low-topped convection. Gusty, erratic surface winds are possible within dry microbursts. ..Grams.. 09/29/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1156 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Southern VA and the Carolinas... A weakening, positive-tilt mid/upper trough will slowly move eastward over the central/southern Appalachians on Monday. Thermodynamic profiles across the region suggest convection should remain shallow due to relatively warm temperatures at mid/upper levels, especially along/south of the quasi-stationary front arcing from central/southern NC to southern WV. Overall thunderstorm coverage should be quite isolated. On the southeast flank of the trough, mid-level southwesterlies will remain enhanced from GA to southern NC. Adequate deep-layer shear with moderate straight-line hodograph elongation should be present near the southeast NC vicinity of the front. But poor mid-level lapse rates (around 4-5 C/km) will temper hail growth. ...FL Peninsula... Rich low-level moisture combined with ascent along the sea breeze should promote isolated to widely scattered thunderstorms during the afternoon. Weak shear will limit organized severe potential. ...Southwest... Limited mid-level moisture within the upper-level ridge may be adequate for very isolated thunderstorms from the southern Rockies to the Mogollon Rim. Consensus of model soundings suggest buoyancy should be scant at most, with high-based, low-topped convection. Gusty, erratic surface winds are possible within dry microbursts. ..Grams.. 09/29/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1156 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Southern VA and the Carolinas... A weakening, positive-tilt mid/upper trough will slowly move eastward over the central/southern Appalachians on Monday. Thermodynamic profiles across the region suggest convection should remain shallow due to relatively warm temperatures at mid/upper levels, especially along/south of the quasi-stationary front arcing from central/southern NC to southern WV. Overall thunderstorm coverage should be quite isolated. On the southeast flank of the trough, mid-level southwesterlies will remain enhanced from GA to southern NC. Adequate deep-layer shear with moderate straight-line hodograph elongation should be present near the southeast NC vicinity of the front. But poor mid-level lapse rates (around 4-5 C/km) will temper hail growth. ...FL Peninsula... Rich low-level moisture combined with ascent along the sea breeze should promote isolated to widely scattered thunderstorms during the afternoon. Weak shear will limit organized severe potential. ...Southwest... Limited mid-level moisture within the upper-level ridge may be adequate for very isolated thunderstorms from the southern Rockies to the Mogollon Rim. Consensus of model soundings suggest buoyancy should be scant at most, with high-based, low-topped convection. Gusty, erratic surface winds are possible within dry microbursts. ..Grams.. 09/29/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Sun Sep 29 2024 Valid 291630Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis... A relatively quiet convective day is expected across the CONUS today. Over portions of UT, weak/peripheral midlevel height falls will promote isolated high-based thunderstorms capable of locally strong gusts, aided by inverted-V thermodynamic profiles. Weak instability and flow/shear should limit thunderstorm intensity and organization. Farther east, isolated thunderstorms will be possible this afternoon and evening over portions of the OH Valley into the Mid-Atlantic -- ahead of a vertically stacked/weakening cyclone. Very poor deep-layer lapse rates and warm air aloft may limit lightning over many areas, though a few isolated flashes cannot be ruled out, given some large-scale ascent. Ahead of a quasi-stationary front draped across northern FL, diurnal heating of a moist/uncapped air mass will support isolated to widely scattered thunderstorms across the FL Peninsula this afternoon. Locally strong water-loaded downbursts could accompany a couple storms over northeast FL, where low-level convergence and midlevel flow will be slightly stronger. However, poor midlevel lapse rates and only marginal deep-layer shear should limit the severe threat. ..Weinman.. 09/29/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Sun Sep 29 2024 Valid 291630Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis... A relatively quiet convective day is expected across the CONUS today. Over portions of UT, weak/peripheral midlevel height falls will promote isolated high-based thunderstorms capable of locally strong gusts, aided by inverted-V thermodynamic profiles. Weak instability and flow/shear should limit thunderstorm intensity and organization. Farther east, isolated thunderstorms will be possible this afternoon and evening over portions of the OH Valley into the Mid-Atlantic -- ahead of a vertically stacked/weakening cyclone. Very poor deep-layer lapse rates and warm air aloft may limit lightning over many areas, though a few isolated flashes cannot be ruled out, given some large-scale ascent. Ahead of a quasi-stationary front draped across northern FL, diurnal heating of a moist/uncapped air mass will support isolated to widely scattered thunderstorms across the FL Peninsula this afternoon. Locally strong water-loaded downbursts could accompany a couple storms over northeast FL, where low-level convergence and midlevel flow will be slightly stronger. However, poor midlevel lapse rates and only marginal deep-layer shear should limit the severe threat. ..Weinman.. 09/29/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Sun Sep 29 2024 Valid 291630Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis... A relatively quiet convective day is expected across the CONUS today. Over portions of UT, weak/peripheral midlevel height falls will promote isolated high-based thunderstorms capable of locally strong gusts, aided by inverted-V thermodynamic profiles. Weak instability and flow/shear should limit thunderstorm intensity and organization. Farther east, isolated thunderstorms will be possible this afternoon and evening over portions of the OH Valley into the Mid-Atlantic -- ahead of a vertically stacked/weakening cyclone. Very poor deep-layer lapse rates and warm air aloft may limit lightning over many areas, though a few isolated flashes cannot be ruled out, given some large-scale ascent. Ahead of a quasi-stationary front draped across northern FL, diurnal heating of a moist/uncapped air mass will support isolated to widely scattered thunderstorms across the FL Peninsula this afternoon. Locally strong water-loaded downbursts could accompany a couple storms over northeast FL, where low-level convergence and midlevel flow will be slightly stronger. However, poor midlevel lapse rates and only marginal deep-layer shear should limit the severe threat. ..Weinman.. 09/29/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Sun Sep 29 2024 Valid 291630Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis... A relatively quiet convective day is expected across the CONUS today. Over portions of UT, weak/peripheral midlevel height falls will promote isolated high-based thunderstorms capable of locally strong gusts, aided by inverted-V thermodynamic profiles. Weak instability and flow/shear should limit thunderstorm intensity and organization. Farther east, isolated thunderstorms will be possible this afternoon and evening over portions of the OH Valley into the Mid-Atlantic -- ahead of a vertically stacked/weakening cyclone. Very poor deep-layer lapse rates and warm air aloft may limit lightning over many areas, though a few isolated flashes cannot be ruled out, given some large-scale ascent. Ahead of a quasi-stationary front draped across northern FL, diurnal heating of a moist/uncapped air mass will support isolated to widely scattered thunderstorms across the FL Peninsula this afternoon. Locally strong water-loaded downbursts could accompany a couple storms over northeast FL, where low-level convergence and midlevel flow will be slightly stronger. However, poor midlevel lapse rates and only marginal deep-layer shear should limit the severe threat. ..Weinman.. 09/29/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Sun Sep 29 2024 Valid 291630Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis... A relatively quiet convective day is expected across the CONUS today. Over portions of UT, weak/peripheral midlevel height falls will promote isolated high-based thunderstorms capable of locally strong gusts, aided by inverted-V thermodynamic profiles. Weak instability and flow/shear should limit thunderstorm intensity and organization. Farther east, isolated thunderstorms will be possible this afternoon and evening over portions of the OH Valley into the Mid-Atlantic -- ahead of a vertically stacked/weakening cyclone. Very poor deep-layer lapse rates and warm air aloft may limit lightning over many areas, though a few isolated flashes cannot be ruled out, given some large-scale ascent. Ahead of a quasi-stationary front draped across northern FL, diurnal heating of a moist/uncapped air mass will support isolated to widely scattered thunderstorms across the FL Peninsula this afternoon. Locally strong water-loaded downbursts could accompany a couple storms over northeast FL, where low-level convergence and midlevel flow will be slightly stronger. However, poor midlevel lapse rates and only marginal deep-layer shear should limit the severe threat. ..Weinman.. 09/29/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Sun Sep 29 2024 Valid 291630Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis... A relatively quiet convective day is expected across the CONUS today. Over portions of UT, weak/peripheral midlevel height falls will promote isolated high-based thunderstorms capable of locally strong gusts, aided by inverted-V thermodynamic profiles. Weak instability and flow/shear should limit thunderstorm intensity and organization. Farther east, isolated thunderstorms will be possible this afternoon and evening over portions of the OH Valley into the Mid-Atlantic -- ahead of a vertically stacked/weakening cyclone. Very poor deep-layer lapse rates and warm air aloft may limit lightning over many areas, though a few isolated flashes cannot be ruled out, given some large-scale ascent. Ahead of a quasi-stationary front draped across northern FL, diurnal heating of a moist/uncapped air mass will support isolated to widely scattered thunderstorms across the FL Peninsula this afternoon. Locally strong water-loaded downbursts could accompany a couple storms over northeast FL, where low-level convergence and midlevel flow will be slightly stronger. However, poor midlevel lapse rates and only marginal deep-layer shear should limit the severe threat. ..Weinman.. 09/29/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Sun Sep 29 2024 Valid 291630Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis... A relatively quiet convective day is expected across the CONUS today. Over portions of UT, weak/peripheral midlevel height falls will promote isolated high-based thunderstorms capable of locally strong gusts, aided by inverted-V thermodynamic profiles. Weak instability and flow/shear should limit thunderstorm intensity and organization. Farther east, isolated thunderstorms will be possible this afternoon and evening over portions of the OH Valley into the Mid-Atlantic -- ahead of a vertically stacked/weakening cyclone. Very poor deep-layer lapse rates and warm air aloft may limit lightning over many areas, though a few isolated flashes cannot be ruled out, given some large-scale ascent. Ahead of a quasi-stationary front draped across northern FL, diurnal heating of a moist/uncapped air mass will support isolated to widely scattered thunderstorms across the FL Peninsula this afternoon. Locally strong water-loaded downbursts could accompany a couple storms over northeast FL, where low-level convergence and midlevel flow will be slightly stronger. However, poor midlevel lapse rates and only marginal deep-layer shear should limit the severe threat. ..Weinman.. 09/29/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1034 AM CDT Sun Sep 29 2024 Valid 291700Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO SOUTHERN NORTH DAKOTA... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL WYOMING... ...Northern Rockies/Plains... The primary adjustment for this update is introducing a Critical risk area to parts of central WY where morning guidance has come into reasonably good agreement in a few hours of sustained 20-25 mph winds with RH values near 15%. Additionally, the Elevated risk areas across the northern Rockies and northern Plains have been combined and expanded into eastern MT to account for two trends. First, morning surface observations are drier/windier along the surface trough that is in place across the High Plains than previously anticipated by guidance. This trend suggests that elevated to critical fire weather conditions may be more pervasive than depicted by the previous outlook. Second, dry and windy conditions are likely overnight tonight as a dry cold front pushes southeast across MT and the western Dakotas. An influx of dry air will limit nocturnal RH recovery with most 12z guidance suggesting that 15-25% RH and 20-30 mph winds will be common for a few hours in the post-frontal regime. ...Utah... Very isolated thunderstorms are expected this afternoon across central UT. The 12z SLC sounding sampled very dry boundary-layer conditions, but cold temperatures aloft with adequate moisture for weak convection. Additionally, recent visible imagery already shows shallow cumulus developing atop the boundary layer. As such, a few dry thunderstorms appear possible and may overlap with the dry fuels that are in place across west-central UT. However, thunderstorm development appears most probable across central UT where orographic ascent will bolster the relatively weak ascent over the region. Given the low probability for dry lightning over receptive fuels, additional risk highlights were withheld. ..Moore.. 09/29/2024 .PREV DISCUSSION... /ISSUED 1228 AM CDT Sun Sep 29 2024/ ...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%. ...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 1034 AM CDT Sun Sep 29 2024 Valid 291700Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO SOUTHERN NORTH DAKOTA... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL WYOMING... ...Northern Rockies/Plains... The primary adjustment for this update is introducing a Critical risk area to parts of central WY where morning guidance has come into reasonably good agreement in a few hours of sustained 20-25 mph winds with RH values near 15%. Additionally, the Elevated risk areas across the northern Rockies and northern Plains have been combined and expanded into eastern MT to account for two trends. First, morning surface observations are drier/windier along the surface trough that is in place across the High Plains than previously anticipated by guidance. This trend suggests that elevated to critical fire weather conditions may be more pervasive than depicted by the previous outlook. Second, dry and windy conditions are likely overnight tonight as a dry cold front pushes southeast across MT and the western Dakotas. An influx of dry air will limit nocturnal RH recovery with most 12z guidance suggesting that 15-25% RH and 20-30 mph winds will be common for a few hours in the post-frontal regime. ...Utah... Very isolated thunderstorms are expected this afternoon across central UT. The 12z SLC sounding sampled very dry boundary-layer conditions, but cold temperatures aloft with adequate moisture for weak convection. Additionally, recent visible imagery already shows shallow cumulus developing atop the boundary layer. As such, a few dry thunderstorms appear possible and may overlap with the dry fuels that are in place across west-central UT. However, thunderstorm development appears most probable across central UT where orographic ascent will bolster the relatively weak ascent over the region. Given the low probability for dry lightning over receptive fuels, additional risk highlights were withheld. ..Moore.. 09/29/2024 .PREV DISCUSSION... /ISSUED 1228 AM CDT Sun Sep 29 2024/ ...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%. ...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 1034 AM CDT Sun Sep 29 2024 Valid 291700Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO SOUTHERN NORTH DAKOTA... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL WYOMING... ...Northern Rockies/Plains... The primary adjustment for this update is introducing a Critical risk area to parts of central WY where morning guidance has come into reasonably good agreement in a few hours of sustained 20-25 mph winds with RH values near 15%. Additionally, the Elevated risk areas across the northern Rockies and northern Plains have been combined and expanded into eastern MT to account for two trends. First, morning surface observations are drier/windier along the surface trough that is in place across the High Plains than previously anticipated by guidance. This trend suggests that elevated to critical fire weather conditions may be more pervasive than depicted by the previous outlook. Second, dry and windy conditions are likely overnight tonight as a dry cold front pushes southeast across MT and the western Dakotas. An influx of dry air will limit nocturnal RH recovery with most 12z guidance suggesting that 15-25% RH and 20-30 mph winds will be common for a few hours in the post-frontal regime. ...Utah... Very isolated thunderstorms are expected this afternoon across central UT. The 12z SLC sounding sampled very dry boundary-layer conditions, but cold temperatures aloft with adequate moisture for weak convection. Additionally, recent visible imagery already shows shallow cumulus developing atop the boundary layer. As such, a few dry thunderstorms appear possible and may overlap with the dry fuels that are in place across west-central UT. However, thunderstorm development appears most probable across central UT where orographic ascent will bolster the relatively weak ascent over the region. Given the low probability for dry lightning over receptive fuels, additional risk highlights were withheld. ..Moore.. 09/29/2024 .PREV DISCUSSION... /ISSUED 1228 AM CDT Sun Sep 29 2024/ ...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%. ...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 1034 AM CDT Sun Sep 29 2024 Valid 291700Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO SOUTHERN NORTH DAKOTA... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL WYOMING... ...Northern Rockies/Plains... The primary adjustment for this update is introducing a Critical risk area to parts of central WY where morning guidance has come into reasonably good agreement in a few hours of sustained 20-25 mph winds with RH values near 15%. Additionally, the Elevated risk areas across the northern Rockies and northern Plains have been combined and expanded into eastern MT to account for two trends. First, morning surface observations are drier/windier along the surface trough that is in place across the High Plains than previously anticipated by guidance. This trend suggests that elevated to critical fire weather conditions may be more pervasive than depicted by the previous outlook. Second, dry and windy conditions are likely overnight tonight as a dry cold front pushes southeast across MT and the western Dakotas. An influx of dry air will limit nocturnal RH recovery with most 12z guidance suggesting that 15-25% RH and 20-30 mph winds will be common for a few hours in the post-frontal regime. ...Utah... Very isolated thunderstorms are expected this afternoon across central UT. The 12z SLC sounding sampled very dry boundary-layer conditions, but cold temperatures aloft with adequate moisture for weak convection. Additionally, recent visible imagery already shows shallow cumulus developing atop the boundary layer. As such, a few dry thunderstorms appear possible and may overlap with the dry fuels that are in place across west-central UT. However, thunderstorm development appears most probable across central UT where orographic ascent will bolster the relatively weak ascent over the region. Given the low probability for dry lightning over receptive fuels, additional risk highlights were withheld. ..Moore.. 09/29/2024 .PREV DISCUSSION... /ISSUED 1228 AM CDT Sun Sep 29 2024/ ...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%. ...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 1034 AM CDT Sun Sep 29 2024 Valid 291700Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO SOUTHERN NORTH DAKOTA... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL WYOMING... ...Northern Rockies/Plains... The primary adjustment for this update is introducing a Critical risk area to parts of central WY where morning guidance has come into reasonably good agreement in a few hours of sustained 20-25 mph winds with RH values near 15%. Additionally, the Elevated risk areas across the northern Rockies and northern Plains have been combined and expanded into eastern MT to account for two trends. First, morning surface observations are drier/windier along the surface trough that is in place across the High Plains than previously anticipated by guidance. This trend suggests that elevated to critical fire weather conditions may be more pervasive than depicted by the previous outlook. Second, dry and windy conditions are likely overnight tonight as a dry cold front pushes southeast across MT and the western Dakotas. An influx of dry air will limit nocturnal RH recovery with most 12z guidance suggesting that 15-25% RH and 20-30 mph winds will be common for a few hours in the post-frontal regime. ...Utah... Very isolated thunderstorms are expected this afternoon across central UT. The 12z SLC sounding sampled very dry boundary-layer conditions, but cold temperatures aloft with adequate moisture for weak convection. Additionally, recent visible imagery already shows shallow cumulus developing atop the boundary layer. As such, a few dry thunderstorms appear possible and may overlap with the dry fuels that are in place across west-central UT. However, thunderstorm development appears most probable across central UT where orographic ascent will bolster the relatively weak ascent over the region. Given the low probability for dry lightning over receptive fuels, additional risk highlights were withheld. ..Moore.. 09/29/2024 .PREV DISCUSSION... /ISSUED 1228 AM CDT Sun Sep 29 2024/ ...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%. ...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 1034 AM CDT Sun Sep 29 2024 Valid 291700Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO SOUTHERN NORTH DAKOTA... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL WYOMING... ...Northern Rockies/Plains... The primary adjustment for this update is introducing a Critical risk area to parts of central WY where morning guidance has come into reasonably good agreement in a few hours of sustained 20-25 mph winds with RH values near 15%. Additionally, the Elevated risk areas across the northern Rockies and northern Plains have been combined and expanded into eastern MT to account for two trends. First, morning surface observations are drier/windier along the surface trough that is in place across the High Plains than previously anticipated by guidance. This trend suggests that elevated to critical fire weather conditions may be more pervasive than depicted by the previous outlook. Second, dry and windy conditions are likely overnight tonight as a dry cold front pushes southeast across MT and the western Dakotas. An influx of dry air will limit nocturnal RH recovery with most 12z guidance suggesting that 15-25% RH and 20-30 mph winds will be common for a few hours in the post-frontal regime. ...Utah... Very isolated thunderstorms are expected this afternoon across central UT. The 12z SLC sounding sampled very dry boundary-layer conditions, but cold temperatures aloft with adequate moisture for weak convection. Additionally, recent visible imagery already shows shallow cumulus developing atop the boundary layer. As such, a few dry thunderstorms appear possible and may overlap with the dry fuels that are in place across west-central UT. However, thunderstorm development appears most probable across central UT where orographic ascent will bolster the relatively weak ascent over the region. Given the low probability for dry lightning over receptive fuels, additional risk highlights were withheld. ..Moore.. 09/29/2024 .PREV DISCUSSION... /ISSUED 1228 AM CDT Sun Sep 29 2024/ ...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%. ...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 1034 AM CDT Sun Sep 29 2024 Valid 291700Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NEBRASKA INTO SOUTHERN NORTH DAKOTA... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL WYOMING... ...Northern Rockies/Plains... The primary adjustment for this update is introducing a Critical risk area to parts of central WY where morning guidance has come into reasonably good agreement in a few hours of sustained 20-25 mph winds with RH values near 15%. Additionally, the Elevated risk areas across the northern Rockies and northern Plains have been combined and expanded into eastern MT to account for two trends. First, morning surface observations are drier/windier along the surface trough that is in place across the High Plains than previously anticipated by guidance. This trend suggests that elevated to critical fire weather conditions may be more pervasive than depicted by the previous outlook. Second, dry and windy conditions are likely overnight tonight as a dry cold front pushes southeast across MT and the western Dakotas. An influx of dry air will limit nocturnal RH recovery with most 12z guidance suggesting that 15-25% RH and 20-30 mph winds will be common for a few hours in the post-frontal regime. ...Utah... Very isolated thunderstorms are expected this afternoon across central UT. The 12z SLC sounding sampled very dry boundary-layer conditions, but cold temperatures aloft with adequate moisture for weak convection. Additionally, recent visible imagery already shows shallow cumulus developing atop the boundary layer. As such, a few dry thunderstorms appear possible and may overlap with the dry fuels that are in place across west-central UT. However, thunderstorm development appears most probable across central UT where orographic ascent will bolster the relatively weak ascent over the region. Given the low probability for dry lightning over receptive fuels, additional risk highlights were withheld. ..Moore.. 09/29/2024 .PREV DISCUSSION... /ISSUED 1228 AM CDT Sun Sep 29 2024/ ...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%. ...Please see www.spc.noaa.gov/fire for graphic product... Read more