Severe Storms

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Mon Sep 09 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF SOUTHEAST LA AND SOUTHERN MS... ...SUMMARY... A few tornadoes are possible across the central Gulf Coast vicinity on Wednesday, in association with Tropical Cyclone Francine. ...Synopsis... Tropical Cyclone Francine is currently forecast to make landfall sometime later Wednesday afternoon or evening near the LA Gulf Coast, potentially as a hurricane. Meanwhile, a relatively deep mid/upper-level trough will move eastward across the Northwest into the Great Basin and central/northern Rockies. In response to the this trough, some deepening of surface low pressure is expected from the eastern Great Basin into Montana. ...Central Gulf Coast vicinity... See NHC forecasts and advisories for additional information regarding Francine. Some tornado threat will spread inland as Francine approaches the coast during the day before making landfall by evening. Based on current forecasts/guidance, the most favorable overlap of strengthening low-level shear/SRH and inland intrusion of tropical moisture (with dewpoints in the mid/upper 70s F) is expected across parts of southern LA/MS, where a small Slight Risk has been included. The northern extent of an appreciable tornado threat remains uncertain, with surface-based buoyancy potentially remaining quite limited into parts of central MS Wednesday night, but the Marginal Risk has been expanded based on the expected track of Francine into early Thursday morning. ...Interior Northwest... Large-scale ascent and cooling temperatures aloft attendant to the approaching trough will support isolated to scattered thunderstorm development across the interior Northwest on Wednesday. Wind profiles will become favorable for organized convection, but moisture will likely remain rather limited, and uncertainty remains regarding whether buoyancy will become sufficient for a severe threat. Locally gusty winds and small hail could accompany the strongest storms. ...Central/northern High Plains... Isolated high-based convection may develop across parts of the central/northern High Plains during the afternoon, to the south of a stationary front that will extend eastward across parts of eastern MT into the Dakotas. While this convection may remain rather disorganized, inverted-v profiles could support localized strong gusts. Near and immediately north of the front, somewhat more favorable moisture and instability may be in place during the afternoon/evening, but capping will tend to limit surface-based development. A few stronger elevated storms will be possible, but potential for any organized severe threat remains uncertain at this time. ..Dean.. 09/09/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Mon Sep 09 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF SOUTHEAST LA AND SOUTHERN MS... ...SUMMARY... A few tornadoes are possible across the central Gulf Coast vicinity on Wednesday, in association with Tropical Cyclone Francine. ...Synopsis... Tropical Cyclone Francine is currently forecast to make landfall sometime later Wednesday afternoon or evening near the LA Gulf Coast, potentially as a hurricane. Meanwhile, a relatively deep mid/upper-level trough will move eastward across the Northwest into the Great Basin and central/northern Rockies. In response to the this trough, some deepening of surface low pressure is expected from the eastern Great Basin into Montana. ...Central Gulf Coast vicinity... See NHC forecasts and advisories for additional information regarding Francine. Some tornado threat will spread inland as Francine approaches the coast during the day before making landfall by evening. Based on current forecasts/guidance, the most favorable overlap of strengthening low-level shear/SRH and inland intrusion of tropical moisture (with dewpoints in the mid/upper 70s F) is expected across parts of southern LA/MS, where a small Slight Risk has been included. The northern extent of an appreciable tornado threat remains uncertain, with surface-based buoyancy potentially remaining quite limited into parts of central MS Wednesday night, but the Marginal Risk has been expanded based on the expected track of Francine into early Thursday morning. ...Interior Northwest... Large-scale ascent and cooling temperatures aloft attendant to the approaching trough will support isolated to scattered thunderstorm development across the interior Northwest on Wednesday. Wind profiles will become favorable for organized convection, but moisture will likely remain rather limited, and uncertainty remains regarding whether buoyancy will become sufficient for a severe threat. Locally gusty winds and small hail could accompany the strongest storms. ...Central/northern High Plains... Isolated high-based convection may develop across parts of the central/northern High Plains during the afternoon, to the south of a stationary front that will extend eastward across parts of eastern MT into the Dakotas. While this convection may remain rather disorganized, inverted-v profiles could support localized strong gusts. Near and immediately north of the front, somewhat more favorable moisture and instability may be in place during the afternoon/evening, but capping will tend to limit surface-based development. A few stronger elevated storms will be possible, but potential for any organized severe threat remains uncertain at this time. ..Dean.. 09/09/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Mon Sep 09 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF SOUTHEAST LA AND SOUTHERN MS... ...SUMMARY... A few tornadoes are possible across the central Gulf Coast vicinity on Wednesday, in association with Tropical Cyclone Francine. ...Synopsis... Tropical Cyclone Francine is currently forecast to make landfall sometime later Wednesday afternoon or evening near the LA Gulf Coast, potentially as a hurricane. Meanwhile, a relatively deep mid/upper-level trough will move eastward across the Northwest into the Great Basin and central/northern Rockies. In response to the this trough, some deepening of surface low pressure is expected from the eastern Great Basin into Montana. ...Central Gulf Coast vicinity... See NHC forecasts and advisories for additional information regarding Francine. Some tornado threat will spread inland as Francine approaches the coast during the day before making landfall by evening. Based on current forecasts/guidance, the most favorable overlap of strengthening low-level shear/SRH and inland intrusion of tropical moisture (with dewpoints in the mid/upper 70s F) is expected across parts of southern LA/MS, where a small Slight Risk has been included. The northern extent of an appreciable tornado threat remains uncertain, with surface-based buoyancy potentially remaining quite limited into parts of central MS Wednesday night, but the Marginal Risk has been expanded based on the expected track of Francine into early Thursday morning. ...Interior Northwest... Large-scale ascent and cooling temperatures aloft attendant to the approaching trough will support isolated to scattered thunderstorm development across the interior Northwest on Wednesday. Wind profiles will become favorable for organized convection, but moisture will likely remain rather limited, and uncertainty remains regarding whether buoyancy will become sufficient for a severe threat. Locally gusty winds and small hail could accompany the strongest storms. ...Central/northern High Plains... Isolated high-based convection may develop across parts of the central/northern High Plains during the afternoon, to the south of a stationary front that will extend eastward across parts of eastern MT into the Dakotas. While this convection may remain rather disorganized, inverted-v profiles could support localized strong gusts. Near and immediately north of the front, somewhat more favorable moisture and instability may be in place during the afternoon/evening, but capping will tend to limit surface-based development. A few stronger elevated storms will be possible, but potential for any organized severe threat remains uncertain at this time. ..Dean.. 09/09/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0157 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z No changes to the ongoing forecast. There is some potential for very isolated thunderstorms in the vicinity of the Blue Mountains in Oregon, but confidence in initiation is quite low. Additional thunderstorms are possible in parts of southwest Montana, but that activity would quickly move into a higher PWAT airmass. ..Wendt.. 09/09/2024 .PREV DISCUSSION... /ISSUED 0151 AM CDT Mon Sep 09 2024/ ...Synopsis... Broad troughing over the Northwest is forecast to gradually intensify Tuesday as a stronger shortwave and mid-level jet approach from the eastern Pacific. Falling heights and increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. ..Great Basin... Fire weather concerns will increase on Tuesday with the approach of the strong trough/mid-level jet. Initially weak surface winds will intensify over northwest and southern Nevada to 15-25 mph as flow aloft increases. Several hours of elevated to locally critical fire-weather conditions are likely as the stronger surface winds develop with a dry air mass with RH values below 20%. Fuels are driest across parts of the northern Great Basin and ID where rainfall has been sparse. However, fuels farther south in NV and CA remain sufficiently dry, and with stronger winds, elevated to near critical conditions are likely. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient to drive 15-20 mph winds through the Gorge and the western Columbia Basin along with RH potentially near 15%. The duration of breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather may occur on Tuesday. ...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 0157 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z No changes to the ongoing forecast. There is some potential for very isolated thunderstorms in the vicinity of the Blue Mountains in Oregon, but confidence in initiation is quite low. Additional thunderstorms are possible in parts of southwest Montana, but that activity would quickly move into a higher PWAT airmass. ..Wendt.. 09/09/2024 .PREV DISCUSSION... /ISSUED 0151 AM CDT Mon Sep 09 2024/ ...Synopsis... Broad troughing over the Northwest is forecast to gradually intensify Tuesday as a stronger shortwave and mid-level jet approach from the eastern Pacific. Falling heights and increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. ..Great Basin... Fire weather concerns will increase on Tuesday with the approach of the strong trough/mid-level jet. Initially weak surface winds will intensify over northwest and southern Nevada to 15-25 mph as flow aloft increases. Several hours of elevated to locally critical fire-weather conditions are likely as the stronger surface winds develop with a dry air mass with RH values below 20%. Fuels are driest across parts of the northern Great Basin and ID where rainfall has been sparse. However, fuels farther south in NV and CA remain sufficiently dry, and with stronger winds, elevated to near critical conditions are likely. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient to drive 15-20 mph winds through the Gorge and the western Columbia Basin along with RH potentially near 15%. The duration of breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather may occur on Tuesday. ...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 0157 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z No changes to the ongoing forecast. There is some potential for very isolated thunderstorms in the vicinity of the Blue Mountains in Oregon, but confidence in initiation is quite low. Additional thunderstorms are possible in parts of southwest Montana, but that activity would quickly move into a higher PWAT airmass. ..Wendt.. 09/09/2024 .PREV DISCUSSION... /ISSUED 0151 AM CDT Mon Sep 09 2024/ ...Synopsis... Broad troughing over the Northwest is forecast to gradually intensify Tuesday as a stronger shortwave and mid-level jet approach from the eastern Pacific. Falling heights and increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. ..Great Basin... Fire weather concerns will increase on Tuesday with the approach of the strong trough/mid-level jet. Initially weak surface winds will intensify over northwest and southern Nevada to 15-25 mph as flow aloft increases. Several hours of elevated to locally critical fire-weather conditions are likely as the stronger surface winds develop with a dry air mass with RH values below 20%. Fuels are driest across parts of the northern Great Basin and ID where rainfall has been sparse. However, fuels farther south in NV and CA remain sufficiently dry, and with stronger winds, elevated to near critical conditions are likely. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient to drive 15-20 mph winds through the Gorge and the western Columbia Basin along with RH potentially near 15%. The duration of breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather may occur on Tuesday. ...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 0157 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z No changes to the ongoing forecast. There is some potential for very isolated thunderstorms in the vicinity of the Blue Mountains in Oregon, but confidence in initiation is quite low. Additional thunderstorms are possible in parts of southwest Montana, but that activity would quickly move into a higher PWAT airmass. ..Wendt.. 09/09/2024 .PREV DISCUSSION... /ISSUED 0151 AM CDT Mon Sep 09 2024/ ...Synopsis... Broad troughing over the Northwest is forecast to gradually intensify Tuesday as a stronger shortwave and mid-level jet approach from the eastern Pacific. Falling heights and increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. ..Great Basin... Fire weather concerns will increase on Tuesday with the approach of the strong trough/mid-level jet. Initially weak surface winds will intensify over northwest and southern Nevada to 15-25 mph as flow aloft increases. Several hours of elevated to locally critical fire-weather conditions are likely as the stronger surface winds develop with a dry air mass with RH values below 20%. Fuels are driest across parts of the northern Great Basin and ID where rainfall has been sparse. However, fuels farther south in NV and CA remain sufficiently dry, and with stronger winds, elevated to near critical conditions are likely. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient to drive 15-20 mph winds through the Gorge and the western Columbia Basin along with RH potentially near 15%. The duration of breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather may occur on Tuesday. ...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 0157 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z No changes to the ongoing forecast. There is some potential for very isolated thunderstorms in the vicinity of the Blue Mountains in Oregon, but confidence in initiation is quite low. Additional thunderstorms are possible in parts of southwest Montana, but that activity would quickly move into a higher PWAT airmass. ..Wendt.. 09/09/2024 .PREV DISCUSSION... /ISSUED 0151 AM CDT Mon Sep 09 2024/ ...Synopsis... Broad troughing over the Northwest is forecast to gradually intensify Tuesday as a stronger shortwave and mid-level jet approach from the eastern Pacific. Falling heights and increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. ..Great Basin... Fire weather concerns will increase on Tuesday with the approach of the strong trough/mid-level jet. Initially weak surface winds will intensify over northwest and southern Nevada to 15-25 mph as flow aloft increases. Several hours of elevated to locally critical fire-weather conditions are likely as the stronger surface winds develop with a dry air mass with RH values below 20%. Fuels are driest across parts of the northern Great Basin and ID where rainfall has been sparse. However, fuels farther south in NV and CA remain sufficiently dry, and with stronger winds, elevated to near critical conditions are likely. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient to drive 15-20 mph winds through the Gorge and the western Columbia Basin along with RH potentially near 15%. The duration of breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather may occur on Tuesday. ...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 0157 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z No changes to the ongoing forecast. There is some potential for very isolated thunderstorms in the vicinity of the Blue Mountains in Oregon, but confidence in initiation is quite low. Additional thunderstorms are possible in parts of southwest Montana, but that activity would quickly move into a higher PWAT airmass. ..Wendt.. 09/09/2024 .PREV DISCUSSION... /ISSUED 0151 AM CDT Mon Sep 09 2024/ ...Synopsis... Broad troughing over the Northwest is forecast to gradually intensify Tuesday as a stronger shortwave and mid-level jet approach from the eastern Pacific. Falling heights and increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. ..Great Basin... Fire weather concerns will increase on Tuesday with the approach of the strong trough/mid-level jet. Initially weak surface winds will intensify over northwest and southern Nevada to 15-25 mph as flow aloft increases. Several hours of elevated to locally critical fire-weather conditions are likely as the stronger surface winds develop with a dry air mass with RH values below 20%. Fuels are driest across parts of the northern Great Basin and ID where rainfall has been sparse. However, fuels farther south in NV and CA remain sufficiently dry, and with stronger winds, elevated to near critical conditions are likely. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient to drive 15-20 mph winds through the Gorge and the western Columbia Basin along with RH potentially near 15%. The duration of breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather may occur on Tuesday. ...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 0157 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z No changes to the ongoing forecast. There is some potential for very isolated thunderstorms in the vicinity of the Blue Mountains in Oregon, but confidence in initiation is quite low. Additional thunderstorms are possible in parts of southwest Montana, but that activity would quickly move into a higher PWAT airmass. ..Wendt.. 09/09/2024 .PREV DISCUSSION... /ISSUED 0151 AM CDT Mon Sep 09 2024/ ...Synopsis... Broad troughing over the Northwest is forecast to gradually intensify Tuesday as a stronger shortwave and mid-level jet approach from the eastern Pacific. Falling heights and increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. ..Great Basin... Fire weather concerns will increase on Tuesday with the approach of the strong trough/mid-level jet. Initially weak surface winds will intensify over northwest and southern Nevada to 15-25 mph as flow aloft increases. Several hours of elevated to locally critical fire-weather conditions are likely as the stronger surface winds develop with a dry air mass with RH values below 20%. Fuels are driest across parts of the northern Great Basin and ID where rainfall has been sparse. However, fuels farther south in NV and CA remain sufficiently dry, and with stronger winds, elevated to near critical conditions are likely. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient to drive 15-20 mph winds through the Gorge and the western Columbia Basin along with RH potentially near 15%. The duration of breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather may occur on Tuesday. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LA GULF COAST... ...SUMMARY... Some tornado threat associated with Tropical Cyclone Francine may approach the Louisiana Gulf Coast by early Wednesday morning. ...Synopsis... Tropical Storm Francine will potentially intensify into a hurricane as it moves north-northeastward across the western Gulf of Mexico. Meanwhile, a strong mid/upper-level shortwave trough is forecast to dig southeastward into the Pacific Northwest and northern CA. Diurnal thunderstorms capable of locally gusty winds will be possible from the eastern Great Basin into parts of the Rockies, and also across the FL Peninsula. More isolated storms will also be possible from the central Plains into the parts of the upper Midwest, which may also be capable of locally gusty winds. Organized severe-thunderstorm potential is expected to remain low, with the possible exception of the LA Gulf Coast region late in the period in association with Francine. ...LA Gulf Coast vicinity... Refer to NHC forecasts and advisories for more information regarding Tropical Storm Francine. Based on the current forecast track, the most favorable environment for low-topped supercells associated with Francine should remain offshore for most of the forecast period. However, some outer bands may begin to approach the LA Gulf Coast prior to 12Z Wednesday morning, accompanied by an increase in low-level shear/SRH. A small Marginal Risk has been included near the immediate LA Gulf Coast for the potential of an increasing tornado threat prior to the end of the forecast period. ..Dean.. 09/09/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LA GULF COAST... ...SUMMARY... Some tornado threat associated with Tropical Cyclone Francine may approach the Louisiana Gulf Coast by early Wednesday morning. ...Synopsis... Tropical Storm Francine will potentially intensify into a hurricane as it moves north-northeastward across the western Gulf of Mexico. Meanwhile, a strong mid/upper-level shortwave trough is forecast to dig southeastward into the Pacific Northwest and northern CA. Diurnal thunderstorms capable of locally gusty winds will be possible from the eastern Great Basin into parts of the Rockies, and also across the FL Peninsula. More isolated storms will also be possible from the central Plains into the parts of the upper Midwest, which may also be capable of locally gusty winds. Organized severe-thunderstorm potential is expected to remain low, with the possible exception of the LA Gulf Coast region late in the period in association with Francine. ...LA Gulf Coast vicinity... Refer to NHC forecasts and advisories for more information regarding Tropical Storm Francine. Based on the current forecast track, the most favorable environment for low-topped supercells associated with Francine should remain offshore for most of the forecast period. However, some outer bands may begin to approach the LA Gulf Coast prior to 12Z Wednesday morning, accompanied by an increase in low-level shear/SRH. A small Marginal Risk has been included near the immediate LA Gulf Coast for the potential of an increasing tornado threat prior to the end of the forecast period. ..Dean.. 09/09/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LA GULF COAST... ...SUMMARY... Some tornado threat associated with Tropical Cyclone Francine may approach the Louisiana Gulf Coast by early Wednesday morning. ...Synopsis... Tropical Storm Francine will potentially intensify into a hurricane as it moves north-northeastward across the western Gulf of Mexico. Meanwhile, a strong mid/upper-level shortwave trough is forecast to dig southeastward into the Pacific Northwest and northern CA. Diurnal thunderstorms capable of locally gusty winds will be possible from the eastern Great Basin into parts of the Rockies, and also across the FL Peninsula. More isolated storms will also be possible from the central Plains into the parts of the upper Midwest, which may also be capable of locally gusty winds. Organized severe-thunderstorm potential is expected to remain low, with the possible exception of the LA Gulf Coast region late in the period in association with Francine. ...LA Gulf Coast vicinity... Refer to NHC forecasts and advisories for more information regarding Tropical Storm Francine. Based on the current forecast track, the most favorable environment for low-topped supercells associated with Francine should remain offshore for most of the forecast period. However, some outer bands may begin to approach the LA Gulf Coast prior to 12Z Wednesday morning, accompanied by an increase in low-level shear/SRH. A small Marginal Risk has been included near the immediate LA Gulf Coast for the potential of an increasing tornado threat prior to the end of the forecast period. ..Dean.. 09/09/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LA GULF COAST... ...SUMMARY... Some tornado threat associated with Tropical Cyclone Francine may approach the Louisiana Gulf Coast by early Wednesday morning. ...Synopsis... Tropical Storm Francine will potentially intensify into a hurricane as it moves north-northeastward across the western Gulf of Mexico. Meanwhile, a strong mid/upper-level shortwave trough is forecast to dig southeastward into the Pacific Northwest and northern CA. Diurnal thunderstorms capable of locally gusty winds will be possible from the eastern Great Basin into parts of the Rockies, and also across the FL Peninsula. More isolated storms will also be possible from the central Plains into the parts of the upper Midwest, which may also be capable of locally gusty winds. Organized severe-thunderstorm potential is expected to remain low, with the possible exception of the LA Gulf Coast region late in the period in association with Francine. ...LA Gulf Coast vicinity... Refer to NHC forecasts and advisories for more information regarding Tropical Storm Francine. Based on the current forecast track, the most favorable environment for low-topped supercells associated with Francine should remain offshore for most of the forecast period. However, some outer bands may begin to approach the LA Gulf Coast prior to 12Z Wednesday morning, accompanied by an increase in low-level shear/SRH. A small Marginal Risk has been included near the immediate LA Gulf Coast for the potential of an increasing tornado threat prior to the end of the forecast period. ..Dean.. 09/09/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LA GULF COAST... ...SUMMARY... Some tornado threat associated with Tropical Cyclone Francine may approach the Louisiana Gulf Coast by early Wednesday morning. ...Synopsis... Tropical Storm Francine will potentially intensify into a hurricane as it moves north-northeastward across the western Gulf of Mexico. Meanwhile, a strong mid/upper-level shortwave trough is forecast to dig southeastward into the Pacific Northwest and northern CA. Diurnal thunderstorms capable of locally gusty winds will be possible from the eastern Great Basin into parts of the Rockies, and also across the FL Peninsula. More isolated storms will also be possible from the central Plains into the parts of the upper Midwest, which may also be capable of locally gusty winds. Organized severe-thunderstorm potential is expected to remain low, with the possible exception of the LA Gulf Coast region late in the period in association with Francine. ...LA Gulf Coast vicinity... Refer to NHC forecasts and advisories for more information regarding Tropical Storm Francine. Based on the current forecast track, the most favorable environment for low-topped supercells associated with Francine should remain offshore for most of the forecast period. However, some outer bands may begin to approach the LA Gulf Coast prior to 12Z Wednesday morning, accompanied by an increase in low-level shear/SRH. A small Marginal Risk has been included near the immediate LA Gulf Coast for the potential of an increasing tornado threat prior to the end of the forecast period. ..Dean.. 09/09/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LA GULF COAST... ...SUMMARY... Some tornado threat associated with Tropical Cyclone Francine may approach the Louisiana Gulf Coast by early Wednesday morning. ...Synopsis... Tropical Storm Francine will potentially intensify into a hurricane as it moves north-northeastward across the western Gulf of Mexico. Meanwhile, a strong mid/upper-level shortwave trough is forecast to dig southeastward into the Pacific Northwest and northern CA. Diurnal thunderstorms capable of locally gusty winds will be possible from the eastern Great Basin into parts of the Rockies, and also across the FL Peninsula. More isolated storms will also be possible from the central Plains into the parts of the upper Midwest, which may also be capable of locally gusty winds. Organized severe-thunderstorm potential is expected to remain low, with the possible exception of the LA Gulf Coast region late in the period in association with Francine. ...LA Gulf Coast vicinity... Refer to NHC forecasts and advisories for more information regarding Tropical Storm Francine. Based on the current forecast track, the most favorable environment for low-topped supercells associated with Francine should remain offshore for most of the forecast period. However, some outer bands may begin to approach the LA Gulf Coast prior to 12Z Wednesday morning, accompanied by an increase in low-level shear/SRH. A small Marginal Risk has been included near the immediate LA Gulf Coast for the potential of an increasing tornado threat prior to the end of the forecast period. ..Dean.. 09/09/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LA GULF COAST... ...SUMMARY... Some tornado threat associated with Tropical Cyclone Francine may approach the Louisiana Gulf Coast by early Wednesday morning. ...Synopsis... Tropical Storm Francine will potentially intensify into a hurricane as it moves north-northeastward across the western Gulf of Mexico. Meanwhile, a strong mid/upper-level shortwave trough is forecast to dig southeastward into the Pacific Northwest and northern CA. Diurnal thunderstorms capable of locally gusty winds will be possible from the eastern Great Basin into parts of the Rockies, and also across the FL Peninsula. More isolated storms will also be possible from the central Plains into the parts of the upper Midwest, which may also be capable of locally gusty winds. Organized severe-thunderstorm potential is expected to remain low, with the possible exception of the LA Gulf Coast region late in the period in association with Francine. ...LA Gulf Coast vicinity... Refer to NHC forecasts and advisories for more information regarding Tropical Storm Francine. Based on the current forecast track, the most favorable environment for low-topped supercells associated with Francine should remain offshore for most of the forecast period. However, some outer bands may begin to approach the LA Gulf Coast prior to 12Z Wednesday morning, accompanied by an increase in low-level shear/SRH. A small Marginal Risk has been included near the immediate LA Gulf Coast for the potential of an increasing tornado threat prior to the end of the forecast period. ..Dean.. 09/09/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Mon Sep 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LA GULF COAST... ...SUMMARY... Some tornado threat associated with Tropical Cyclone Francine may approach the Louisiana Gulf Coast by early Wednesday morning. ...Synopsis... Tropical Storm Francine will potentially intensify into a hurricane as it moves north-northeastward across the western Gulf of Mexico. Meanwhile, a strong mid/upper-level shortwave trough is forecast to dig southeastward into the Pacific Northwest and northern CA. Diurnal thunderstorms capable of locally gusty winds will be possible from the eastern Great Basin into parts of the Rockies, and also across the FL Peninsula. More isolated storms will also be possible from the central Plains into the parts of the upper Midwest, which may also be capable of locally gusty winds. Organized severe-thunderstorm potential is expected to remain low, with the possible exception of the LA Gulf Coast region late in the period in association with Francine. ...LA Gulf Coast vicinity... Refer to NHC forecasts and advisories for more information regarding Tropical Storm Francine. Based on the current forecast track, the most favorable environment for low-topped supercells associated with Francine should remain offshore for most of the forecast period. However, some outer bands may begin to approach the LA Gulf Coast prior to 12Z Wednesday morning, accompanied by an increase in low-level shear/SRH. A small Marginal Risk has been included near the immediate LA Gulf Coast for the potential of an increasing tornado threat prior to the end of the forecast period. ..Dean.. 09/09/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Mon Sep 09 2024 Valid 091700Z - 101200Z Minor modifications have been made to the ongoing forecast based on recent observations and model guidance. See the previous discussion for greater details. ..Wendt.. 09/09/2024 .PREV DISCUSSION... /ISSUED 0150 AM CDT Mon Sep 09 2024/ ...Synopsis... Broad trouhging over the Northwest should continue today as an embedded perturbation moves eastward over the northern Rockies. Southwesterly flow aloft is forecast to increase over much of the West as the broad trough slowly shifts east. At the surface, a cold front will move into the Rockies, bringing a cooler air mass to parts of the Northwest, but gusty winds to parts of the Cascades. A lee trough developing east of the Rockies will help support isolated dry thunderstorms over parts of WY and MT. Periods of stronger surface winds and low RH will support elevated to near-critical fire-weather conditions. ...Northwest and Great Basin.... Stronger flow aloft is expected to persist today over much of the Northwest and northern Great Basin. Surface winds should increase to 15-25 mph as momentum from aloft mixes down. Downsloping and mid-level drying should keep the air mass quite dry with diurnal RH minimums below 15% likely. Several hours of widespread elevated to near-critical fire-weather conditions are likely across the northern Sierra and Great Basin. Farther north, more moderate RH of 25-30% is expected beneath the upper trough and behind the cold front. Despite the arrival of a cooler Pacific air mass, downslope winds of 15-25 mph should overlap with dry fuels and pockets of lower RH during the day. Overlapping with recent lightning and fire activity, a few hours of elevated to near-critical conditions are possible in the lee of the Cascades as winds increase. ...Northern Rockies... Stronger westerly flow head of the embedded shortwave will aid in deepening a lee trough east of the Rockies. Westerly surface winds should strengthen in turn, supporting pockets of downslope winds of 15-25 mph across parts of MT and WY. With hot temperatures and little recent rainfall, afternoon RH values should remain quite low, generally below 20%. Increasing winds, receptive fuels, and persistent dry conditions should support several hours of elevated to near critical fire-weather conditions over parts of the northern Rockies. ...Dry Thunder... Isolated, high-based thunderstorms appear likely over parts of the Rockies (mainly WY and MT) today ahead of the shortwave trough. Weak buoyancy, and PWATs of 0.5 to 0.7 inches, atop dry and well-mixed low levels will support poor precipitation efficiency and the potential for strong outflow winds. At least isolated storms are expected over areas of receptive fuels. Thus, dry lightning ignitions are possible, especially across parts of north-central WY, where storm coverage appears greatest. ...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 1133 AM CDT Mon Sep 09 2024 Valid 091700Z - 101200Z Minor modifications have been made to the ongoing forecast based on recent observations and model guidance. See the previous discussion for greater details. ..Wendt.. 09/09/2024 .PREV DISCUSSION... /ISSUED 0150 AM CDT Mon Sep 09 2024/ ...Synopsis... Broad trouhging over the Northwest should continue today as an embedded perturbation moves eastward over the northern Rockies. Southwesterly flow aloft is forecast to increase over much of the West as the broad trough slowly shifts east. At the surface, a cold front will move into the Rockies, bringing a cooler air mass to parts of the Northwest, but gusty winds to parts of the Cascades. A lee trough developing east of the Rockies will help support isolated dry thunderstorms over parts of WY and MT. Periods of stronger surface winds and low RH will support elevated to near-critical fire-weather conditions. ...Northwest and Great Basin.... Stronger flow aloft is expected to persist today over much of the Northwest and northern Great Basin. Surface winds should increase to 15-25 mph as momentum from aloft mixes down. Downsloping and mid-level drying should keep the air mass quite dry with diurnal RH minimums below 15% likely. Several hours of widespread elevated to near-critical fire-weather conditions are likely across the northern Sierra and Great Basin. Farther north, more moderate RH of 25-30% is expected beneath the upper trough and behind the cold front. Despite the arrival of a cooler Pacific air mass, downslope winds of 15-25 mph should overlap with dry fuels and pockets of lower RH during the day. Overlapping with recent lightning and fire activity, a few hours of elevated to near-critical conditions are possible in the lee of the Cascades as winds increase. ...Northern Rockies... Stronger westerly flow head of the embedded shortwave will aid in deepening a lee trough east of the Rockies. Westerly surface winds should strengthen in turn, supporting pockets of downslope winds of 15-25 mph across parts of MT and WY. With hot temperatures and little recent rainfall, afternoon RH values should remain quite low, generally below 20%. Increasing winds, receptive fuels, and persistent dry conditions should support several hours of elevated to near critical fire-weather conditions over parts of the northern Rockies. ...Dry Thunder... Isolated, high-based thunderstorms appear likely over parts of the Rockies (mainly WY and MT) today ahead of the shortwave trough. Weak buoyancy, and PWATs of 0.5 to 0.7 inches, atop dry and well-mixed low levels will support poor precipitation efficiency and the potential for strong outflow winds. At least isolated storms are expected over areas of receptive fuels. Thus, dry lightning ignitions are possible, especially across parts of north-central WY, where storm coverage appears greatest. ...Please see www.spc.noaa.gov/fire for graphic product... Read more