Severe Storms

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Tue Sep 10 2024 Valid 131200Z - 181200Z ...DISCUSSION... Severe potential appears low through the period. Primary concern for D4/Friday is any lingering tornado threat associated with the remnants of TC Francine. It is forecast by NHC to drift into the Mid-South/MS Valley to Lower OH Valley vicinity. Latest guidance indicates further weakening of low-level wind fields on Friday, likely becoming inadequate to sustain a synoptically evident TC tornado threat. Beyond this time frame, a quiescent pattern for severe is expected this weekend into early next week. Towards mid-week, majority of ensemble guidance suggests potential large-scale amplification of an upper trough into the West. This may yield an increase of low-probability severe around D8 and beyond over parts of the Great Plains, where many preceding days of above-normal temps will occur. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Tue Sep 10 2024 Valid 131200Z - 181200Z ...DISCUSSION... Severe potential appears low through the period. Primary concern for D4/Friday is any lingering tornado threat associated with the remnants of TC Francine. It is forecast by NHC to drift into the Mid-South/MS Valley to Lower OH Valley vicinity. Latest guidance indicates further weakening of low-level wind fields on Friday, likely becoming inadequate to sustain a synoptically evident TC tornado threat. Beyond this time frame, a quiescent pattern for severe is expected this weekend into early next week. Towards mid-week, majority of ensemble guidance suggests potential large-scale amplification of an upper trough into the West. This may yield an increase of low-probability severe around D8 and beyond over parts of the Great Plains, where many preceding days of above-normal temps will occur. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Tue Sep 10 2024 Valid 131200Z - 181200Z ...DISCUSSION... Severe potential appears low through the period. Primary concern for D4/Friday is any lingering tornado threat associated with the remnants of TC Francine. It is forecast by NHC to drift into the Mid-South/MS Valley to Lower OH Valley vicinity. Latest guidance indicates further weakening of low-level wind fields on Friday, likely becoming inadequate to sustain a synoptically evident TC tornado threat. Beyond this time frame, a quiescent pattern for severe is expected this weekend into early next week. Towards mid-week, majority of ensemble guidance suggests potential large-scale amplification of an upper trough into the West. This may yield an increase of low-probability severe around D8 and beyond over parts of the Great Plains, where many preceding days of above-normal temps will occur. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Tue Sep 10 2024 Valid 131200Z - 181200Z ...DISCUSSION... Severe potential appears low through the period. Primary concern for D4/Friday is any lingering tornado threat associated with the remnants of TC Francine. It is forecast by NHC to drift into the Mid-South/MS Valley to Lower OH Valley vicinity. Latest guidance indicates further weakening of low-level wind fields on Friday, likely becoming inadequate to sustain a synoptically evident TC tornado threat. Beyond this time frame, a quiescent pattern for severe is expected this weekend into early next week. Towards mid-week, majority of ensemble guidance suggests potential large-scale amplification of an upper trough into the West. This may yield an increase of low-probability severe around D8 and beyond over parts of the Great Plains, where many preceding days of above-normal temps will occur. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Tue Sep 10 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE DEEP SOUTH AND THE NORTHERN HIGH PLAINS... ...SUMMARY... A low-probability tornado threat may persist into Thursday across parts of the Deep South. Isolated large hail and severe gusts will be possible over the northern High Plains vicinity on Thursday afternoon and evening. ...Deep South/TN Valley... TC Francine is forecast by NHC to be in a weakening phase on Thursday as it tracks northward across parts of the Lower MS Valley to Mid-South. Model consensus suggests the bulk of strong low-level wind fields will become increasingly confined within the northeast quadrant of the cyclone. This will yield decreasing low-level hodograph curvature through the period, initially along the central/northeast Gulf Coast and gradually expanding northward. This will result in decreasing overlap of favorable SRH with rich tropical moisture, characterized by 70s surface dew points. Tornado potential may be less than on D2, but should still have a diurnal morning to afternoon peak before diminishing during the latter half of D3. Confidence is low with the northern extent of the low-probability tornado threat, which will likely contain scant surface-based instability coincident with moderate to large SRH. The TN Valley vicinity appears to be the northern demarcation. ...Eastern MT to western Dakotas... The northern Rockies to Great Basin shortwave trough should shift east into the northern High Plains to central Rockies by Thursday evening. Guidance has above-average consistency with the depiction of an embedded impulse and attendant meridional mid-level jet impinging on the eastern MT/WY region during the late afternoon to early evening. This will increase large-scale ascent and deep-layer shear, becoming favorably timed with peak boundary-layer heating. Two convective regimes are apparent, one within the post-frontal upslope flow regime in central to eastern MT and the other near the lee surface trough/cyclone close to the MT/Dakotas border area. Isolated large hail will be favored in the western regime, while isolated severe gusts should be favored east. The primary limiting factor to greater severe probs is progged weak buoyancy, with pre-convective surface dew points around the upper 40s to low 50s. ..Grams.. 09/10/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Tue Sep 10 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE DEEP SOUTH AND THE NORTHERN HIGH PLAINS... ...SUMMARY... A low-probability tornado threat may persist into Thursday across parts of the Deep South. Isolated large hail and severe gusts will be possible over the northern High Plains vicinity on Thursday afternoon and evening. ...Deep South/TN Valley... TC Francine is forecast by NHC to be in a weakening phase on Thursday as it tracks northward across parts of the Lower MS Valley to Mid-South. Model consensus suggests the bulk of strong low-level wind fields will become increasingly confined within the northeast quadrant of the cyclone. This will yield decreasing low-level hodograph curvature through the period, initially along the central/northeast Gulf Coast and gradually expanding northward. This will result in decreasing overlap of favorable SRH with rich tropical moisture, characterized by 70s surface dew points. Tornado potential may be less than on D2, but should still have a diurnal morning to afternoon peak before diminishing during the latter half of D3. Confidence is low with the northern extent of the low-probability tornado threat, which will likely contain scant surface-based instability coincident with moderate to large SRH. The TN Valley vicinity appears to be the northern demarcation. ...Eastern MT to western Dakotas... The northern Rockies to Great Basin shortwave trough should shift east into the northern High Plains to central Rockies by Thursday evening. Guidance has above-average consistency with the depiction of an embedded impulse and attendant meridional mid-level jet impinging on the eastern MT/WY region during the late afternoon to early evening. This will increase large-scale ascent and deep-layer shear, becoming favorably timed with peak boundary-layer heating. Two convective regimes are apparent, one within the post-frontal upslope flow regime in central to eastern MT and the other near the lee surface trough/cyclone close to the MT/Dakotas border area. Isolated large hail will be favored in the western regime, while isolated severe gusts should be favored east. The primary limiting factor to greater severe probs is progged weak buoyancy, with pre-convective surface dew points around the upper 40s to low 50s. ..Grams.. 09/10/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Tue Sep 10 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE DEEP SOUTH AND THE NORTHERN HIGH PLAINS... ...SUMMARY... A low-probability tornado threat may persist into Thursday across parts of the Deep South. Isolated large hail and severe gusts will be possible over the northern High Plains vicinity on Thursday afternoon and evening. ...Deep South/TN Valley... TC Francine is forecast by NHC to be in a weakening phase on Thursday as it tracks northward across parts of the Lower MS Valley to Mid-South. Model consensus suggests the bulk of strong low-level wind fields will become increasingly confined within the northeast quadrant of the cyclone. This will yield decreasing low-level hodograph curvature through the period, initially along the central/northeast Gulf Coast and gradually expanding northward. This will result in decreasing overlap of favorable SRH with rich tropical moisture, characterized by 70s surface dew points. Tornado potential may be less than on D2, but should still have a diurnal morning to afternoon peak before diminishing during the latter half of D3. Confidence is low with the northern extent of the low-probability tornado threat, which will likely contain scant surface-based instability coincident with moderate to large SRH. The TN Valley vicinity appears to be the northern demarcation. ...Eastern MT to western Dakotas... The northern Rockies to Great Basin shortwave trough should shift east into the northern High Plains to central Rockies by Thursday evening. Guidance has above-average consistency with the depiction of an embedded impulse and attendant meridional mid-level jet impinging on the eastern MT/WY region during the late afternoon to early evening. This will increase large-scale ascent and deep-layer shear, becoming favorably timed with peak boundary-layer heating. Two convective regimes are apparent, one within the post-frontal upslope flow regime in central to eastern MT and the other near the lee surface trough/cyclone close to the MT/Dakotas border area. Isolated large hail will be favored in the western regime, while isolated severe gusts should be favored east. The primary limiting factor to greater severe probs is progged weak buoyancy, with pre-convective surface dew points around the upper 40s to low 50s. ..Grams.. 09/10/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Tue Sep 10 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE DEEP SOUTH AND THE NORTHERN HIGH PLAINS... ...SUMMARY... A low-probability tornado threat may persist into Thursday across parts of the Deep South. Isolated large hail and severe gusts will be possible over the northern High Plains vicinity on Thursday afternoon and evening. ...Deep South/TN Valley... TC Francine is forecast by NHC to be in a weakening phase on Thursday as it tracks northward across parts of the Lower MS Valley to Mid-South. Model consensus suggests the bulk of strong low-level wind fields will become increasingly confined within the northeast quadrant of the cyclone. This will yield decreasing low-level hodograph curvature through the period, initially along the central/northeast Gulf Coast and gradually expanding northward. This will result in decreasing overlap of favorable SRH with rich tropical moisture, characterized by 70s surface dew points. Tornado potential may be less than on D2, but should still have a diurnal morning to afternoon peak before diminishing during the latter half of D3. Confidence is low with the northern extent of the low-probability tornado threat, which will likely contain scant surface-based instability coincident with moderate to large SRH. The TN Valley vicinity appears to be the northern demarcation. ...Eastern MT to western Dakotas... The northern Rockies to Great Basin shortwave trough should shift east into the northern High Plains to central Rockies by Thursday evening. Guidance has above-average consistency with the depiction of an embedded impulse and attendant meridional mid-level jet impinging on the eastern MT/WY region during the late afternoon to early evening. This will increase large-scale ascent and deep-layer shear, becoming favorably timed with peak boundary-layer heating. Two convective regimes are apparent, one within the post-frontal upslope flow regime in central to eastern MT and the other near the lee surface trough/cyclone close to the MT/Dakotas border area. Isolated large hail will be favored in the western regime, while isolated severe gusts should be favored east. The primary limiting factor to greater severe probs is progged weak buoyancy, with pre-convective surface dew points around the upper 40s to low 50s. ..Grams.. 09/10/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Tue Sep 10 2024 Valid 111200Z - 121200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN... ...Synopsis... The upper trough over the western US will quickly intensify Wednesday, as a shortwave perturbation and mid-level jet streak move onshore over the West Coast. As the trough strengthens, mid-level flow over much of the West will increase. A surface low will deepen over the northern Great Basin, while a cold front moves onshore and also strengthens. To the east, TS Francine will approach the Gulf Coast with offshore winds likely over parts of the mid South. Strong surface winds, low humidity, and thunderstorms over parts of the West and central US will support critical fire-weather concerns Wednesday. ...Great Basin... Ahead of the deepening trough, a potent mid-level jet streak will move over parts of the western Great Basin beginning early Wednesday. A deepening surface low in parts of the eastern Basin will drive 20-25 mph winds over much of NV into western UT. Augmented by downslope flow off the Sierra and the approaching cold front, a brief period of winds of 25-30 mph will be possible along with RH below 15%. Widespread critical fire-weather conditions are likely over parts of the Great Basin. Fire-weather concerns should diminish behind the front as cooler and more quiescent conditions are expected behind the front into early Thursday. ...Lee of the Rockies and High Plains... As the trough approaches, height falls and stronger flow aloft will overspread the Rockies and High Plains. A surface low will deepen first in eastern MT, with a lee trough extending south into the central High Plains. Near the lee trough, strong southerly winds will overlap with areas of low RH and drying fine fuels. Elevated fire weather concerns are expected over parts of the High Plains Wednesday afternoon and evening. ...Mid South... As Francine approaches the Gulf Coast Wednesday and Wednesday night, offshore pressure gradients will increase over parts of the lower MS Valley and Mid South. While humidity values are not expected to be overly low with the tropical air mass approaching, strong gusts are expected to overlap with areas of relatively dry fuels and little recent rainfall. Brief elevated fire-weather conditions are possible before rain chances increase into early Thursday. ...Northwest Thunder... Ahead of the cold front, increasing mid-level moisture and strong lift from the trough will promote scattered thunderstorms Wednesday afternoon. Lightning may interact with areas of somewhat drier fuels over parts of the Northwest and northern Rockies before broader wetting rainfall develops. However, these storms will likely have higher precipitation efficiency with a cooler air mass and more plentiful Pacific moisture in place. This lends significant uncertainty on the threat for any lightning ignitions. ..Lyons.. 09/10/2024 ...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 0202 AM CDT Tue Sep 10 2024 Valid 111200Z - 121200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN... ...Synopsis... The upper trough over the western US will quickly intensify Wednesday, as a shortwave perturbation and mid-level jet streak move onshore over the West Coast. As the trough strengthens, mid-level flow over much of the West will increase. A surface low will deepen over the northern Great Basin, while a cold front moves onshore and also strengthens. To the east, TS Francine will approach the Gulf Coast with offshore winds likely over parts of the mid South. Strong surface winds, low humidity, and thunderstorms over parts of the West and central US will support critical fire-weather concerns Wednesday. ...Great Basin... Ahead of the deepening trough, a potent mid-level jet streak will move over parts of the western Great Basin beginning early Wednesday. A deepening surface low in parts of the eastern Basin will drive 20-25 mph winds over much of NV into western UT. Augmented by downslope flow off the Sierra and the approaching cold front, a brief period of winds of 25-30 mph will be possible along with RH below 15%. Widespread critical fire-weather conditions are likely over parts of the Great Basin. Fire-weather concerns should diminish behind the front as cooler and more quiescent conditions are expected behind the front into early Thursday. ...Lee of the Rockies and High Plains... As the trough approaches, height falls and stronger flow aloft will overspread the Rockies and High Plains. A surface low will deepen first in eastern MT, with a lee trough extending south into the central High Plains. Near the lee trough, strong southerly winds will overlap with areas of low RH and drying fine fuels. Elevated fire weather concerns are expected over parts of the High Plains Wednesday afternoon and evening. ...Mid South... As Francine approaches the Gulf Coast Wednesday and Wednesday night, offshore pressure gradients will increase over parts of the lower MS Valley and Mid South. While humidity values are not expected to be overly low with the tropical air mass approaching, strong gusts are expected to overlap with areas of relatively dry fuels and little recent rainfall. Brief elevated fire-weather conditions are possible before rain chances increase into early Thursday. ...Northwest Thunder... Ahead of the cold front, increasing mid-level moisture and strong lift from the trough will promote scattered thunderstorms Wednesday afternoon. Lightning may interact with areas of somewhat drier fuels over parts of the Northwest and northern Rockies before broader wetting rainfall develops. However, these storms will likely have higher precipitation efficiency with a cooler air mass and more plentiful Pacific moisture in place. This lends significant uncertainty on the threat for any lightning ignitions. ..Lyons.. 09/10/2024 ...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 0202 AM CDT Tue Sep 10 2024 Valid 111200Z - 121200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN... ...Synopsis... The upper trough over the western US will quickly intensify Wednesday, as a shortwave perturbation and mid-level jet streak move onshore over the West Coast. As the trough strengthens, mid-level flow over much of the West will increase. A surface low will deepen over the northern Great Basin, while a cold front moves onshore and also strengthens. To the east, TS Francine will approach the Gulf Coast with offshore winds likely over parts of the mid South. Strong surface winds, low humidity, and thunderstorms over parts of the West and central US will support critical fire-weather concerns Wednesday. ...Great Basin... Ahead of the deepening trough, a potent mid-level jet streak will move over parts of the western Great Basin beginning early Wednesday. A deepening surface low in parts of the eastern Basin will drive 20-25 mph winds over much of NV into western UT. Augmented by downslope flow off the Sierra and the approaching cold front, a brief period of winds of 25-30 mph will be possible along with RH below 15%. Widespread critical fire-weather conditions are likely over parts of the Great Basin. Fire-weather concerns should diminish behind the front as cooler and more quiescent conditions are expected behind the front into early Thursday. ...Lee of the Rockies and High Plains... As the trough approaches, height falls and stronger flow aloft will overspread the Rockies and High Plains. A surface low will deepen first in eastern MT, with a lee trough extending south into the central High Plains. Near the lee trough, strong southerly winds will overlap with areas of low RH and drying fine fuels. Elevated fire weather concerns are expected over parts of the High Plains Wednesday afternoon and evening. ...Mid South... As Francine approaches the Gulf Coast Wednesday and Wednesday night, offshore pressure gradients will increase over parts of the lower MS Valley and Mid South. While humidity values are not expected to be overly low with the tropical air mass approaching, strong gusts are expected to overlap with areas of relatively dry fuels and little recent rainfall. Brief elevated fire-weather conditions are possible before rain chances increase into early Thursday. ...Northwest Thunder... Ahead of the cold front, increasing mid-level moisture and strong lift from the trough will promote scattered thunderstorms Wednesday afternoon. Lightning may interact with areas of somewhat drier fuels over parts of the Northwest and northern Rockies before broader wetting rainfall develops. However, these storms will likely have higher precipitation efficiency with a cooler air mass and more plentiful Pacific moisture in place. This lends significant uncertainty on the threat for any lightning ignitions. ..Lyons.. 09/10/2024 ...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 0202 AM CDT Tue Sep 10 2024 Valid 111200Z - 121200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN... ...Synopsis... The upper trough over the western US will quickly intensify Wednesday, as a shortwave perturbation and mid-level jet streak move onshore over the West Coast. As the trough strengthens, mid-level flow over much of the West will increase. A surface low will deepen over the northern Great Basin, while a cold front moves onshore and also strengthens. To the east, TS Francine will approach the Gulf Coast with offshore winds likely over parts of the mid South. Strong surface winds, low humidity, and thunderstorms over parts of the West and central US will support critical fire-weather concerns Wednesday. ...Great Basin... Ahead of the deepening trough, a potent mid-level jet streak will move over parts of the western Great Basin beginning early Wednesday. A deepening surface low in parts of the eastern Basin will drive 20-25 mph winds over much of NV into western UT. Augmented by downslope flow off the Sierra and the approaching cold front, a brief period of winds of 25-30 mph will be possible along with RH below 15%. Widespread critical fire-weather conditions are likely over parts of the Great Basin. Fire-weather concerns should diminish behind the front as cooler and more quiescent conditions are expected behind the front into early Thursday. ...Lee of the Rockies and High Plains... As the trough approaches, height falls and stronger flow aloft will overspread the Rockies and High Plains. A surface low will deepen first in eastern MT, with a lee trough extending south into the central High Plains. Near the lee trough, strong southerly winds will overlap with areas of low RH and drying fine fuels. Elevated fire weather concerns are expected over parts of the High Plains Wednesday afternoon and evening. ...Mid South... As Francine approaches the Gulf Coast Wednesday and Wednesday night, offshore pressure gradients will increase over parts of the lower MS Valley and Mid South. While humidity values are not expected to be overly low with the tropical air mass approaching, strong gusts are expected to overlap with areas of relatively dry fuels and little recent rainfall. Brief elevated fire-weather conditions are possible before rain chances increase into early Thursday. ...Northwest Thunder... Ahead of the cold front, increasing mid-level moisture and strong lift from the trough will promote scattered thunderstorms Wednesday afternoon. Lightning may interact with areas of somewhat drier fuels over parts of the Northwest and northern Rockies before broader wetting rainfall develops. However, these storms will likely have higher precipitation efficiency with a cooler air mass and more plentiful Pacific moisture in place. This lends significant uncertainty on the threat for any lightning ignitions. ..Lyons.. 09/10/2024 ...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 0159 AM CDT Tue Sep 10 2024 Valid 101200Z - 111200Z ...Synopsis... Broad troughing over the Northwest will gradually intensify later today and tonight, as a stronger shortwave and mid-level jet approach from the eastern Pacific. Increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. Elevated to near-critical fire-weather conditions are likely. ...Great Basin... As the upper trough shifts east, mid-level flow should strengthen over parts of the western Great Basin. Gusty downslope winds are likely in the lee of the Sierra and across parts of southern NV and western UT. Surface winds of 15-25 mph should overlap with RH below 15%, and within areas of dry fuels this afternoon. Elevated to near-critical fire-weather conditions are likely across much of NV and into portions of northern CA, southern ID and far western UT. Confidence in the development of nearly to briefly critical meteorological conditions is highest over parts of southern NV where winds are expected to be slightly stronger. However, fuels here are also slightly less receptive, and the overlap of favorable wind/RH may also be briefer. Thus, confidence remains too low for critical highlights currently. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient behind the departing cold front to drive 15-20 mph winds through Cascade Gaps and into the western Columbia Basin. While cooler and more moderate, pockets of RH below 25% should overlap with the stronger winds. The duration of these breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather conditions are possible within dry fuels. ..Lyons.. 09/10/2024 ...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 0159 AM CDT Tue Sep 10 2024 Valid 101200Z - 111200Z ...Synopsis... Broad troughing over the Northwest will gradually intensify later today and tonight, as a stronger shortwave and mid-level jet approach from the eastern Pacific. Increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. Elevated to near-critical fire-weather conditions are likely. ...Great Basin... As the upper trough shifts east, mid-level flow should strengthen over parts of the western Great Basin. Gusty downslope winds are likely in the lee of the Sierra and across parts of southern NV and western UT. Surface winds of 15-25 mph should overlap with RH below 15%, and within areas of dry fuels this afternoon. Elevated to near-critical fire-weather conditions are likely across much of NV and into portions of northern CA, southern ID and far western UT. Confidence in the development of nearly to briefly critical meteorological conditions is highest over parts of southern NV where winds are expected to be slightly stronger. However, fuels here are also slightly less receptive, and the overlap of favorable wind/RH may also be briefer. Thus, confidence remains too low for critical highlights currently. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient behind the departing cold front to drive 15-20 mph winds through Cascade Gaps and into the western Columbia Basin. While cooler and more moderate, pockets of RH below 25% should overlap with the stronger winds. The duration of these breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather conditions are possible within dry fuels. ..Lyons.. 09/10/2024 ...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 0159 AM CDT Tue Sep 10 2024 Valid 101200Z - 111200Z ...Synopsis... Broad troughing over the Northwest will gradually intensify later today and tonight, as a stronger shortwave and mid-level jet approach from the eastern Pacific. Increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. Elevated to near-critical fire-weather conditions are likely. ...Great Basin... As the upper trough shifts east, mid-level flow should strengthen over parts of the western Great Basin. Gusty downslope winds are likely in the lee of the Sierra and across parts of southern NV and western UT. Surface winds of 15-25 mph should overlap with RH below 15%, and within areas of dry fuels this afternoon. Elevated to near-critical fire-weather conditions are likely across much of NV and into portions of northern CA, southern ID and far western UT. Confidence in the development of nearly to briefly critical meteorological conditions is highest over parts of southern NV where winds are expected to be slightly stronger. However, fuels here are also slightly less receptive, and the overlap of favorable wind/RH may also be briefer. Thus, confidence remains too low for critical highlights currently. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient behind the departing cold front to drive 15-20 mph winds through Cascade Gaps and into the western Columbia Basin. While cooler and more moderate, pockets of RH below 25% should overlap with the stronger winds. The duration of these breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather conditions are possible within dry fuels. ..Lyons.. 09/10/2024 ...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 0159 AM CDT Tue Sep 10 2024 Valid 101200Z - 111200Z ...Synopsis... Broad troughing over the Northwest will gradually intensify later today and tonight, as a stronger shortwave and mid-level jet approach from the eastern Pacific. Increasing flow aloft will move inland, supporting the potential for strong surface winds and low humidity over parts of the Northwest and Great Basin. Elevated to near-critical fire-weather conditions are likely. ...Great Basin... As the upper trough shifts east, mid-level flow should strengthen over parts of the western Great Basin. Gusty downslope winds are likely in the lee of the Sierra and across parts of southern NV and western UT. Surface winds of 15-25 mph should overlap with RH below 15%, and within areas of dry fuels this afternoon. Elevated to near-critical fire-weather conditions are likely across much of NV and into portions of northern CA, southern ID and far western UT. Confidence in the development of nearly to briefly critical meteorological conditions is highest over parts of southern NV where winds are expected to be slightly stronger. However, fuels here are also slightly less receptive, and the overlap of favorable wind/RH may also be briefer. Thus, confidence remains too low for critical highlights currently. ...Cascades and Columbia Gorge... Increasing mid-level winds will combine with a strong onshore pressure gradient behind the departing cold front to drive 15-20 mph winds through Cascade Gaps and into the western Columbia Basin. While cooler and more moderate, pockets of RH below 25% should overlap with the stronger winds. The duration of these breezy and somewhat dry conditions may be somewhat limited, but elevated to briefly critical fire weather conditions are possible within dry fuels. ..Lyons.. 09/10/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Tue Sep 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH LA TO THE COASTAL WESTERN FL PANHANDLE... ...SUMMARY... A few tornadoes are possible across the central Gulf Coast vicinity on Wednesday into Wednesday night, in association with Tropical Cyclone Francine. ...Central Gulf Coast... Per latest NHC forecasts and ensemble guidance, Tropical Storm Francine is expected to become a hurricane over the northwest Gulf and make landfall along the LA coast around Wednesday evening. A low-probability tornado threat with outer-band convection should reach coastal LA by Wednesday morning. The more favorable overlap of strengthening low-level shear/SRH and intrusion of deeper tropical moisture (surface dew points in the mid/upper 70s F) is expected during the afternoon and evening across parts of south-central to southeast LA and far southeast MS/southwest AL. As the TC progresses inland and weakens Wednesday night, some broadening of the favorable SRH/surface-based buoyancy environment should spread east into the coastal FL Panhandle. The northern extent of a low-probability tornado threat remains uncertain, with surface-based buoyancy potentially remaining quite limited into parts of central MS and interior south AL Wednesday night. ...Interior Northwest to the northern High Plains... A shortwave trough will progress inland from the coastal Pacific Northwest, likely reaching the northern Rockies to central Great Basin by 12Z Thursday. Large-scale ascent and cooling mid-level temperatures attendant to the approaching trough will support scattered thunderstorms across the interior Northwest on Wednesday afternoon. While the bulk of strong mid-level flow will remain displaced west of the shortwave trough, moderate enhancement of southwesterlies will occur ahead of it. This should be adequate for marginal updraft rotation amid weak surface-based buoyancy. Isolated strong to localized severe gusts along with small to marginally severe hail will be possible into the early evening. Separately, isolated to widely scattered high-based, low-topped thunderstorms should form in the late afternoon along a lee trough towards a quasi-stationary front over the northern High Plains. Meager buoyancy and modest deep-layer shear within a meridional wind profile suggest sporadic severe gusts in microbursts will be the main threat. Along the immediate north of the front, a confined corridor of greater moisture/instability should be in place during the afternoon/evening, but capping will likely limit surface-based development. A few stronger elevated storms will be possible into Wednesday night, but potential for severe hail appears negligible. ..Grams.. 09/10/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Tue Sep 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH LA TO THE COASTAL WESTERN FL PANHANDLE... ...SUMMARY... A few tornadoes are possible across the central Gulf Coast vicinity on Wednesday into Wednesday night, in association with Tropical Cyclone Francine. ...Central Gulf Coast... Per latest NHC forecasts and ensemble guidance, Tropical Storm Francine is expected to become a hurricane over the northwest Gulf and make landfall along the LA coast around Wednesday evening. A low-probability tornado threat with outer-band convection should reach coastal LA by Wednesday morning. The more favorable overlap of strengthening low-level shear/SRH and intrusion of deeper tropical moisture (surface dew points in the mid/upper 70s F) is expected during the afternoon and evening across parts of south-central to southeast LA and far southeast MS/southwest AL. As the TC progresses inland and weakens Wednesday night, some broadening of the favorable SRH/surface-based buoyancy environment should spread east into the coastal FL Panhandle. The northern extent of a low-probability tornado threat remains uncertain, with surface-based buoyancy potentially remaining quite limited into parts of central MS and interior south AL Wednesday night. ...Interior Northwest to the northern High Plains... A shortwave trough will progress inland from the coastal Pacific Northwest, likely reaching the northern Rockies to central Great Basin by 12Z Thursday. Large-scale ascent and cooling mid-level temperatures attendant to the approaching trough will support scattered thunderstorms across the interior Northwest on Wednesday afternoon. While the bulk of strong mid-level flow will remain displaced west of the shortwave trough, moderate enhancement of southwesterlies will occur ahead of it. This should be adequate for marginal updraft rotation amid weak surface-based buoyancy. Isolated strong to localized severe gusts along with small to marginally severe hail will be possible into the early evening. Separately, isolated to widely scattered high-based, low-topped thunderstorms should form in the late afternoon along a lee trough towards a quasi-stationary front over the northern High Plains. Meager buoyancy and modest deep-layer shear within a meridional wind profile suggest sporadic severe gusts in microbursts will be the main threat. Along the immediate north of the front, a confined corridor of greater moisture/instability should be in place during the afternoon/evening, but capping will likely limit surface-based development. A few stronger elevated storms will be possible into Wednesday night, but potential for severe hail appears negligible. ..Grams.. 09/10/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Tue Sep 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH LA TO THE COASTAL WESTERN FL PANHANDLE... ...SUMMARY... A few tornadoes are possible across the central Gulf Coast vicinity on Wednesday into Wednesday night, in association with Tropical Cyclone Francine. ...Central Gulf Coast... Per latest NHC forecasts and ensemble guidance, Tropical Storm Francine is expected to become a hurricane over the northwest Gulf and make landfall along the LA coast around Wednesday evening. A low-probability tornado threat with outer-band convection should reach coastal LA by Wednesday morning. The more favorable overlap of strengthening low-level shear/SRH and intrusion of deeper tropical moisture (surface dew points in the mid/upper 70s F) is expected during the afternoon and evening across parts of south-central to southeast LA and far southeast MS/southwest AL. As the TC progresses inland and weakens Wednesday night, some broadening of the favorable SRH/surface-based buoyancy environment should spread east into the coastal FL Panhandle. The northern extent of a low-probability tornado threat remains uncertain, with surface-based buoyancy potentially remaining quite limited into parts of central MS and interior south AL Wednesday night. ...Interior Northwest to the northern High Plains... A shortwave trough will progress inland from the coastal Pacific Northwest, likely reaching the northern Rockies to central Great Basin by 12Z Thursday. Large-scale ascent and cooling mid-level temperatures attendant to the approaching trough will support scattered thunderstorms across the interior Northwest on Wednesday afternoon. While the bulk of strong mid-level flow will remain displaced west of the shortwave trough, moderate enhancement of southwesterlies will occur ahead of it. This should be adequate for marginal updraft rotation amid weak surface-based buoyancy. Isolated strong to localized severe gusts along with small to marginally severe hail will be possible into the early evening. Separately, isolated to widely scattered high-based, low-topped thunderstorms should form in the late afternoon along a lee trough towards a quasi-stationary front over the northern High Plains. Meager buoyancy and modest deep-layer shear within a meridional wind profile suggest sporadic severe gusts in microbursts will be the main threat. Along the immediate north of the front, a confined corridor of greater moisture/instability should be in place during the afternoon/evening, but capping will likely limit surface-based development. A few stronger elevated storms will be possible into Wednesday night, but potential for severe hail appears negligible. ..Grams.. 09/10/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Tue Sep 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH LA TO THE COASTAL WESTERN FL PANHANDLE... ...SUMMARY... A few tornadoes are possible across the central Gulf Coast vicinity on Wednesday into Wednesday night, in association with Tropical Cyclone Francine. ...Central Gulf Coast... Per latest NHC forecasts and ensemble guidance, Tropical Storm Francine is expected to become a hurricane over the northwest Gulf and make landfall along the LA coast around Wednesday evening. A low-probability tornado threat with outer-band convection should reach coastal LA by Wednesday morning. The more favorable overlap of strengthening low-level shear/SRH and intrusion of deeper tropical moisture (surface dew points in the mid/upper 70s F) is expected during the afternoon and evening across parts of south-central to southeast LA and far southeast MS/southwest AL. As the TC progresses inland and weakens Wednesday night, some broadening of the favorable SRH/surface-based buoyancy environment should spread east into the coastal FL Panhandle. The northern extent of a low-probability tornado threat remains uncertain, with surface-based buoyancy potentially remaining quite limited into parts of central MS and interior south AL Wednesday night. ...Interior Northwest to the northern High Plains... A shortwave trough will progress inland from the coastal Pacific Northwest, likely reaching the northern Rockies to central Great Basin by 12Z Thursday. Large-scale ascent and cooling mid-level temperatures attendant to the approaching trough will support scattered thunderstorms across the interior Northwest on Wednesday afternoon. While the bulk of strong mid-level flow will remain displaced west of the shortwave trough, moderate enhancement of southwesterlies will occur ahead of it. This should be adequate for marginal updraft rotation amid weak surface-based buoyancy. Isolated strong to localized severe gusts along with small to marginally severe hail will be possible into the early evening. Separately, isolated to widely scattered high-based, low-topped thunderstorms should form in the late afternoon along a lee trough towards a quasi-stationary front over the northern High Plains. Meager buoyancy and modest deep-layer shear within a meridional wind profile suggest sporadic severe gusts in microbursts will be the main threat. Along the immediate north of the front, a confined corridor of greater moisture/instability should be in place during the afternoon/evening, but capping will likely limit surface-based development. A few stronger elevated storms will be possible into Wednesday night, but potential for severe hail appears negligible. ..Grams.. 09/10/2024 Read more