Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 14 2024 Valid 141700Z - 151200Z The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0144 AM CDT Sat Sep 14 2024/ ...Synopsis... A midlevel jet streak will cross the northern Rockies today, encouraging lee troughing along the northern/central High Plains. Over portions of WY, 15-20 mph sustained west-southwesterly surface winds and 10-15 percent RH will develop in response to the lee troughing and deep boundary-layer mixing into the enhanced flow aloft. Given modestly receptive fuels across the area, elevated fire-weather conditions are expected during the afternoon. Farther west, breezy southerly surface winds are expected amid 15-20 percent RH across portions of the southern Great Basin -- within the base of a gradually amplifying large-scale trough. While locally elevated fire-weather conditions are possible, a lack of stronger sustained surface winds should limit the overall fire-weather risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 14 2024 Valid 141700Z - 151200Z The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0144 AM CDT Sat Sep 14 2024/ ...Synopsis... A midlevel jet streak will cross the northern Rockies today, encouraging lee troughing along the northern/central High Plains. Over portions of WY, 15-20 mph sustained west-southwesterly surface winds and 10-15 percent RH will develop in response to the lee troughing and deep boundary-layer mixing into the enhanced flow aloft. Given modestly receptive fuels across the area, elevated fire-weather conditions are expected during the afternoon. Farther west, breezy southerly surface winds are expected amid 15-20 percent RH across portions of the southern Great Basin -- within the base of a gradually amplifying large-scale trough. While locally elevated fire-weather conditions are possible, a lack of stronger sustained surface winds should limit the overall fire-weather risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 14 2024 Valid 141700Z - 151200Z The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0144 AM CDT Sat Sep 14 2024/ ...Synopsis... A midlevel jet streak will cross the northern Rockies today, encouraging lee troughing along the northern/central High Plains. Over portions of WY, 15-20 mph sustained west-southwesterly surface winds and 10-15 percent RH will develop in response to the lee troughing and deep boundary-layer mixing into the enhanced flow aloft. Given modestly receptive fuels across the area, elevated fire-weather conditions are expected during the afternoon. Farther west, breezy southerly surface winds are expected amid 15-20 percent RH across portions of the southern Great Basin -- within the base of a gradually amplifying large-scale trough. While locally elevated fire-weather conditions are possible, a lack of stronger sustained surface winds should limit the overall fire-weather risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 14 2024 Valid 141700Z - 151200Z The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0144 AM CDT Sat Sep 14 2024/ ...Synopsis... A midlevel jet streak will cross the northern Rockies today, encouraging lee troughing along the northern/central High Plains. Over portions of WY, 15-20 mph sustained west-southwesterly surface winds and 10-15 percent RH will develop in response to the lee troughing and deep boundary-layer mixing into the enhanced flow aloft. Given modestly receptive fuels across the area, elevated fire-weather conditions are expected during the afternoon. Farther west, breezy southerly surface winds are expected amid 15-20 percent RH across portions of the southern Great Basin -- within the base of a gradually amplifying large-scale trough. While locally elevated fire-weather conditions are possible, a lack of stronger sustained surface winds should limit the overall fire-weather risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 14 2024 Valid 141700Z - 151200Z The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0144 AM CDT Sat Sep 14 2024/ ...Synopsis... A midlevel jet streak will cross the northern Rockies today, encouraging lee troughing along the northern/central High Plains. Over portions of WY, 15-20 mph sustained west-southwesterly surface winds and 10-15 percent RH will develop in response to the lee troughing and deep boundary-layer mixing into the enhanced flow aloft. Given modestly receptive fuels across the area, elevated fire-weather conditions are expected during the afternoon. Farther west, breezy southerly surface winds are expected amid 15-20 percent RH across portions of the southern Great Basin -- within the base of a gradually amplifying large-scale trough. While locally elevated fire-weather conditions are possible, a lack of stronger sustained surface winds should limit the overall fire-weather risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 14 2024 Valid 141700Z - 151200Z The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0144 AM CDT Sat Sep 14 2024/ ...Synopsis... A midlevel jet streak will cross the northern Rockies today, encouraging lee troughing along the northern/central High Plains. Over portions of WY, 15-20 mph sustained west-southwesterly surface winds and 10-15 percent RH will develop in response to the lee troughing and deep boundary-layer mixing into the enhanced flow aloft. Given modestly receptive fuels across the area, elevated fire-weather conditions are expected during the afternoon. Farther west, breezy southerly surface winds are expected amid 15-20 percent RH across portions of the southern Great Basin -- within the base of a gradually amplifying large-scale trough. While locally elevated fire-weather conditions are possible, a lack of stronger sustained surface winds should limit the overall fire-weather risk. ...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 1222 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible Sunday afternoon and evening across parts of the central High Plains. ...Synopsis... An upper-level trough currently residing over the northeastern Pacific is forecast to deepen substantially over the next 48 hours along the West Coast. This will establish a broad swath of strengthening south/southwesterly flow across the greater Great Basin region into the central/northern Rockies. Low-level moisture return into the central Plains should increase as a lee surface trough slowly deepens in response to the evolving upper-level pattern. The increasing moisture/buoyancy quality may support some intensification of convection as it migrates out of the central Rockies and into the High Plains Sunday afternoon and evening. ...Central High Plains... High-based convection is expected to develop within the central Rockies by mid/late afternoon Sunday as a combination of deep-layer ascent and diurnal warming steepen lapse rates. Isolated thunderstorms are also possible in the vicinity of a deepening surface trough across eastern WY/northeast CO where surface pressure falls are currently expected to be strongest. Forecast guidance suggests that this activity will intensify as it migrates northeast and impinges on the western periphery of the moisture reservoir to the east of the surface trough where MLCAPE values may be as high as 1000-2000 J/kg. While the central High Plains will likely remain displaced from the strongest mid/upper-level flow, 25-30 knot mid-level winds with modest low-level flow should provide sufficient deep-layer shear to support some degree of storm organization with an attendant large hail threat. Additionally, boundary-layer mixing on the edge of the deeper moisture will be adequately deep (mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts with the more organized cells and/or clusters. ...Great Basin/Four Corners... Increasing broad scale ascent over the Great Basin and Four Corners region should result in isolated to scattered thunderstorm development by late afternoon. While some degree of moisture return is anticipated from the Gulf of California across southern AZ, most regions will remain fairly warm and dry in the low-levels. Such thermodynamic conditions will be conducive for dry downbursts that may be capable of very localized strong to severe gusts. The predictability of where such gusts are most likely across the broader region remains too limited to warrant risk probabilities. ..Moore.. 09/14/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible Sunday afternoon and evening across parts of the central High Plains. ...Synopsis... An upper-level trough currently residing over the northeastern Pacific is forecast to deepen substantially over the next 48 hours along the West Coast. This will establish a broad swath of strengthening south/southwesterly flow across the greater Great Basin region into the central/northern Rockies. Low-level moisture return into the central Plains should increase as a lee surface trough slowly deepens in response to the evolving upper-level pattern. The increasing moisture/buoyancy quality may support some intensification of convection as it migrates out of the central Rockies and into the High Plains Sunday afternoon and evening. ...Central High Plains... High-based convection is expected to develop within the central Rockies by mid/late afternoon Sunday as a combination of deep-layer ascent and diurnal warming steepen lapse rates. Isolated thunderstorms are also possible in the vicinity of a deepening surface trough across eastern WY/northeast CO where surface pressure falls are currently expected to be strongest. Forecast guidance suggests that this activity will intensify as it migrates northeast and impinges on the western periphery of the moisture reservoir to the east of the surface trough where MLCAPE values may be as high as 1000-2000 J/kg. While the central High Plains will likely remain displaced from the strongest mid/upper-level flow, 25-30 knot mid-level winds with modest low-level flow should provide sufficient deep-layer shear to support some degree of storm organization with an attendant large hail threat. Additionally, boundary-layer mixing on the edge of the deeper moisture will be adequately deep (mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts with the more organized cells and/or clusters. ...Great Basin/Four Corners... Increasing broad scale ascent over the Great Basin and Four Corners region should result in isolated to scattered thunderstorm development by late afternoon. While some degree of moisture return is anticipated from the Gulf of California across southern AZ, most regions will remain fairly warm and dry in the low-levels. Such thermodynamic conditions will be conducive for dry downbursts that may be capable of very localized strong to severe gusts. The predictability of where such gusts are most likely across the broader region remains too limited to warrant risk probabilities. ..Moore.. 09/14/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible Sunday afternoon and evening across parts of the central High Plains. ...Synopsis... An upper-level trough currently residing over the northeastern Pacific is forecast to deepen substantially over the next 48 hours along the West Coast. This will establish a broad swath of strengthening south/southwesterly flow across the greater Great Basin region into the central/northern Rockies. Low-level moisture return into the central Plains should increase as a lee surface trough slowly deepens in response to the evolving upper-level pattern. The increasing moisture/buoyancy quality may support some intensification of convection as it migrates out of the central Rockies and into the High Plains Sunday afternoon and evening. ...Central High Plains... High-based convection is expected to develop within the central Rockies by mid/late afternoon Sunday as a combination of deep-layer ascent and diurnal warming steepen lapse rates. Isolated thunderstorms are also possible in the vicinity of a deepening surface trough across eastern WY/northeast CO where surface pressure falls are currently expected to be strongest. Forecast guidance suggests that this activity will intensify as it migrates northeast and impinges on the western periphery of the moisture reservoir to the east of the surface trough where MLCAPE values may be as high as 1000-2000 J/kg. While the central High Plains will likely remain displaced from the strongest mid/upper-level flow, 25-30 knot mid-level winds with modest low-level flow should provide sufficient deep-layer shear to support some degree of storm organization with an attendant large hail threat. Additionally, boundary-layer mixing on the edge of the deeper moisture will be adequately deep (mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts with the more organized cells and/or clusters. ...Great Basin/Four Corners... Increasing broad scale ascent over the Great Basin and Four Corners region should result in isolated to scattered thunderstorm development by late afternoon. While some degree of moisture return is anticipated from the Gulf of California across southern AZ, most regions will remain fairly warm and dry in the low-levels. Such thermodynamic conditions will be conducive for dry downbursts that may be capable of very localized strong to severe gusts. The predictability of where such gusts are most likely across the broader region remains too limited to warrant risk probabilities. ..Moore.. 09/14/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible Sunday afternoon and evening across parts of the central High Plains. ...Synopsis... An upper-level trough currently residing over the northeastern Pacific is forecast to deepen substantially over the next 48 hours along the West Coast. This will establish a broad swath of strengthening south/southwesterly flow across the greater Great Basin region into the central/northern Rockies. Low-level moisture return into the central Plains should increase as a lee surface trough slowly deepens in response to the evolving upper-level pattern. The increasing moisture/buoyancy quality may support some intensification of convection as it migrates out of the central Rockies and into the High Plains Sunday afternoon and evening. ...Central High Plains... High-based convection is expected to develop within the central Rockies by mid/late afternoon Sunday as a combination of deep-layer ascent and diurnal warming steepen lapse rates. Isolated thunderstorms are also possible in the vicinity of a deepening surface trough across eastern WY/northeast CO where surface pressure falls are currently expected to be strongest. Forecast guidance suggests that this activity will intensify as it migrates northeast and impinges on the western periphery of the moisture reservoir to the east of the surface trough where MLCAPE values may be as high as 1000-2000 J/kg. While the central High Plains will likely remain displaced from the strongest mid/upper-level flow, 25-30 knot mid-level winds with modest low-level flow should provide sufficient deep-layer shear to support some degree of storm organization with an attendant large hail threat. Additionally, boundary-layer mixing on the edge of the deeper moisture will be adequately deep (mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts with the more organized cells and/or clusters. ...Great Basin/Four Corners... Increasing broad scale ascent over the Great Basin and Four Corners region should result in isolated to scattered thunderstorm development by late afternoon. While some degree of moisture return is anticipated from the Gulf of California across southern AZ, most regions will remain fairly warm and dry in the low-levels. Such thermodynamic conditions will be conducive for dry downbursts that may be capable of very localized strong to severe gusts. The predictability of where such gusts are most likely across the broader region remains too limited to warrant risk probabilities. ..Moore.. 09/14/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible Sunday afternoon and evening across parts of the central High Plains. ...Synopsis... An upper-level trough currently residing over the northeastern Pacific is forecast to deepen substantially over the next 48 hours along the West Coast. This will establish a broad swath of strengthening south/southwesterly flow across the greater Great Basin region into the central/northern Rockies. Low-level moisture return into the central Plains should increase as a lee surface trough slowly deepens in response to the evolving upper-level pattern. The increasing moisture/buoyancy quality may support some intensification of convection as it migrates out of the central Rockies and into the High Plains Sunday afternoon and evening. ...Central High Plains... High-based convection is expected to develop within the central Rockies by mid/late afternoon Sunday as a combination of deep-layer ascent and diurnal warming steepen lapse rates. Isolated thunderstorms are also possible in the vicinity of a deepening surface trough across eastern WY/northeast CO where surface pressure falls are currently expected to be strongest. Forecast guidance suggests that this activity will intensify as it migrates northeast and impinges on the western periphery of the moisture reservoir to the east of the surface trough where MLCAPE values may be as high as 1000-2000 J/kg. While the central High Plains will likely remain displaced from the strongest mid/upper-level flow, 25-30 knot mid-level winds with modest low-level flow should provide sufficient deep-layer shear to support some degree of storm organization with an attendant large hail threat. Additionally, boundary-layer mixing on the edge of the deeper moisture will be adequately deep (mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts with the more organized cells and/or clusters. ...Great Basin/Four Corners... Increasing broad scale ascent over the Great Basin and Four Corners region should result in isolated to scattered thunderstorm development by late afternoon. While some degree of moisture return is anticipated from the Gulf of California across southern AZ, most regions will remain fairly warm and dry in the low-levels. Such thermodynamic conditions will be conducive for dry downbursts that may be capable of very localized strong to severe gusts. The predictability of where such gusts are most likely across the broader region remains too limited to warrant risk probabilities. ..Moore.. 09/14/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible Sunday afternoon and evening across parts of the central High Plains. ...Synopsis... An upper-level trough currently residing over the northeastern Pacific is forecast to deepen substantially over the next 48 hours along the West Coast. This will establish a broad swath of strengthening south/southwesterly flow across the greater Great Basin region into the central/northern Rockies. Low-level moisture return into the central Plains should increase as a lee surface trough slowly deepens in response to the evolving upper-level pattern. The increasing moisture/buoyancy quality may support some intensification of convection as it migrates out of the central Rockies and into the High Plains Sunday afternoon and evening. ...Central High Plains... High-based convection is expected to develop within the central Rockies by mid/late afternoon Sunday as a combination of deep-layer ascent and diurnal warming steepen lapse rates. Isolated thunderstorms are also possible in the vicinity of a deepening surface trough across eastern WY/northeast CO where surface pressure falls are currently expected to be strongest. Forecast guidance suggests that this activity will intensify as it migrates northeast and impinges on the western periphery of the moisture reservoir to the east of the surface trough where MLCAPE values may be as high as 1000-2000 J/kg. While the central High Plains will likely remain displaced from the strongest mid/upper-level flow, 25-30 knot mid-level winds with modest low-level flow should provide sufficient deep-layer shear to support some degree of storm organization with an attendant large hail threat. Additionally, boundary-layer mixing on the edge of the deeper moisture will be adequately deep (mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts with the more organized cells and/or clusters. ...Great Basin/Four Corners... Increasing broad scale ascent over the Great Basin and Four Corners region should result in isolated to scattered thunderstorm development by late afternoon. While some degree of moisture return is anticipated from the Gulf of California across southern AZ, most regions will remain fairly warm and dry in the low-levels. Such thermodynamic conditions will be conducive for dry downbursts that may be capable of very localized strong to severe gusts. The predictability of where such gusts are most likely across the broader region remains too limited to warrant risk probabilities. ..Moore.. 09/14/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible Sunday afternoon and evening across parts of the central High Plains. ...Synopsis... An upper-level trough currently residing over the northeastern Pacific is forecast to deepen substantially over the next 48 hours along the West Coast. This will establish a broad swath of strengthening south/southwesterly flow across the greater Great Basin region into the central/northern Rockies. Low-level moisture return into the central Plains should increase as a lee surface trough slowly deepens in response to the evolving upper-level pattern. The increasing moisture/buoyancy quality may support some intensification of convection as it migrates out of the central Rockies and into the High Plains Sunday afternoon and evening. ...Central High Plains... High-based convection is expected to develop within the central Rockies by mid/late afternoon Sunday as a combination of deep-layer ascent and diurnal warming steepen lapse rates. Isolated thunderstorms are also possible in the vicinity of a deepening surface trough across eastern WY/northeast CO where surface pressure falls are currently expected to be strongest. Forecast guidance suggests that this activity will intensify as it migrates northeast and impinges on the western periphery of the moisture reservoir to the east of the surface trough where MLCAPE values may be as high as 1000-2000 J/kg. While the central High Plains will likely remain displaced from the strongest mid/upper-level flow, 25-30 knot mid-level winds with modest low-level flow should provide sufficient deep-layer shear to support some degree of storm organization with an attendant large hail threat. Additionally, boundary-layer mixing on the edge of the deeper moisture will be adequately deep (mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts with the more organized cells and/or clusters. ...Great Basin/Four Corners... Increasing broad scale ascent over the Great Basin and Four Corners region should result in isolated to scattered thunderstorm development by late afternoon. While some degree of moisture return is anticipated from the Gulf of California across southern AZ, most regions will remain fairly warm and dry in the low-levels. Such thermodynamic conditions will be conducive for dry downbursts that may be capable of very localized strong to severe gusts. The predictability of where such gusts are most likely across the broader region remains too limited to warrant risk probabilities. ..Moore.. 09/14/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible Sunday afternoon and evening across parts of the central High Plains. ...Synopsis... An upper-level trough currently residing over the northeastern Pacific is forecast to deepen substantially over the next 48 hours along the West Coast. This will establish a broad swath of strengthening south/southwesterly flow across the greater Great Basin region into the central/northern Rockies. Low-level moisture return into the central Plains should increase as a lee surface trough slowly deepens in response to the evolving upper-level pattern. The increasing moisture/buoyancy quality may support some intensification of convection as it migrates out of the central Rockies and into the High Plains Sunday afternoon and evening. ...Central High Plains... High-based convection is expected to develop within the central Rockies by mid/late afternoon Sunday as a combination of deep-layer ascent and diurnal warming steepen lapse rates. Isolated thunderstorms are also possible in the vicinity of a deepening surface trough across eastern WY/northeast CO where surface pressure falls are currently expected to be strongest. Forecast guidance suggests that this activity will intensify as it migrates northeast and impinges on the western periphery of the moisture reservoir to the east of the surface trough where MLCAPE values may be as high as 1000-2000 J/kg. While the central High Plains will likely remain displaced from the strongest mid/upper-level flow, 25-30 knot mid-level winds with modest low-level flow should provide sufficient deep-layer shear to support some degree of storm organization with an attendant large hail threat. Additionally, boundary-layer mixing on the edge of the deeper moisture will be adequately deep (mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts with the more organized cells and/or clusters. ...Great Basin/Four Corners... Increasing broad scale ascent over the Great Basin and Four Corners region should result in isolated to scattered thunderstorm development by late afternoon. While some degree of moisture return is anticipated from the Gulf of California across southern AZ, most regions will remain fairly warm and dry in the low-levels. Such thermodynamic conditions will be conducive for dry downbursts that may be capable of very localized strong to severe gusts. The predictability of where such gusts are most likely across the broader region remains too limited to warrant risk probabilities. ..Moore.. 09/14/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible Sunday afternoon and evening across parts of the central High Plains. ...Synopsis... An upper-level trough currently residing over the northeastern Pacific is forecast to deepen substantially over the next 48 hours along the West Coast. This will establish a broad swath of strengthening south/southwesterly flow across the greater Great Basin region into the central/northern Rockies. Low-level moisture return into the central Plains should increase as a lee surface trough slowly deepens in response to the evolving upper-level pattern. The increasing moisture/buoyancy quality may support some intensification of convection as it migrates out of the central Rockies and into the High Plains Sunday afternoon and evening. ...Central High Plains... High-based convection is expected to develop within the central Rockies by mid/late afternoon Sunday as a combination of deep-layer ascent and diurnal warming steepen lapse rates. Isolated thunderstorms are also possible in the vicinity of a deepening surface trough across eastern WY/northeast CO where surface pressure falls are currently expected to be strongest. Forecast guidance suggests that this activity will intensify as it migrates northeast and impinges on the western periphery of the moisture reservoir to the east of the surface trough where MLCAPE values may be as high as 1000-2000 J/kg. While the central High Plains will likely remain displaced from the strongest mid/upper-level flow, 25-30 knot mid-level winds with modest low-level flow should provide sufficient deep-layer shear to support some degree of storm organization with an attendant large hail threat. Additionally, boundary-layer mixing on the edge of the deeper moisture will be adequately deep (mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts with the more organized cells and/or clusters. ...Great Basin/Four Corners... Increasing broad scale ascent over the Great Basin and Four Corners region should result in isolated to scattered thunderstorm development by late afternoon. While some degree of moisture return is anticipated from the Gulf of California across southern AZ, most regions will remain fairly warm and dry in the low-levels. Such thermodynamic conditions will be conducive for dry downbursts that may be capable of very localized strong to severe gusts. The predictability of where such gusts are most likely across the broader region remains too limited to warrant risk probabilities. ..Moore.. 09/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Sat Sep 14 2024 Valid 141630Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. ..Gleason/Dean.. 09/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Sat Sep 14 2024 Valid 141630Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. ..Gleason/Dean.. 09/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Sat Sep 14 2024 Valid 141630Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. ..Gleason/Dean.. 09/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Sat Sep 14 2024 Valid 141630Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. ..Gleason/Dean.. 09/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Sat Sep 14 2024 Valid 141630Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. ..Gleason/Dean.. 09/14/2024 Read more