Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0217 PM CDT Mon Jul 21 2025 Valid 221200Z - 231200Z No changes are needed to the D2 Fire Weather Outlook. ..Thornton.. 07/21/2025 .PREV DISCUSSION... /ISSUED 0201 AM CDT Mon Jul 21 2025/ ...Synopsis... The upper-level trough in the Northwest will become more diffuse on Tuesday. Mid-level winds will slacken across the Great Basin. A weak surface trough/boundary will remain in northern Nevada. ...Southern/central Nevada... While surface winds will generally be weaker than previous days, the surface pressure gradient near the boundary will support 15-20 mph in portions of southern/central Nevada. RH of 15-20% appears possible during the afternoon. Area fuels remain dry enough to support elevated fire weather conditions. ...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 0217 PM CDT Mon Jul 21 2025 Valid 221200Z - 231200Z No changes are needed to the D2 Fire Weather Outlook. ..Thornton.. 07/21/2025 .PREV DISCUSSION... /ISSUED 0201 AM CDT Mon Jul 21 2025/ ...Synopsis... The upper-level trough in the Northwest will become more diffuse on Tuesday. Mid-level winds will slacken across the Great Basin. A weak surface trough/boundary will remain in northern Nevada. ...Southern/central Nevada... While surface winds will generally be weaker than previous days, the surface pressure gradient near the boundary will support 15-20 mph in portions of southern/central Nevada. RH of 15-20% appears possible during the afternoon. Area fuels remain dry enough to support elevated fire weather conditions. ...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 0217 PM CDT Mon Jul 21 2025 Valid 221200Z - 231200Z No changes are needed to the D2 Fire Weather Outlook. ..Thornton.. 07/21/2025 .PREV DISCUSSION... /ISSUED 0201 AM CDT Mon Jul 21 2025/ ...Synopsis... The upper-level trough in the Northwest will become more diffuse on Tuesday. Mid-level winds will slacken across the Great Basin. A weak surface trough/boundary will remain in northern Nevada. ...Southern/central Nevada... While surface winds will generally be weaker than previous days, the surface pressure gradient near the boundary will support 15-20 mph in portions of southern/central Nevada. RH of 15-20% appears possible during the afternoon. Area fuels remain dry enough to support elevated fire weather conditions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0732 AM CDT Mon Jul 21 2025 Valid 211300Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS... ...SUMMARY... Severe thunderstorms capable of producing large hail, severe gusts, and perhaps a tornado or two will be possible today and tonight across parts of the northern Plains. Additional isolated strong to severe storms may occur across portions of the central Plains. ...Northern Plains into the Upper Midwest... A long-lived and compact MCS has advanced into parts of west-central MN this morning. This convection is on the northern periphery of meaningful low-level moisture and related instability. It should generally weaken over the next few hours while it tracks southeastward over southern MN as a low-level jet gradually lessens. But in the short term, it may still be capable of producing occasional strong to severe wind gusts. Behind this activity, a moist and rather unstable airmass will exist across the northern Plains along and south of a convectively reinforced front that should become oriented generally east-west along the ND/SD border by late this afternoon. Large-scale ascent across the northern Plains will likely be weak for much of the day, as upper ridging remains prominent over the central CONUS. Even so, there are indications that a weak mid-level perturbation emanating from upper troughing over the Pacific Northwest should overspread the northern Rockies and adjacent High Plains of central/eastern MT by mid/late afternoon as ample daytime heating of a slowly moistening low-level airmass occurs. A belt of enhanced west-southwesterly mid-level flow will accompany this feature, supporting ample veering/strengthening of the wind profile with height through mid/upper levels. Related strong deep-layer shear of 40-50+ kt will easily support supercells with initial development off the Bighorns given the presence of at least moderate instability across the High Plains. Large hail will be possible with these supercells this afternoon, followed by an increasing severe wind threat with time this evening/overnight into parts of the Dakotas as convection potentially grows upscale, and where ample MUCAPE and strong deep-layer shear will be present along/north of the surface boundary. The development of elevated supercells also appears possible across parts of the Dakotas late tonight as a low-level jet gradually strengthens, with a related threat for at least isolated severe hail if they occur. ...Central Plains... Much of the central Plains will remain capped today, as the upper ridge and warm temperatures aloft exert their influence. A surface trough is expected to extend southward across the central High Plains this afternoon, and a remnant MCV related to earlier convection should move eastward along/near the NE/KS border. Both of these features may aid in at least isolated thunderstorm development this afternoon, in the presence of moderate to strong instability amid modest deep-layer shear. Isolated severe hail and wind gusts may occur with any of the more robust cores that can develop and be maintained in an otherwise weak forcing regime. The Marginal Risk has been expanded southward a little to include more of northern KS and southeast NE, where strong to severe convection may develop later today in close proximity to the MCV. ...Tennessee Valley into the Southeast... A weak MCV related to ongoing convection across MO and southern IL this morning will track southeastward across the TN Valley and vicinity through this afternoon. Modest west-northwesterly flow should be in place today across parts of the OH/TN Valleys into the Southeast. This may support loosely organized multicells and pulse thunderstorms today, as mostly sunny conditions aid in the development of moderate to locally strong instability this afternoon. While deep-layer shear is forecast to remain weak, some of this convection may still be capable of producing strong to locally damaging winds. Parts of these regions may be considered for inclusion in a Marginal Risk in a later outlook update, pending additional observational/model trends. ..Gleason/Bentley.. 07/21/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0353 AM CDT Mon Jul 21 2025 Valid 241200Z - 291200Z ...DISCUSSION... Medium-range models indicate that mid-level ridging, initially centered over the Ohio Valley, will weaken late this work week through next weekend, as flow undergoes substantive amplification upstream. This appears likely to include a significant short wave trough digging southeast of the Aleutians, accompanied by lower/mid-tropospheric cyclogenesis across the northeastern Pacific. Part of a higher latitude blocking pattern, little subsequent movement of this cyclone is forecast through early next week, as an expansive, prominent mid-level ridge also evolves in the downstream lower latitudes, across much of the Intermountain West, Rockies and Great Plains into mid and lower Mississippi Valley. However, as a notable mid-level low continues slowly east of Hudson Bay, across northern Quebec and Newfoundland and Labrador, a belt of seasonably strong westerly mid/upper flow may be maintained across Ontario and Quebec this Thursday through Friday. Along the favorably sheared southern fringe of this regime, seasonably moist low-level air advecting ahead of a stalled to southward advancing frontal zone may contribute to sufficient destabilization for the evolution of organizing thunderstorm clusters capable of producing swaths of damaging wind gusts. The extent to which this may impact U.S. portions of the Great Lakes into New England remains unclear. It might not be out of the question that a similar type regime could evolve beneath developing northwesterly mid-level flow, from the North Dakota/Minnesota international border area into the Upper Midwest/Great Lakes late next weekend into early next week. Current guidance is still suggestive that this is a lower probability, but this could be due to the low predictability of the pertinent features at this extended range. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0353 AM CDT Mon Jul 21 2025 Valid 241200Z - 291200Z ...DISCUSSION... Medium-range models indicate that mid-level ridging, initially centered over the Ohio Valley, will weaken late this work week through next weekend, as flow undergoes substantive amplification upstream. This appears likely to include a significant short wave trough digging southeast of the Aleutians, accompanied by lower/mid-tropospheric cyclogenesis across the northeastern Pacific. Part of a higher latitude blocking pattern, little subsequent movement of this cyclone is forecast through early next week, as an expansive, prominent mid-level ridge also evolves in the downstream lower latitudes, across much of the Intermountain West, Rockies and Great Plains into mid and lower Mississippi Valley. However, as a notable mid-level low continues slowly east of Hudson Bay, across northern Quebec and Newfoundland and Labrador, a belt of seasonably strong westerly mid/upper flow may be maintained across Ontario and Quebec this Thursday through Friday. Along the favorably sheared southern fringe of this regime, seasonably moist low-level air advecting ahead of a stalled to southward advancing frontal zone may contribute to sufficient destabilization for the evolution of organizing thunderstorm clusters capable of producing swaths of damaging wind gusts. The extent to which this may impact U.S. portions of the Great Lakes into New England remains unclear. It might not be out of the question that a similar type regime could evolve beneath developing northwesterly mid-level flow, from the North Dakota/Minnesota international border area into the Upper Midwest/Great Lakes late next weekend into early next week. Current guidance is still suggestive that this is a lower probability, but this could be due to the low predictability of the pertinent features at this extended range. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0353 AM CDT Mon Jul 21 2025 Valid 241200Z - 291200Z ...DISCUSSION... Medium-range models indicate that mid-level ridging, initially centered over the Ohio Valley, will weaken late this work week through next weekend, as flow undergoes substantive amplification upstream. This appears likely to include a significant short wave trough digging southeast of the Aleutians, accompanied by lower/mid-tropospheric cyclogenesis across the northeastern Pacific. Part of a higher latitude blocking pattern, little subsequent movement of this cyclone is forecast through early next week, as an expansive, prominent mid-level ridge also evolves in the downstream lower latitudes, across much of the Intermountain West, Rockies and Great Plains into mid and lower Mississippi Valley. However, as a notable mid-level low continues slowly east of Hudson Bay, across northern Quebec and Newfoundland and Labrador, a belt of seasonably strong westerly mid/upper flow may be maintained across Ontario and Quebec this Thursday through Friday. Along the favorably sheared southern fringe of this regime, seasonably moist low-level air advecting ahead of a stalled to southward advancing frontal zone may contribute to sufficient destabilization for the evolution of organizing thunderstorm clusters capable of producing swaths of damaging wind gusts. The extent to which this may impact U.S. portions of the Great Lakes into New England remains unclear. It might not be out of the question that a similar type regime could evolve beneath developing northwesterly mid-level flow, from the North Dakota/Minnesota international border area into the Upper Midwest/Great Lakes late next weekend into early next week. Current guidance is still suggestive that this is a lower probability, but this could be due to the low predictability of the pertinent features at this extended range. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0353 AM CDT Mon Jul 21 2025 Valid 241200Z - 291200Z ...DISCUSSION... Medium-range models indicate that mid-level ridging, initially centered over the Ohio Valley, will weaken late this work week through next weekend, as flow undergoes substantive amplification upstream. This appears likely to include a significant short wave trough digging southeast of the Aleutians, accompanied by lower/mid-tropospheric cyclogenesis across the northeastern Pacific. Part of a higher latitude blocking pattern, little subsequent movement of this cyclone is forecast through early next week, as an expansive, prominent mid-level ridge also evolves in the downstream lower latitudes, across much of the Intermountain West, Rockies and Great Plains into mid and lower Mississippi Valley. However, as a notable mid-level low continues slowly east of Hudson Bay, across northern Quebec and Newfoundland and Labrador, a belt of seasonably strong westerly mid/upper flow may be maintained across Ontario and Quebec this Thursday through Friday. Along the favorably sheared southern fringe of this regime, seasonably moist low-level air advecting ahead of a stalled to southward advancing frontal zone may contribute to sufficient destabilization for the evolution of organizing thunderstorm clusters capable of producing swaths of damaging wind gusts. The extent to which this may impact U.S. portions of the Great Lakes into New England remains unclear. It might not be out of the question that a similar type regime could evolve beneath developing northwesterly mid-level flow, from the North Dakota/Minnesota international border area into the Upper Midwest/Great Lakes late next weekend into early next week. Current guidance is still suggestive that this is a lower probability, but this could be due to the low predictability of the pertinent features at this extended range. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0353 AM CDT Mon Jul 21 2025 Valid 241200Z - 291200Z ...DISCUSSION... Medium-range models indicate that mid-level ridging, initially centered over the Ohio Valley, will weaken late this work week through next weekend, as flow undergoes substantive amplification upstream. This appears likely to include a significant short wave trough digging southeast of the Aleutians, accompanied by lower/mid-tropospheric cyclogenesis across the northeastern Pacific. Part of a higher latitude blocking pattern, little subsequent movement of this cyclone is forecast through early next week, as an expansive, prominent mid-level ridge also evolves in the downstream lower latitudes, across much of the Intermountain West, Rockies and Great Plains into mid and lower Mississippi Valley. However, as a notable mid-level low continues slowly east of Hudson Bay, across northern Quebec and Newfoundland and Labrador, a belt of seasonably strong westerly mid/upper flow may be maintained across Ontario and Quebec this Thursday through Friday. Along the favorably sheared southern fringe of this regime, seasonably moist low-level air advecting ahead of a stalled to southward advancing frontal zone may contribute to sufficient destabilization for the evolution of organizing thunderstorm clusters capable of producing swaths of damaging wind gusts. The extent to which this may impact U.S. portions of the Great Lakes into New England remains unclear. It might not be out of the question that a similar type regime could evolve beneath developing northwesterly mid-level flow, from the North Dakota/Minnesota international border area into the Upper Midwest/Great Lakes late next weekend into early next week. Current guidance is still suggestive that this is a lower probability, but this could be due to the low predictability of the pertinent features at this extended range. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Mon Jul 21 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WEDNESDAY INTO WEDNESDAY NIGHT ACROSS PARTS OF EAST CENTRAL MINNESOTA...NORTHERN AND CENTRAL WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... One or two organizing clusters of storms posing a risk for severe wind and perhaps some hail are possible across parts of the Upper Midwest into adjacent Great Lakes region Wednesday through Wednesday night. ...Discussion... Models indicate some further suppression of the northeastern Pacific mid-level ridging, with flow becoming more zonal and progressive across the British Columbia coast into the Canadian Prairies during this period. A lingering short wave perturbation emerging from the northern U.S. intermountain region may accelerate east of the Montana Rockies, along the central Canadian/U.S. border. This appears likely to be preceded by more subtle smaller-scale impulses migrating around the northern periphery of persistent mid-level ridging centered over the Ohio Valley. It appears that these will accelerate into the southern fringe of strengthening mid-level westerly flow across parts of the Upper Midwest/Great Lakes region into Ontario and Quebec, between the mid-level ridge and a significant mid-level trough/cyclone migrating slowly across Hudson Bay. While a cold front trailing the surface cyclone may continue to advance southward through the Great Plains to the lee of the Rockies, models suggest that it probably will stall across parts of the Upper Midwest into adjacent Great Lakes Wednesday into Wednesday night, near the northern periphery of the mid-level ridge. ...Upper Midwest/Great Lakes... It appears that a seasonably moist boundary layer (including dew points around or above 70F) advecting into the region during the day Wednesday, if not earlier, will become supportive of moderate to strong potential instability beneath a remnant plume of modestly steep lower/mid-tropospheric lapse rates. Models suggest that this will generally focus along the stalling surface front, where 30-40 kt west-southwesterly flow in the 700-500 mb layer will contribute to the possible evolution of organizing, eastward propagating convective systems with the potential to produce strong to severe surface gusts. There appears a general signal within the model output that a stalling, trailing flank of outflow associated with an initial cluster of storms may become a focus for renewed convective development, near where it intersects the front, just ahead of an eastward migrating frontal wave, across northern Wisconsin into Upper Michigan during the peak late afternoon into evening instability. ...Lee of northern Rockies into Front Range... In the presence of steep lapse rates, moistening easterly to southeasterly near-surface flow, beneath modest westerly flow aloft, may contribute to sufficient destabilization and shear to support widely scattered strong to severe storms. This may include evolving supercells near/just east of the higher terrain late Wednesday afternoon and evening. ..Kerr.. 07/21/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Mon Jul 21 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WEDNESDAY INTO WEDNESDAY NIGHT ACROSS PARTS OF EAST CENTRAL MINNESOTA...NORTHERN AND CENTRAL WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... One or two organizing clusters of storms posing a risk for severe wind and perhaps some hail are possible across parts of the Upper Midwest into adjacent Great Lakes region Wednesday through Wednesday night. ...Discussion... Models indicate some further suppression of the northeastern Pacific mid-level ridging, with flow becoming more zonal and progressive across the British Columbia coast into the Canadian Prairies during this period. A lingering short wave perturbation emerging from the northern U.S. intermountain region may accelerate east of the Montana Rockies, along the central Canadian/U.S. border. This appears likely to be preceded by more subtle smaller-scale impulses migrating around the northern periphery of persistent mid-level ridging centered over the Ohio Valley. It appears that these will accelerate into the southern fringe of strengthening mid-level westerly flow across parts of the Upper Midwest/Great Lakes region into Ontario and Quebec, between the mid-level ridge and a significant mid-level trough/cyclone migrating slowly across Hudson Bay. While a cold front trailing the surface cyclone may continue to advance southward through the Great Plains to the lee of the Rockies, models suggest that it probably will stall across parts of the Upper Midwest into adjacent Great Lakes Wednesday into Wednesday night, near the northern periphery of the mid-level ridge. ...Upper Midwest/Great Lakes... It appears that a seasonably moist boundary layer (including dew points around or above 70F) advecting into the region during the day Wednesday, if not earlier, will become supportive of moderate to strong potential instability beneath a remnant plume of modestly steep lower/mid-tropospheric lapse rates. Models suggest that this will generally focus along the stalling surface front, where 30-40 kt west-southwesterly flow in the 700-500 mb layer will contribute to the possible evolution of organizing, eastward propagating convective systems with the potential to produce strong to severe surface gusts. There appears a general signal within the model output that a stalling, trailing flank of outflow associated with an initial cluster of storms may become a focus for renewed convective development, near where it intersects the front, just ahead of an eastward migrating frontal wave, across northern Wisconsin into Upper Michigan during the peak late afternoon into evening instability. ...Lee of northern Rockies into Front Range... In the presence of steep lapse rates, moistening easterly to southeasterly near-surface flow, beneath modest westerly flow aloft, may contribute to sufficient destabilization and shear to support widely scattered strong to severe storms. This may include evolving supercells near/just east of the higher terrain late Wednesday afternoon and evening. ..Kerr.. 07/21/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Mon Jul 21 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WEDNESDAY INTO WEDNESDAY NIGHT ACROSS PARTS OF EAST CENTRAL MINNESOTA...NORTHERN AND CENTRAL WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... One or two organizing clusters of storms posing a risk for severe wind and perhaps some hail are possible across parts of the Upper Midwest into adjacent Great Lakes region Wednesday through Wednesday night. ...Discussion... Models indicate some further suppression of the northeastern Pacific mid-level ridging, with flow becoming more zonal and progressive across the British Columbia coast into the Canadian Prairies during this period. A lingering short wave perturbation emerging from the northern U.S. intermountain region may accelerate east of the Montana Rockies, along the central Canadian/U.S. border. This appears likely to be preceded by more subtle smaller-scale impulses migrating around the northern periphery of persistent mid-level ridging centered over the Ohio Valley. It appears that these will accelerate into the southern fringe of strengthening mid-level westerly flow across parts of the Upper Midwest/Great Lakes region into Ontario and Quebec, between the mid-level ridge and a significant mid-level trough/cyclone migrating slowly across Hudson Bay. While a cold front trailing the surface cyclone may continue to advance southward through the Great Plains to the lee of the Rockies, models suggest that it probably will stall across parts of the Upper Midwest into adjacent Great Lakes Wednesday into Wednesday night, near the northern periphery of the mid-level ridge. ...Upper Midwest/Great Lakes... It appears that a seasonably moist boundary layer (including dew points around or above 70F) advecting into the region during the day Wednesday, if not earlier, will become supportive of moderate to strong potential instability beneath a remnant plume of modestly steep lower/mid-tropospheric lapse rates. Models suggest that this will generally focus along the stalling surface front, where 30-40 kt west-southwesterly flow in the 700-500 mb layer will contribute to the possible evolution of organizing, eastward propagating convective systems with the potential to produce strong to severe surface gusts. There appears a general signal within the model output that a stalling, trailing flank of outflow associated with an initial cluster of storms may become a focus for renewed convective development, near where it intersects the front, just ahead of an eastward migrating frontal wave, across northern Wisconsin into Upper Michigan during the peak late afternoon into evening instability. ...Lee of northern Rockies into Front Range... In the presence of steep lapse rates, moistening easterly to southeasterly near-surface flow, beneath modest westerly flow aloft, may contribute to sufficient destabilization and shear to support widely scattered strong to severe storms. This may include evolving supercells near/just east of the higher terrain late Wednesday afternoon and evening. ..Kerr.. 07/21/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Mon Jul 21 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WEDNESDAY INTO WEDNESDAY NIGHT ACROSS PARTS OF EAST CENTRAL MINNESOTA...NORTHERN AND CENTRAL WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... One or two organizing clusters of storms posing a risk for severe wind and perhaps some hail are possible across parts of the Upper Midwest into adjacent Great Lakes region Wednesday through Wednesday night. ...Discussion... Models indicate some further suppression of the northeastern Pacific mid-level ridging, with flow becoming more zonal and progressive across the British Columbia coast into the Canadian Prairies during this period. A lingering short wave perturbation emerging from the northern U.S. intermountain region may accelerate east of the Montana Rockies, along the central Canadian/U.S. border. This appears likely to be preceded by more subtle smaller-scale impulses migrating around the northern periphery of persistent mid-level ridging centered over the Ohio Valley. It appears that these will accelerate into the southern fringe of strengthening mid-level westerly flow across parts of the Upper Midwest/Great Lakes region into Ontario and Quebec, between the mid-level ridge and a significant mid-level trough/cyclone migrating slowly across Hudson Bay. While a cold front trailing the surface cyclone may continue to advance southward through the Great Plains to the lee of the Rockies, models suggest that it probably will stall across parts of the Upper Midwest into adjacent Great Lakes Wednesday into Wednesday night, near the northern periphery of the mid-level ridge. ...Upper Midwest/Great Lakes... It appears that a seasonably moist boundary layer (including dew points around or above 70F) advecting into the region during the day Wednesday, if not earlier, will become supportive of moderate to strong potential instability beneath a remnant plume of modestly steep lower/mid-tropospheric lapse rates. Models suggest that this will generally focus along the stalling surface front, where 30-40 kt west-southwesterly flow in the 700-500 mb layer will contribute to the possible evolution of organizing, eastward propagating convective systems with the potential to produce strong to severe surface gusts. There appears a general signal within the model output that a stalling, trailing flank of outflow associated with an initial cluster of storms may become a focus for renewed convective development, near where it intersects the front, just ahead of an eastward migrating frontal wave, across northern Wisconsin into Upper Michigan during the peak late afternoon into evening instability. ...Lee of northern Rockies into Front Range... In the presence of steep lapse rates, moistening easterly to southeasterly near-surface flow, beneath modest westerly flow aloft, may contribute to sufficient destabilization and shear to support widely scattered strong to severe storms. This may include evolving supercells near/just east of the higher terrain late Wednesday afternoon and evening. ..Kerr.. 07/21/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 AM CDT Mon Jul 21 2025 Valid 221200Z - 231200Z ...Synopsis... The upper-level trough in the Northwest will become more diffuse on Tuesday. Mid-level winds will slacken across the Great Basin. A weak surface trough/boundary will remain in northern Nevada. ...Southern/central Nevada... While surface winds will generally be weaker than previous days, the surface pressure gradient near the boundary will support 15-20 mph in portions of southern/central Nevada. RH of 15-20% appears possible during the afternoon. Area fuels remain dry enough to support elevated fire weather conditions. ..Wendt.. 07/21/2025 ...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 0201 AM CDT Mon Jul 21 2025 Valid 221200Z - 231200Z ...Synopsis... The upper-level trough in the Northwest will become more diffuse on Tuesday. Mid-level winds will slacken across the Great Basin. A weak surface trough/boundary will remain in northern Nevada. ...Southern/central Nevada... While surface winds will generally be weaker than previous days, the surface pressure gradient near the boundary will support 15-20 mph in portions of southern/central Nevada. RH of 15-20% appears possible during the afternoon. Area fuels remain dry enough to support elevated fire weather conditions. ..Wendt.. 07/21/2025 ...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 0201 AM CDT Mon Jul 21 2025 Valid 221200Z - 231200Z ...Synopsis... The upper-level trough in the Northwest will become more diffuse on Tuesday. Mid-level winds will slacken across the Great Basin. A weak surface trough/boundary will remain in northern Nevada. ...Southern/central Nevada... While surface winds will generally be weaker than previous days, the surface pressure gradient near the boundary will support 15-20 mph in portions of southern/central Nevada. RH of 15-20% appears possible during the afternoon. Area fuels remain dry enough to support elevated fire weather conditions. ..Wendt.. 07/21/2025 ...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 0200 AM CDT Mon Jul 21 2025 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN AND NORTH-CENTRAL NEVADA... ...Synopsis... With the base of the upper-level trough pivoting into the northern Great Basin today, a belt of stronger mid-level flow will stretch from northern California into northern Nevada and the northern Rockies. At the surface, a low in northeast Nevada/northern Utah will modestly deepen. ...Western/central Great Basin into western Wyoming... A relatively broad area of elevated fire weather is expected across much of the western/northern Great Basin into western Wyoming. RH will fall to 10-20% in Nevada while 15-20% will be more common farther north and east. Surface winds of 15-20 mph will develop by the afternoon. Critical fire weather is expected to occur in northwest and north-central Nevada. Here, the marginally stronger pressure gradient, stronger mid-level flow aloft, and terrain influences from the Sierra will promote winds of around 20 mph with gusts of around 30 mph. Very dry fuels (ERCs above the 90th percentile) in these areas will support rapid fire spread. ..Wendt.. 07/21/2025 ...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 0200 AM CDT Mon Jul 21 2025 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN AND NORTH-CENTRAL NEVADA... ...Synopsis... With the base of the upper-level trough pivoting into the northern Great Basin today, a belt of stronger mid-level flow will stretch from northern California into northern Nevada and the northern Rockies. At the surface, a low in northeast Nevada/northern Utah will modestly deepen. ...Western/central Great Basin into western Wyoming... A relatively broad area of elevated fire weather is expected across much of the western/northern Great Basin into western Wyoming. RH will fall to 10-20% in Nevada while 15-20% will be more common farther north and east. Surface winds of 15-20 mph will develop by the afternoon. Critical fire weather is expected to occur in northwest and north-central Nevada. Here, the marginally stronger pressure gradient, stronger mid-level flow aloft, and terrain influences from the Sierra will promote winds of around 20 mph with gusts of around 30 mph. Very dry fuels (ERCs above the 90th percentile) in these areas will support rapid fire spread. ..Wendt.. 07/21/2025 ...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 0200 AM CDT Mon Jul 21 2025 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN AND NORTH-CENTRAL NEVADA... ...Synopsis... With the base of the upper-level trough pivoting into the northern Great Basin today, a belt of stronger mid-level flow will stretch from northern California into northern Nevada and the northern Rockies. At the surface, a low in northeast Nevada/northern Utah will modestly deepen. ...Western/central Great Basin into western Wyoming... A relatively broad area of elevated fire weather is expected across much of the western/northern Great Basin into western Wyoming. RH will fall to 10-20% in Nevada while 15-20% will be more common farther north and east. Surface winds of 15-20 mph will develop by the afternoon. Critical fire weather is expected to occur in northwest and north-central Nevada. Here, the marginally stronger pressure gradient, stronger mid-level flow aloft, and terrain influences from the Sierra will promote winds of around 20 mph with gusts of around 30 mph. Very dry fuels (ERCs above the 90th percentile) in these areas will support rapid fire spread. ..Wendt.. 07/21/2025 ...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 0200 AM CDT Mon Jul 21 2025 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN AND NORTH-CENTRAL NEVADA... ...Synopsis... With the base of the upper-level trough pivoting into the northern Great Basin today, a belt of stronger mid-level flow will stretch from northern California into northern Nevada and the northern Rockies. At the surface, a low in northeast Nevada/northern Utah will modestly deepen. ...Western/central Great Basin into western Wyoming... A relatively broad area of elevated fire weather is expected across much of the western/northern Great Basin into western Wyoming. RH will fall to 10-20% in Nevada while 15-20% will be more common farther north and east. Surface winds of 15-20 mph will develop by the afternoon. Critical fire weather is expected to occur in northwest and north-central Nevada. Here, the marginally stronger pressure gradient, stronger mid-level flow aloft, and terrain influences from the Sierra will promote winds of around 20 mph with gusts of around 30 mph. Very dry fuels (ERCs above the 90th percentile) in these areas will support rapid fire spread. ..Wendt.. 07/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more