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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Tue Jul 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...20z Update... The forecast largely remains on track with the early stages of convective initiation underway across portions of north/northwest WY and along the central High Plains per recent satellite imagery and regional radar composites. The primary change for this forecast update was the introduction of significant hail/wind areas to portions of the northern Rockies. Latest GOES imagery shows convection beginning to develop across northern WY/southern MT ahead of a shortwave trough over the Great Basin. Regional 18z soundings continue to sample steep (8-9 C/km) mid-level lapse rates, and GOES imagery suggests 30-40 knot mid-level winds are overspreading the region. As such, a favorable environment for a few supercells appears to be in place and should support the potential for very large hail. This activity should grow upscale through late evening with the potential for a few significant (75+ mph) wind gusts. See MCD #1833 for additional short-term details. Across the Plains, the significant wind risk area has been adjusted to better align with recent convective development along a stationary boundary draped from southwest to northeast across NE and where boundary-layer mixing appears to be deepest (based on observed dewpoint depressions), which should favor stronger downdrafts and a higher potential for significant gusts. See MCD #1834 for additional short-term details. ..Moore.. 07/29/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Tue Jul 29 2025/ ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Tue Jul 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...20z Update... The forecast largely remains on track with the early stages of convective initiation underway across portions of north/northwest WY and along the central High Plains per recent satellite imagery and regional radar composites. The primary change for this forecast update was the introduction of significant hail/wind areas to portions of the northern Rockies. Latest GOES imagery shows convection beginning to develop across northern WY/southern MT ahead of a shortwave trough over the Great Basin. Regional 18z soundings continue to sample steep (8-9 C/km) mid-level lapse rates, and GOES imagery suggests 30-40 knot mid-level winds are overspreading the region. As such, a favorable environment for a few supercells appears to be in place and should support the potential for very large hail. This activity should grow upscale through late evening with the potential for a few significant (75+ mph) wind gusts. See MCD #1833 for additional short-term details. Across the Plains, the significant wind risk area has been adjusted to better align with recent convective development along a stationary boundary draped from southwest to northeast across NE and where boundary-layer mixing appears to be deepest (based on observed dewpoint depressions), which should favor stronger downdrafts and a higher potential for significant gusts. See MCD #1834 for additional short-term details. ..Moore.. 07/29/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Tue Jul 29 2025/ ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...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 0242 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA/NEVADA AND OREGON... ...20z Update... Confidence continues to increase in widespread thunderstorms across parts of the Northwest and northern Great Basin Wednesday. As moisture associated with a prominent shortwave trough lifts northward, thunderstorm development is likely by early afternoon across the higher terrain of northern CA/NV and southern OR. Forecast soundings depict weak buoyancy atop inverted-v thermodynamic profiles, which would support high-based, fast-moving thunderstorms over receptive fuels. With minimal rainfall accumulations, lightning ignitions are likely. A few storms may persist overnight as the shortwave trough continues northward into southern WA and the Cascades. Given the threat for scattered to numerous thunderstorms, critical dry thunderstorm highlights will be maintained and shifted west/south for recent model guidance. ...Southern and eastern Great Basin... Dry and breezy conditions are likely across parts of southern NV and western UT D2/Wednesday afternoon. Aided by enhanced westerly flow aloft, surface gusts of 15-25 mph and RH below 15% are likely. With dry fuels, elevated fire-weather conditions are expected. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0217 AM CDT Tue Jul 29 2025/ ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 PM CDT Tue Jul 29 2025 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected on Thursday. ...Discussion... Heights will increase with the upper-level ridge on Wednesday across the central US. Thunderstorm activity is expected to continue near and south of a surface cold front extending from the central Plains into the Missouri and Ohio Valleys and the Northeast. The increasing subsidence influence from the high and generally weak lapse rates will lead to less widespread severe potential with thunderstorms across the central Plains into the Missouri/Ohio Valley. Given the moderate to strong instability, an occasional stronger gust from a wet micro burst could not be entirely ruled out, however, this risk appears too isolated to include probabilities. Along the edge of the upper level ridge across the Carolinas/Virginia near to the front, a few stronger storms may be possible. However, despite some steeper low-level lapse rates, poor mid-level lapse rates and little to no shear will likely negate any more widespread organized severe risk. ..Thornton.. 07/29/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 PM CDT Tue Jul 29 2025 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected on Thursday. ...Discussion... Heights will increase with the upper-level ridge on Wednesday across the central US. Thunderstorm activity is expected to continue near and south of a surface cold front extending from the central Plains into the Missouri and Ohio Valleys and the Northeast. The increasing subsidence influence from the high and generally weak lapse rates will lead to less widespread severe potential with thunderstorms across the central Plains into the Missouri/Ohio Valley. Given the moderate to strong instability, an occasional stronger gust from a wet micro burst could not be entirely ruled out, however, this risk appears too isolated to include probabilities. Along the edge of the upper level ridge across the Carolinas/Virginia near to the front, a few stronger storms may be possible. However, despite some steeper low-level lapse rates, poor mid-level lapse rates and little to no shear will likely negate any more widespread organized severe risk. ..Thornton.. 07/29/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 PM CDT Tue Jul 29 2025 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected on Thursday. ...Discussion... Heights will increase with the upper-level ridge on Wednesday across the central US. Thunderstorm activity is expected to continue near and south of a surface cold front extending from the central Plains into the Missouri and Ohio Valleys and the Northeast. The increasing subsidence influence from the high and generally weak lapse rates will lead to less widespread severe potential with thunderstorms across the central Plains into the Missouri/Ohio Valley. Given the moderate to strong instability, an occasional stronger gust from a wet micro burst could not be entirely ruled out, however, this risk appears too isolated to include probabilities. Along the edge of the upper level ridge across the Carolinas/Virginia near to the front, a few stronger storms may be possible. However, despite some steeper low-level lapse rates, poor mid-level lapse rates and little to no shear will likely negate any more widespread organized severe risk. ..Thornton.. 07/29/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 PM CDT Tue Jul 29 2025 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected on Thursday. ...Discussion... Heights will increase with the upper-level ridge on Wednesday across the central US. Thunderstorm activity is expected to continue near and south of a surface cold front extending from the central Plains into the Missouri and Ohio Valleys and the Northeast. The increasing subsidence influence from the high and generally weak lapse rates will lead to less widespread severe potential with thunderstorms across the central Plains into the Missouri/Ohio Valley. Given the moderate to strong instability, an occasional stronger gust from a wet micro burst could not be entirely ruled out, however, this risk appears too isolated to include probabilities. Along the edge of the upper level ridge across the Carolinas/Virginia near to the front, a few stronger storms may be possible. However, despite some steeper low-level lapse rates, poor mid-level lapse rates and little to no shear will likely negate any more widespread organized severe risk. ..Thornton.. 07/29/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 PM CDT Tue Jul 29 2025 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected on Thursday. ...Discussion... Heights will increase with the upper-level ridge on Wednesday across the central US. Thunderstorm activity is expected to continue near and south of a surface cold front extending from the central Plains into the Missouri and Ohio Valleys and the Northeast. The increasing subsidence influence from the high and generally weak lapse rates will lead to less widespread severe potential with thunderstorms across the central Plains into the Missouri/Ohio Valley. Given the moderate to strong instability, an occasional stronger gust from a wet micro burst could not be entirely ruled out, however, this risk appears too isolated to include probabilities. Along the edge of the upper level ridge across the Carolinas/Virginia near to the front, a few stronger storms may be possible. However, despite some steeper low-level lapse rates, poor mid-level lapse rates and little to no shear will likely negate any more widespread organized severe risk. ..Thornton.. 07/29/2025 Read more