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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 22 2025 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN/CENTRAL HIGH PLAINS TO THE UPPER MIDWEST/GREAT LAKES...AND PORTIONS OF SOUTHERN/CENTRAL ARIZONA... ...SUMMARY... Strong to locally severe thunderstorms may occur today from parts of the northern and central High Plains to the Upper Midwest/Great Lakes, and separately across parts of Arizona. Damaging winds and occasional hail should be the main threats. ...Synopsis... A mid/upper-level trough/low centered over Manitoba late this morning will move east-southeastward across Ontario and the Upper Midwest/Great Lakes through the period. At the surface, a weak cold front is forecast to develop southeastward across the northern/central High Plains and Upper Midwest this afternoon and evening. This boundary should serve as a focus for additional thunderstorm development later today, some of which could become strong to severe. A mid/upper-level anticyclone will remain anchored over the Four Corners region today, with modest easterly mid-level flow persisting over parts of AZ. ...Northern/Central High Plains to the Upper Midwest/Great Lakes... A broad zone of isolated strong to severe thunderstorm potential remains evident today, generally along/near a convectively reinforced cold front extending from the central High Plains east-northeastward to the Upper Midwest/Great Lakes. Within this broad zone, three somewhat separate regimes of severe potential are apparent. Thunderstorms have recently developed across parts of central/eastern MN and far northwest WI ahead of a remnant MCV/subtle mid-level shortwave trough. The airmass downstream from this activity across northern WI into the U.P. of MI is only weakly unstable, with scattered to broken mid/upper-level clouds present. Stronger mid-level flow is also forecast to generally lag behind the surface cold front across this region. Still, a small cluster or two may eventually evolve from the ongoing convection in MN, and spread eastward through the afternoon/early evening. Occasional damaging winds should be the main threat, but some hail may also occur with the stronger cores given cool mid-level temperatures and around 25-35 kt of deep-layer shear aiding updraft organization. Considered adding a Slight Risk for severe/damaging winds across parts of northern WI and vicinity, but confidence in more robust destabilization occurring remains low. Trends will be monitored for a possible upgrade at 20Z, if needed. Outflow from earlier thunderstorms continues to advance southward across parts of eastern NE and northwest IA per recent surface observations and visible satellite imagery. The effect of this outflow surge on additional thunderstorm development this afternoon remains unclear, as the primary cold front lags the outflow by a considerable extent. Some guidance suggests that a couple of supercells or perhaps a small cluster may develop over far southeast SD into eastern NE and western IA later today as the airmass across these areas gradually destabilizes. At least an isolated risk for severe hail and damaging winds will exist if this occurs. But, the overall severe threat remains too uncertain for a categorical upgrade with this outlook update. Farther west, a subtle mid-level ridge-peripheral disturbance noted in water vapor imagery across southern WY and northwest CO, along with strong daytime heating, should aid thunderstorm development initially across the higher terrain of the central Rockies later this afternoon. This activity should propagate east-southeastward toward lower elevations in the presence of moist, post-frontal low-level upslope flow. Isolated severe hail and winds are possible with this activity, especially within a corridor across interior/southeast WY into northeast/east-central CO. ...Arizona... A fair amount of convective cloud debris is present today across parts of AZ per recent visible satellite imagery. This may tend to delay diurnal heating and related steepening of low-level lapse rates to some extent. But, eventual airmass recovery is still expected by late afternoon/early evening, with seasonably moist low-levels still noted on the 12Z observed PHX sounding. Thunderstorms should once again form initially along the higher terrain of the Mogollon Rim and southeastern AZ before spreading west-southwestward across the lower elevations of central/southern AZ through the evening. Sufficient instability, a very well-mixed boundary layer, and modest easterly mid-level flow should all support an isolated threat for severe/damaging winds with this activity. ..Gleason/Moore.. 08/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 22 2025 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN/CENTRAL HIGH PLAINS TO THE UPPER MIDWEST/GREAT LAKES...AND PORTIONS OF SOUTHERN/CENTRAL ARIZONA... ...SUMMARY... Strong to locally severe thunderstorms may occur today from parts of the northern and central High Plains to the Upper Midwest/Great Lakes, and separately across parts of Arizona. Damaging winds and occasional hail should be the main threats. ...Synopsis... A mid/upper-level trough/low centered over Manitoba late this morning will move east-southeastward across Ontario and the Upper Midwest/Great Lakes through the period. At the surface, a weak cold front is forecast to develop southeastward across the northern/central High Plains and Upper Midwest this afternoon and evening. This boundary should serve as a focus for additional thunderstorm development later today, some of which could become strong to severe. A mid/upper-level anticyclone will remain anchored over the Four Corners region today, with modest easterly mid-level flow persisting over parts of AZ. ...Northern/Central High Plains to the Upper Midwest/Great Lakes... A broad zone of isolated strong to severe thunderstorm potential remains evident today, generally along/near a convectively reinforced cold front extending from the central High Plains east-northeastward to the Upper Midwest/Great Lakes. Within this broad zone, three somewhat separate regimes of severe potential are apparent. Thunderstorms have recently developed across parts of central/eastern MN and far northwest WI ahead of a remnant MCV/subtle mid-level shortwave trough. The airmass downstream from this activity across northern WI into the U.P. of MI is only weakly unstable, with scattered to broken mid/upper-level clouds present. Stronger mid-level flow is also forecast to generally lag behind the surface cold front across this region. Still, a small cluster or two may eventually evolve from the ongoing convection in MN, and spread eastward through the afternoon/early evening. Occasional damaging winds should be the main threat, but some hail may also occur with the stronger cores given cool mid-level temperatures and around 25-35 kt of deep-layer shear aiding updraft organization. Considered adding a Slight Risk for severe/damaging winds across parts of northern WI and vicinity, but confidence in more robust destabilization occurring remains low. Trends will be monitored for a possible upgrade at 20Z, if needed. Outflow from earlier thunderstorms continues to advance southward across parts of eastern NE and northwest IA per recent surface observations and visible satellite imagery. The effect of this outflow surge on additional thunderstorm development this afternoon remains unclear, as the primary cold front lags the outflow by a considerable extent. Some guidance suggests that a couple of supercells or perhaps a small cluster may develop over far southeast SD into eastern NE and western IA later today as the airmass across these areas gradually destabilizes. At least an isolated risk for severe hail and damaging winds will exist if this occurs. But, the overall severe threat remains too uncertain for a categorical upgrade with this outlook update. Farther west, a subtle mid-level ridge-peripheral disturbance noted in water vapor imagery across southern WY and northwest CO, along with strong daytime heating, should aid thunderstorm development initially across the higher terrain of the central Rockies later this afternoon. This activity should propagate east-southeastward toward lower elevations in the presence of moist, post-frontal low-level upslope flow. Isolated severe hail and winds are possible with this activity, especially within a corridor across interior/southeast WY into northeast/east-central CO. ...Arizona... A fair amount of convective cloud debris is present today across parts of AZ per recent visible satellite imagery. This may tend to delay diurnal heating and related steepening of low-level lapse rates to some extent. But, eventual airmass recovery is still expected by late afternoon/early evening, with seasonably moist low-levels still noted on the 12Z observed PHX sounding. Thunderstorms should once again form initially along the higher terrain of the Mogollon Rim and southeastern AZ before spreading west-southwestward across the lower elevations of central/southern AZ through the evening. Sufficient instability, a very well-mixed boundary layer, and modest easterly mid-level flow should all support an isolated threat for severe/damaging winds with this activity. ..Gleason/Moore.. 08/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 22 2025 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN/CENTRAL HIGH PLAINS TO THE UPPER MIDWEST/GREAT LAKES...AND PORTIONS OF SOUTHERN/CENTRAL ARIZONA... ...SUMMARY... Strong to locally severe thunderstorms may occur today from parts of the northern and central High Plains to the Upper Midwest/Great Lakes, and separately across parts of Arizona. Damaging winds and occasional hail should be the main threats. ...Synopsis... A mid/upper-level trough/low centered over Manitoba late this morning will move east-southeastward across Ontario and the Upper Midwest/Great Lakes through the period. At the surface, a weak cold front is forecast to develop southeastward across the northern/central High Plains and Upper Midwest this afternoon and evening. This boundary should serve as a focus for additional thunderstorm development later today, some of which could become strong to severe. A mid/upper-level anticyclone will remain anchored over the Four Corners region today, with modest easterly mid-level flow persisting over parts of AZ. ...Northern/Central High Plains to the Upper Midwest/Great Lakes... A broad zone of isolated strong to severe thunderstorm potential remains evident today, generally along/near a convectively reinforced cold front extending from the central High Plains east-northeastward to the Upper Midwest/Great Lakes. Within this broad zone, three somewhat separate regimes of severe potential are apparent. Thunderstorms have recently developed across parts of central/eastern MN and far northwest WI ahead of a remnant MCV/subtle mid-level shortwave trough. The airmass downstream from this activity across northern WI into the U.P. of MI is only weakly unstable, with scattered to broken mid/upper-level clouds present. Stronger mid-level flow is also forecast to generally lag behind the surface cold front across this region. Still, a small cluster or two may eventually evolve from the ongoing convection in MN, and spread eastward through the afternoon/early evening. Occasional damaging winds should be the main threat, but some hail may also occur with the stronger cores given cool mid-level temperatures and around 25-35 kt of deep-layer shear aiding updraft organization. Considered adding a Slight Risk for severe/damaging winds across parts of northern WI and vicinity, but confidence in more robust destabilization occurring remains low. Trends will be monitored for a possible upgrade at 20Z, if needed. Outflow from earlier thunderstorms continues to advance southward across parts of eastern NE and northwest IA per recent surface observations and visible satellite imagery. The effect of this outflow surge on additional thunderstorm development this afternoon remains unclear, as the primary cold front lags the outflow by a considerable extent. Some guidance suggests that a couple of supercells or perhaps a small cluster may develop over far southeast SD into eastern NE and western IA later today as the airmass across these areas gradually destabilizes. At least an isolated risk for severe hail and damaging winds will exist if this occurs. But, the overall severe threat remains too uncertain for a categorical upgrade with this outlook update. Farther west, a subtle mid-level ridge-peripheral disturbance noted in water vapor imagery across southern WY and northwest CO, along with strong daytime heating, should aid thunderstorm development initially across the higher terrain of the central Rockies later this afternoon. This activity should propagate east-southeastward toward lower elevations in the presence of moist, post-frontal low-level upslope flow. Isolated severe hail and winds are possible with this activity, especially within a corridor across interior/southeast WY into northeast/east-central CO. ...Arizona... A fair amount of convective cloud debris is present today across parts of AZ per recent visible satellite imagery. This may tend to delay diurnal heating and related steepening of low-level lapse rates to some extent. But, eventual airmass recovery is still expected by late afternoon/early evening, with seasonably moist low-levels still noted on the 12Z observed PHX sounding. Thunderstorms should once again form initially along the higher terrain of the Mogollon Rim and southeastern AZ before spreading west-southwestward across the lower elevations of central/southern AZ through the evening. Sufficient instability, a very well-mixed boundary layer, and modest easterly mid-level flow should all support an isolated threat for severe/damaging winds with this activity. ..Gleason/Moore.. 08/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 22 2025 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN/CENTRAL HIGH PLAINS TO THE UPPER MIDWEST/GREAT LAKES...AND PORTIONS OF SOUTHERN/CENTRAL ARIZONA... ...SUMMARY... Strong to locally severe thunderstorms may occur today from parts of the northern and central High Plains to the Upper Midwest/Great Lakes, and separately across parts of Arizona. Damaging winds and occasional hail should be the main threats. ...Synopsis... A mid/upper-level trough/low centered over Manitoba late this morning will move east-southeastward across Ontario and the Upper Midwest/Great Lakes through the period. At the surface, a weak cold front is forecast to develop southeastward across the northern/central High Plains and Upper Midwest this afternoon and evening. This boundary should serve as a focus for additional thunderstorm development later today, some of which could become strong to severe. A mid/upper-level anticyclone will remain anchored over the Four Corners region today, with modest easterly mid-level flow persisting over parts of AZ. ...Northern/Central High Plains to the Upper Midwest/Great Lakes... A broad zone of isolated strong to severe thunderstorm potential remains evident today, generally along/near a convectively reinforced cold front extending from the central High Plains east-northeastward to the Upper Midwest/Great Lakes. Within this broad zone, three somewhat separate regimes of severe potential are apparent. Thunderstorms have recently developed across parts of central/eastern MN and far northwest WI ahead of a remnant MCV/subtle mid-level shortwave trough. The airmass downstream from this activity across northern WI into the U.P. of MI is only weakly unstable, with scattered to broken mid/upper-level clouds present. Stronger mid-level flow is also forecast to generally lag behind the surface cold front across this region. Still, a small cluster or two may eventually evolve from the ongoing convection in MN, and spread eastward through the afternoon/early evening. Occasional damaging winds should be the main threat, but some hail may also occur with the stronger cores given cool mid-level temperatures and around 25-35 kt of deep-layer shear aiding updraft organization. Considered adding a Slight Risk for severe/damaging winds across parts of northern WI and vicinity, but confidence in more robust destabilization occurring remains low. Trends will be monitored for a possible upgrade at 20Z, if needed. Outflow from earlier thunderstorms continues to advance southward across parts of eastern NE and northwest IA per recent surface observations and visible satellite imagery. The effect of this outflow surge on additional thunderstorm development this afternoon remains unclear, as the primary cold front lags the outflow by a considerable extent. Some guidance suggests that a couple of supercells or perhaps a small cluster may develop over far southeast SD into eastern NE and western IA later today as the airmass across these areas gradually destabilizes. At least an isolated risk for severe hail and damaging winds will exist if this occurs. But, the overall severe threat remains too uncertain for a categorical upgrade with this outlook update. Farther west, a subtle mid-level ridge-peripheral disturbance noted in water vapor imagery across southern WY and northwest CO, along with strong daytime heating, should aid thunderstorm development initially across the higher terrain of the central Rockies later this afternoon. This activity should propagate east-southeastward toward lower elevations in the presence of moist, post-frontal low-level upslope flow. Isolated severe hail and winds are possible with this activity, especially within a corridor across interior/southeast WY into northeast/east-central CO. ...Arizona... A fair amount of convective cloud debris is present today across parts of AZ per recent visible satellite imagery. This may tend to delay diurnal heating and related steepening of low-level lapse rates to some extent. But, eventual airmass recovery is still expected by late afternoon/early evening, with seasonably moist low-levels still noted on the 12Z observed PHX sounding. Thunderstorms should once again form initially along the higher terrain of the Mogollon Rim and southeastern AZ before spreading west-southwestward across the lower elevations of central/southern AZ through the evening. Sufficient instability, a very well-mixed boundary layer, and modest easterly mid-level flow should all support an isolated threat for severe/damaging winds with this activity. ..Gleason/Moore.. 08/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Aug 22 2025 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN/CENTRAL HIGH PLAINS TO THE UPPER MIDWEST/GREAT LAKES...AND PORTIONS OF SOUTHERN/CENTRAL ARIZONA... ...SUMMARY... Strong to locally severe thunderstorms may occur today from parts of the northern and central High Plains to the Upper Midwest/Great Lakes, and separately across parts of Arizona. Damaging winds and occasional hail should be the main threats. ...Synopsis... A mid/upper-level trough/low centered over Manitoba late this morning will move east-southeastward across Ontario and the Upper Midwest/Great Lakes through the period. At the surface, a weak cold front is forecast to develop southeastward across the northern/central High Plains and Upper Midwest this afternoon and evening. This boundary should serve as a focus for additional thunderstorm development later today, some of which could become strong to severe. A mid/upper-level anticyclone will remain anchored over the Four Corners region today, with modest easterly mid-level flow persisting over parts of AZ. ...Northern/Central High Plains to the Upper Midwest/Great Lakes... A broad zone of isolated strong to severe thunderstorm potential remains evident today, generally along/near a convectively reinforced cold front extending from the central High Plains east-northeastward to the Upper Midwest/Great Lakes. Within this broad zone, three somewhat separate regimes of severe potential are apparent. Thunderstorms have recently developed across parts of central/eastern MN and far northwest WI ahead of a remnant MCV/subtle mid-level shortwave trough. The airmass downstream from this activity across northern WI into the U.P. of MI is only weakly unstable, with scattered to broken mid/upper-level clouds present. Stronger mid-level flow is also forecast to generally lag behind the surface cold front across this region. Still, a small cluster or two may eventually evolve from the ongoing convection in MN, and spread eastward through the afternoon/early evening. Occasional damaging winds should be the main threat, but some hail may also occur with the stronger cores given cool mid-level temperatures and around 25-35 kt of deep-layer shear aiding updraft organization. Considered adding a Slight Risk for severe/damaging winds across parts of northern WI and vicinity, but confidence in more robust destabilization occurring remains low. Trends will be monitored for a possible upgrade at 20Z, if needed. Outflow from earlier thunderstorms continues to advance southward across parts of eastern NE and northwest IA per recent surface observations and visible satellite imagery. The effect of this outflow surge on additional thunderstorm development this afternoon remains unclear, as the primary cold front lags the outflow by a considerable extent. Some guidance suggests that a couple of supercells or perhaps a small cluster may develop over far southeast SD into eastern NE and western IA later today as the airmass across these areas gradually destabilizes. At least an isolated risk for severe hail and damaging winds will exist if this occurs. But, the overall severe threat remains too uncertain for a categorical upgrade with this outlook update. Farther west, a subtle mid-level ridge-peripheral disturbance noted in water vapor imagery across southern WY and northwest CO, along with strong daytime heating, should aid thunderstorm development initially across the higher terrain of the central Rockies later this afternoon. This activity should propagate east-southeastward toward lower elevations in the presence of moist, post-frontal low-level upslope flow. Isolated severe hail and winds are possible with this activity, especially within a corridor across interior/southeast WY into northeast/east-central CO. ...Arizona... A fair amount of convective cloud debris is present today across parts of AZ per recent visible satellite imagery. This may tend to delay diurnal heating and related steepening of low-level lapse rates to some extent. But, eventual airmass recovery is still expected by late afternoon/early evening, with seasonably moist low-levels still noted on the 12Z observed PHX sounding. Thunderstorms should once again form initially along the higher terrain of the Mogollon Rim and southeastern AZ before spreading west-southwestward across the lower elevations of central/southern AZ through the evening. Sufficient instability, a very well-mixed boundary layer, and modest easterly mid-level flow should all support an isolated threat for severe/damaging winds with this activity. ..Gleason/Moore.. 08/22/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 1115 AM CDT Fri Aug 22 2025 Valid 221700Z - 231200Z ...Update... No changes are required for today's forecast. Please see the previous discussion below for additional details. ..Barnes.. 08/22/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Fri Aug 22 2025/ ...Synopsis... An expansive midlevel ridge will remain in place across much of the West, while a well-established monsoonal moisture plume persists across the Southwest into the Great Basin. ...Dry Thunderstorms... Diurnal heating/boundary-layer mixing amid the monsoonal moisture will yield sufficient buoyancy for isolated to widely scattered thunderstorms across a broad region extending from the Sierra into the Great Basin and central Rockies during the afternoon/evening. Inverted-V profiles, characterized by 0.70 to 0.90 inch PW, will favor a mix of wet/dry high-based storms -- posing a risk of lightning-induced ignitions and gusty/erratic outflow winds over dry/receptive fuels. ...North-central Oregon... Along the northern periphery of surface high pressure over the Southwest/Great Basin, a modest offshore pressure gradient will develop across the Northwest. As a result, breezy/gusty east-northeasterly surface winds are expected amid 15-percent RH across north-central OR, with locally enhanced winds expected through the Columbia Gorge. Given dry fuels, elevated fire-weather conditions are expected. ...Coastal New England... On the far western fringes of Hurricane Erin, dry/breezy northerly winds atop receptive fuels will favor elevated fire-weather conditions across coastal New England during the afternoon. ...Southern California... An unseasonably hot and unstable air mass along with critically dry fuels will continue to promote elevated fire-weather conditions away from the coast in southern CA, despite only modest surface winds. Additionally, isolated high-based thunderstorms will pose a localized risk of lightning-induced ignitions and gusty/erratic winds away from any heavier rain cores. ...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 0750 AM CDT Fri Aug 22 2025 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS TO THE UPPER MIDWEST AS WELL AS ARIZONA... ...SUMMARY... Strong to locally severe thunderstorms are possible from parts of the central and northern High Plains to the Upper Midwest, and across parts of Arizona. ...Upper Midwest/Upper Great Lakes... Upper trough amplification will continue to occur over Manitoba/northern Ontario through tonight, with consequential height falls over the upper Great Lakes. A cold front will continue to advance southeastward regionally, with a semi-moist air mass preceding it. A consequential factor for portions of the region will be an MCS centered across far eastern South Dakota early this morning, which will continue to disturb the frontal zone and nearby warm sector for the first part of the day. This may especially be the case across southern Minnesota and vicinity. But on the periphery of the MCS-influenced corridor, potential severe storm development could occur by late afternoon, perhaps most likely across eastern Nebraska and western Iowa, but also across northwest Wisconsin/Upper Michigan where vertical shear will be stronger but with more modest buoyancy. Hail and damaging winds would be possible in both scenarios, but likely on a relatively isolated basis. ...Wyoming/Colorado and central High Plains... A subtle ridge-peripheral disturbance noted in water vapor imagery, along with strong surface heating, should aid thunderstorm development initially across Wyoming/Colorado. This activity should propagate east-southeast toward lower elevations in the presence of moist low-level upslope flow. Hail and wind are possible with this activity, especially within a corridor across interior/southeast Wyoming into northeast/east-central Colorado. ...Arizona... The upper high will shift west-northwestward through tonight, maintaining and potentially strengthening easterly mid-level winds across southern Arizona, in addition to the possibility of slightly cooler (degree or two C) mid-level temperatures. Lingering morning cloud cover should gradually abate into the afternoon, with a very hot/residually moist boundary layer contributing to widely scattered thunderstorm development, initially over higher terrain. West/southwestward spreading storms will pose the potential for strong wind gusts/blowing dust onto the desert floor. ..Guyer/Kerr.. 08/22/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Fri Aug 22 2025 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS TO THE UPPER MIDWEST AS WELL AS ARIZONA... ...SUMMARY... Strong to locally severe thunderstorms are possible from parts of the central and northern High Plains to the Upper Midwest, and across parts of Arizona. ...Upper Midwest/Upper Great Lakes... Upper trough amplification will continue to occur over Manitoba/northern Ontario through tonight, with consequential height falls over the upper Great Lakes. A cold front will continue to advance southeastward regionally, with a semi-moist air mass preceding it. A consequential factor for portions of the region will be an MCS centered across far eastern South Dakota early this morning, which will continue to disturb the frontal zone and nearby warm sector for the first part of the day. This may especially be the case across southern Minnesota and vicinity. But on the periphery of the MCS-influenced corridor, potential severe storm development could occur by late afternoon, perhaps most likely across eastern Nebraska and western Iowa, but also across northwest Wisconsin/Upper Michigan where vertical shear will be stronger but with more modest buoyancy. Hail and damaging winds would be possible in both scenarios, but likely on a relatively isolated basis. ...Wyoming/Colorado and central High Plains... A subtle ridge-peripheral disturbance noted in water vapor imagery, along with strong surface heating, should aid thunderstorm development initially across Wyoming/Colorado. This activity should propagate east-southeast toward lower elevations in the presence of moist low-level upslope flow. Hail and wind are possible with this activity, especially within a corridor across interior/southeast Wyoming into northeast/east-central Colorado. ...Arizona... The upper high will shift west-northwestward through tonight, maintaining and potentially strengthening easterly mid-level winds across southern Arizona, in addition to the possibility of slightly cooler (degree or two C) mid-level temperatures. Lingering morning cloud cover should gradually abate into the afternoon, with a very hot/residually moist boundary layer contributing to widely scattered thunderstorm development, initially over higher terrain. West/southwestward spreading storms will pose the potential for strong wind gusts/blowing dust onto the desert floor. ..Guyer/Kerr.. 08/22/2025 Read more