Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0155 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN INTO THE CENTRAL ROCKIES... Much of the forecast remains on track, with only minor changes made to ongoing highlights to reflect the latest guidance consensus. ..Squitieri.. 08/06/2025 .PREV DISCUSSION... /ISSUED 0155 AM CDT Wed Aug 06 2025/ ...Synopsis... A robust midlevel trough will advance eastward across the northwestern CONUS, while an expansive large-scale ridge remains in place across the southern Rockies and adjacent Plains. ...Great Basin into the Central Rockies... Compared to Day 1/Wednesday, slightly stronger deep-layer west-southwesterly flow will overspread the Great Basin into the central Rockies -- between the robust midlevel trough and expansive large-scale ridge. Diurnal heating amid a dry antecedent air mass will yield deep boundary-layer mixing into the strengthening flow aloft, resulting in 5-10 percent RH and 20-25 mph sustained west-southwesterly surface winds (with higher gusts). These hot, dry, and windy conditions atop receptive fuels will lead to another critical fire-weather day across the region. ...Dry Thunderstorms - Southwest into the Central Rockies... Midlevel moisture beneath the expansive large-scale ridge will once again contribute to inverted-V soundings and sufficient instability for diurnally driven high-based thunderstorms. Around 0.5 to 0.70 inch PW will favor dry thunderstorms, and given receptive fuels, lightning-induced ignitions will be a continued concern (along with strong/erratic outflow winds). ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ...SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ...Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ...IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ..Grams.. 08/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ...SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ...Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ...IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ..Grams.. 08/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ...SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ...Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ...IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ..Grams.. 08/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ...SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ...Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ...IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ..Grams.. 08/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ...SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ...Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ...IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ..Grams.. 08/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ...SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ...Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ...IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ..Grams.. 08/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ...SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ...Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ...IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ..Grams.. 08/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ...SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ...Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ...IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ..Grams.. 08/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ...SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ...Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ...IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ..Grams.. 08/06/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Wed Aug 06 2025 Valid 061630Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS TO THE MID-MISSISSIPPI VALLEY. AND PART OF NORTHERN MINNESOTA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the northern/central Plains to the Mid-Mississippi Valley, and over part of northern Minnesota this afternoon and tonight. ...Northern/Central Plains into the Mid MS Valley... Water-vapor imagery late this morning shows a quasi-zonal flow regime from the northern Intermountain region east into the central Great Plains. A disturbance along the ND/Canadian border will continue east into the western ON vicinity late tonight. Weak mid-level height rises are forecast over the northern Great Plains downstream of a trough moving east into the northwestern CONUS from the eastern Pacific. A belt of stronger mid-level flow (i.e. around 40 kt at 500 mb) will extend across the region, and diurnal heating of the moist airmass in place will foster moderate to strong buoyancy. Forecast soundings show a vigorous combination of shear/buoyancy but nebulous forcing mechanisms suggest storm coverage later today/tonight will likely remain isolated/sparse. Little in the way of large-scale forcing for ascent will contribute to suppressing convective development through at least mid afternoon. Considerable uncertainty in storm development is apparent in convection-allowing models and some of these models show isolated storms perhaps favoring the greater Black Hills area. Will maintain a Marginal risk (level 1 of 5) despite favorable environmental conditions for supercells. Later tonight in association with low-level warm-air advection, a cluster or two of storms may evolve from the eastern half of SD/NE into the lower MO Valley/mid MS Valley. An isolated hail/wind threat could accompany this activity. ...Northern MN... A few storms may develop along the southern periphery of the Canadian Prairies shortwave upper trough and surface low. Lapse rates will be weaker across this area and the favorable thermodynamic environment will be narrow. Any stronger storms will likely remain close to the international border, but could produce locally strong gusts or marginal hail. ..Smith/Wendt.. 08/06/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Wed Aug 06 2025 Valid 061630Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS TO THE MID-MISSISSIPPI VALLEY. AND PART OF NORTHERN MINNESOTA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the northern/central Plains to the Mid-Mississippi Valley, and over part of northern Minnesota this afternoon and tonight. ...Northern/Central Plains into the Mid MS Valley... Water-vapor imagery late this morning shows a quasi-zonal flow regime from the northern Intermountain region east into the central Great Plains. A disturbance along the ND/Canadian border will continue east into the western ON vicinity late tonight. Weak mid-level height rises are forecast over the northern Great Plains downstream of a trough moving east into the northwestern CONUS from the eastern Pacific. A belt of stronger mid-level flow (i.e. around 40 kt at 500 mb) will extend across the region, and diurnal heating of the moist airmass in place will foster moderate to strong buoyancy. Forecast soundings show a vigorous combination of shear/buoyancy but nebulous forcing mechanisms suggest storm coverage later today/tonight will likely remain isolated/sparse. Little in the way of large-scale forcing for ascent will contribute to suppressing convective development through at least mid afternoon. Considerable uncertainty in storm development is apparent in convection-allowing models and some of these models show isolated storms perhaps favoring the greater Black Hills area. Will maintain a Marginal risk (level 1 of 5) despite favorable environmental conditions for supercells. Later tonight in association with low-level warm-air advection, a cluster or two of storms may evolve from the eastern half of SD/NE into the lower MO Valley/mid MS Valley. An isolated hail/wind threat could accompany this activity. ...Northern MN... A few storms may develop along the southern periphery of the Canadian Prairies shortwave upper trough and surface low. Lapse rates will be weaker across this area and the favorable thermodynamic environment will be narrow. Any stronger storms will likely remain close to the international border, but could produce locally strong gusts or marginal hail. ..Smith/Wendt.. 08/06/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Wed Aug 06 2025 Valid 061630Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS TO THE MID-MISSISSIPPI VALLEY. AND PART OF NORTHERN MINNESOTA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the northern/central Plains to the Mid-Mississippi Valley, and over part of northern Minnesota this afternoon and tonight. ...Northern/Central Plains into the Mid MS Valley... Water-vapor imagery late this morning shows a quasi-zonal flow regime from the northern Intermountain region east into the central Great Plains. A disturbance along the ND/Canadian border will continue east into the western ON vicinity late tonight. Weak mid-level height rises are forecast over the northern Great Plains downstream of a trough moving east into the northwestern CONUS from the eastern Pacific. A belt of stronger mid-level flow (i.e. around 40 kt at 500 mb) will extend across the region, and diurnal heating of the moist airmass in place will foster moderate to strong buoyancy. Forecast soundings show a vigorous combination of shear/buoyancy but nebulous forcing mechanisms suggest storm coverage later today/tonight will likely remain isolated/sparse. Little in the way of large-scale forcing for ascent will contribute to suppressing convective development through at least mid afternoon. Considerable uncertainty in storm development is apparent in convection-allowing models and some of these models show isolated storms perhaps favoring the greater Black Hills area. Will maintain a Marginal risk (level 1 of 5) despite favorable environmental conditions for supercells. Later tonight in association with low-level warm-air advection, a cluster or two of storms may evolve from the eastern half of SD/NE into the lower MO Valley/mid MS Valley. An isolated hail/wind threat could accompany this activity. ...Northern MN... A few storms may develop along the southern periphery of the Canadian Prairies shortwave upper trough and surface low. Lapse rates will be weaker across this area and the favorable thermodynamic environment will be narrow. Any stronger storms will likely remain close to the international border, but could produce locally strong gusts or marginal hail. ..Smith/Wendt.. 08/06/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Wed Aug 06 2025 Valid 061630Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS TO THE MID-MISSISSIPPI VALLEY. AND PART OF NORTHERN MINNESOTA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the northern/central Plains to the Mid-Mississippi Valley, and over part of northern Minnesota this afternoon and tonight. ...Northern/Central Plains into the Mid MS Valley... Water-vapor imagery late this morning shows a quasi-zonal flow regime from the northern Intermountain region east into the central Great Plains. A disturbance along the ND/Canadian border will continue east into the western ON vicinity late tonight. Weak mid-level height rises are forecast over the northern Great Plains downstream of a trough moving east into the northwestern CONUS from the eastern Pacific. A belt of stronger mid-level flow (i.e. around 40 kt at 500 mb) will extend across the region, and diurnal heating of the moist airmass in place will foster moderate to strong buoyancy. Forecast soundings show a vigorous combination of shear/buoyancy but nebulous forcing mechanisms suggest storm coverage later today/tonight will likely remain isolated/sparse. Little in the way of large-scale forcing for ascent will contribute to suppressing convective development through at least mid afternoon. Considerable uncertainty in storm development is apparent in convection-allowing models and some of these models show isolated storms perhaps favoring the greater Black Hills area. Will maintain a Marginal risk (level 1 of 5) despite favorable environmental conditions for supercells. Later tonight in association with low-level warm-air advection, a cluster or two of storms may evolve from the eastern half of SD/NE into the lower MO Valley/mid MS Valley. An isolated hail/wind threat could accompany this activity. ...Northern MN... A few storms may develop along the southern periphery of the Canadian Prairies shortwave upper trough and surface low. Lapse rates will be weaker across this area and the favorable thermodynamic environment will be narrow. Any stronger storms will likely remain close to the international border, but could produce locally strong gusts or marginal hail. ..Smith/Wendt.. 08/06/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Wed Aug 06 2025 Valid 061630Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS TO THE MID-MISSISSIPPI VALLEY. AND PART OF NORTHERN MINNESOTA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the northern/central Plains to the Mid-Mississippi Valley, and over part of northern Minnesota this afternoon and tonight. ...Northern/Central Plains into the Mid MS Valley... Water-vapor imagery late this morning shows a quasi-zonal flow regime from the northern Intermountain region east into the central Great Plains. A disturbance along the ND/Canadian border will continue east into the western ON vicinity late tonight. Weak mid-level height rises are forecast over the northern Great Plains downstream of a trough moving east into the northwestern CONUS from the eastern Pacific. A belt of stronger mid-level flow (i.e. around 40 kt at 500 mb) will extend across the region, and diurnal heating of the moist airmass in place will foster moderate to strong buoyancy. Forecast soundings show a vigorous combination of shear/buoyancy but nebulous forcing mechanisms suggest storm coverage later today/tonight will likely remain isolated/sparse. Little in the way of large-scale forcing for ascent will contribute to suppressing convective development through at least mid afternoon. Considerable uncertainty in storm development is apparent in convection-allowing models and some of these models show isolated storms perhaps favoring the greater Black Hills area. Will maintain a Marginal risk (level 1 of 5) despite favorable environmental conditions for supercells. Later tonight in association with low-level warm-air advection, a cluster or two of storms may evolve from the eastern half of SD/NE into the lower MO Valley/mid MS Valley. An isolated hail/wind threat could accompany this activity. ...Northern MN... A few storms may develop along the southern periphery of the Canadian Prairies shortwave upper trough and surface low. Lapse rates will be weaker across this area and the favorable thermodynamic environment will be narrow. Any stronger storms will likely remain close to the international border, but could produce locally strong gusts or marginal hail. ..Smith/Wendt.. 08/06/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Wed Aug 06 2025 Valid 061630Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS TO THE MID-MISSISSIPPI VALLEY. AND PART OF NORTHERN MINNESOTA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the northern/central Plains to the Mid-Mississippi Valley, and over part of northern Minnesota this afternoon and tonight. ...Northern/Central Plains into the Mid MS Valley... Water-vapor imagery late this morning shows a quasi-zonal flow regime from the northern Intermountain region east into the central Great Plains. A disturbance along the ND/Canadian border will continue east into the western ON vicinity late tonight. Weak mid-level height rises are forecast over the northern Great Plains downstream of a trough moving east into the northwestern CONUS from the eastern Pacific. A belt of stronger mid-level flow (i.e. around 40 kt at 500 mb) will extend across the region, and diurnal heating of the moist airmass in place will foster moderate to strong buoyancy. Forecast soundings show a vigorous combination of shear/buoyancy but nebulous forcing mechanisms suggest storm coverage later today/tonight will likely remain isolated/sparse. Little in the way of large-scale forcing for ascent will contribute to suppressing convective development through at least mid afternoon. Considerable uncertainty in storm development is apparent in convection-allowing models and some of these models show isolated storms perhaps favoring the greater Black Hills area. Will maintain a Marginal risk (level 1 of 5) despite favorable environmental conditions for supercells. Later tonight in association with low-level warm-air advection, a cluster or two of storms may evolve from the eastern half of SD/NE into the lower MO Valley/mid MS Valley. An isolated hail/wind threat could accompany this activity. ...Northern MN... A few storms may develop along the southern periphery of the Canadian Prairies shortwave upper trough and surface low. Lapse rates will be weaker across this area and the favorable thermodynamic environment will be narrow. Any stronger storms will likely remain close to the international border, but could produce locally strong gusts or marginal hail. ..Smith/Wendt.. 08/06/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Wed Aug 06 2025 Valid 061630Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS TO THE MID-MISSISSIPPI VALLEY. AND PART OF NORTHERN MINNESOTA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the northern/central Plains to the Mid-Mississippi Valley, and over part of northern Minnesota this afternoon and tonight. ...Northern/Central Plains into the Mid MS Valley... Water-vapor imagery late this morning shows a quasi-zonal flow regime from the northern Intermountain region east into the central Great Plains. A disturbance along the ND/Canadian border will continue east into the western ON vicinity late tonight. Weak mid-level height rises are forecast over the northern Great Plains downstream of a trough moving east into the northwestern CONUS from the eastern Pacific. A belt of stronger mid-level flow (i.e. around 40 kt at 500 mb) will extend across the region, and diurnal heating of the moist airmass in place will foster moderate to strong buoyancy. Forecast soundings show a vigorous combination of shear/buoyancy but nebulous forcing mechanisms suggest storm coverage later today/tonight will likely remain isolated/sparse. Little in the way of large-scale forcing for ascent will contribute to suppressing convective development through at least mid afternoon. Considerable uncertainty in storm development is apparent in convection-allowing models and some of these models show isolated storms perhaps favoring the greater Black Hills area. Will maintain a Marginal risk (level 1 of 5) despite favorable environmental conditions for supercells. Later tonight in association with low-level warm-air advection, a cluster or two of storms may evolve from the eastern half of SD/NE into the lower MO Valley/mid MS Valley. An isolated hail/wind threat could accompany this activity. ...Northern MN... A few storms may develop along the southern periphery of the Canadian Prairies shortwave upper trough and surface low. Lapse rates will be weaker across this area and the favorable thermodynamic environment will be narrow. Any stronger storms will likely remain close to the international border, but could produce locally strong gusts or marginal hail. ..Smith/Wendt.. 08/06/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Wed Aug 06 2025 Valid 061630Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS TO THE MID-MISSISSIPPI VALLEY. AND PART OF NORTHERN MINNESOTA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the northern/central Plains to the Mid-Mississippi Valley, and over part of northern Minnesota this afternoon and tonight. ...Northern/Central Plains into the Mid MS Valley... Water-vapor imagery late this morning shows a quasi-zonal flow regime from the northern Intermountain region east into the central Great Plains. A disturbance along the ND/Canadian border will continue east into the western ON vicinity late tonight. Weak mid-level height rises are forecast over the northern Great Plains downstream of a trough moving east into the northwestern CONUS from the eastern Pacific. A belt of stronger mid-level flow (i.e. around 40 kt at 500 mb) will extend across the region, and diurnal heating of the moist airmass in place will foster moderate to strong buoyancy. Forecast soundings show a vigorous combination of shear/buoyancy but nebulous forcing mechanisms suggest storm coverage later today/tonight will likely remain isolated/sparse. Little in the way of large-scale forcing for ascent will contribute to suppressing convective development through at least mid afternoon. Considerable uncertainty in storm development is apparent in convection-allowing models and some of these models show isolated storms perhaps favoring the greater Black Hills area. Will maintain a Marginal risk (level 1 of 5) despite favorable environmental conditions for supercells. Later tonight in association with low-level warm-air advection, a cluster or two of storms may evolve from the eastern half of SD/NE into the lower MO Valley/mid MS Valley. An isolated hail/wind threat could accompany this activity. ...Northern MN... A few storms may develop along the southern periphery of the Canadian Prairies shortwave upper trough and surface low. Lapse rates will be weaker across this area and the favorable thermodynamic environment will be narrow. Any stronger storms will likely remain close to the international border, but could produce locally strong gusts or marginal hail. ..Smith/Wendt.. 08/06/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1113 AM CDT Wed Aug 06 2025 Valid 061700Z - 071200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN INTO THE CENTRAL ROCKIES... The previous forecast remains on track, with only slight adjustments made to the ongoing highlights to reflect the latest guidance consensus. ..Squitieri.. 08/06/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Wed Aug 06 2025/ ...Synopsis... Broad midlevel troughing will persist across the northwestern CONUS, while an expansive mid/upper-level anticyclone remains centered on the Southwest/southern Rockies. ...Great Basin into the Central Rockies... Between the midlevel troughing and expansive mid/upper-level anticyclone, a belt of enhanced deep-layer west-southwesterly flow will remain in place across the Great Basin into the central Rockies. A diurnally deepening PBL will extent into this enhanced flow aloft, yielding an expansive overlap of around 20 mph sustained west-southwesterly surface winds and 10-15 percent RH. These conditions, combined with highly receptive fuels, will favor another day of critical fire-weather conditions across the region. ...Dry Thunderstorms - Southwest into the Central Rockies... Boundary-layer mixing beneath a plume of well-established midlevel moisture extending from the Southwest into the central Rockies will yield sufficient instability (characterized by inverted-V soundings) for isolated to widely scattered thunderstorm development -- generally focused along terrain features. PW values of 0.50 to 0.75 inches will promote mostly dry thunderstorms, which will pose a risk of lightning-induced ignitions and strong outflow winds. ...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 1113 AM CDT Wed Aug 06 2025 Valid 061700Z - 071200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN INTO THE CENTRAL ROCKIES... The previous forecast remains on track, with only slight adjustments made to the ongoing highlights to reflect the latest guidance consensus. ..Squitieri.. 08/06/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Wed Aug 06 2025/ ...Synopsis... Broad midlevel troughing will persist across the northwestern CONUS, while an expansive mid/upper-level anticyclone remains centered on the Southwest/southern Rockies. ...Great Basin into the Central Rockies... Between the midlevel troughing and expansive mid/upper-level anticyclone, a belt of enhanced deep-layer west-southwesterly flow will remain in place across the Great Basin into the central Rockies. A diurnally deepening PBL will extent into this enhanced flow aloft, yielding an expansive overlap of around 20 mph sustained west-southwesterly surface winds and 10-15 percent RH. These conditions, combined with highly receptive fuels, will favor another day of critical fire-weather conditions across the region. ...Dry Thunderstorms - Southwest into the Central Rockies... Boundary-layer mixing beneath a plume of well-established midlevel moisture extending from the Southwest into the central Rockies will yield sufficient instability (characterized by inverted-V soundings) for isolated to widely scattered thunderstorm development -- generally focused along terrain features. PW values of 0.50 to 0.75 inches will promote mostly dry thunderstorms, which will pose a risk of lightning-induced ignitions and strong outflow winds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more