Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sat Jul 19 2025 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHEAST...AND OVER THE DAKOTAS... ...SUMMARY... A few severe thunderstorms with damaging wind gusts and some hail are possible Sunday across parts of New England into the northern Mid Atlantic. Scattered severe hail and wind are also possible over the central Dakotas. ...Northeast... An upper trough will pivot eastward across Quebec, with cooling aloft from NY into New England. Low pressure will deepen into southern New England during the afternoon, with a cold front progressing southeastward across the region, and nearing the coast around 00Z. A moist air mass will remain ahead of the front, with MUCAPE up to 2000 J/kg possible. This will occur beneath 40-50 kt midlevel westerlies, resulting in a few long-lived cells producing localized hail. As storm coverage maximizes during the late afternoon, a few small bowing structures will be possible, with corridors of damaging gusts as well. ...Dakotas... A broad upper trough will remain from the Pacific Northwest into the northern Rockies, with minor shortwave ridging over the northern Plains where midlevel temperatures will still remain cool. A surface trough will develop from southeast MT into the western SD/NE/KS, where heating will be strong. Moderate uncapped instability and moist southeast winds east of the surface trough should yield clusters of storms developing from central ND into SD, moving southeastward through evening. Large hail is likely, along with aggregating/severe outflow/wind. ...Mid MS and OH Valleys... Although well south of the upper trough, modest west/northwest flow aloft will remain over the Midwest and OH Valley, near a stalled front with 70s F dewpoints. Tall/moist CAPE profiles with high PWAT suggest sporadic multicelluar clusters of storms will be possible from southeast IA into KY/WV during the afternoon. Localized wind damage will be possible. Higher probability corridors cannot be ruled out in later outlooks as predictability increases on the mesoscale. ..Jewell.. 07/19/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sat Jul 19 2025 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHEAST...AND OVER THE DAKOTAS... ...SUMMARY... A few severe thunderstorms with damaging wind gusts and some hail are possible Sunday across parts of New England into the northern Mid Atlantic. Scattered severe hail and wind are also possible over the central Dakotas. ...Northeast... An upper trough will pivot eastward across Quebec, with cooling aloft from NY into New England. Low pressure will deepen into southern New England during the afternoon, with a cold front progressing southeastward across the region, and nearing the coast around 00Z. A moist air mass will remain ahead of the front, with MUCAPE up to 2000 J/kg possible. This will occur beneath 40-50 kt midlevel westerlies, resulting in a few long-lived cells producing localized hail. As storm coverage maximizes during the late afternoon, a few small bowing structures will be possible, with corridors of damaging gusts as well. ...Dakotas... A broad upper trough will remain from the Pacific Northwest into the northern Rockies, with minor shortwave ridging over the northern Plains where midlevel temperatures will still remain cool. A surface trough will develop from southeast MT into the western SD/NE/KS, where heating will be strong. Moderate uncapped instability and moist southeast winds east of the surface trough should yield clusters of storms developing from central ND into SD, moving southeastward through evening. Large hail is likely, along with aggregating/severe outflow/wind. ...Mid MS and OH Valleys... Although well south of the upper trough, modest west/northwest flow aloft will remain over the Midwest and OH Valley, near a stalled front with 70s F dewpoints. Tall/moist CAPE profiles with high PWAT suggest sporadic multicelluar clusters of storms will be possible from southeast IA into KY/WV during the afternoon. Localized wind damage will be possible. Higher probability corridors cannot be ruled out in later outlooks as predictability increases on the mesoscale. ..Jewell.. 07/19/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sat Jul 19 2025 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHEAST...AND OVER THE DAKOTAS... ...SUMMARY... A few severe thunderstorms with damaging wind gusts and some hail are possible Sunday across parts of New England into the northern Mid Atlantic. Scattered severe hail and wind are also possible over the central Dakotas. ...Northeast... An upper trough will pivot eastward across Quebec, with cooling aloft from NY into New England. Low pressure will deepen into southern New England during the afternoon, with a cold front progressing southeastward across the region, and nearing the coast around 00Z. A moist air mass will remain ahead of the front, with MUCAPE up to 2000 J/kg possible. This will occur beneath 40-50 kt midlevel westerlies, resulting in a few long-lived cells producing localized hail. As storm coverage maximizes during the late afternoon, a few small bowing structures will be possible, with corridors of damaging gusts as well. ...Dakotas... A broad upper trough will remain from the Pacific Northwest into the northern Rockies, with minor shortwave ridging over the northern Plains where midlevel temperatures will still remain cool. A surface trough will develop from southeast MT into the western SD/NE/KS, where heating will be strong. Moderate uncapped instability and moist southeast winds east of the surface trough should yield clusters of storms developing from central ND into SD, moving southeastward through evening. Large hail is likely, along with aggregating/severe outflow/wind. ...Mid MS and OH Valleys... Although well south of the upper trough, modest west/northwest flow aloft will remain over the Midwest and OH Valley, near a stalled front with 70s F dewpoints. Tall/moist CAPE profiles with high PWAT suggest sporadic multicelluar clusters of storms will be possible from southeast IA into KY/WV during the afternoon. Localized wind damage will be possible. Higher probability corridors cannot be ruled out in later outlooks as predictability increases on the mesoscale. ..Jewell.. 07/19/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...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 1133 AM CDT Sat Jul 19 2025 Valid 191700Z - 201200Z Today's fire weather forecast remains largely on-track with only minor changes needed based on the latest ensemble forecast guidance. Primary change with this forecast update was to expand the elevated area across the northern Great Basin a bit farther south into portions of central Nevada, where several hours of dry and breezy conditions are expected. The dry/breezy conditions may also lead to the emergence of lightning holdovers across portions of the northern Great Basin, where a combination of wet/dry thunderstorms have occurred over the last week. Lightning data over the past 24-72 hours suggests holdover potential is greatest across portions of central/northeast Nevada into southeast Idaho. Relatively stronger sustained surface winds (near 25 mph) across the Snake River Plain in Idaho will promote locally critical conditions, especially along the periphery of heavier storm cores from the past few days (several heavier cores had 0.5+ inch rainfall), and also in areas devoid of recent rainfall. Please see the previous discussion below for more information on today's fire weather forecast. ..Elliott.. 07/19/2025 .PREV DISCUSSION... /ISSUED 1238 AM CDT Sat Jul 19 2025/ ...Synopsis... Upper-level ridging will persist across much of the southern half of the U.S. today. A weak upper-level low will be positioned over southern California into northern Baja. A belt of stronger mid-level winds will exist across the northern tier states with a low-amplitude shortwave trough moving through the Northwest. A surface trough will deepen in the lee of the northern Rockies. ...Columbia Basin into the northern Great Basin... Offshore high pressure and the deepening trough to the east will promote modestly strong westerly winds across the Cascades. Winds in the Columbia Basin will reach 15-20 mph with perhaps higher speeds within some of the Cascade gaps. RH of 15-20% is possible by the afternoon. In the northern Great Basin, surface winds of 15-20 mph are possible with RH falling into the 10-20% range. Stronger winds are possible in the Snake River Plain as mid-level winds will be stronger and better aligned with the terrain. There, up to 25 mph winds will be possible for a short duration. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Jul 19 2025 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS...MIDWEST/GREAT LAKES...AND VIRGINIA/NORTH CAROLINA... ...SUMMARY... Scattered damaging winds are possible today across parts of the Midwest/Great Lakes and southern Mid-Atlantic. Scattered large to very large hail and severe gusts are possible, along with a potential tornado threat, across the northern/central Plains during the late afternoon and evening. ...Midwest/Great Lakes... An ongoing sub-severe MCS continues east-southeast across IL with an attendant warm advection cluster of thunderstorms downstream over the lower Wabash Valley. Considerable convective overturning coupled with convective cloud debris have acted to limit destabilization thus far across IL into western IN and northward into the southwest Great Lakes. Have reduced severe probabilities this outlook update for northern IL into WI due to limited destabilization, and models converging on limited storm coverage through the remainder of the day and their depiction of primary thunderstorm activity tonight occurring farther south/southwest over IA into central IL towards daybreak. However, downstream of the ongoing thunderstorm clusters over IL/IN, gradual heating will probably support some intensification of storms into the afternoon. Isolated to perhaps scattered damaging winds in small clusters appear to be the primary severe hazard. Other thunderstorm development is possible over Lower MI where a wind-damage threat may materialize with the stronger storms that develop this afternoon. Later this afternoon but more likely into tonight, additional storms are forecast to develop on the trailing outflow with an attendant risk for mainly hail/wind. ...Virginia/North Carolina... A west-east draped frontal zone resides over southern PA to the north of this region. However, a very moist low-level airmass featuring lower to mid 70s dewpoints will continue to heat/destabilize through mid-late afternoon and promote the development of moderate buoyancy. Despite weak mid-level lapse rates, high PW (around 2 inches) will promote water-loaded downdrafts capable of strong to severe gusts and scattered wind damage with the more organized cluster(s). Around 15-25 kt of mid-level westerly flow will favor eastward-moving storm activity. The severe risk is expected to concentrate during the 20-01 UTC period as storms move towards central VA and into eastern VA by this evening. ...Northern/Central Plains... Water-vapor imagery shows a mid-level impulse moving eastward across the northwest quarter of MT this morning. This will continue eastward towards eastern MT and the western Dakotas by early evening. Weaker mid-level westerly flow will remain farther south into the central High Plains. At the surface, a lee trough will extend southward from eastern MT to eastern CO. Generally low to mid 60s surface dewpoints should exist this afternoon along/east of the lee trough, with upper 60s to lower 70s F dewpoints present near a remnant front/boundary in NE. Scattered thunderstorms will likely develop initially over the higher terrain of the northern/central Rockies this afternoon, with additional development farther east along the lee trough. As this convection spreads eastward into a moderately to strongly unstable airmass across the northern/central High Plains, it should strengthen. Weak low-level winds are forecast to veer and increase with height through mid/upper levels, supporting strong deep-layer shear and the potential for supercells. Scattered large hail will be possible with any supercells that can persist, with most guidance indicating a greater concentration of severe thunderstorms across eastern MT into western ND, and separately across western/central NE. Given the presence of steep mid-level lapse rates and 40-50+ kt of deep-layer shear, isolated very large hail appears possible. Recent model guidance indicates a few supercells may develop across west-central NE late this afternoon into the evening. Some enlargement of the hodograph during the evening combined with moist low levels may support a couple hour window for a locally higher tornado risk compared to within this broader region. ..Smith/Weinman.. 07/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Jul 19 2025 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS...MIDWEST/GREAT LAKES...AND VIRGINIA/NORTH CAROLINA... ...SUMMARY... Scattered damaging winds are possible today across parts of the Midwest/Great Lakes and southern Mid-Atlantic. Scattered large to very large hail and severe gusts are possible, along with a potential tornado threat, across the northern/central Plains during the late afternoon and evening. ...Midwest/Great Lakes... An ongoing sub-severe MCS continues east-southeast across IL with an attendant warm advection cluster of thunderstorms downstream over the lower Wabash Valley. Considerable convective overturning coupled with convective cloud debris have acted to limit destabilization thus far across IL into western IN and northward into the southwest Great Lakes. Have reduced severe probabilities this outlook update for northern IL into WI due to limited destabilization, and models converging on limited storm coverage through the remainder of the day and their depiction of primary thunderstorm activity tonight occurring farther south/southwest over IA into central IL towards daybreak. However, downstream of the ongoing thunderstorm clusters over IL/IN, gradual heating will probably support some intensification of storms into the afternoon. Isolated to perhaps scattered damaging winds in small clusters appear to be the primary severe hazard. Other thunderstorm development is possible over Lower MI where a wind-damage threat may materialize with the stronger storms that develop this afternoon. Later this afternoon but more likely into tonight, additional storms are forecast to develop on the trailing outflow with an attendant risk for mainly hail/wind. ...Virginia/North Carolina... A west-east draped frontal zone resides over southern PA to the north of this region. However, a very moist low-level airmass featuring lower to mid 70s dewpoints will continue to heat/destabilize through mid-late afternoon and promote the development of moderate buoyancy. Despite weak mid-level lapse rates, high PW (around 2 inches) will promote water-loaded downdrafts capable of strong to severe gusts and scattered wind damage with the more organized cluster(s). Around 15-25 kt of mid-level westerly flow will favor eastward-moving storm activity. The severe risk is expected to concentrate during the 20-01 UTC period as storms move towards central VA and into eastern VA by this evening. ...Northern/Central Plains... Water-vapor imagery shows a mid-level impulse moving eastward across the northwest quarter of MT this morning. This will continue eastward towards eastern MT and the western Dakotas by early evening. Weaker mid-level westerly flow will remain farther south into the central High Plains. At the surface, a lee trough will extend southward from eastern MT to eastern CO. Generally low to mid 60s surface dewpoints should exist this afternoon along/east of the lee trough, with upper 60s to lower 70s F dewpoints present near a remnant front/boundary in NE. Scattered thunderstorms will likely develop initially over the higher terrain of the northern/central Rockies this afternoon, with additional development farther east along the lee trough. As this convection spreads eastward into a moderately to strongly unstable airmass across the northern/central High Plains, it should strengthen. Weak low-level winds are forecast to veer and increase with height through mid/upper levels, supporting strong deep-layer shear and the potential for supercells. Scattered large hail will be possible with any supercells that can persist, with most guidance indicating a greater concentration of severe thunderstorms across eastern MT into western ND, and separately across western/central NE. Given the presence of steep mid-level lapse rates and 40-50+ kt of deep-layer shear, isolated very large hail appears possible. Recent model guidance indicates a few supercells may develop across west-central NE late this afternoon into the evening. Some enlargement of the hodograph during the evening combined with moist low levels may support a couple hour window for a locally higher tornado risk compared to within this broader region. ..Smith/Weinman.. 07/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Jul 19 2025 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS...MIDWEST/GREAT LAKES...AND VIRGINIA/NORTH CAROLINA... ...SUMMARY... Scattered damaging winds are possible today across parts of the Midwest/Great Lakes and southern Mid-Atlantic. Scattered large to very large hail and severe gusts are possible, along with a potential tornado threat, across the northern/central Plains during the late afternoon and evening. ...Midwest/Great Lakes... An ongoing sub-severe MCS continues east-southeast across IL with an attendant warm advection cluster of thunderstorms downstream over the lower Wabash Valley. Considerable convective overturning coupled with convective cloud debris have acted to limit destabilization thus far across IL into western IN and northward into the southwest Great Lakes. Have reduced severe probabilities this outlook update for northern IL into WI due to limited destabilization, and models converging on limited storm coverage through the remainder of the day and their depiction of primary thunderstorm activity tonight occurring farther south/southwest over IA into central IL towards daybreak. However, downstream of the ongoing thunderstorm clusters over IL/IN, gradual heating will probably support some intensification of storms into the afternoon. Isolated to perhaps scattered damaging winds in small clusters appear to be the primary severe hazard. Other thunderstorm development is possible over Lower MI where a wind-damage threat may materialize with the stronger storms that develop this afternoon. Later this afternoon but more likely into tonight, additional storms are forecast to develop on the trailing outflow with an attendant risk for mainly hail/wind. ...Virginia/North Carolina... A west-east draped frontal zone resides over southern PA to the north of this region. However, a very moist low-level airmass featuring lower to mid 70s dewpoints will continue to heat/destabilize through mid-late afternoon and promote the development of moderate buoyancy. Despite weak mid-level lapse rates, high PW (around 2 inches) will promote water-loaded downdrafts capable of strong to severe gusts and scattered wind damage with the more organized cluster(s). Around 15-25 kt of mid-level westerly flow will favor eastward-moving storm activity. The severe risk is expected to concentrate during the 20-01 UTC period as storms move towards central VA and into eastern VA by this evening. ...Northern/Central Plains... Water-vapor imagery shows a mid-level impulse moving eastward across the northwest quarter of MT this morning. This will continue eastward towards eastern MT and the western Dakotas by early evening. Weaker mid-level westerly flow will remain farther south into the central High Plains. At the surface, a lee trough will extend southward from eastern MT to eastern CO. Generally low to mid 60s surface dewpoints should exist this afternoon along/east of the lee trough, with upper 60s to lower 70s F dewpoints present near a remnant front/boundary in NE. Scattered thunderstorms will likely develop initially over the higher terrain of the northern/central Rockies this afternoon, with additional development farther east along the lee trough. As this convection spreads eastward into a moderately to strongly unstable airmass across the northern/central High Plains, it should strengthen. Weak low-level winds are forecast to veer and increase with height through mid/upper levels, supporting strong deep-layer shear and the potential for supercells. Scattered large hail will be possible with any supercells that can persist, with most guidance indicating a greater concentration of severe thunderstorms across eastern MT into western ND, and separately across western/central NE. Given the presence of steep mid-level lapse rates and 40-50+ kt of deep-layer shear, isolated very large hail appears possible. Recent model guidance indicates a few supercells may develop across west-central NE late this afternoon into the evening. Some enlargement of the hodograph during the evening combined with moist low levels may support a couple hour window for a locally higher tornado risk compared to within this broader region. ..Smith/Weinman.. 07/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Jul 19 2025 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS...MIDWEST/GREAT LAKES...AND VIRGINIA/NORTH CAROLINA... ...SUMMARY... Scattered damaging winds are possible today across parts of the Midwest/Great Lakes and southern Mid-Atlantic. Scattered large to very large hail and severe gusts are possible, along with a potential tornado threat, across the northern/central Plains during the late afternoon and evening. ...Midwest/Great Lakes... An ongoing sub-severe MCS continues east-southeast across IL with an attendant warm advection cluster of thunderstorms downstream over the lower Wabash Valley. Considerable convective overturning coupled with convective cloud debris have acted to limit destabilization thus far across IL into western IN and northward into the southwest Great Lakes. Have reduced severe probabilities this outlook update for northern IL into WI due to limited destabilization, and models converging on limited storm coverage through the remainder of the day and their depiction of primary thunderstorm activity tonight occurring farther south/southwest over IA into central IL towards daybreak. However, downstream of the ongoing thunderstorm clusters over IL/IN, gradual heating will probably support some intensification of storms into the afternoon. Isolated to perhaps scattered damaging winds in small clusters appear to be the primary severe hazard. Other thunderstorm development is possible over Lower MI where a wind-damage threat may materialize with the stronger storms that develop this afternoon. Later this afternoon but more likely into tonight, additional storms are forecast to develop on the trailing outflow with an attendant risk for mainly hail/wind. ...Virginia/North Carolina... A west-east draped frontal zone resides over southern PA to the north of this region. However, a very moist low-level airmass featuring lower to mid 70s dewpoints will continue to heat/destabilize through mid-late afternoon and promote the development of moderate buoyancy. Despite weak mid-level lapse rates, high PW (around 2 inches) will promote water-loaded downdrafts capable of strong to severe gusts and scattered wind damage with the more organized cluster(s). Around 15-25 kt of mid-level westerly flow will favor eastward-moving storm activity. The severe risk is expected to concentrate during the 20-01 UTC period as storms move towards central VA and into eastern VA by this evening. ...Northern/Central Plains... Water-vapor imagery shows a mid-level impulse moving eastward across the northwest quarter of MT this morning. This will continue eastward towards eastern MT and the western Dakotas by early evening. Weaker mid-level westerly flow will remain farther south into the central High Plains. At the surface, a lee trough will extend southward from eastern MT to eastern CO. Generally low to mid 60s surface dewpoints should exist this afternoon along/east of the lee trough, with upper 60s to lower 70s F dewpoints present near a remnant front/boundary in NE. Scattered thunderstorms will likely develop initially over the higher terrain of the northern/central Rockies this afternoon, with additional development farther east along the lee trough. As this convection spreads eastward into a moderately to strongly unstable airmass across the northern/central High Plains, it should strengthen. Weak low-level winds are forecast to veer and increase with height through mid/upper levels, supporting strong deep-layer shear and the potential for supercells. Scattered large hail will be possible with any supercells that can persist, with most guidance indicating a greater concentration of severe thunderstorms across eastern MT into western ND, and separately across western/central NE. Given the presence of steep mid-level lapse rates and 40-50+ kt of deep-layer shear, isolated very large hail appears possible. Recent model guidance indicates a few supercells may develop across west-central NE late this afternoon into the evening. Some enlargement of the hodograph during the evening combined with moist low levels may support a couple hour window for a locally higher tornado risk compared to within this broader region. ..Smith/Weinman.. 07/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Jul 19 2025 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS...MIDWEST/GREAT LAKES...AND VIRGINIA/NORTH CAROLINA... ...SUMMARY... Scattered damaging winds are possible today across parts of the Midwest/Great Lakes and southern Mid-Atlantic. Scattered large to very large hail and severe gusts are possible, along with a potential tornado threat, across the northern/central Plains during the late afternoon and evening. ...Midwest/Great Lakes... An ongoing sub-severe MCS continues east-southeast across IL with an attendant warm advection cluster of thunderstorms downstream over the lower Wabash Valley. Considerable convective overturning coupled with convective cloud debris have acted to limit destabilization thus far across IL into western IN and northward into the southwest Great Lakes. Have reduced severe probabilities this outlook update for northern IL into WI due to limited destabilization, and models converging on limited storm coverage through the remainder of the day and their depiction of primary thunderstorm activity tonight occurring farther south/southwest over IA into central IL towards daybreak. However, downstream of the ongoing thunderstorm clusters over IL/IN, gradual heating will probably support some intensification of storms into the afternoon. Isolated to perhaps scattered damaging winds in small clusters appear to be the primary severe hazard. Other thunderstorm development is possible over Lower MI where a wind-damage threat may materialize with the stronger storms that develop this afternoon. Later this afternoon but more likely into tonight, additional storms are forecast to develop on the trailing outflow with an attendant risk for mainly hail/wind. ...Virginia/North Carolina... A west-east draped frontal zone resides over southern PA to the north of this region. However, a very moist low-level airmass featuring lower to mid 70s dewpoints will continue to heat/destabilize through mid-late afternoon and promote the development of moderate buoyancy. Despite weak mid-level lapse rates, high PW (around 2 inches) will promote water-loaded downdrafts capable of strong to severe gusts and scattered wind damage with the more organized cluster(s). Around 15-25 kt of mid-level westerly flow will favor eastward-moving storm activity. The severe risk is expected to concentrate during the 20-01 UTC period as storms move towards central VA and into eastern VA by this evening. ...Northern/Central Plains... Water-vapor imagery shows a mid-level impulse moving eastward across the northwest quarter of MT this morning. This will continue eastward towards eastern MT and the western Dakotas by early evening. Weaker mid-level westerly flow will remain farther south into the central High Plains. At the surface, a lee trough will extend southward from eastern MT to eastern CO. Generally low to mid 60s surface dewpoints should exist this afternoon along/east of the lee trough, with upper 60s to lower 70s F dewpoints present near a remnant front/boundary in NE. Scattered thunderstorms will likely develop initially over the higher terrain of the northern/central Rockies this afternoon, with additional development farther east along the lee trough. As this convection spreads eastward into a moderately to strongly unstable airmass across the northern/central High Plains, it should strengthen. Weak low-level winds are forecast to veer and increase with height through mid/upper levels, supporting strong deep-layer shear and the potential for supercells. Scattered large hail will be possible with any supercells that can persist, with most guidance indicating a greater concentration of severe thunderstorms across eastern MT into western ND, and separately across western/central NE. Given the presence of steep mid-level lapse rates and 40-50+ kt of deep-layer shear, isolated very large hail appears possible. Recent model guidance indicates a few supercells may develop across west-central NE late this afternoon into the evening. Some enlargement of the hodograph during the evening combined with moist low levels may support a couple hour window for a locally higher tornado risk compared to within this broader region. ..Smith/Weinman.. 07/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Jul 19 2025 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS...MIDWEST/GREAT LAKES...AND VIRGINIA/NORTH CAROLINA... ...SUMMARY... Scattered damaging winds are possible today across parts of the Midwest/Great Lakes and southern Mid-Atlantic. Scattered large to very large hail and severe gusts are possible, along with a potential tornado threat, across the northern/central Plains during the late afternoon and evening. ...Midwest/Great Lakes... An ongoing sub-severe MCS continues east-southeast across IL with an attendant warm advection cluster of thunderstorms downstream over the lower Wabash Valley. Considerable convective overturning coupled with convective cloud debris have acted to limit destabilization thus far across IL into western IN and northward into the southwest Great Lakes. Have reduced severe probabilities this outlook update for northern IL into WI due to limited destabilization, and models converging on limited storm coverage through the remainder of the day and their depiction of primary thunderstorm activity tonight occurring farther south/southwest over IA into central IL towards daybreak. However, downstream of the ongoing thunderstorm clusters over IL/IN, gradual heating will probably support some intensification of storms into the afternoon. Isolated to perhaps scattered damaging winds in small clusters appear to be the primary severe hazard. Other thunderstorm development is possible over Lower MI where a wind-damage threat may materialize with the stronger storms that develop this afternoon. Later this afternoon but more likely into tonight, additional storms are forecast to develop on the trailing outflow with an attendant risk for mainly hail/wind. ...Virginia/North Carolina... A west-east draped frontal zone resides over southern PA to the north of this region. However, a very moist low-level airmass featuring lower to mid 70s dewpoints will continue to heat/destabilize through mid-late afternoon and promote the development of moderate buoyancy. Despite weak mid-level lapse rates, high PW (around 2 inches) will promote water-loaded downdrafts capable of strong to severe gusts and scattered wind damage with the more organized cluster(s). Around 15-25 kt of mid-level westerly flow will favor eastward-moving storm activity. The severe risk is expected to concentrate during the 20-01 UTC period as storms move towards central VA and into eastern VA by this evening. ...Northern/Central Plains... Water-vapor imagery shows a mid-level impulse moving eastward across the northwest quarter of MT this morning. This will continue eastward towards eastern MT and the western Dakotas by early evening. Weaker mid-level westerly flow will remain farther south into the central High Plains. At the surface, a lee trough will extend southward from eastern MT to eastern CO. Generally low to mid 60s surface dewpoints should exist this afternoon along/east of the lee trough, with upper 60s to lower 70s F dewpoints present near a remnant front/boundary in NE. Scattered thunderstorms will likely develop initially over the higher terrain of the northern/central Rockies this afternoon, with additional development farther east along the lee trough. As this convection spreads eastward into a moderately to strongly unstable airmass across the northern/central High Plains, it should strengthen. Weak low-level winds are forecast to veer and increase with height through mid/upper levels, supporting strong deep-layer shear and the potential for supercells. Scattered large hail will be possible with any supercells that can persist, with most guidance indicating a greater concentration of severe thunderstorms across eastern MT into western ND, and separately across western/central NE. Given the presence of steep mid-level lapse rates and 40-50+ kt of deep-layer shear, isolated very large hail appears possible. Recent model guidance indicates a few supercells may develop across west-central NE late this afternoon into the evening. Some enlargement of the hodograph during the evening combined with moist low levels may support a couple hour window for a locally higher tornado risk compared to within this broader region. ..Smith/Weinman.. 07/19/2025 Read more