Severe Storms

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Thu Aug 14 2025 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL/NORTHERN PLAINS TO LOWER MICHIGAN... ...SUMMARY... Isolated to scattered strong to severe storms are possible Saturday from the central/northern Plains to Lower Michigan. ...Discussion... Thunderstorms may be ongoing Saturday morning along a frontal zone from the northern Plains to the western Great Lakes. The location and strength of this morning convection will have significant impacts on more focused zones of severe weather threat on Saturday. A MCS may be ongoing across Wisconsin/northern Illinois/western Michigan on Saturday morning. This MCS or a remnant MCV in its wake, may provide a focus for severe storms across Lower Michigan Saturday afternoon. In addition, a MCS may be ongoing across eastern South Dakota and southwest Minnesota on the nose of the low-level jet. If the environment downstream of this MCS can destabilize during the morning, a severe weather threat may materialize as this MCS moves east along the front. If neither of these solutions occur, the severe weather threat may be somewhat more isolated. However, very strong to extreme instability is expected along the frontal zone with sufficient shear for some storm organization. Strong heating in the Plains may result in a few isolated high-based storms from central Nebraska to western South Dakota and potentially into far southwest Montana with a primary severe wind threat during the afternoon/early evening. Convection is expected along most of the frontal zone from eastern South Dakota to Michigan Saturday night as the low-level jet strengthens and height falls overspread the region. Isolated large hail is possible from these storms. ..Bentley.. 08/14/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Thu Aug 14 2025 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL/NORTHERN PLAINS TO LOWER MICHIGAN... ...SUMMARY... Isolated to scattered strong to severe storms are possible Saturday from the central/northern Plains to Lower Michigan. ...Discussion... Thunderstorms may be ongoing Saturday morning along a frontal zone from the northern Plains to the western Great Lakes. The location and strength of this morning convection will have significant impacts on more focused zones of severe weather threat on Saturday. A MCS may be ongoing across Wisconsin/northern Illinois/western Michigan on Saturday morning. This MCS or a remnant MCV in its wake, may provide a focus for severe storms across Lower Michigan Saturday afternoon. In addition, a MCS may be ongoing across eastern South Dakota and southwest Minnesota on the nose of the low-level jet. If the environment downstream of this MCS can destabilize during the morning, a severe weather threat may materialize as this MCS moves east along the front. If neither of these solutions occur, the severe weather threat may be somewhat more isolated. However, very strong to extreme instability is expected along the frontal zone with sufficient shear for some storm organization. Strong heating in the Plains may result in a few isolated high-based storms from central Nebraska to western South Dakota and potentially into far southwest Montana with a primary severe wind threat during the afternoon/early evening. Convection is expected along most of the frontal zone from eastern South Dakota to Michigan Saturday night as the low-level jet strengthens and height falls overspread the region. Isolated large hail is possible from these storms. ..Bentley.. 08/14/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Thu Aug 14 2025 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL/NORTHERN PLAINS TO LOWER MICHIGAN... ...SUMMARY... Isolated to scattered strong to severe storms are possible Saturday from the central/northern Plains to Lower Michigan. ...Discussion... Thunderstorms may be ongoing Saturday morning along a frontal zone from the northern Plains to the western Great Lakes. The location and strength of this morning convection will have significant impacts on more focused zones of severe weather threat on Saturday. A MCS may be ongoing across Wisconsin/northern Illinois/western Michigan on Saturday morning. This MCS or a remnant MCV in its wake, may provide a focus for severe storms across Lower Michigan Saturday afternoon. In addition, a MCS may be ongoing across eastern South Dakota and southwest Minnesota on the nose of the low-level jet. If the environment downstream of this MCS can destabilize during the morning, a severe weather threat may materialize as this MCS moves east along the front. If neither of these solutions occur, the severe weather threat may be somewhat more isolated. However, very strong to extreme instability is expected along the frontal zone with sufficient shear for some storm organization. Strong heating in the Plains may result in a few isolated high-based storms from central Nebraska to western South Dakota and potentially into far southwest Montana with a primary severe wind threat during the afternoon/early evening. Convection is expected along most of the frontal zone from eastern South Dakota to Michigan Saturday night as the low-level jet strengthens and height falls overspread the region. Isolated large hail is possible from these storms. ..Bentley.. 08/14/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL WISCONSIN AND FAR EASTERN MINNESOTA... ...SUMMARY... Scattered severe storms are likely over parts of the northern Plains and Upper Mississippi Valley on Friday. ...Synopsis... A belt of stronger mid-level flow will be present across the northern Plains on Friday along the northern periphery of a broad mid-level ridge. Within this flow, a weak mid-level shortwave trough (perhaps amplified by Day1/Thursday convection across the central Rockies) will move across the northern Plains and into the Upper Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is forecast to traverse the central Rockies with associated ascent overspreading the central/northern High Plains. At the surface, weak lee troughing will be present across the central/northern High Plains with a front extending northeast across the northern Plains and into the Upper Midwest. ...Upper Midwest... Moderate to strong instability is forecast to develop south of a stationary front across the Upper Midwest Friday afternoon. The combination of ascent associated with a passing weak mid-level shortwave trough and strengthening isentropic ascent as the low-level jet strengthens, may provide ample lift for scattered thunderstorms Friday afternoon/evening. Several CAMS are in relatively good agreement for convective initiation across eastern Minnesota with the potential for upscale growth into a MCS across Wisconsin late Friday evening. Have introduced a Slight Risk across this region for an initial large hail threat, followed by an increasing severe wind threat if storms grow upscale. However, this area may need to be moved or enlarged in later outlooks due to the inherent lack of predictability within a low-amplitude pattern. Some of this unpredictability can be seen by relative outliers (HRRR and MPAS) which seems to stem from difference in convective evolution on Day 1/Thursday across the central Rockies and adjacent Plains tonight. ...Central/Northern High Plains into the northern Plains... Another weak mid-level shortwave trough is expected to traverse the Rockies on Friday and eventually overspread the northern Plains by Friday evening. Moderate to strong instability and moderate shear along the southern periphery of the stronger mid-level westerlies may result severe storms. Large hail would be possible in the initial, cellular stages (isolated severe wind across the NE Panhandle where a hot/well-mixed environment will be present), before an increasing severe wind threat may develop by later in the evening across South Dakota. If this MCS can maintain itself far enough east during the evening, the strengthening low-level jet across central and eastern South Dakota could maintain this MCS with some isolated severe wind threat into the early morning hours on Saturday across eastern South Dakota and perhaps far western Minnesota and northwest Iowa. ..Bentley.. 08/14/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL WISCONSIN AND FAR EASTERN MINNESOTA... ...SUMMARY... Scattered severe storms are likely over parts of the northern Plains and Upper Mississippi Valley on Friday. ...Synopsis... A belt of stronger mid-level flow will be present across the northern Plains on Friday along the northern periphery of a broad mid-level ridge. Within this flow, a weak mid-level shortwave trough (perhaps amplified by Day1/Thursday convection across the central Rockies) will move across the northern Plains and into the Upper Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is forecast to traverse the central Rockies with associated ascent overspreading the central/northern High Plains. At the surface, weak lee troughing will be present across the central/northern High Plains with a front extending northeast across the northern Plains and into the Upper Midwest. ...Upper Midwest... Moderate to strong instability is forecast to develop south of a stationary front across the Upper Midwest Friday afternoon. The combination of ascent associated with a passing weak mid-level shortwave trough and strengthening isentropic ascent as the low-level jet strengthens, may provide ample lift for scattered thunderstorms Friday afternoon/evening. Several CAMS are in relatively good agreement for convective initiation across eastern Minnesota with the potential for upscale growth into a MCS across Wisconsin late Friday evening. Have introduced a Slight Risk across this region for an initial large hail threat, followed by an increasing severe wind threat if storms grow upscale. However, this area may need to be moved or enlarged in later outlooks due to the inherent lack of predictability within a low-amplitude pattern. Some of this unpredictability can be seen by relative outliers (HRRR and MPAS) which seems to stem from difference in convective evolution on Day 1/Thursday across the central Rockies and adjacent Plains tonight. ...Central/Northern High Plains into the northern Plains... Another weak mid-level shortwave trough is expected to traverse the Rockies on Friday and eventually overspread the northern Plains by Friday evening. Moderate to strong instability and moderate shear along the southern periphery of the stronger mid-level westerlies may result severe storms. Large hail would be possible in the initial, cellular stages (isolated severe wind across the NE Panhandle where a hot/well-mixed environment will be present), before an increasing severe wind threat may develop by later in the evening across South Dakota. If this MCS can maintain itself far enough east during the evening, the strengthening low-level jet across central and eastern South Dakota could maintain this MCS with some isolated severe wind threat into the early morning hours on Saturday across eastern South Dakota and perhaps far western Minnesota and northwest Iowa. ..Bentley.. 08/14/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL WISCONSIN AND FAR EASTERN MINNESOTA... ...SUMMARY... Scattered severe storms are likely over parts of the northern Plains and Upper Mississippi Valley on Friday. ...Synopsis... A belt of stronger mid-level flow will be present across the northern Plains on Friday along the northern periphery of a broad mid-level ridge. Within this flow, a weak mid-level shortwave trough (perhaps amplified by Day1/Thursday convection across the central Rockies) will move across the northern Plains and into the Upper Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is forecast to traverse the central Rockies with associated ascent overspreading the central/northern High Plains. At the surface, weak lee troughing will be present across the central/northern High Plains with a front extending northeast across the northern Plains and into the Upper Midwest. ...Upper Midwest... Moderate to strong instability is forecast to develop south of a stationary front across the Upper Midwest Friday afternoon. The combination of ascent associated with a passing weak mid-level shortwave trough and strengthening isentropic ascent as the low-level jet strengthens, may provide ample lift for scattered thunderstorms Friday afternoon/evening. Several CAMS are in relatively good agreement for convective initiation across eastern Minnesota with the potential for upscale growth into a MCS across Wisconsin late Friday evening. Have introduced a Slight Risk across this region for an initial large hail threat, followed by an increasing severe wind threat if storms grow upscale. However, this area may need to be moved or enlarged in later outlooks due to the inherent lack of predictability within a low-amplitude pattern. Some of this unpredictability can be seen by relative outliers (HRRR and MPAS) which seems to stem from difference in convective evolution on Day 1/Thursday across the central Rockies and adjacent Plains tonight. ...Central/Northern High Plains into the northern Plains... Another weak mid-level shortwave trough is expected to traverse the Rockies on Friday and eventually overspread the northern Plains by Friday evening. Moderate to strong instability and moderate shear along the southern periphery of the stronger mid-level westerlies may result severe storms. Large hail would be possible in the initial, cellular stages (isolated severe wind across the NE Panhandle where a hot/well-mixed environment will be present), before an increasing severe wind threat may develop by later in the evening across South Dakota. If this MCS can maintain itself far enough east during the evening, the strengthening low-level jet across central and eastern South Dakota could maintain this MCS with some isolated severe wind threat into the early morning hours on Saturday across eastern South Dakota and perhaps far western Minnesota and northwest Iowa. ..Bentley.. 08/14/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL WISCONSIN AND FAR EASTERN MINNESOTA... ...SUMMARY... Scattered severe storms are likely over parts of the northern Plains and Upper Mississippi Valley on Friday. ...Synopsis... A belt of stronger mid-level flow will be present across the northern Plains on Friday along the northern periphery of a broad mid-level ridge. Within this flow, a weak mid-level shortwave trough (perhaps amplified by Day1/Thursday convection across the central Rockies) will move across the northern Plains and into the Upper Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is forecast to traverse the central Rockies with associated ascent overspreading the central/northern High Plains. At the surface, weak lee troughing will be present across the central/northern High Plains with a front extending northeast across the northern Plains and into the Upper Midwest. ...Upper Midwest... Moderate to strong instability is forecast to develop south of a stationary front across the Upper Midwest Friday afternoon. The combination of ascent associated with a passing weak mid-level shortwave trough and strengthening isentropic ascent as the low-level jet strengthens, may provide ample lift for scattered thunderstorms Friday afternoon/evening. Several CAMS are in relatively good agreement for convective initiation across eastern Minnesota with the potential for upscale growth into a MCS across Wisconsin late Friday evening. Have introduced a Slight Risk across this region for an initial large hail threat, followed by an increasing severe wind threat if storms grow upscale. However, this area may need to be moved or enlarged in later outlooks due to the inherent lack of predictability within a low-amplitude pattern. Some of this unpredictability can be seen by relative outliers (HRRR and MPAS) which seems to stem from difference in convective evolution on Day 1/Thursday across the central Rockies and adjacent Plains tonight. ...Central/Northern High Plains into the northern Plains... Another weak mid-level shortwave trough is expected to traverse the Rockies on Friday and eventually overspread the northern Plains by Friday evening. Moderate to strong instability and moderate shear along the southern periphery of the stronger mid-level westerlies may result severe storms. Large hail would be possible in the initial, cellular stages (isolated severe wind across the NE Panhandle where a hot/well-mixed environment will be present), before an increasing severe wind threat may develop by later in the evening across South Dakota. If this MCS can maintain itself far enough east during the evening, the strengthening low-level jet across central and eastern South Dakota could maintain this MCS with some isolated severe wind threat into the early morning hours on Saturday across eastern South Dakota and perhaps far western Minnesota and northwest Iowa. ..Bentley.. 08/14/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL WISCONSIN AND FAR EASTERN MINNESOTA... ...SUMMARY... Scattered severe storms are likely over parts of the northern Plains and Upper Mississippi Valley on Friday. ...Synopsis... A belt of stronger mid-level flow will be present across the northern Plains on Friday along the northern periphery of a broad mid-level ridge. Within this flow, a weak mid-level shortwave trough (perhaps amplified by Day1/Thursday convection across the central Rockies) will move across the northern Plains and into the Upper Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is forecast to traverse the central Rockies with associated ascent overspreading the central/northern High Plains. At the surface, weak lee troughing will be present across the central/northern High Plains with a front extending northeast across the northern Plains and into the Upper Midwest. ...Upper Midwest... Moderate to strong instability is forecast to develop south of a stationary front across the Upper Midwest Friday afternoon. The combination of ascent associated with a passing weak mid-level shortwave trough and strengthening isentropic ascent as the low-level jet strengthens, may provide ample lift for scattered thunderstorms Friday afternoon/evening. Several CAMS are in relatively good agreement for convective initiation across eastern Minnesota with the potential for upscale growth into a MCS across Wisconsin late Friday evening. Have introduced a Slight Risk across this region for an initial large hail threat, followed by an increasing severe wind threat if storms grow upscale. However, this area may need to be moved or enlarged in later outlooks due to the inherent lack of predictability within a low-amplitude pattern. Some of this unpredictability can be seen by relative outliers (HRRR and MPAS) which seems to stem from difference in convective evolution on Day 1/Thursday across the central Rockies and adjacent Plains tonight. ...Central/Northern High Plains into the northern Plains... Another weak mid-level shortwave trough is expected to traverse the Rockies on Friday and eventually overspread the northern Plains by Friday evening. Moderate to strong instability and moderate shear along the southern periphery of the stronger mid-level westerlies may result severe storms. Large hail would be possible in the initial, cellular stages (isolated severe wind across the NE Panhandle where a hot/well-mixed environment will be present), before an increasing severe wind threat may develop by later in the evening across South Dakota. If this MCS can maintain itself far enough east during the evening, the strengthening low-level jet across central and eastern South Dakota could maintain this MCS with some isolated severe wind threat into the early morning hours on Saturday across eastern South Dakota and perhaps far western Minnesota and northwest Iowa. ..Bentley.. 08/14/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL WISCONSIN AND FAR EASTERN MINNESOTA... ...SUMMARY... Scattered severe storms are likely over parts of the northern Plains and Upper Mississippi Valley on Friday. ...Synopsis... A belt of stronger mid-level flow will be present across the northern Plains on Friday along the northern periphery of a broad mid-level ridge. Within this flow, a weak mid-level shortwave trough (perhaps amplified by Day1/Thursday convection across the central Rockies) will move across the northern Plains and into the Upper Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is forecast to traverse the central Rockies with associated ascent overspreading the central/northern High Plains. At the surface, weak lee troughing will be present across the central/northern High Plains with a front extending northeast across the northern Plains and into the Upper Midwest. ...Upper Midwest... Moderate to strong instability is forecast to develop south of a stationary front across the Upper Midwest Friday afternoon. The combination of ascent associated with a passing weak mid-level shortwave trough and strengthening isentropic ascent as the low-level jet strengthens, may provide ample lift for scattered thunderstorms Friday afternoon/evening. Several CAMS are in relatively good agreement for convective initiation across eastern Minnesota with the potential for upscale growth into a MCS across Wisconsin late Friday evening. Have introduced a Slight Risk across this region for an initial large hail threat, followed by an increasing severe wind threat if storms grow upscale. However, this area may need to be moved or enlarged in later outlooks due to the inherent lack of predictability within a low-amplitude pattern. Some of this unpredictability can be seen by relative outliers (HRRR and MPAS) which seems to stem from difference in convective evolution on Day 1/Thursday across the central Rockies and adjacent Plains tonight. ...Central/Northern High Plains into the northern Plains... Another weak mid-level shortwave trough is expected to traverse the Rockies on Friday and eventually overspread the northern Plains by Friday evening. Moderate to strong instability and moderate shear along the southern periphery of the stronger mid-level westerlies may result severe storms. Large hail would be possible in the initial, cellular stages (isolated severe wind across the NE Panhandle where a hot/well-mixed environment will be present), before an increasing severe wind threat may develop by later in the evening across South Dakota. If this MCS can maintain itself far enough east during the evening, the strengthening low-level jet across central and eastern South Dakota could maintain this MCS with some isolated severe wind threat into the early morning hours on Saturday across eastern South Dakota and perhaps far western Minnesota and northwest Iowa. ..Bentley.. 08/14/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL WISCONSIN AND FAR EASTERN MINNESOTA... ...SUMMARY... Scattered severe storms are likely over parts of the northern Plains and Upper Mississippi Valley on Friday. ...Synopsis... A belt of stronger mid-level flow will be present across the northern Plains on Friday along the northern periphery of a broad mid-level ridge. Within this flow, a weak mid-level shortwave trough (perhaps amplified by Day1/Thursday convection across the central Rockies) will move across the northern Plains and into the Upper Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is forecast to traverse the central Rockies with associated ascent overspreading the central/northern High Plains. At the surface, weak lee troughing will be present across the central/northern High Plains with a front extending northeast across the northern Plains and into the Upper Midwest. ...Upper Midwest... Moderate to strong instability is forecast to develop south of a stationary front across the Upper Midwest Friday afternoon. The combination of ascent associated with a passing weak mid-level shortwave trough and strengthening isentropic ascent as the low-level jet strengthens, may provide ample lift for scattered thunderstorms Friday afternoon/evening. Several CAMS are in relatively good agreement for convective initiation across eastern Minnesota with the potential for upscale growth into a MCS across Wisconsin late Friday evening. Have introduced a Slight Risk across this region for an initial large hail threat, followed by an increasing severe wind threat if storms grow upscale. However, this area may need to be moved or enlarged in later outlooks due to the inherent lack of predictability within a low-amplitude pattern. Some of this unpredictability can be seen by relative outliers (HRRR and MPAS) which seems to stem from difference in convective evolution on Day 1/Thursday across the central Rockies and adjacent Plains tonight. ...Central/Northern High Plains into the northern Plains... Another weak mid-level shortwave trough is expected to traverse the Rockies on Friday and eventually overspread the northern Plains by Friday evening. Moderate to strong instability and moderate shear along the southern periphery of the stronger mid-level westerlies may result severe storms. Large hail would be possible in the initial, cellular stages (isolated severe wind across the NE Panhandle where a hot/well-mixed environment will be present), before an increasing severe wind threat may develop by later in the evening across South Dakota. If this MCS can maintain itself far enough east during the evening, the strengthening low-level jet across central and eastern South Dakota could maintain this MCS with some isolated severe wind threat into the early morning hours on Saturday across eastern South Dakota and perhaps far western Minnesota and northwest Iowa. ..Bentley.. 08/14/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL WISCONSIN AND FAR EASTERN MINNESOTA... ...SUMMARY... Scattered severe storms are likely over parts of the northern Plains and Upper Mississippi Valley on Friday. ...Synopsis... A belt of stronger mid-level flow will be present across the northern Plains on Friday along the northern periphery of a broad mid-level ridge. Within this flow, a weak mid-level shortwave trough (perhaps amplified by Day1/Thursday convection across the central Rockies) will move across the northern Plains and into the Upper Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is forecast to traverse the central Rockies with associated ascent overspreading the central/northern High Plains. At the surface, weak lee troughing will be present across the central/northern High Plains with a front extending northeast across the northern Plains and into the Upper Midwest. ...Upper Midwest... Moderate to strong instability is forecast to develop south of a stationary front across the Upper Midwest Friday afternoon. The combination of ascent associated with a passing weak mid-level shortwave trough and strengthening isentropic ascent as the low-level jet strengthens, may provide ample lift for scattered thunderstorms Friday afternoon/evening. Several CAMS are in relatively good agreement for convective initiation across eastern Minnesota with the potential for upscale growth into a MCS across Wisconsin late Friday evening. Have introduced a Slight Risk across this region for an initial large hail threat, followed by an increasing severe wind threat if storms grow upscale. However, this area may need to be moved or enlarged in later outlooks due to the inherent lack of predictability within a low-amplitude pattern. Some of this unpredictability can be seen by relative outliers (HRRR and MPAS) which seems to stem from difference in convective evolution on Day 1/Thursday across the central Rockies and adjacent Plains tonight. ...Central/Northern High Plains into the northern Plains... Another weak mid-level shortwave trough is expected to traverse the Rockies on Friday and eventually overspread the northern Plains by Friday evening. Moderate to strong instability and moderate shear along the southern periphery of the stronger mid-level westerlies may result severe storms. Large hail would be possible in the initial, cellular stages (isolated severe wind across the NE Panhandle where a hot/well-mixed environment will be present), before an increasing severe wind threat may develop by later in the evening across South Dakota. If this MCS can maintain itself far enough east during the evening, the strengthening low-level jet across central and eastern South Dakota could maintain this MCS with some isolated severe wind threat into the early morning hours on Saturday across eastern South Dakota and perhaps far western Minnesota and northwest Iowa. ..Bentley.. 08/14/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL WISCONSIN AND FAR EASTERN MINNESOTA... ...SUMMARY... Scattered severe storms are likely over parts of the northern Plains and Upper Mississippi Valley on Friday. ...Synopsis... A belt of stronger mid-level flow will be present across the northern Plains on Friday along the northern periphery of a broad mid-level ridge. Within this flow, a weak mid-level shortwave trough (perhaps amplified by Day1/Thursday convection across the central Rockies) will move across the northern Plains and into the Upper Midwest. This feature may be a focus for severe storms on Friday afternoon/evening. Another weak mid-level shortwave trough is forecast to traverse the central Rockies with associated ascent overspreading the central/northern High Plains. At the surface, weak lee troughing will be present across the central/northern High Plains with a front extending northeast across the northern Plains and into the Upper Midwest. ...Upper Midwest... Moderate to strong instability is forecast to develop south of a stationary front across the Upper Midwest Friday afternoon. The combination of ascent associated with a passing weak mid-level shortwave trough and strengthening isentropic ascent as the low-level jet strengthens, may provide ample lift for scattered thunderstorms Friday afternoon/evening. Several CAMS are in relatively good agreement for convective initiation across eastern Minnesota with the potential for upscale growth into a MCS across Wisconsin late Friday evening. Have introduced a Slight Risk across this region for an initial large hail threat, followed by an increasing severe wind threat if storms grow upscale. However, this area may need to be moved or enlarged in later outlooks due to the inherent lack of predictability within a low-amplitude pattern. Some of this unpredictability can be seen by relative outliers (HRRR and MPAS) which seems to stem from difference in convective evolution on Day 1/Thursday across the central Rockies and adjacent Plains tonight. ...Central/Northern High Plains into the northern Plains... Another weak mid-level shortwave trough is expected to traverse the Rockies on Friday and eventually overspread the northern Plains by Friday evening. Moderate to strong instability and moderate shear along the southern periphery of the stronger mid-level westerlies may result severe storms. Large hail would be possible in the initial, cellular stages (isolated severe wind across the NE Panhandle where a hot/well-mixed environment will be present), before an increasing severe wind threat may develop by later in the evening across South Dakota. If this MCS can maintain itself far enough east during the evening, the strengthening low-level jet across central and eastern South Dakota could maintain this MCS with some isolated severe wind threat into the early morning hours on Saturday across eastern South Dakota and perhaps far western Minnesota and northwest Iowa. ..Bentley.. 08/14/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1148 AM CDT Thu Aug 14 2025 Valid 141700Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEASTERN GREAT BASIN... Minor updates were made to extend Isolated Dry Thunderstorm chances into portions of the Sierra Nevada in southern California in alignment with trends in guidance. The Scattered Dry Thunderstorm area across northeastern Nevada into northern Utah, southern Idaho, and western Wyoming remains unchanged. Highest confidence in the best coverage of thunderstorms remains across this region. The Elevated delineations across the Snake River Plain and portions of the Great Basin also remain unchanged. Across the Great Basin, south to southwesterly winds will overlap afternoon relative humidity reductions to 10-15%. Winds in the Snake River Plain will be more west to southwesterly, with relative humidity reductions to 10-15%. Gusty and erratic winds will be possible near thunderstorms. See previous discussion below. ..Thornton.. 08/14/2025 .PREV DISCUSSION... /ISSUED 1252 AM CDT Thu Aug 14 2025/ ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today across the northeastern Great Basin, though warm, dry, and windy conditions will likely develop across parts of the Great Basin and northern Rockies. A slight uptick in fire activity over the past 24 hours across the Great Basin and northern Rockies confirms that receptive fuels remain in place across much of the region. ...Dry Thunderstorms... Early-morning water-vapor imagery depicts a plume of mid-level moisture across the Great Basin ahead of a migratory upper trough moving into CA. This moisture plume supported isolated dry thunderstorms yesterday across the region, and will similarly foster 100-500 J/kg MUCAPE from central NV northeastward into portions of ID, WY, UT, and CO. Regional 00z soundings and recent GOES imagery are sampling PWAT values between 0.3 to 0.6 inch, which when combined with very dry boundary-layer conditions, will support dry thunderstorms. A combination of ascent ahead of the approaching wave, modest lift within the right-entrance region of a departing upper jet, and orographic ascent will support isolated thunderstorms across a broad swath of the region. Latest CAM guidance continues to show the potential for several smaller corridors of concentrated thunderstorms. Where exactly these corridors will emerge through the afternoon remains somewhat uncertain, but the general consensus is that areas of higher thunderstorm coverage are likely. The Isolated dry thunderstorm risk area has been expanded to capture the reasonable envelope of dry thunderstorm potential with receptive fuels. Similarly, the Scattered dry thunderstorm risk area was adjusted to highlight the most probable corridors of greater thunderstorm coverage. ...Hot/Dry/Windy... Very dry conditions will prevail across the Great Basin region with another day of RH minimums in the single digits to low teens. Surface pressure falls ahead of the approaching trough will promote breezy conditions with sustained winds around 15 mph across much of the eastern Great Basin into far western Colorado. Portions of the Snake River Plain in eastern ID, as well as the eastern slopes of the Bitterroot Mountains will see similar wind speeds within a modest downslope flow regime. Gusts between 20-25 mph will support transient critical fire weather conditions across both regions. ...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 1148 AM CDT Thu Aug 14 2025 Valid 141700Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEASTERN GREAT BASIN... Minor updates were made to extend Isolated Dry Thunderstorm chances into portions of the Sierra Nevada in southern California in alignment with trends in guidance. The Scattered Dry Thunderstorm area across northeastern Nevada into northern Utah, southern Idaho, and western Wyoming remains unchanged. Highest confidence in the best coverage of thunderstorms remains across this region. The Elevated delineations across the Snake River Plain and portions of the Great Basin also remain unchanged. Across the Great Basin, south to southwesterly winds will overlap afternoon relative humidity reductions to 10-15%. Winds in the Snake River Plain will be more west to southwesterly, with relative humidity reductions to 10-15%. Gusty and erratic winds will be possible near thunderstorms. See previous discussion below. ..Thornton.. 08/14/2025 .PREV DISCUSSION... /ISSUED 1252 AM CDT Thu Aug 14 2025/ ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today across the northeastern Great Basin, though warm, dry, and windy conditions will likely develop across parts of the Great Basin and northern Rockies. A slight uptick in fire activity over the past 24 hours across the Great Basin and northern Rockies confirms that receptive fuels remain in place across much of the region. ...Dry Thunderstorms... Early-morning water-vapor imagery depicts a plume of mid-level moisture across the Great Basin ahead of a migratory upper trough moving into CA. This moisture plume supported isolated dry thunderstorms yesterday across the region, and will similarly foster 100-500 J/kg MUCAPE from central NV northeastward into portions of ID, WY, UT, and CO. Regional 00z soundings and recent GOES imagery are sampling PWAT values between 0.3 to 0.6 inch, which when combined with very dry boundary-layer conditions, will support dry thunderstorms. A combination of ascent ahead of the approaching wave, modest lift within the right-entrance region of a departing upper jet, and orographic ascent will support isolated thunderstorms across a broad swath of the region. Latest CAM guidance continues to show the potential for several smaller corridors of concentrated thunderstorms. Where exactly these corridors will emerge through the afternoon remains somewhat uncertain, but the general consensus is that areas of higher thunderstorm coverage are likely. The Isolated dry thunderstorm risk area has been expanded to capture the reasonable envelope of dry thunderstorm potential with receptive fuels. Similarly, the Scattered dry thunderstorm risk area was adjusted to highlight the most probable corridors of greater thunderstorm coverage. ...Hot/Dry/Windy... Very dry conditions will prevail across the Great Basin region with another day of RH minimums in the single digits to low teens. Surface pressure falls ahead of the approaching trough will promote breezy conditions with sustained winds around 15 mph across much of the eastern Great Basin into far western Colorado. Portions of the Snake River Plain in eastern ID, as well as the eastern slopes of the Bitterroot Mountains will see similar wind speeds within a modest downslope flow regime. Gusts between 20-25 mph will support transient critical fire weather conditions across both regions. ...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 1148 AM CDT Thu Aug 14 2025 Valid 141700Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEASTERN GREAT BASIN... Minor updates were made to extend Isolated Dry Thunderstorm chances into portions of the Sierra Nevada in southern California in alignment with trends in guidance. The Scattered Dry Thunderstorm area across northeastern Nevada into northern Utah, southern Idaho, and western Wyoming remains unchanged. Highest confidence in the best coverage of thunderstorms remains across this region. The Elevated delineations across the Snake River Plain and portions of the Great Basin also remain unchanged. Across the Great Basin, south to southwesterly winds will overlap afternoon relative humidity reductions to 10-15%. Winds in the Snake River Plain will be more west to southwesterly, with relative humidity reductions to 10-15%. Gusty and erratic winds will be possible near thunderstorms. See previous discussion below. ..Thornton.. 08/14/2025 .PREV DISCUSSION... /ISSUED 1252 AM CDT Thu Aug 14 2025/ ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today across the northeastern Great Basin, though warm, dry, and windy conditions will likely develop across parts of the Great Basin and northern Rockies. A slight uptick in fire activity over the past 24 hours across the Great Basin and northern Rockies confirms that receptive fuels remain in place across much of the region. ...Dry Thunderstorms... Early-morning water-vapor imagery depicts a plume of mid-level moisture across the Great Basin ahead of a migratory upper trough moving into CA. This moisture plume supported isolated dry thunderstorms yesterday across the region, and will similarly foster 100-500 J/kg MUCAPE from central NV northeastward into portions of ID, WY, UT, and CO. Regional 00z soundings and recent GOES imagery are sampling PWAT values between 0.3 to 0.6 inch, which when combined with very dry boundary-layer conditions, will support dry thunderstorms. A combination of ascent ahead of the approaching wave, modest lift within the right-entrance region of a departing upper jet, and orographic ascent will support isolated thunderstorms across a broad swath of the region. Latest CAM guidance continues to show the potential for several smaller corridors of concentrated thunderstorms. Where exactly these corridors will emerge through the afternoon remains somewhat uncertain, but the general consensus is that areas of higher thunderstorm coverage are likely. The Isolated dry thunderstorm risk area has been expanded to capture the reasonable envelope of dry thunderstorm potential with receptive fuels. Similarly, the Scattered dry thunderstorm risk area was adjusted to highlight the most probable corridors of greater thunderstorm coverage. ...Hot/Dry/Windy... Very dry conditions will prevail across the Great Basin region with another day of RH minimums in the single digits to low teens. Surface pressure falls ahead of the approaching trough will promote breezy conditions with sustained winds around 15 mph across much of the eastern Great Basin into far western Colorado. Portions of the Snake River Plain in eastern ID, as well as the eastern slopes of the Bitterroot Mountains will see similar wind speeds within a modest downslope flow regime. Gusts between 20-25 mph will support transient critical fire weather conditions across both regions. ...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 1148 AM CDT Thu Aug 14 2025 Valid 141700Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEASTERN GREAT BASIN... Minor updates were made to extend Isolated Dry Thunderstorm chances into portions of the Sierra Nevada in southern California in alignment with trends in guidance. The Scattered Dry Thunderstorm area across northeastern Nevada into northern Utah, southern Idaho, and western Wyoming remains unchanged. Highest confidence in the best coverage of thunderstorms remains across this region. The Elevated delineations across the Snake River Plain and portions of the Great Basin also remain unchanged. Across the Great Basin, south to southwesterly winds will overlap afternoon relative humidity reductions to 10-15%. Winds in the Snake River Plain will be more west to southwesterly, with relative humidity reductions to 10-15%. Gusty and erratic winds will be possible near thunderstorms. See previous discussion below. ..Thornton.. 08/14/2025 .PREV DISCUSSION... /ISSUED 1252 AM CDT Thu Aug 14 2025/ ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today across the northeastern Great Basin, though warm, dry, and windy conditions will likely develop across parts of the Great Basin and northern Rockies. A slight uptick in fire activity over the past 24 hours across the Great Basin and northern Rockies confirms that receptive fuels remain in place across much of the region. ...Dry Thunderstorms... Early-morning water-vapor imagery depicts a plume of mid-level moisture across the Great Basin ahead of a migratory upper trough moving into CA. This moisture plume supported isolated dry thunderstorms yesterday across the region, and will similarly foster 100-500 J/kg MUCAPE from central NV northeastward into portions of ID, WY, UT, and CO. Regional 00z soundings and recent GOES imagery are sampling PWAT values between 0.3 to 0.6 inch, which when combined with very dry boundary-layer conditions, will support dry thunderstorms. A combination of ascent ahead of the approaching wave, modest lift within the right-entrance region of a departing upper jet, and orographic ascent will support isolated thunderstorms across a broad swath of the region. Latest CAM guidance continues to show the potential for several smaller corridors of concentrated thunderstorms. Where exactly these corridors will emerge through the afternoon remains somewhat uncertain, but the general consensus is that areas of higher thunderstorm coverage are likely. The Isolated dry thunderstorm risk area has been expanded to capture the reasonable envelope of dry thunderstorm potential with receptive fuels. Similarly, the Scattered dry thunderstorm risk area was adjusted to highlight the most probable corridors of greater thunderstorm coverage. ...Hot/Dry/Windy... Very dry conditions will prevail across the Great Basin region with another day of RH minimums in the single digits to low teens. Surface pressure falls ahead of the approaching trough will promote breezy conditions with sustained winds around 15 mph across much of the eastern Great Basin into far western Colorado. Portions of the Snake River Plain in eastern ID, as well as the eastern slopes of the Bitterroot Mountains will see similar wind speeds within a modest downslope flow regime. Gusts between 20-25 mph will support transient critical fire weather conditions across both regions. ...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 1148 AM CDT Thu Aug 14 2025 Valid 141700Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEASTERN GREAT BASIN... Minor updates were made to extend Isolated Dry Thunderstorm chances into portions of the Sierra Nevada in southern California in alignment with trends in guidance. The Scattered Dry Thunderstorm area across northeastern Nevada into northern Utah, southern Idaho, and western Wyoming remains unchanged. Highest confidence in the best coverage of thunderstorms remains across this region. The Elevated delineations across the Snake River Plain and portions of the Great Basin also remain unchanged. Across the Great Basin, south to southwesterly winds will overlap afternoon relative humidity reductions to 10-15%. Winds in the Snake River Plain will be more west to southwesterly, with relative humidity reductions to 10-15%. Gusty and erratic winds will be possible near thunderstorms. See previous discussion below. ..Thornton.. 08/14/2025 .PREV DISCUSSION... /ISSUED 1252 AM CDT Thu Aug 14 2025/ ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today across the northeastern Great Basin, though warm, dry, and windy conditions will likely develop across parts of the Great Basin and northern Rockies. A slight uptick in fire activity over the past 24 hours across the Great Basin and northern Rockies confirms that receptive fuels remain in place across much of the region. ...Dry Thunderstorms... Early-morning water-vapor imagery depicts a plume of mid-level moisture across the Great Basin ahead of a migratory upper trough moving into CA. This moisture plume supported isolated dry thunderstorms yesterday across the region, and will similarly foster 100-500 J/kg MUCAPE from central NV northeastward into portions of ID, WY, UT, and CO. Regional 00z soundings and recent GOES imagery are sampling PWAT values between 0.3 to 0.6 inch, which when combined with very dry boundary-layer conditions, will support dry thunderstorms. A combination of ascent ahead of the approaching wave, modest lift within the right-entrance region of a departing upper jet, and orographic ascent will support isolated thunderstorms across a broad swath of the region. Latest CAM guidance continues to show the potential for several smaller corridors of concentrated thunderstorms. Where exactly these corridors will emerge through the afternoon remains somewhat uncertain, but the general consensus is that areas of higher thunderstorm coverage are likely. The Isolated dry thunderstorm risk area has been expanded to capture the reasonable envelope of dry thunderstorm potential with receptive fuels. Similarly, the Scattered dry thunderstorm risk area was adjusted to highlight the most probable corridors of greater thunderstorm coverage. ...Hot/Dry/Windy... Very dry conditions will prevail across the Great Basin region with another day of RH minimums in the single digits to low teens. Surface pressure falls ahead of the approaching trough will promote breezy conditions with sustained winds around 15 mph across much of the eastern Great Basin into far western Colorado. Portions of the Snake River Plain in eastern ID, as well as the eastern slopes of the Bitterroot Mountains will see similar wind speeds within a modest downslope flow regime. Gusts between 20-25 mph will support transient critical fire weather conditions across both regions. ...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 1148 AM CDT Thu Aug 14 2025 Valid 141700Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEASTERN GREAT BASIN... Minor updates were made to extend Isolated Dry Thunderstorm chances into portions of the Sierra Nevada in southern California in alignment with trends in guidance. The Scattered Dry Thunderstorm area across northeastern Nevada into northern Utah, southern Idaho, and western Wyoming remains unchanged. Highest confidence in the best coverage of thunderstorms remains across this region. The Elevated delineations across the Snake River Plain and portions of the Great Basin also remain unchanged. Across the Great Basin, south to southwesterly winds will overlap afternoon relative humidity reductions to 10-15%. Winds in the Snake River Plain will be more west to southwesterly, with relative humidity reductions to 10-15%. Gusty and erratic winds will be possible near thunderstorms. See previous discussion below. ..Thornton.. 08/14/2025 .PREV DISCUSSION... /ISSUED 1252 AM CDT Thu Aug 14 2025/ ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today across the northeastern Great Basin, though warm, dry, and windy conditions will likely develop across parts of the Great Basin and northern Rockies. A slight uptick in fire activity over the past 24 hours across the Great Basin and northern Rockies confirms that receptive fuels remain in place across much of the region. ...Dry Thunderstorms... Early-morning water-vapor imagery depicts a plume of mid-level moisture across the Great Basin ahead of a migratory upper trough moving into CA. This moisture plume supported isolated dry thunderstorms yesterday across the region, and will similarly foster 100-500 J/kg MUCAPE from central NV northeastward into portions of ID, WY, UT, and CO. Regional 00z soundings and recent GOES imagery are sampling PWAT values between 0.3 to 0.6 inch, which when combined with very dry boundary-layer conditions, will support dry thunderstorms. A combination of ascent ahead of the approaching wave, modest lift within the right-entrance region of a departing upper jet, and orographic ascent will support isolated thunderstorms across a broad swath of the region. Latest CAM guidance continues to show the potential for several smaller corridors of concentrated thunderstorms. Where exactly these corridors will emerge through the afternoon remains somewhat uncertain, but the general consensus is that areas of higher thunderstorm coverage are likely. The Isolated dry thunderstorm risk area has been expanded to capture the reasonable envelope of dry thunderstorm potential with receptive fuels. Similarly, the Scattered dry thunderstorm risk area was adjusted to highlight the most probable corridors of greater thunderstorm coverage. ...Hot/Dry/Windy... Very dry conditions will prevail across the Great Basin region with another day of RH minimums in the single digits to low teens. Surface pressure falls ahead of the approaching trough will promote breezy conditions with sustained winds around 15 mph across much of the eastern Great Basin into far western Colorado. Portions of the Snake River Plain in eastern ID, as well as the eastern slopes of the Bitterroot Mountains will see similar wind speeds within a modest downslope flow regime. Gusts between 20-25 mph will support transient critical fire weather conditions across both regions. ...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 1148 AM CDT Thu Aug 14 2025 Valid 141700Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEASTERN GREAT BASIN... Minor updates were made to extend Isolated Dry Thunderstorm chances into portions of the Sierra Nevada in southern California in alignment with trends in guidance. The Scattered Dry Thunderstorm area across northeastern Nevada into northern Utah, southern Idaho, and western Wyoming remains unchanged. Highest confidence in the best coverage of thunderstorms remains across this region. The Elevated delineations across the Snake River Plain and portions of the Great Basin also remain unchanged. Across the Great Basin, south to southwesterly winds will overlap afternoon relative humidity reductions to 10-15%. Winds in the Snake River Plain will be more west to southwesterly, with relative humidity reductions to 10-15%. Gusty and erratic winds will be possible near thunderstorms. See previous discussion below. ..Thornton.. 08/14/2025 .PREV DISCUSSION... /ISSUED 1252 AM CDT Thu Aug 14 2025/ ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today across the northeastern Great Basin, though warm, dry, and windy conditions will likely develop across parts of the Great Basin and northern Rockies. A slight uptick in fire activity over the past 24 hours across the Great Basin and northern Rockies confirms that receptive fuels remain in place across much of the region. ...Dry Thunderstorms... Early-morning water-vapor imagery depicts a plume of mid-level moisture across the Great Basin ahead of a migratory upper trough moving into CA. This moisture plume supported isolated dry thunderstorms yesterday across the region, and will similarly foster 100-500 J/kg MUCAPE from central NV northeastward into portions of ID, WY, UT, and CO. Regional 00z soundings and recent GOES imagery are sampling PWAT values between 0.3 to 0.6 inch, which when combined with very dry boundary-layer conditions, will support dry thunderstorms. A combination of ascent ahead of the approaching wave, modest lift within the right-entrance region of a departing upper jet, and orographic ascent will support isolated thunderstorms across a broad swath of the region. Latest CAM guidance continues to show the potential for several smaller corridors of concentrated thunderstorms. Where exactly these corridors will emerge through the afternoon remains somewhat uncertain, but the general consensus is that areas of higher thunderstorm coverage are likely. The Isolated dry thunderstorm risk area has been expanded to capture the reasonable envelope of dry thunderstorm potential with receptive fuels. Similarly, the Scattered dry thunderstorm risk area was adjusted to highlight the most probable corridors of greater thunderstorm coverage. ...Hot/Dry/Windy... Very dry conditions will prevail across the Great Basin region with another day of RH minimums in the single digits to low teens. Surface pressure falls ahead of the approaching trough will promote breezy conditions with sustained winds around 15 mph across much of the eastern Great Basin into far western Colorado. Portions of the Snake River Plain in eastern ID, as well as the eastern slopes of the Bitterroot Mountains will see similar wind speeds within a modest downslope flow regime. Gusts between 20-25 mph will support transient critical fire weather conditions across both regions. ...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 1129 AM CDT Thu Aug 14 2025 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NORTH DAKOTA INTO NORTHWEST MINNESOTA... ...SUMMARY... Thunderstorms capable of producing large hail and severe wind gusts may occur this afternoon into tonight across parts of the northern/central Plains and upper Mississippi Valley. Isolated strong to severe gusts are also possible from the eastern Great Basin into the central Rockies. ...Northern Plains into the Upper MS Valley... Recent surface analysis places a low over northwest ND, along a cold front arcing from west-central Manitoba into south-central MT. A surface trough also extends southward from this low to another weak low in southeast CO. Ample low-level moisture exists across the Plains east of this surface troughing, with mid 60s dewpoints extending up through central and eastern ND. Moist southerly low-level flow is forecast to persist throughout the day. This low-level moisture advection combined with evapotranspiration and low-level convergence near the front is expected to result in upper 60s to perhaps low 70s dewpoints ahead of the front across the eastern Dakotas by early evening. Cooling mid-level temperatures are expected across the region, which will combine with the abundant low-level moisture to support strong to very strong buoyancy by the late afternoon/early evening. Recent guidance suggests MLCAPE will range from 3000 to 4000 J/kg across the eastern Dakotas, western MN, and central/eastern NE by 00Z Friday. Despite this robust buoyancy, warm low to mid-level temperatures and related capping introduce uncertainty regarding convective initiation, particularly with southward extent. Greatest potential for convective initiation remains across eastern ND where glancing large-scale ascent attendant to the substantial shortwave trough moving through Saskatchewan will augment low-level convergence along the southeastward-progressing cold front. Any convection which can be sustained could pose a threat for large to isolated very large hail given a favorable thermodynamic and kinematic environment. Given the warm and dry low to mid-levels, strong downdrafts are possible as well. Upscale growth into clusters along the front is possible, and some damaging gusts could occur with these storms as well. Inhibition will quickly increase with eastward extent across MN as nocturnal cooling of the boundary layer occurs, limiting the eastward extent of the severe threat. Additionally, the low-level jet will likely weaken throughout the day but then strengthen again later this evening from western KS into western IA. Associated warm-air advection could result in isolated elevated convection across central MN. Most of these storms should be sub-severe, but a few instances of hail are possible. ...Central High Plains/Central Plains... Scattered high-based thunderstorms should develop across the central Rockies this afternoon before the spreading eastward/southeastward into the central High Plains. A deeply mixed boundary layer and high cloud bases will support strong gusts with this activity as it moves across central High Plains. As this convection spreads eastward and encounters greater instability along/east of a surface lee trough, it may reintensify, with the potential for severe gusts continuing into central NE. The lack of stronger forcing aloft and modest deep-layer shear should temper the overall severe threat with southward extent. ...Eastern Great Basin into central Rockies... The shortwave trough currently moving into central CA will continue eastward/southeastward throughout the day. Lift associated with this wave will interact with the modest mid-level moisture across the Great Basin to support scattered thunderstorm development. High cloud bases and a deeply mixed boundary layer could support strong downdrafts within the strongest storms, particularly across northern UT where the best overlap between forcing, buoyancy, and modest southwesterly flow aloft exists. ..Mosier/Squitieri.. 08/14/2025 Read more