Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS IN NORTHEASTERN NEVADA...SOUTHERN IDAHO...NORTHERN UTAH...AND WESTERN WYOMING... A Scattered Dry Thunderstorm area was added with this outlook update. Calibrated thunderstorm guidance from the HREF/SREF in addition to hi-res CAM guidance suggests that coverage of thunderstorm activity will increase on Thursday morning/afternoon across these regions. While there may be a mix of wet/dry thunderstorm modes, faster storm motions (20-25 kts) are expected amid very dry surface conditions and increasing lightning efficiency, making new lightning ignitions probable. A portion of this area remains under a Fuels and Fire Behavior Advisory and fuels remain critically dry across much of the Great Basin into the Northern Rockies. Otherwise, the Elevated delineation remains unchanged. See previous discussion for more information. ..Thornton.. 08/13/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 13 2025/ ...Synopsis... Upper-level troughing is expected to persist along the West Coast through Thursday, which will maintain southwesterly flow over the southern to central Sierra Nevada. This will maintain a downslope flow regime across NV and aid in advecting hot/dry air northeastward into adjacent portions of UT and northwest AZ. Although winds won't be as strong as today (Wednesday), sustained winds in the mid-teens will support a broad swath of elevated fire weather conditions over a region with dry fuels. ...Dry Thunderstorms... A plume of monsoonal moisture sampled by regional 00z soundings will linger across the eastern Great Basin on Thursday. The combination of weak synoptic ascent ahead of the upper trough and orographic lift will promote isolated to scattered thunderstorm development from northeast NV to western CO by late afternoon. An ensemble of forecast soundings show good agreement in PWAT values near/below 0.7 inches along with deeply mixed boundary layers and around 100-300 J/kg MLCAPE. This, along with a fairly strong convective signal in recent CAM guidance, lends high confidence in thunderstorm development. These thermodynamic conditions are favorable for dry thunderstorms, which will pose a threat for new lightning starts given widespread ERC values near/above the 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Wed Aug 13 2025 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... At least isolated severe storms may occur over parts of the northern Plains and Upper Midwest on Friday. ...Discussion... An upper-ridge will strengthen on Friday with building heights across the northern Plains. A diffuse surface low will be present somewhere in the Nebraska/South Dakota vicinity with a dryline extending to the south and a front extending northeast. This front across eastern South Dakota into southeast North Dakota and northern Minnesota will likely be the primary focus for organized severe storm potential on Friday. Upper-level forcing should be weak with rising heights across the region, but low-level convergence along the front may be sufficient for storm development. Steep mid-level lapse rates with moderate to strong shear and strong instability supports a conditional risk for supercells capable of large to very large hail and severe wind gusts from central South Dakota to portions of northern Minnesota. Away from the front, warm temperatures aloft and weak large scale forcing should limit storm development Friday afternoon/early evening. However, some modest enhancement of the low-level jet is forecast by late Friday evening which could result in some elevated storm development. If these storms form, moderate to strong shear and strong instability would support at least isolated severe storm risk. The CAPE/shear space on Friday supports a conditional threat for strong supercells, but storm coverage remains questionable due to an ambient environment featuring rising heights aloft and weak large-scale forcing. Therefore, a broad Marginal risk seems appropriate at this time, but storm intensity would likely support higher probabilities in later outlooks if a concentrated zone of higher storm coverage appears likely. ..Bentley.. 08/13/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Wed Aug 13 2025 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... At least isolated severe storms may occur over parts of the northern Plains and Upper Midwest on Friday. ...Discussion... An upper-ridge will strengthen on Friday with building heights across the northern Plains. A diffuse surface low will be present somewhere in the Nebraska/South Dakota vicinity with a dryline extending to the south and a front extending northeast. This front across eastern South Dakota into southeast North Dakota and northern Minnesota will likely be the primary focus for organized severe storm potential on Friday. Upper-level forcing should be weak with rising heights across the region, but low-level convergence along the front may be sufficient for storm development. Steep mid-level lapse rates with moderate to strong shear and strong instability supports a conditional risk for supercells capable of large to very large hail and severe wind gusts from central South Dakota to portions of northern Minnesota. Away from the front, warm temperatures aloft and weak large scale forcing should limit storm development Friday afternoon/early evening. However, some modest enhancement of the low-level jet is forecast by late Friday evening which could result in some elevated storm development. If these storms form, moderate to strong shear and strong instability would support at least isolated severe storm risk. The CAPE/shear space on Friday supports a conditional threat for strong supercells, but storm coverage remains questionable due to an ambient environment featuring rising heights aloft and weak large-scale forcing. Therefore, a broad Marginal risk seems appropriate at this time, but storm intensity would likely support higher probabilities in later outlooks if a concentrated zone of higher storm coverage appears likely. ..Bentley.. 08/13/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Wed Aug 13 2025 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... At least isolated severe storms may occur over parts of the northern Plains and Upper Midwest on Friday. ...Discussion... An upper-ridge will strengthen on Friday with building heights across the northern Plains. A diffuse surface low will be present somewhere in the Nebraska/South Dakota vicinity with a dryline extending to the south and a front extending northeast. This front across eastern South Dakota into southeast North Dakota and northern Minnesota will likely be the primary focus for organized severe storm potential on Friday. Upper-level forcing should be weak with rising heights across the region, but low-level convergence along the front may be sufficient for storm development. Steep mid-level lapse rates with moderate to strong shear and strong instability supports a conditional risk for supercells capable of large to very large hail and severe wind gusts from central South Dakota to portions of northern Minnesota. Away from the front, warm temperatures aloft and weak large scale forcing should limit storm development Friday afternoon/early evening. However, some modest enhancement of the low-level jet is forecast by late Friday evening which could result in some elevated storm development. If these storms form, moderate to strong shear and strong instability would support at least isolated severe storm risk. The CAPE/shear space on Friday supports a conditional threat for strong supercells, but storm coverage remains questionable due to an ambient environment featuring rising heights aloft and weak large-scale forcing. Therefore, a broad Marginal risk seems appropriate at this time, but storm intensity would likely support higher probabilities in later outlooks if a concentrated zone of higher storm coverage appears likely. ..Bentley.. 08/13/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Wed Aug 13 2025 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN PLAINS AND UPPER MIDWEST... ...SUMMARY... At least isolated severe storms may occur over parts of the northern Plains and Upper Midwest on Friday. ...Discussion... An upper-ridge will strengthen on Friday with building heights across the northern Plains. A diffuse surface low will be present somewhere in the Nebraska/South Dakota vicinity with a dryline extending to the south and a front extending northeast. This front across eastern South Dakota into southeast North Dakota and northern Minnesota will likely be the primary focus for organized severe storm potential on Friday. Upper-level forcing should be weak with rising heights across the region, but low-level convergence along the front may be sufficient for storm development. Steep mid-level lapse rates with moderate to strong shear and strong instability supports a conditional risk for supercells capable of large to very large hail and severe wind gusts from central South Dakota to portions of northern Minnesota. Away from the front, warm temperatures aloft and weak large scale forcing should limit storm development Friday afternoon/early evening. However, some modest enhancement of the low-level jet is forecast by late Friday evening which could result in some elevated storm development. If these storms form, moderate to strong shear and strong instability would support at least isolated severe storm risk. The CAPE/shear space on Friday supports a conditional threat for strong supercells, but storm coverage remains questionable due to an ambient environment featuring rising heights aloft and weak large-scale forcing. Therefore, a broad Marginal risk seems appropriate at this time, but storm intensity would likely support higher probabilities in later outlooks if a concentrated zone of higher storm coverage appears likely. ..Bentley.. 08/13/2025 Read more

MD 1938 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF THE NORTHEAST
Mesoscale Discussion 1938 NWS Storm Prediction Center Norman OK 1142 AM CDT Wed Aug 13 2025 Areas affected...parts of the Northeast Concerning...Severe potential...Watch unlikely Valid 131642Z - 131845Z Probability of Watch Issuance...5 percent SUMMARY...Locally strong gusts are possible through this afternoon from parts of the Delaware Valley into western New England, capable of sporadic tree damage. A Severe Thunderstorm Watch is not expected. DISCUSSION...Similar to yesterday's setup in the Midwest, convection has increased along/ahead of remnant outflows from overnight/morning activity. Additional congested CU has developed across the higher terrain of the interior Northeast/western New England, as lower elevation temperatures have reached the mid 80s to low 90s. Weakness in both mid-level lapse rates and low to mid-level winds will limit updraft strength and organization. But the increasing number of storms combined with the warm airmass downstream should support sporadic microbursts capable of producing 45-60 mph gusts. Based on latest trends, this may be centered across the Lower Hudson Valley and eventually into parts of CT/MA/NH. ..Grams/Mosier.. 08/13/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM... LAT...LON 42807397 43607350 43837309 43937206 43787134 43417122 42487165 41387253 40657369 40417407 40507524 40707554 41657489 42467402 42807397 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN NORTH DAKOTA...NORTHWEST MINNESOTA...AND FAR NORTHEAST SOUTH DAKOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A mid-level shortwave trough and ongoing convection should be located somewhere near eastern South Dakota Thursday morning and weaken as it moves toward Lake Superior by 12Z Friday. Stronger mid-level flow along the northern periphery of a broad ridge centered over the Plains will shift east across the Canadian Prairies and northern Plains during the day on Thursday. A lee cyclone will be present across Saskatchewan/Manitoba at the beginning of the period and move east through the day. A surface trough/dryline will extend south from this surface low into the northern/central Plains. A cold front will strengthen through the period and eventually shift south across eastern Montana/North Dakota. ...Northern Plains... Thunderstorms associated with a passing mid-level shortwave trough will likely be across eastern South Dakota at the start of the period and advance east through the day. In the wake of this wave, subsidence should suppress convection for most of the day. By evening, strong heating should result in an uncapped environment amid strong instability. Upper forcing appears quite nebulous amid neutral to slightly rising heights. Therefore, storm coverage remains questionable. The best chance for scattered storm coverage will be across northeast North Dakota and far northwest Minnesota where scattered supercells capable of large hail (some very large) and severe wind gusts are expected. Farther south, storm coverage is less likely. However, given the strong heating along the dryline/surface trough, at least isolated storm development should occur and the environment would support severe storms. ...Central South Dakota into northwest Nebraska... Strong heating and very strong instability is expected to develop along the trough from central South Dakota into northwest Nebraska. Weak forcing should result in isolated storm coverage along this boundary during the late afternoon/evening. Shear will not be as strong this far south, but high-based storms may still be capable of isolated large hail and severe wind gusts. ..Bentley.. 08/13/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN NORTH DAKOTA...NORTHWEST MINNESOTA...AND FAR NORTHEAST SOUTH DAKOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A mid-level shortwave trough and ongoing convection should be located somewhere near eastern South Dakota Thursday morning and weaken as it moves toward Lake Superior by 12Z Friday. Stronger mid-level flow along the northern periphery of a broad ridge centered over the Plains will shift east across the Canadian Prairies and northern Plains during the day on Thursday. A lee cyclone will be present across Saskatchewan/Manitoba at the beginning of the period and move east through the day. A surface trough/dryline will extend south from this surface low into the northern/central Plains. A cold front will strengthen through the period and eventually shift south across eastern Montana/North Dakota. ...Northern Plains... Thunderstorms associated with a passing mid-level shortwave trough will likely be across eastern South Dakota at the start of the period and advance east through the day. In the wake of this wave, subsidence should suppress convection for most of the day. By evening, strong heating should result in an uncapped environment amid strong instability. Upper forcing appears quite nebulous amid neutral to slightly rising heights. Therefore, storm coverage remains questionable. The best chance for scattered storm coverage will be across northeast North Dakota and far northwest Minnesota where scattered supercells capable of large hail (some very large) and severe wind gusts are expected. Farther south, storm coverage is less likely. However, given the strong heating along the dryline/surface trough, at least isolated storm development should occur and the environment would support severe storms. ...Central South Dakota into northwest Nebraska... Strong heating and very strong instability is expected to develop along the trough from central South Dakota into northwest Nebraska. Weak forcing should result in isolated storm coverage along this boundary during the late afternoon/evening. Shear will not be as strong this far south, but high-based storms may still be capable of isolated large hail and severe wind gusts. ..Bentley.. 08/13/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN NORTH DAKOTA...NORTHWEST MINNESOTA...AND FAR NORTHEAST SOUTH DAKOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A mid-level shortwave trough and ongoing convection should be located somewhere near eastern South Dakota Thursday morning and weaken as it moves toward Lake Superior by 12Z Friday. Stronger mid-level flow along the northern periphery of a broad ridge centered over the Plains will shift east across the Canadian Prairies and northern Plains during the day on Thursday. A lee cyclone will be present across Saskatchewan/Manitoba at the beginning of the period and move east through the day. A surface trough/dryline will extend south from this surface low into the northern/central Plains. A cold front will strengthen through the period and eventually shift south across eastern Montana/North Dakota. ...Northern Plains... Thunderstorms associated with a passing mid-level shortwave trough will likely be across eastern South Dakota at the start of the period and advance east through the day. In the wake of this wave, subsidence should suppress convection for most of the day. By evening, strong heating should result in an uncapped environment amid strong instability. Upper forcing appears quite nebulous amid neutral to slightly rising heights. Therefore, storm coverage remains questionable. The best chance for scattered storm coverage will be across northeast North Dakota and far northwest Minnesota where scattered supercells capable of large hail (some very large) and severe wind gusts are expected. Farther south, storm coverage is less likely. However, given the strong heating along the dryline/surface trough, at least isolated storm development should occur and the environment would support severe storms. ...Central South Dakota into northwest Nebraska... Strong heating and very strong instability is expected to develop along the trough from central South Dakota into northwest Nebraska. Weak forcing should result in isolated storm coverage along this boundary during the late afternoon/evening. Shear will not be as strong this far south, but high-based storms may still be capable of isolated large hail and severe wind gusts. ..Bentley.. 08/13/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN NORTH DAKOTA...NORTHWEST MINNESOTA...AND FAR NORTHEAST SOUTH DAKOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A mid-level shortwave trough and ongoing convection should be located somewhere near eastern South Dakota Thursday morning and weaken as it moves toward Lake Superior by 12Z Friday. Stronger mid-level flow along the northern periphery of a broad ridge centered over the Plains will shift east across the Canadian Prairies and northern Plains during the day on Thursday. A lee cyclone will be present across Saskatchewan/Manitoba at the beginning of the period and move east through the day. A surface trough/dryline will extend south from this surface low into the northern/central Plains. A cold front will strengthen through the period and eventually shift south across eastern Montana/North Dakota. ...Northern Plains... Thunderstorms associated with a passing mid-level shortwave trough will likely be across eastern South Dakota at the start of the period and advance east through the day. In the wake of this wave, subsidence should suppress convection for most of the day. By evening, strong heating should result in an uncapped environment amid strong instability. Upper forcing appears quite nebulous amid neutral to slightly rising heights. Therefore, storm coverage remains questionable. The best chance for scattered storm coverage will be across northeast North Dakota and far northwest Minnesota where scattered supercells capable of large hail (some very large) and severe wind gusts are expected. Farther south, storm coverage is less likely. However, given the strong heating along the dryline/surface trough, at least isolated storm development should occur and the environment would support severe storms. ...Central South Dakota into northwest Nebraska... Strong heating and very strong instability is expected to develop along the trough from central South Dakota into northwest Nebraska. Weak forcing should result in isolated storm coverage along this boundary during the late afternoon/evening. Shear will not be as strong this far south, but high-based storms may still be capable of isolated large hail and severe wind gusts. ..Bentley.. 08/13/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN NORTH DAKOTA...NORTHWEST MINNESOTA...AND FAR NORTHEAST SOUTH DAKOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A mid-level shortwave trough and ongoing convection should be located somewhere near eastern South Dakota Thursday morning and weaken as it moves toward Lake Superior by 12Z Friday. Stronger mid-level flow along the northern periphery of a broad ridge centered over the Plains will shift east across the Canadian Prairies and northern Plains during the day on Thursday. A lee cyclone will be present across Saskatchewan/Manitoba at the beginning of the period and move east through the day. A surface trough/dryline will extend south from this surface low into the northern/central Plains. A cold front will strengthen through the period and eventually shift south across eastern Montana/North Dakota. ...Northern Plains... Thunderstorms associated with a passing mid-level shortwave trough will likely be across eastern South Dakota at the start of the period and advance east through the day. In the wake of this wave, subsidence should suppress convection for most of the day. By evening, strong heating should result in an uncapped environment amid strong instability. Upper forcing appears quite nebulous amid neutral to slightly rising heights. Therefore, storm coverage remains questionable. The best chance for scattered storm coverage will be across northeast North Dakota and far northwest Minnesota where scattered supercells capable of large hail (some very large) and severe wind gusts are expected. Farther south, storm coverage is less likely. However, given the strong heating along the dryline/surface trough, at least isolated storm development should occur and the environment would support severe storms. ...Central South Dakota into northwest Nebraska... Strong heating and very strong instability is expected to develop along the trough from central South Dakota into northwest Nebraska. Weak forcing should result in isolated storm coverage along this boundary during the late afternoon/evening. Shear will not be as strong this far south, but high-based storms may still be capable of isolated large hail and severe wind gusts. ..Bentley.. 08/13/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Wed Aug 13 2025 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN NORTH DAKOTA...NORTHWEST MINNESOTA...AND FAR NORTHEAST SOUTH DAKOTA... ...SUMMARY... Severe storms producing hail and wind are possible mainly from eastern North Dakota into northwest Minnesota Thursday afternoon and evening. Isolated severe storms may occur across parts of South Dakota into western Nebraska. ...Synopsis... A mid-level shortwave trough and ongoing convection should be located somewhere near eastern South Dakota Thursday morning and weaken as it moves toward Lake Superior by 12Z Friday. Stronger mid-level flow along the northern periphery of a broad ridge centered over the Plains will shift east across the Canadian Prairies and northern Plains during the day on Thursday. A lee cyclone will be present across Saskatchewan/Manitoba at the beginning of the period and move east through the day. A surface trough/dryline will extend south from this surface low into the northern/central Plains. A cold front will strengthen through the period and eventually shift south across eastern Montana/North Dakota. ...Northern Plains... Thunderstorms associated with a passing mid-level shortwave trough will likely be across eastern South Dakota at the start of the period and advance east through the day. In the wake of this wave, subsidence should suppress convection for most of the day. By evening, strong heating should result in an uncapped environment amid strong instability. Upper forcing appears quite nebulous amid neutral to slightly rising heights. Therefore, storm coverage remains questionable. The best chance for scattered storm coverage will be across northeast North Dakota and far northwest Minnesota where scattered supercells capable of large hail (some very large) and severe wind gusts are expected. Farther south, storm coverage is less likely. However, given the strong heating along the dryline/surface trough, at least isolated storm development should occur and the environment would support severe storms. ...Central South Dakota into northwest Nebraska... Strong heating and very strong instability is expected to develop along the trough from central South Dakota into northwest Nebraska. Weak forcing should result in isolated storm coverage along this boundary during the late afternoon/evening. Shear will not be as strong this far south, but high-based storms may still be capable of isolated large hail and severe wind gusts. ..Bentley.. 08/13/2025 Read more