Severe Storms

MD 1697 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FAR EASTERN NORTH CAROLINA AND FAR SOUTHEASTERN VIRGINIA
Mesoscale Discussion 1697 NWS Storm Prediction Center Norman OK 0131 PM CDT Tue Jul 23 2024 Areas affected...Far eastern North Carolina and far southeastern Virginia Concerning...Severe potential...Watch unlikely Valid 231831Z - 232030Z Probability of Watch Issuance...5 percent SUMMARY...Localized damaging wind gusts may accompany a thunderstorm cluster or two near the coastal region of NC and VA over the next couple of hours. DISCUSSION...The latest visible satellite and radar imagery indicates a small area of thunderstorms developing along a sea breeze. Surface observations near this area continue to suggest a very moist, moderately unstable, uninhibited boundary layer in place. Although modest deep layer shear will likely limit overall thunderstorm organization, a few multicellular clusters will be possible near the aforementioned instability axis extending southwest to northeast immediately inland. Given the considerable deep layer of moisture present within mostly unidirectional southwesterlies, precipitation loading and deepening cold pools could support localized damaging wind gusts over the next 1-2 hours. A WW is not anticipated. ..Barnes/Smith.. 07/23/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH... LAT...LON 36117565 35427657 35107730 34897791 34917812 35277822 35687806 36117771 36427729 37237701 37537674 37597627 37217596 36117565 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Tue Jul 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...20z Update... The Marginal Risk across far southeastern California into west-central Arizona was expanded eastward to include areas just west of the Phoenix Metro. Thunderstorm activity is expected to develop across the high terrain of the Mogollon Rim before drifting southwestward into the lower deserts. A similar environment of steep lapse rates and large inverted-V soundings extends further east into the Tonopah Desert, where recent CAM guidance indicates thunderstorm development will be ongoing by late afternoon. This will support expansion of the 5% wind, with potential for a few severe gusts (60-70 mph). Thunderstorm activity has been ongoing within the Marginal Risks across the Midwest and the eastern, where the treat for a couple of strong to severe gusts are possible through the afternoon and evening. ..Thornton/Smith.. 07/23/2024 .PREV DISCUSSION... /ISSUED 1241 PM CDT Tue Jul 23 2024/ ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Tue Jul 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...20z Update... The Marginal Risk across far southeastern California into west-central Arizona was expanded eastward to include areas just west of the Phoenix Metro. Thunderstorm activity is expected to develop across the high terrain of the Mogollon Rim before drifting southwestward into the lower deserts. A similar environment of steep lapse rates and large inverted-V soundings extends further east into the Tonopah Desert, where recent CAM guidance indicates thunderstorm development will be ongoing by late afternoon. This will support expansion of the 5% wind, with potential for a few severe gusts (60-70 mph). Thunderstorm activity has been ongoing within the Marginal Risks across the Midwest and the eastern, where the treat for a couple of strong to severe gusts are possible through the afternoon and evening. ..Thornton/Smith.. 07/23/2024 .PREV DISCUSSION... /ISSUED 1241 PM CDT Tue Jul 23 2024/ ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Tue Jul 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...20z Update... The Marginal Risk across far southeastern California into west-central Arizona was expanded eastward to include areas just west of the Phoenix Metro. Thunderstorm activity is expected to develop across the high terrain of the Mogollon Rim before drifting southwestward into the lower deserts. A similar environment of steep lapse rates and large inverted-V soundings extends further east into the Tonopah Desert, where recent CAM guidance indicates thunderstorm development will be ongoing by late afternoon. This will support expansion of the 5% wind, with potential for a few severe gusts (60-70 mph). Thunderstorm activity has been ongoing within the Marginal Risks across the Midwest and the eastern, where the treat for a couple of strong to severe gusts are possible through the afternoon and evening. ..Thornton/Smith.. 07/23/2024 .PREV DISCUSSION... /ISSUED 1241 PM CDT Tue Jul 23 2024/ ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Tue Jul 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...20z Update... The Marginal Risk across far southeastern California into west-central Arizona was expanded eastward to include areas just west of the Phoenix Metro. Thunderstorm activity is expected to develop across the high terrain of the Mogollon Rim before drifting southwestward into the lower deserts. A similar environment of steep lapse rates and large inverted-V soundings extends further east into the Tonopah Desert, where recent CAM guidance indicates thunderstorm development will be ongoing by late afternoon. This will support expansion of the 5% wind, with potential for a few severe gusts (60-70 mph). Thunderstorm activity has been ongoing within the Marginal Risks across the Midwest and the eastern, where the treat for a couple of strong to severe gusts are possible through the afternoon and evening. ..Thornton/Smith.. 07/23/2024 .PREV DISCUSSION... /ISSUED 1241 PM CDT Tue Jul 23 2024/ ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Tue Jul 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...20z Update... The Marginal Risk across far southeastern California into west-central Arizona was expanded eastward to include areas just west of the Phoenix Metro. Thunderstorm activity is expected to develop across the high terrain of the Mogollon Rim before drifting southwestward into the lower deserts. A similar environment of steep lapse rates and large inverted-V soundings extends further east into the Tonopah Desert, where recent CAM guidance indicates thunderstorm development will be ongoing by late afternoon. This will support expansion of the 5% wind, with potential for a few severe gusts (60-70 mph). Thunderstorm activity has been ongoing within the Marginal Risks across the Midwest and the eastern, where the treat for a couple of strong to severe gusts are possible through the afternoon and evening. ..Thornton/Smith.. 07/23/2024 .PREV DISCUSSION... /ISSUED 1241 PM CDT Tue Jul 23 2024/ ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Tue Jul 23 2024 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN OREGON...MUCH OF CENTRAL IDAHO...AND SOUTHWEST MONTANA... An active fire weather day is likely across portions of the interior Pacific Northwest. Scattered dry thunderstorms are expected to occur in two possible waves tomorrow: the first developing across the higher terrain in and around southwest Montana; the second developing a little later across portions of Oregon and quickly moving northeast. Across both areas, storms should be moving fairly quickly, limiting the potential of any single thunderstorm to produce wetting rains at any one location. Thermal profiles will favor strong, gusty outflows with these thunderstorms causing erratic local winds near any ongoing fire. Additionally, multiple rounds of storms will be possible in some locations, which may result in localize flash flood potential across burn scars. Across interior portions of Oregon and Washington, hot, dry conditions will once again be present. Winds will also increase a bit from today owing to the proximity to a short-wave trough glancing the region. This won't necessarily result in widespread critical fire-weather conditions (per SPC criteria), but elevated-to-locally-critical fire-weather conditions along with the combined threat of multiple fire hazards (hot, dry, windy along with dry thunderstorms) will result in the overall fire threat being higher than any single SPC highlight. ..Marsh.. 07/23/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Tue Jul 23 2024/ ...Synopsis... An upper ridge over the Rockies will gradually break down under the influence of a deepening Pacific trough entrenched over the Northwest. Strong mid-level flow moving onshore will aid in mid-level destabilization, supporting scattered to widespread thunderstorms and the potential for significant lightning Wed afternoon and evening. Dry downslope winds are also possible in the lee of the Cascades supporting elevated fire-weather potential. ...Northern Great Basin Northwest and the northern Rockies... A widespread and potentially significant lightning event appears possible over parts of the Northwest and northern Rockies Wed and Wed night. As the upper trough over the northwest continues to deepen, weak height falls and stronger flow aloft will gradually overspread the Intermountain West. Diurnal heating with increasing mid-level moisture (PWATs of 0.8-1 in) will support elevated buoyancy atop deep and well-mixed boundary layers. In addition to the very dry sub-cloud layer, mean storm motions of 35-40 kt suggest poor to very poor precipitation efficiency. Scattered thunderstorms appear likely by early to mid afternoon ahead of a weak cold front and across the higher terrain of eastern OR, central ID and west-central MT. Storm coverage should gradually increase through the afternoon and evening as storms move east/northeast into the northern Rockies. Scattered to numerous cloud to ground lightning strikes, and occasional strong downdrafts will be possible over areas of very dry fuels, warranting the introduction of Critical Dry Thunder probabilities. In addition to the Critical risk for lightning, increasing flow aloft twill support gusty downslope winds and low RH in the lee of the Cascades. Very warm temperatures and wind gusts of 15-25 mph will overlap with RH below 20% across the western Columbia Basin and Cascade Gaps, as well as across western MT. With numerous ongoing fires and robust fuels, elevated to locally critical fire-weather conditions are expected across parts of the Pacific Northwest and northern Rockies Wed. ...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 0241 PM CDT Tue Jul 23 2024 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN OREGON...MUCH OF CENTRAL IDAHO...AND SOUTHWEST MONTANA... An active fire weather day is likely across portions of the interior Pacific Northwest. Scattered dry thunderstorms are expected to occur in two possible waves tomorrow: the first developing across the higher terrain in and around southwest Montana; the second developing a little later across portions of Oregon and quickly moving northeast. Across both areas, storms should be moving fairly quickly, limiting the potential of any single thunderstorm to produce wetting rains at any one location. Thermal profiles will favor strong, gusty outflows with these thunderstorms causing erratic local winds near any ongoing fire. Additionally, multiple rounds of storms will be possible in some locations, which may result in localize flash flood potential across burn scars. Across interior portions of Oregon and Washington, hot, dry conditions will once again be present. Winds will also increase a bit from today owing to the proximity to a short-wave trough glancing the region. This won't necessarily result in widespread critical fire-weather conditions (per SPC criteria), but elevated-to-locally-critical fire-weather conditions along with the combined threat of multiple fire hazards (hot, dry, windy along with dry thunderstorms) will result in the overall fire threat being higher than any single SPC highlight. ..Marsh.. 07/23/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Tue Jul 23 2024/ ...Synopsis... An upper ridge over the Rockies will gradually break down under the influence of a deepening Pacific trough entrenched over the Northwest. Strong mid-level flow moving onshore will aid in mid-level destabilization, supporting scattered to widespread thunderstorms and the potential for significant lightning Wed afternoon and evening. Dry downslope winds are also possible in the lee of the Cascades supporting elevated fire-weather potential. ...Northern Great Basin Northwest and the northern Rockies... A widespread and potentially significant lightning event appears possible over parts of the Northwest and northern Rockies Wed and Wed night. As the upper trough over the northwest continues to deepen, weak height falls and stronger flow aloft will gradually overspread the Intermountain West. Diurnal heating with increasing mid-level moisture (PWATs of 0.8-1 in) will support elevated buoyancy atop deep and well-mixed boundary layers. In addition to the very dry sub-cloud layer, mean storm motions of 35-40 kt suggest poor to very poor precipitation efficiency. Scattered thunderstorms appear likely by early to mid afternoon ahead of a weak cold front and across the higher terrain of eastern OR, central ID and west-central MT. Storm coverage should gradually increase through the afternoon and evening as storms move east/northeast into the northern Rockies. Scattered to numerous cloud to ground lightning strikes, and occasional strong downdrafts will be possible over areas of very dry fuels, warranting the introduction of Critical Dry Thunder probabilities. In addition to the Critical risk for lightning, increasing flow aloft twill support gusty downslope winds and low RH in the lee of the Cascades. Very warm temperatures and wind gusts of 15-25 mph will overlap with RH below 20% across the western Columbia Basin and Cascade Gaps, as well as across western MT. With numerous ongoing fires and robust fuels, elevated to locally critical fire-weather conditions are expected across parts of the Pacific Northwest and northern Rockies Wed. ...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 0241 PM CDT Tue Jul 23 2024 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN OREGON...MUCH OF CENTRAL IDAHO...AND SOUTHWEST MONTANA... An active fire weather day is likely across portions of the interior Pacific Northwest. Scattered dry thunderstorms are expected to occur in two possible waves tomorrow: the first developing across the higher terrain in and around southwest Montana; the second developing a little later across portions of Oregon and quickly moving northeast. Across both areas, storms should be moving fairly quickly, limiting the potential of any single thunderstorm to produce wetting rains at any one location. Thermal profiles will favor strong, gusty outflows with these thunderstorms causing erratic local winds near any ongoing fire. Additionally, multiple rounds of storms will be possible in some locations, which may result in localize flash flood potential across burn scars. Across interior portions of Oregon and Washington, hot, dry conditions will once again be present. Winds will also increase a bit from today owing to the proximity to a short-wave trough glancing the region. This won't necessarily result in widespread critical fire-weather conditions (per SPC criteria), but elevated-to-locally-critical fire-weather conditions along with the combined threat of multiple fire hazards (hot, dry, windy along with dry thunderstorms) will result in the overall fire threat being higher than any single SPC highlight. ..Marsh.. 07/23/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Tue Jul 23 2024/ ...Synopsis... An upper ridge over the Rockies will gradually break down under the influence of a deepening Pacific trough entrenched over the Northwest. Strong mid-level flow moving onshore will aid in mid-level destabilization, supporting scattered to widespread thunderstorms and the potential for significant lightning Wed afternoon and evening. Dry downslope winds are also possible in the lee of the Cascades supporting elevated fire-weather potential. ...Northern Great Basin Northwest and the northern Rockies... A widespread and potentially significant lightning event appears possible over parts of the Northwest and northern Rockies Wed and Wed night. As the upper trough over the northwest continues to deepen, weak height falls and stronger flow aloft will gradually overspread the Intermountain West. Diurnal heating with increasing mid-level moisture (PWATs of 0.8-1 in) will support elevated buoyancy atop deep and well-mixed boundary layers. In addition to the very dry sub-cloud layer, mean storm motions of 35-40 kt suggest poor to very poor precipitation efficiency. Scattered thunderstorms appear likely by early to mid afternoon ahead of a weak cold front and across the higher terrain of eastern OR, central ID and west-central MT. Storm coverage should gradually increase through the afternoon and evening as storms move east/northeast into the northern Rockies. Scattered to numerous cloud to ground lightning strikes, and occasional strong downdrafts will be possible over areas of very dry fuels, warranting the introduction of Critical Dry Thunder probabilities. In addition to the Critical risk for lightning, increasing flow aloft twill support gusty downslope winds and low RH in the lee of the Cascades. Very warm temperatures and wind gusts of 15-25 mph will overlap with RH below 20% across the western Columbia Basin and Cascade Gaps, as well as across western MT. With numerous ongoing fires and robust fuels, elevated to locally critical fire-weather conditions are expected across parts of the Pacific Northwest and northern Rockies Wed. ...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 0241 PM CDT Tue Jul 23 2024 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN OREGON...MUCH OF CENTRAL IDAHO...AND SOUTHWEST MONTANA... An active fire weather day is likely across portions of the interior Pacific Northwest. Scattered dry thunderstorms are expected to occur in two possible waves tomorrow: the first developing across the higher terrain in and around southwest Montana; the second developing a little later across portions of Oregon and quickly moving northeast. Across both areas, storms should be moving fairly quickly, limiting the potential of any single thunderstorm to produce wetting rains at any one location. Thermal profiles will favor strong, gusty outflows with these thunderstorms causing erratic local winds near any ongoing fire. Additionally, multiple rounds of storms will be possible in some locations, which may result in localize flash flood potential across burn scars. Across interior portions of Oregon and Washington, hot, dry conditions will once again be present. Winds will also increase a bit from today owing to the proximity to a short-wave trough glancing the region. This won't necessarily result in widespread critical fire-weather conditions (per SPC criteria), but elevated-to-locally-critical fire-weather conditions along with the combined threat of multiple fire hazards (hot, dry, windy along with dry thunderstorms) will result in the overall fire threat being higher than any single SPC highlight. ..Marsh.. 07/23/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Tue Jul 23 2024/ ...Synopsis... An upper ridge over the Rockies will gradually break down under the influence of a deepening Pacific trough entrenched over the Northwest. Strong mid-level flow moving onshore will aid in mid-level destabilization, supporting scattered to widespread thunderstorms and the potential for significant lightning Wed afternoon and evening. Dry downslope winds are also possible in the lee of the Cascades supporting elevated fire-weather potential. ...Northern Great Basin Northwest and the northern Rockies... A widespread and potentially significant lightning event appears possible over parts of the Northwest and northern Rockies Wed and Wed night. As the upper trough over the northwest continues to deepen, weak height falls and stronger flow aloft will gradually overspread the Intermountain West. Diurnal heating with increasing mid-level moisture (PWATs of 0.8-1 in) will support elevated buoyancy atop deep and well-mixed boundary layers. In addition to the very dry sub-cloud layer, mean storm motions of 35-40 kt suggest poor to very poor precipitation efficiency. Scattered thunderstorms appear likely by early to mid afternoon ahead of a weak cold front and across the higher terrain of eastern OR, central ID and west-central MT. Storm coverage should gradually increase through the afternoon and evening as storms move east/northeast into the northern Rockies. Scattered to numerous cloud to ground lightning strikes, and occasional strong downdrafts will be possible over areas of very dry fuels, warranting the introduction of Critical Dry Thunder probabilities. In addition to the Critical risk for lightning, increasing flow aloft twill support gusty downslope winds and low RH in the lee of the Cascades. Very warm temperatures and wind gusts of 15-25 mph will overlap with RH below 20% across the western Columbia Basin and Cascade Gaps, as well as across western MT. With numerous ongoing fires and robust fuels, elevated to locally critical fire-weather conditions are expected across parts of the Pacific Northwest and northern Rockies Wed. ...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 0241 PM CDT Tue Jul 23 2024 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN OREGON...MUCH OF CENTRAL IDAHO...AND SOUTHWEST MONTANA... An active fire weather day is likely across portions of the interior Pacific Northwest. Scattered dry thunderstorms are expected to occur in two possible waves tomorrow: the first developing across the higher terrain in and around southwest Montana; the second developing a little later across portions of Oregon and quickly moving northeast. Across both areas, storms should be moving fairly quickly, limiting the potential of any single thunderstorm to produce wetting rains at any one location. Thermal profiles will favor strong, gusty outflows with these thunderstorms causing erratic local winds near any ongoing fire. Additionally, multiple rounds of storms will be possible in some locations, which may result in localize flash flood potential across burn scars. Across interior portions of Oregon and Washington, hot, dry conditions will once again be present. Winds will also increase a bit from today owing to the proximity to a short-wave trough glancing the region. This won't necessarily result in widespread critical fire-weather conditions (per SPC criteria), but elevated-to-locally-critical fire-weather conditions along with the combined threat of multiple fire hazards (hot, dry, windy along with dry thunderstorms) will result in the overall fire threat being higher than any single SPC highlight. ..Marsh.. 07/23/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Tue Jul 23 2024/ ...Synopsis... An upper ridge over the Rockies will gradually break down under the influence of a deepening Pacific trough entrenched over the Northwest. Strong mid-level flow moving onshore will aid in mid-level destabilization, supporting scattered to widespread thunderstorms and the potential for significant lightning Wed afternoon and evening. Dry downslope winds are also possible in the lee of the Cascades supporting elevated fire-weather potential. ...Northern Great Basin Northwest and the northern Rockies... A widespread and potentially significant lightning event appears possible over parts of the Northwest and northern Rockies Wed and Wed night. As the upper trough over the northwest continues to deepen, weak height falls and stronger flow aloft will gradually overspread the Intermountain West. Diurnal heating with increasing mid-level moisture (PWATs of 0.8-1 in) will support elevated buoyancy atop deep and well-mixed boundary layers. In addition to the very dry sub-cloud layer, mean storm motions of 35-40 kt suggest poor to very poor precipitation efficiency. Scattered thunderstorms appear likely by early to mid afternoon ahead of a weak cold front and across the higher terrain of eastern OR, central ID and west-central MT. Storm coverage should gradually increase through the afternoon and evening as storms move east/northeast into the northern Rockies. Scattered to numerous cloud to ground lightning strikes, and occasional strong downdrafts will be possible over areas of very dry fuels, warranting the introduction of Critical Dry Thunder probabilities. In addition to the Critical risk for lightning, increasing flow aloft twill support gusty downslope winds and low RH in the lee of the Cascades. Very warm temperatures and wind gusts of 15-25 mph will overlap with RH below 20% across the western Columbia Basin and Cascade Gaps, as well as across western MT. With numerous ongoing fires and robust fuels, elevated to locally critical fire-weather conditions are expected across parts of the Pacific Northwest and northern Rockies Wed. ...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 0241 PM CDT Tue Jul 23 2024 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN OREGON...MUCH OF CENTRAL IDAHO...AND SOUTHWEST MONTANA... An active fire weather day is likely across portions of the interior Pacific Northwest. Scattered dry thunderstorms are expected to occur in two possible waves tomorrow: the first developing across the higher terrain in and around southwest Montana; the second developing a little later across portions of Oregon and quickly moving northeast. Across both areas, storms should be moving fairly quickly, limiting the potential of any single thunderstorm to produce wetting rains at any one location. Thermal profiles will favor strong, gusty outflows with these thunderstorms causing erratic local winds near any ongoing fire. Additionally, multiple rounds of storms will be possible in some locations, which may result in localize flash flood potential across burn scars. Across interior portions of Oregon and Washington, hot, dry conditions will once again be present. Winds will also increase a bit from today owing to the proximity to a short-wave trough glancing the region. This won't necessarily result in widespread critical fire-weather conditions (per SPC criteria), but elevated-to-locally-critical fire-weather conditions along with the combined threat of multiple fire hazards (hot, dry, windy along with dry thunderstorms) will result in the overall fire threat being higher than any single SPC highlight. ..Marsh.. 07/23/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Tue Jul 23 2024/ ...Synopsis... An upper ridge over the Rockies will gradually break down under the influence of a deepening Pacific trough entrenched over the Northwest. Strong mid-level flow moving onshore will aid in mid-level destabilization, supporting scattered to widespread thunderstorms and the potential for significant lightning Wed afternoon and evening. Dry downslope winds are also possible in the lee of the Cascades supporting elevated fire-weather potential. ...Northern Great Basin Northwest and the northern Rockies... A widespread and potentially significant lightning event appears possible over parts of the Northwest and northern Rockies Wed and Wed night. As the upper trough over the northwest continues to deepen, weak height falls and stronger flow aloft will gradually overspread the Intermountain West. Diurnal heating with increasing mid-level moisture (PWATs of 0.8-1 in) will support elevated buoyancy atop deep and well-mixed boundary layers. In addition to the very dry sub-cloud layer, mean storm motions of 35-40 kt suggest poor to very poor precipitation efficiency. Scattered thunderstorms appear likely by early to mid afternoon ahead of a weak cold front and across the higher terrain of eastern OR, central ID and west-central MT. Storm coverage should gradually increase through the afternoon and evening as storms move east/northeast into the northern Rockies. Scattered to numerous cloud to ground lightning strikes, and occasional strong downdrafts will be possible over areas of very dry fuels, warranting the introduction of Critical Dry Thunder probabilities. In addition to the Critical risk for lightning, increasing flow aloft twill support gusty downslope winds and low RH in the lee of the Cascades. Very warm temperatures and wind gusts of 15-25 mph will overlap with RH below 20% across the western Columbia Basin and Cascade Gaps, as well as across western MT. With numerous ongoing fires and robust fuels, elevated to locally critical fire-weather conditions are expected across parts of the Pacific Northwest and northern Rockies Wed. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1696 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR CENTRAL/EASTERN IOWA...SOUTHWEST WISCONSIN...AND NORTHWEST ILLINOIS
Mesoscale Discussion 1696 NWS Storm Prediction Center Norman OK 1256 PM CDT Tue Jul 23 2024 Areas affected...central/eastern Iowa...southwest Wisconsin...and northwest Illinois Concerning...Severe potential...Watch unlikely Valid 231756Z - 231930Z Probability of Watch Issuance...20 percent SUMMARY...A few storms capable of marginally severe hail and damaging wind gusts are possible this afternoon/evening across eastern Iowa into southwest Wisconsin and northwest Illinois. DISCUSSION...Thunderstorms have developed along the outflow boundary on the western edge of ongoing thunderstorm activity from this morning. These storms, and additional development which has begun ahead of this activity will likely congeal into a cluster and move east this afternoon, despite each run of the HRRR suggesting its demise. This expected cluster will move through through an area with 1500-2000 J/kg MLCAPE and 20-25 knots of effective shear, which should support some marginally large hail and damaging wind gusts from this cluster of storms. Despite some obstruction from wildfire smoke ahead of these storms, additional heating into the mid 80s is expected which should maintain these storms into the evening. Once boundary layer cooling begins in earnest, expect the severe weather threat to decrease. Due to the somewhat marginal and isolated severe weather threat expected, no watch is anticipated. ..Bentley/Smith.. 07/23/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...MKX...DVN...ARX...DMX... LAT...LON 42899421 43119355 43509257 43239095 42799016 42108967 41499007 41339054 41619309 41819423 42309453 42889458 42899421 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1241 PM CDT Tue Jul 23 2024 Valid 231630Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... CORRECTED FOR THUNDERSTORM BOUND PLACEMENT OVER THE NORTHEAST ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. ..Smith.. 07/23/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1241 PM CDT Tue Jul 23 2024 Valid 231630Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... CORRECTED FOR THUNDERSTORM BOUND PLACEMENT OVER THE NORTHEAST ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. ..Smith.. 07/23/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1241 PM CDT Tue Jul 23 2024 Valid 231630Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... CORRECTED FOR THUNDERSTORM BOUND PLACEMENT OVER THE NORTHEAST ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. ..Smith.. 07/23/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1241 PM CDT Tue Jul 23 2024 Valid 231630Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... CORRECTED FOR THUNDERSTORM BOUND PLACEMENT OVER THE NORTHEAST ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. ..Smith.. 07/23/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1241 PM CDT Tue Jul 23 2024 Valid 231630Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... CORRECTED FOR THUNDERSTORM BOUND PLACEMENT OVER THE NORTHEAST ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. ..Smith.. 07/23/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1241 PM CDT Tue Jul 23 2024 Valid 231630Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... CORRECTED FOR THUNDERSTORM BOUND PLACEMENT OVER THE NORTHEAST ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. ..Smith.. 07/23/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1241 PM CDT Tue Jul 23 2024 Valid 231630Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTH CAROLINA AND VIRGINIA...IOWA INTO NORTHERN ILLINOIS...AND WESTERN ARIZONA AND MOJAVE DESERT... CORRECTED FOR THUNDERSTORM BOUND PLACEMENT OVER THE NORTHEAST ...SUMMARY... Isolated severe storms are possible across parts of the Mid-Atlantic states, portions of the Midwest, and parts of the Desert Southwest. ...Mid-Atlantic/Carolinas/Southeast States... Visible-satellite imagery shows a building cumulus field over the region amidst a very moist airmass located over the Carolina coastal plain (mid to upper 70s deg F surface dewpoints). Strong heating will contribute to moderate destabilization by early afternoon. A belt of moderate west-southwesterly mid-level flow may aid in some multicellular storm organization in the form of a few clusters. Water-loaded downdrafts capable of an isolated risk for wet microbursts (peak gusts 50-60 mph) appear to be the primary severe hazard. ...IA into northern IL... Thunderstorms are expected to redevelop along the northern front from southern Wisconsin across Iowa and southern Minnesota this afternoon, perhaps aided by a weak MCV from morning storms. Models show the development of moderate buoyancy with deep-layer shear around 25 kt. A few of the stronger storms may be capable of an isolated risk for strong to locally severe gusts (50-60 mph) and marginally severe hail. This activity will likely diminish by early to mid evening. ...Western AZ into the Mojave Desert... Thunderstorms are expected to develop over the Mogollon Rim of Arizona again this afternoon, with relatively weak northeast mid-level flow steering storms southwest into the lower elevations. Widely scattered storms are forecast to develop late this afternoon into the evening. The inverted-v thermodynamic profiles will potentially support an isolated risk for severe gusts (60-70 mph) with the stronger evaporatively cooled downdrafts. ..Smith.. 07/23/2024 Read more