Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0210 AM CDT Sun Sep 01 2024 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHEAST CALIFORNIA INTO SOUTHERN OREGON AND NORTHWEST NEVADA... ...Synopsis... Fire weather concerns are expected across parts of the Pacific Northwest/Great Basin as well as central to northern High Plains on Monday afternoon. ...Pacific Northwest/Great Basin... South/southwest mid-level flow along the West Coast will gradually increase over the next 24-48 hours with the approach of an upper wave currently off the northern CA coast. This will act to strengthen downslope flow off the northern Sierra Nevada with most deterministic and ensemble solutions indicating that winds between 15-25 mph will be common by peak heating Monday afternoon when RH values will fall into the teens. Elevated to critical fire weather conditions appear likely - especially across the CA/NV/OR tri-state region where the strongest winds are expected under the mid-level jet max. A warming trend over the past week (featuring multiple days of sub-20% RH minimums) has maintained ERC values well within the 80-90th percentiles across much of the Pacific Northwest and Great Basin. While thunderstorms are anticipated across parts of the region today (Sunday), little rain accumulation is expected, and holdover fires from dry-lightning starts may become more active Monday as winds increase. Dry thunderstorms will also be a concern across much of NV, central to eastern OR, and western ID. A plume of mid-level moisture (noted in 00z soundings and water-vapor imagery across NV into southern OR) is expected to continue spreading north through Monday afternoon. Lift associated with the wave should support another day of isolated thunderstorms. Dry boundary-layer conditions will promote limited rainfall and an attendant threat of dry lightning. While thunderstorms are possible across a broader swath of the region, the dry-lightning risk area was confined to areas with receptive fuels and low probability for wetting rainfall per ensemble guidance. ...High Plains... A surface high currently building across the northern Plains in the wake of a cold front is forecast to shift east towards the Midwest by Monday afternoon. Modest lee troughing juxtaposed with the nearby surface high will bolster southerly pressure gradient winds across northeast CO and western NE/SD. The displacement of richer low-level moisture to the south across the southern Plains will promote a dry return flow regime with afternoon RH values falling to near 20%. When combined with 15-20 mph winds and very dry fuels (ERCs are currently estimated to be above the 90th percentile), elevated to locally critical fire weather conditions appear probable. ..Moore.. 09/01/2024 ...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 0210 AM CDT Sun Sep 01 2024 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHEAST CALIFORNIA INTO SOUTHERN OREGON AND NORTHWEST NEVADA... ...Synopsis... Fire weather concerns are expected across parts of the Pacific Northwest/Great Basin as well as central to northern High Plains on Monday afternoon. ...Pacific Northwest/Great Basin... South/southwest mid-level flow along the West Coast will gradually increase over the next 24-48 hours with the approach of an upper wave currently off the northern CA coast. This will act to strengthen downslope flow off the northern Sierra Nevada with most deterministic and ensemble solutions indicating that winds between 15-25 mph will be common by peak heating Monday afternoon when RH values will fall into the teens. Elevated to critical fire weather conditions appear likely - especially across the CA/NV/OR tri-state region where the strongest winds are expected under the mid-level jet max. A warming trend over the past week (featuring multiple days of sub-20% RH minimums) has maintained ERC values well within the 80-90th percentiles across much of the Pacific Northwest and Great Basin. While thunderstorms are anticipated across parts of the region today (Sunday), little rain accumulation is expected, and holdover fires from dry-lightning starts may become more active Monday as winds increase. Dry thunderstorms will also be a concern across much of NV, central to eastern OR, and western ID. A plume of mid-level moisture (noted in 00z soundings and water-vapor imagery across NV into southern OR) is expected to continue spreading north through Monday afternoon. Lift associated with the wave should support another day of isolated thunderstorms. Dry boundary-layer conditions will promote limited rainfall and an attendant threat of dry lightning. While thunderstorms are possible across a broader swath of the region, the dry-lightning risk area was confined to areas with receptive fuels and low probability for wetting rainfall per ensemble guidance. ...High Plains... A surface high currently building across the northern Plains in the wake of a cold front is forecast to shift east towards the Midwest by Monday afternoon. Modest lee troughing juxtaposed with the nearby surface high will bolster southerly pressure gradient winds across northeast CO and western NE/SD. The displacement of richer low-level moisture to the south across the southern Plains will promote a dry return flow regime with afternoon RH values falling to near 20%. When combined with 15-20 mph winds and very dry fuels (ERCs are currently estimated to be above the 90th percentile), elevated to locally critical fire weather conditions appear probable. ..Moore.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today. Isolated dry thunderstorms were observed yesterday (Saturday) across portions of central NV on the fringe of a modest monsoonal moisture plume. This air mass is currently advecting northward into north-central NV and adjacent portions of OR/ID per latest water-vapor imagery. 00z soundings along the West Coast have already begun to sample this mid-level moisture as well as cool mid-level temperatures, which should support MUCAPE values between 100-250 J/kg this afternoon. Concurrently, an upper wave off the northern CA coast is forecast to move onshore over the next 24-48 hours. Lift ahead of this wave will overspread the moisture plume, resulting in isolated to widely scattered thunderstorms from central OR into eastern NV/far western UT. Dry boundary layer conditions (as well as fast storm motions across OR) will limit rainfall accumulation and favor dry lightning strikes. Given regional ERCs at or above the 80th percentile, dry lightning will pose a fire weather concern. Elsewhere across the West, dry conditions will prevail with another day of afternoon RH minimums in the teens expected. Strengthening southerly mid-level winds may support areas of dry/windy conditions in the immediate lee of the central and northern Sierra Nevada, but such conditions should remain too limited to warrant highlights. ..Moore.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today. Isolated dry thunderstorms were observed yesterday (Saturday) across portions of central NV on the fringe of a modest monsoonal moisture plume. This air mass is currently advecting northward into north-central NV and adjacent portions of OR/ID per latest water-vapor imagery. 00z soundings along the West Coast have already begun to sample this mid-level moisture as well as cool mid-level temperatures, which should support MUCAPE values between 100-250 J/kg this afternoon. Concurrently, an upper wave off the northern CA coast is forecast to move onshore over the next 24-48 hours. Lift ahead of this wave will overspread the moisture plume, resulting in isolated to widely scattered thunderstorms from central OR into eastern NV/far western UT. Dry boundary layer conditions (as well as fast storm motions across OR) will limit rainfall accumulation and favor dry lightning strikes. Given regional ERCs at or above the 80th percentile, dry lightning will pose a fire weather concern. Elsewhere across the West, dry conditions will prevail with another day of afternoon RH minimums in the teens expected. Strengthening southerly mid-level winds may support areas of dry/windy conditions in the immediate lee of the central and northern Sierra Nevada, but such conditions should remain too limited to warrant highlights. ..Moore.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today. Isolated dry thunderstorms were observed yesterday (Saturday) across portions of central NV on the fringe of a modest monsoonal moisture plume. This air mass is currently advecting northward into north-central NV and adjacent portions of OR/ID per latest water-vapor imagery. 00z soundings along the West Coast have already begun to sample this mid-level moisture as well as cool mid-level temperatures, which should support MUCAPE values between 100-250 J/kg this afternoon. Concurrently, an upper wave off the northern CA coast is forecast to move onshore over the next 24-48 hours. Lift ahead of this wave will overspread the moisture plume, resulting in isolated to widely scattered thunderstorms from central OR into eastern NV/far western UT. Dry boundary layer conditions (as well as fast storm motions across OR) will limit rainfall accumulation and favor dry lightning strikes. Given regional ERCs at or above the 80th percentile, dry lightning will pose a fire weather concern. Elsewhere across the West, dry conditions will prevail with another day of afternoon RH minimums in the teens expected. Strengthening southerly mid-level winds may support areas of dry/windy conditions in the immediate lee of the central and northern Sierra Nevada, but such conditions should remain too limited to warrant highlights. ..Moore.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today. Isolated dry thunderstorms were observed yesterday (Saturday) across portions of central NV on the fringe of a modest monsoonal moisture plume. This air mass is currently advecting northward into north-central NV and adjacent portions of OR/ID per latest water-vapor imagery. 00z soundings along the West Coast have already begun to sample this mid-level moisture as well as cool mid-level temperatures, which should support MUCAPE values between 100-250 J/kg this afternoon. Concurrently, an upper wave off the northern CA coast is forecast to move onshore over the next 24-48 hours. Lift ahead of this wave will overspread the moisture plume, resulting in isolated to widely scattered thunderstorms from central OR into eastern NV/far western UT. Dry boundary layer conditions (as well as fast storm motions across OR) will limit rainfall accumulation and favor dry lightning strikes. Given regional ERCs at or above the 80th percentile, dry lightning will pose a fire weather concern. Elsewhere across the West, dry conditions will prevail with another day of afternoon RH minimums in the teens expected. Strengthening southerly mid-level winds may support areas of dry/windy conditions in the immediate lee of the central and northern Sierra Nevada, but such conditions should remain too limited to warrant highlights. ..Moore.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today. Isolated dry thunderstorms were observed yesterday (Saturday) across portions of central NV on the fringe of a modest monsoonal moisture plume. This air mass is currently advecting northward into north-central NV and adjacent portions of OR/ID per latest water-vapor imagery. 00z soundings along the West Coast have already begun to sample this mid-level moisture as well as cool mid-level temperatures, which should support MUCAPE values between 100-250 J/kg this afternoon. Concurrently, an upper wave off the northern CA coast is forecast to move onshore over the next 24-48 hours. Lift ahead of this wave will overspread the moisture plume, resulting in isolated to widely scattered thunderstorms from central OR into eastern NV/far western UT. Dry boundary layer conditions (as well as fast storm motions across OR) will limit rainfall accumulation and favor dry lightning strikes. Given regional ERCs at or above the 80th percentile, dry lightning will pose a fire weather concern. Elsewhere across the West, dry conditions will prevail with another day of afternoon RH minimums in the teens expected. Strengthening southerly mid-level winds may support areas of dry/windy conditions in the immediate lee of the central and northern Sierra Nevada, but such conditions should remain too limited to warrant highlights. ..Moore.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today. Isolated dry thunderstorms were observed yesterday (Saturday) across portions of central NV on the fringe of a modest monsoonal moisture plume. This air mass is currently advecting northward into north-central NV and adjacent portions of OR/ID per latest water-vapor imagery. 00z soundings along the West Coast have already begun to sample this mid-level moisture as well as cool mid-level temperatures, which should support MUCAPE values between 100-250 J/kg this afternoon. Concurrently, an upper wave off the northern CA coast is forecast to move onshore over the next 24-48 hours. Lift ahead of this wave will overspread the moisture plume, resulting in isolated to widely scattered thunderstorms from central OR into eastern NV/far western UT. Dry boundary layer conditions (as well as fast storm motions across OR) will limit rainfall accumulation and favor dry lightning strikes. Given regional ERCs at or above the 80th percentile, dry lightning will pose a fire weather concern. Elsewhere across the West, dry conditions will prevail with another day of afternoon RH minimums in the teens expected. Strengthening southerly mid-level winds may support areas of dry/windy conditions in the immediate lee of the central and northern Sierra Nevada, but such conditions should remain too limited to warrant highlights. ..Moore.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Sun Sep 01 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential remains quite limited across the U.S. on Monday. ...Discussion... A progressive long-wave upper trough will continue shifting across eastern NOAM on Monday, while large-scale ridging expands across the central and eastern U.S. in its wake. Farther west, an upper low near the southwestern Oregon/northwestern California coastal area will shift inland/eastward with time, devolving into an open wave with time. At the surface, a cold front will likely have cleared the New England and Mid-Atlantic Coasts by Monday morning, and should linger from the vicinity of the Southern Atlantic Coast westward across the Gulf Coast area and into Texas. Meanwhile, high pressure will prevail east of the Rockies, in the wake of the surface front. Showers and thunderstorms are expected across parts of the southern U.S. near and ahead of the stalling surface front. While a couple of stronger storms may occur during the day in the vicinity of the Carolinas, the overall risk for severe weather appears limited at best over the entire southern CONUS. In the West, meager mixed-layer CAPE atop a deep mixed layer can be expected across portions of the Oregon/Idaho/western Montana vicinity and into portions of the Great Basin. With enhanced flow aloft ahead of the aforementioned upper short-wave trough, a stronger storm or two may evolve, with some enhancement convective downdrafts provided by evaporative potential in the deep surface-based mixed layer. However, with only very isolated thunderstorms anticipated -- coverage of stronger convection appears insufficient to warrant inclusion of a 5% wind/MRGL risk area at this time. ..Goss.. 09/01/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Sun Sep 01 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential remains quite limited across the U.S. on Monday. ...Discussion... A progressive long-wave upper trough will continue shifting across eastern NOAM on Monday, while large-scale ridging expands across the central and eastern U.S. in its wake. Farther west, an upper low near the southwestern Oregon/northwestern California coastal area will shift inland/eastward with time, devolving into an open wave with time. At the surface, a cold front will likely have cleared the New England and Mid-Atlantic Coasts by Monday morning, and should linger from the vicinity of the Southern Atlantic Coast westward across the Gulf Coast area and into Texas. Meanwhile, high pressure will prevail east of the Rockies, in the wake of the surface front. Showers and thunderstorms are expected across parts of the southern U.S. near and ahead of the stalling surface front. While a couple of stronger storms may occur during the day in the vicinity of the Carolinas, the overall risk for severe weather appears limited at best over the entire southern CONUS. In the West, meager mixed-layer CAPE atop a deep mixed layer can be expected across portions of the Oregon/Idaho/western Montana vicinity and into portions of the Great Basin. With enhanced flow aloft ahead of the aforementioned upper short-wave trough, a stronger storm or two may evolve, with some enhancement convective downdrafts provided by evaporative potential in the deep surface-based mixed layer. However, with only very isolated thunderstorms anticipated -- coverage of stronger convection appears insufficient to warrant inclusion of a 5% wind/MRGL risk area at this time. ..Goss.. 09/01/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Sun Sep 01 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential remains quite limited across the U.S. on Monday. ...Discussion... A progressive long-wave upper trough will continue shifting across eastern NOAM on Monday, while large-scale ridging expands across the central and eastern U.S. in its wake. Farther west, an upper low near the southwestern Oregon/northwestern California coastal area will shift inland/eastward with time, devolving into an open wave with time. At the surface, a cold front will likely have cleared the New England and Mid-Atlantic Coasts by Monday morning, and should linger from the vicinity of the Southern Atlantic Coast westward across the Gulf Coast area and into Texas. Meanwhile, high pressure will prevail east of the Rockies, in the wake of the surface front. Showers and thunderstorms are expected across parts of the southern U.S. near and ahead of the stalling surface front. While a couple of stronger storms may occur during the day in the vicinity of the Carolinas, the overall risk for severe weather appears limited at best over the entire southern CONUS. In the West, meager mixed-layer CAPE atop a deep mixed layer can be expected across portions of the Oregon/Idaho/western Montana vicinity and into portions of the Great Basin. With enhanced flow aloft ahead of the aforementioned upper short-wave trough, a stronger storm or two may evolve, with some enhancement convective downdrafts provided by evaporative potential in the deep surface-based mixed layer. However, with only very isolated thunderstorms anticipated -- coverage of stronger convection appears insufficient to warrant inclusion of a 5% wind/MRGL risk area at this time. ..Goss.. 09/01/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Sun Sep 01 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential remains quite limited across the U.S. on Monday. ...Discussion... A progressive long-wave upper trough will continue shifting across eastern NOAM on Monday, while large-scale ridging expands across the central and eastern U.S. in its wake. Farther west, an upper low near the southwestern Oregon/northwestern California coastal area will shift inland/eastward with time, devolving into an open wave with time. At the surface, a cold front will likely have cleared the New England and Mid-Atlantic Coasts by Monday morning, and should linger from the vicinity of the Southern Atlantic Coast westward across the Gulf Coast area and into Texas. Meanwhile, high pressure will prevail east of the Rockies, in the wake of the surface front. Showers and thunderstorms are expected across parts of the southern U.S. near and ahead of the stalling surface front. While a couple of stronger storms may occur during the day in the vicinity of the Carolinas, the overall risk for severe weather appears limited at best over the entire southern CONUS. In the West, meager mixed-layer CAPE atop a deep mixed layer can be expected across portions of the Oregon/Idaho/western Montana vicinity and into portions of the Great Basin. With enhanced flow aloft ahead of the aforementioned upper short-wave trough, a stronger storm or two may evolve, with some enhancement convective downdrafts provided by evaporative potential in the deep surface-based mixed layer. However, with only very isolated thunderstorms anticipated -- coverage of stronger convection appears insufficient to warrant inclusion of a 5% wind/MRGL risk area at this time. ..Goss.. 09/01/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Sun Sep 01 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential remains quite limited across the U.S. on Monday. ...Discussion... A progressive long-wave upper trough will continue shifting across eastern NOAM on Monday, while large-scale ridging expands across the central and eastern U.S. in its wake. Farther west, an upper low near the southwestern Oregon/northwestern California coastal area will shift inland/eastward with time, devolving into an open wave with time. At the surface, a cold front will likely have cleared the New England and Mid-Atlantic Coasts by Monday morning, and should linger from the vicinity of the Southern Atlantic Coast westward across the Gulf Coast area and into Texas. Meanwhile, high pressure will prevail east of the Rockies, in the wake of the surface front. Showers and thunderstorms are expected across parts of the southern U.S. near and ahead of the stalling surface front. While a couple of stronger storms may occur during the day in the vicinity of the Carolinas, the overall risk for severe weather appears limited at best over the entire southern CONUS. In the West, meager mixed-layer CAPE atop a deep mixed layer can be expected across portions of the Oregon/Idaho/western Montana vicinity and into portions of the Great Basin. With enhanced flow aloft ahead of the aforementioned upper short-wave trough, a stronger storm or two may evolve, with some enhancement convective downdrafts provided by evaporative potential in the deep surface-based mixed layer. However, with only very isolated thunderstorms anticipated -- coverage of stronger convection appears insufficient to warrant inclusion of a 5% wind/MRGL risk area at this time. ..Goss.. 09/01/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN APPALACHIANS INTO THE MID-ATLANTIC AND PARTS OF NEW ENGLAND.... ...SUMMARY... Strong thunderstorms capable of producing damaging wind gusts are probable this afternoon across the southern Appalachians and Mid-Atlantic region, as well as across parts of southern New England. ...Synopsis... Latest water-vapor imagery depicts a deepening upper trough over the Great Lakes region with an attendant cold front noted in surface observations extending from the Great Lakes region into the central Plains. The northern portion of the cold front will continue to surge to the east in tandem with the upper trough; to the south, the front will begin to slow as it becomes increasingly frontolytic over the TN Valley and Ozark Plateau later today. Thunderstorm development will mainly be focused along this front as it impinges on a moist, weakly capped air mass currently in place from the Mid-MS River Valley into the Mid-Atlantic. More isolated thunderstorm chances are anticipated across the southern U.S. and over portions of the Southwest/Great Basin. ...Southern Appalachians/Mid-Atlantic... Initially isolated thunderstorm development is expected along the cold front as it approaches the TN Valley/southern Appalachians, but the weakly capped environment will favor additional development along convective outflows as well as orographically-initiated convection within the higher terrain of the southern Appalachians. As such, convective coverage should increase through mid-afternoon as storms propagate east into the Mid-Atlantic region. Mid-level flow on the southern periphery of the upper trough will be strong enough to support around 20 knots of effective bulk shear, which should support loosely organized convective clusters/multi-cells with an attendant risk for damaging wind gusts. Recent CAM guidance suggests central NC/VA may see the best potential for such clusters, and consequently could have a relatively higher potential for damaging winds. Further to the northeast into parts of southern New England, thunderstorm coverage is expected to be much more isolated and tied primarily to a deepening surface trough during the mid/late afternoon hours. While buoyancy will remain somewhat meager due to poor mid-level lapse rates, stronger mid-level flow in closer proximity to the upper trough may support an organized storm or two. ...Northwest New York... Consideration for a small Marginal risk area was made across far northwest NY. Forcing along the cold front will be much stronger along the international border with several CAM solutions hinting that shallow convection may accompany the front with an attendant damaging wind risk (as was observed Saturday evening across the upper Great Lakes region). However, warmer mid-level temperatures further over the Northeast should limit overall buoyancy values and casts uncertainty onto convective depth and intensity. Additionally, most CAM solutions hint that this potential will remain fairly confined to along the NY international border. Due to these concerns risk probabilities were withheld, but trends will continue to be monitored. ..Moore.. 09/01/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN APPALACHIANS INTO THE MID-ATLANTIC AND PARTS OF NEW ENGLAND.... ...SUMMARY... Strong thunderstorms capable of producing damaging wind gusts are probable this afternoon across the southern Appalachians and Mid-Atlantic region, as well as across parts of southern New England. ...Synopsis... Latest water-vapor imagery depicts a deepening upper trough over the Great Lakes region with an attendant cold front noted in surface observations extending from the Great Lakes region into the central Plains. The northern portion of the cold front will continue to surge to the east in tandem with the upper trough; to the south, the front will begin to slow as it becomes increasingly frontolytic over the TN Valley and Ozark Plateau later today. Thunderstorm development will mainly be focused along this front as it impinges on a moist, weakly capped air mass currently in place from the Mid-MS River Valley into the Mid-Atlantic. More isolated thunderstorm chances are anticipated across the southern U.S. and over portions of the Southwest/Great Basin. ...Southern Appalachians/Mid-Atlantic... Initially isolated thunderstorm development is expected along the cold front as it approaches the TN Valley/southern Appalachians, but the weakly capped environment will favor additional development along convective outflows as well as orographically-initiated convection within the higher terrain of the southern Appalachians. As such, convective coverage should increase through mid-afternoon as storms propagate east into the Mid-Atlantic region. Mid-level flow on the southern periphery of the upper trough will be strong enough to support around 20 knots of effective bulk shear, which should support loosely organized convective clusters/multi-cells with an attendant risk for damaging wind gusts. Recent CAM guidance suggests central NC/VA may see the best potential for such clusters, and consequently could have a relatively higher potential for damaging winds. Further to the northeast into parts of southern New England, thunderstorm coverage is expected to be much more isolated and tied primarily to a deepening surface trough during the mid/late afternoon hours. While buoyancy will remain somewhat meager due to poor mid-level lapse rates, stronger mid-level flow in closer proximity to the upper trough may support an organized storm or two. ...Northwest New York... Consideration for a small Marginal risk area was made across far northwest NY. Forcing along the cold front will be much stronger along the international border with several CAM solutions hinting that shallow convection may accompany the front with an attendant damaging wind risk (as was observed Saturday evening across the upper Great Lakes region). However, warmer mid-level temperatures further over the Northeast should limit overall buoyancy values and casts uncertainty onto convective depth and intensity. Additionally, most CAM solutions hint that this potential will remain fairly confined to along the NY international border. Due to these concerns risk probabilities were withheld, but trends will continue to be monitored. ..Moore.. 09/01/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN APPALACHIANS INTO THE MID-ATLANTIC AND PARTS OF NEW ENGLAND.... ...SUMMARY... Strong thunderstorms capable of producing damaging wind gusts are probable this afternoon across the southern Appalachians and Mid-Atlantic region, as well as across parts of southern New England. ...Synopsis... Latest water-vapor imagery depicts a deepening upper trough over the Great Lakes region with an attendant cold front noted in surface observations extending from the Great Lakes region into the central Plains. The northern portion of the cold front will continue to surge to the east in tandem with the upper trough; to the south, the front will begin to slow as it becomes increasingly frontolytic over the TN Valley and Ozark Plateau later today. Thunderstorm development will mainly be focused along this front as it impinges on a moist, weakly capped air mass currently in place from the Mid-MS River Valley into the Mid-Atlantic. More isolated thunderstorm chances are anticipated across the southern U.S. and over portions of the Southwest/Great Basin. ...Southern Appalachians/Mid-Atlantic... Initially isolated thunderstorm development is expected along the cold front as it approaches the TN Valley/southern Appalachians, but the weakly capped environment will favor additional development along convective outflows as well as orographically-initiated convection within the higher terrain of the southern Appalachians. As such, convective coverage should increase through mid-afternoon as storms propagate east into the Mid-Atlantic region. Mid-level flow on the southern periphery of the upper trough will be strong enough to support around 20 knots of effective bulk shear, which should support loosely organized convective clusters/multi-cells with an attendant risk for damaging wind gusts. Recent CAM guidance suggests central NC/VA may see the best potential for such clusters, and consequently could have a relatively higher potential for damaging winds. Further to the northeast into parts of southern New England, thunderstorm coverage is expected to be much more isolated and tied primarily to a deepening surface trough during the mid/late afternoon hours. While buoyancy will remain somewhat meager due to poor mid-level lapse rates, stronger mid-level flow in closer proximity to the upper trough may support an organized storm or two. ...Northwest New York... Consideration for a small Marginal risk area was made across far northwest NY. Forcing along the cold front will be much stronger along the international border with several CAM solutions hinting that shallow convection may accompany the front with an attendant damaging wind risk (as was observed Saturday evening across the upper Great Lakes region). However, warmer mid-level temperatures further over the Northeast should limit overall buoyancy values and casts uncertainty onto convective depth and intensity. Additionally, most CAM solutions hint that this potential will remain fairly confined to along the NY international border. Due to these concerns risk probabilities were withheld, but trends will continue to be monitored. ..Moore.. 09/01/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN APPALACHIANS INTO THE MID-ATLANTIC AND PARTS OF NEW ENGLAND.... ...SUMMARY... Strong thunderstorms capable of producing damaging wind gusts are probable this afternoon across the southern Appalachians and Mid-Atlantic region, as well as across parts of southern New England. ...Synopsis... Latest water-vapor imagery depicts a deepening upper trough over the Great Lakes region with an attendant cold front noted in surface observations extending from the Great Lakes region into the central Plains. The northern portion of the cold front will continue to surge to the east in tandem with the upper trough; to the south, the front will begin to slow as it becomes increasingly frontolytic over the TN Valley and Ozark Plateau later today. Thunderstorm development will mainly be focused along this front as it impinges on a moist, weakly capped air mass currently in place from the Mid-MS River Valley into the Mid-Atlantic. More isolated thunderstorm chances are anticipated across the southern U.S. and over portions of the Southwest/Great Basin. ...Southern Appalachians/Mid-Atlantic... Initially isolated thunderstorm development is expected along the cold front as it approaches the TN Valley/southern Appalachians, but the weakly capped environment will favor additional development along convective outflows as well as orographically-initiated convection within the higher terrain of the southern Appalachians. As such, convective coverage should increase through mid-afternoon as storms propagate east into the Mid-Atlantic region. Mid-level flow on the southern periphery of the upper trough will be strong enough to support around 20 knots of effective bulk shear, which should support loosely organized convective clusters/multi-cells with an attendant risk for damaging wind gusts. Recent CAM guidance suggests central NC/VA may see the best potential for such clusters, and consequently could have a relatively higher potential for damaging winds. Further to the northeast into parts of southern New England, thunderstorm coverage is expected to be much more isolated and tied primarily to a deepening surface trough during the mid/late afternoon hours. While buoyancy will remain somewhat meager due to poor mid-level lapse rates, stronger mid-level flow in closer proximity to the upper trough may support an organized storm or two. ...Northwest New York... Consideration for a small Marginal risk area was made across far northwest NY. Forcing along the cold front will be much stronger along the international border with several CAM solutions hinting that shallow convection may accompany the front with an attendant damaging wind risk (as was observed Saturday evening across the upper Great Lakes region). However, warmer mid-level temperatures further over the Northeast should limit overall buoyancy values and casts uncertainty onto convective depth and intensity. Additionally, most CAM solutions hint that this potential will remain fairly confined to along the NY international border. Due to these concerns risk probabilities were withheld, but trends will continue to be monitored. ..Moore.. 09/01/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN APPALACHIANS INTO THE MID-ATLANTIC AND PARTS OF NEW ENGLAND.... ...SUMMARY... Strong thunderstorms capable of producing damaging wind gusts are probable this afternoon across the southern Appalachians and Mid-Atlantic region, as well as across parts of southern New England. ...Synopsis... Latest water-vapor imagery depicts a deepening upper trough over the Great Lakes region with an attendant cold front noted in surface observations extending from the Great Lakes region into the central Plains. The northern portion of the cold front will continue to surge to the east in tandem with the upper trough; to the south, the front will begin to slow as it becomes increasingly frontolytic over the TN Valley and Ozark Plateau later today. Thunderstorm development will mainly be focused along this front as it impinges on a moist, weakly capped air mass currently in place from the Mid-MS River Valley into the Mid-Atlantic. More isolated thunderstorm chances are anticipated across the southern U.S. and over portions of the Southwest/Great Basin. ...Southern Appalachians/Mid-Atlantic... Initially isolated thunderstorm development is expected along the cold front as it approaches the TN Valley/southern Appalachians, but the weakly capped environment will favor additional development along convective outflows as well as orographically-initiated convection within the higher terrain of the southern Appalachians. As such, convective coverage should increase through mid-afternoon as storms propagate east into the Mid-Atlantic region. Mid-level flow on the southern periphery of the upper trough will be strong enough to support around 20 knots of effective bulk shear, which should support loosely organized convective clusters/multi-cells with an attendant risk for damaging wind gusts. Recent CAM guidance suggests central NC/VA may see the best potential for such clusters, and consequently could have a relatively higher potential for damaging winds. Further to the northeast into parts of southern New England, thunderstorm coverage is expected to be much more isolated and tied primarily to a deepening surface trough during the mid/late afternoon hours. While buoyancy will remain somewhat meager due to poor mid-level lapse rates, stronger mid-level flow in closer proximity to the upper trough may support an organized storm or two. ...Northwest New York... Consideration for a small Marginal risk area was made across far northwest NY. Forcing along the cold front will be much stronger along the international border with several CAM solutions hinting that shallow convection may accompany the front with an attendant damaging wind risk (as was observed Saturday evening across the upper Great Lakes region). However, warmer mid-level temperatures further over the Northeast should limit overall buoyancy values and casts uncertainty onto convective depth and intensity. Additionally, most CAM solutions hint that this potential will remain fairly confined to along the NY international border. Due to these concerns risk probabilities were withheld, but trends will continue to be monitored. ..Moore.. 09/01/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 PM CDT Sat Aug 31 2024 Valid 010100Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN GREAT LAKES... ...SUMMARY... Isolated severe wind gusts will be possible this evening across parts of the northern Great Lakes. ...Northern Great Lakes... Water vapor imagery shows a low-amplitude shortwave trough over southern Ontario extending into northern Minnesota. Ahead of the shortwave trough, a band of large-scale ascent appears to be moving through the vicinity of Lake Superior, where a broken line of thunderstorms is ongoing. Ahead of this line, surface dewpoints are in the mid 50s F, and the RAP has SBCAPE of 250 to 500 J/kg. RAP forecast soundings over upper Michigan have strong deep-layer shear exceeding 60 knots, and steep low to mid-level lapse rates. This may be enough for an isolated threat of severe wind gusts. This threat may persist for another hour or two. ..Broyles.. 09/01/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 PM CDT Sat Aug 31 2024 Valid 010100Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN GREAT LAKES... ...SUMMARY... Isolated severe wind gusts will be possible this evening across parts of the northern Great Lakes. ...Northern Great Lakes... Water vapor imagery shows a low-amplitude shortwave trough over southern Ontario extending into northern Minnesota. Ahead of the shortwave trough, a band of large-scale ascent appears to be moving through the vicinity of Lake Superior, where a broken line of thunderstorms is ongoing. Ahead of this line, surface dewpoints are in the mid 50s F, and the RAP has SBCAPE of 250 to 500 J/kg. RAP forecast soundings over upper Michigan have strong deep-layer shear exceeding 60 knots, and steep low to mid-level lapse rates. This may be enough for an isolated threat of severe wind gusts. This threat may persist for another hour or two. ..Broyles.. 09/01/2024 Read more