Aggregator

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Sep 20 2024 Valid 221200Z - 281200Z ...Synopsis... By late this weekend through early next week, mid to upper-level troughing is generally expected from the central to eastern CONUS, while ridging impacts the Southwest and Great Basin. This pattern will promote cooler air masses and precipitation chances from the Plains into the Midwest, with warmer and drier conditions west of the Rockies. The latter will likely lead to more receptive fuels developing across the Great Basin, Southwest, and portions of the Pacific Northwest. However, a lack of stronger flow aloft and significant low pressure areas developing will keep the overall fire weather wind threat very low across much of these regions. By mid to late next week, north Pacific mid to upper-level shortwave troughs traversing the western Canadian provinces will result in increasing southwesterly flow through the troposphere over the Pacific Northwest. Confidence in at least elevated fire weather conditions impacting any specific region, however, appears far too low to introduce 40 percent probabilities at this time. ..Barnes.. 09/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Sep 20 2024 Valid 221200Z - 281200Z ...Synopsis... By late this weekend through early next week, mid to upper-level troughing is generally expected from the central to eastern CONUS, while ridging impacts the Southwest and Great Basin. This pattern will promote cooler air masses and precipitation chances from the Plains into the Midwest, with warmer and drier conditions west of the Rockies. The latter will likely lead to more receptive fuels developing across the Great Basin, Southwest, and portions of the Pacific Northwest. However, a lack of stronger flow aloft and significant low pressure areas developing will keep the overall fire weather wind threat very low across much of these regions. By mid to late next week, north Pacific mid to upper-level shortwave troughs traversing the western Canadian provinces will result in increasing southwesterly flow through the troposphere over the Pacific Northwest. Confidence in at least elevated fire weather conditions impacting any specific region, however, appears far too low to introduce 40 percent probabilities at this time. ..Barnes.. 09/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Sep 20 2024 Valid 221200Z - 281200Z ...Synopsis... By late this weekend through early next week, mid to upper-level troughing is generally expected from the central to eastern CONUS, while ridging impacts the Southwest and Great Basin. This pattern will promote cooler air masses and precipitation chances from the Plains into the Midwest, with warmer and drier conditions west of the Rockies. The latter will likely lead to more receptive fuels developing across the Great Basin, Southwest, and portions of the Pacific Northwest. However, a lack of stronger flow aloft and significant low pressure areas developing will keep the overall fire weather wind threat very low across much of these regions. By mid to late next week, north Pacific mid to upper-level shortwave troughs traversing the western Canadian provinces will result in increasing southwesterly flow through the troposphere over the Pacific Northwest. Confidence in at least elevated fire weather conditions impacting any specific region, however, appears far too low to introduce 40 percent probabilities at this time. ..Barnes.. 09/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Sep 20 2024 Valid 221200Z - 281200Z ...Synopsis... By late this weekend through early next week, mid to upper-level troughing is generally expected from the central to eastern CONUS, while ridging impacts the Southwest and Great Basin. This pattern will promote cooler air masses and precipitation chances from the Plains into the Midwest, with warmer and drier conditions west of the Rockies. The latter will likely lead to more receptive fuels developing across the Great Basin, Southwest, and portions of the Pacific Northwest. However, a lack of stronger flow aloft and significant low pressure areas developing will keep the overall fire weather wind threat very low across much of these regions. By mid to late next week, north Pacific mid to upper-level shortwave troughs traversing the western Canadian provinces will result in increasing southwesterly flow through the troposphere over the Pacific Northwest. Confidence in at least elevated fire weather conditions impacting any specific region, however, appears far too low to introduce 40 percent probabilities at this time. ..Barnes.. 09/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Sep 20 2024 Valid 221200Z - 281200Z ...Synopsis... By late this weekend through early next week, mid to upper-level troughing is generally expected from the central to eastern CONUS, while ridging impacts the Southwest and Great Basin. This pattern will promote cooler air masses and precipitation chances from the Plains into the Midwest, with warmer and drier conditions west of the Rockies. The latter will likely lead to more receptive fuels developing across the Great Basin, Southwest, and portions of the Pacific Northwest. However, a lack of stronger flow aloft and significant low pressure areas developing will keep the overall fire weather wind threat very low across much of these regions. By mid to late next week, north Pacific mid to upper-level shortwave troughs traversing the western Canadian provinces will result in increasing southwesterly flow through the troposphere over the Pacific Northwest. Confidence in at least elevated fire weather conditions impacting any specific region, however, appears far too low to introduce 40 percent probabilities at this time. ..Barnes.. 09/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Sep 20 2024 Valid 221200Z - 281200Z ...Synopsis... By late this weekend through early next week, mid to upper-level troughing is generally expected from the central to eastern CONUS, while ridging impacts the Southwest and Great Basin. This pattern will promote cooler air masses and precipitation chances from the Plains into the Midwest, with warmer and drier conditions west of the Rockies. The latter will likely lead to more receptive fuels developing across the Great Basin, Southwest, and portions of the Pacific Northwest. However, a lack of stronger flow aloft and significant low pressure areas developing will keep the overall fire weather wind threat very low across much of these regions. By mid to late next week, north Pacific mid to upper-level shortwave troughs traversing the western Canadian provinces will result in increasing southwesterly flow through the troposphere over the Pacific Northwest. Confidence in at least elevated fire weather conditions impacting any specific region, however, appears far too low to introduce 40 percent probabilities at this time. ..Barnes.. 09/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Sep 20 2024 Valid 221200Z - 281200Z ...Synopsis... By late this weekend through early next week, mid to upper-level troughing is generally expected from the central to eastern CONUS, while ridging impacts the Southwest and Great Basin. This pattern will promote cooler air masses and precipitation chances from the Plains into the Midwest, with warmer and drier conditions west of the Rockies. The latter will likely lead to more receptive fuels developing across the Great Basin, Southwest, and portions of the Pacific Northwest. However, a lack of stronger flow aloft and significant low pressure areas developing will keep the overall fire weather wind threat very low across much of these regions. By mid to late next week, north Pacific mid to upper-level shortwave troughs traversing the western Canadian provinces will result in increasing southwesterly flow through the troposphere over the Pacific Northwest. Confidence in at least elevated fire weather conditions impacting any specific region, however, appears far too low to introduce 40 percent probabilities at this time. ..Barnes.. 09/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Sep 20 2024 Valid 221200Z - 281200Z ...Synopsis... By late this weekend through early next week, mid to upper-level troughing is generally expected from the central to eastern CONUS, while ridging impacts the Southwest and Great Basin. This pattern will promote cooler air masses and precipitation chances from the Plains into the Midwest, with warmer and drier conditions west of the Rockies. The latter will likely lead to more receptive fuels developing across the Great Basin, Southwest, and portions of the Pacific Northwest. However, a lack of stronger flow aloft and significant low pressure areas developing will keep the overall fire weather wind threat very low across much of these regions. By mid to late next week, north Pacific mid to upper-level shortwave troughs traversing the western Canadian provinces will result in increasing southwesterly flow through the troposphere over the Pacific Northwest. Confidence in at least elevated fire weather conditions impacting any specific region, however, appears far too low to introduce 40 percent probabilities at this time. ..Barnes.. 09/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

No Mesoscale Discussions are in effect as of Fri Sep 20 19:59:02 UTC 2024.

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more