Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 PM CDT Sun Aug 24 2025 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR SOUTH-CENTRAL ARIZONA... ...SUMMARY... Isolated severe gusts cannot be ruled out over a small part of south-central Arizona Monday afternoon. Otherwise, potential for severe storms is low across the remainder of the continental U.S. ...Synopsis... A large upper trough will be situated over eastern Canada and across much of the central and eastern states on Monday, with a relative ridge over the Rockies. At the surface, high pressure will result in mostly stable conditions from the northern and central Plains toward the Gulf Coast and Mid Atlantic, but residual instability may remain over New England and across south TX and FL. Southerly winds over the southern Plains may also interact with a southward-moving cold front, with general thunderstorms from OK into parts of northwest TX. ...Southern AZ... With the upper high centered over NM, southeasterly midlevel winds will exist over AZ, on the order of 20-25 kt. Meanwhile, light westerly winds will exist within the deepening boundary layer as heating occurs. Low to mid level moisture will already be in place, and 1000-1500 J/kg MUCAPE appear likely by late afternoon. Storms are expected to form over eastern Santa Cruz County (and perhaps isolated development into eastern Pima County), with steering currents and propagation yielding west/northwest motions. With time, aggregate outflow may produce strong to perhaps severe gusts on the local level as activity moves into the diurnally primed air mass, with gusty winds possible through early evening. ..Jewell.. 08/24/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...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 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...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 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...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 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...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 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...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 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...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 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...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 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...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 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...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 1138 AM CDT Sun Aug 24 2025 Valid 241700Z - 251200Z The IsoDryT was expanded slightly in northern California and portions of Oregon based on the latest observations and high-resolution forecast guidance. On the western and northern fringes of the monsoonal moisture induced cloud cover, isolated thunderstorms are already occurring this morning in portions of southern/central/eastern Oregon. A weak mid-level shortwave trough is evident via satellite imagery and mesoanalysis in northern California, which should continue to drift north and expand westward coverage of mixed wet/dry thunderstorms in northern California and Oregon, including west of the Cascades. Isolated mixed wet/dry thunderstorms are also possible across southeast Oregon and along/near the Idaho border with Nevada and Utah into western Wyoming. Hot, dry, unstable, and locally breezy conditions will continue from northwest California, through western Oregon, and into portions of Washington near a thermal trough. Eastern Idaho, western Wyoming, and portions of California also have the potential on the fringe of the monsoonal moisture/thunderstorm potential for deep pyroconvection on active large wildfires. ..Nauslar.. 08/24/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Sun Aug 24 2025/ ...Synopsis... Monsoonal moisture is well established beneath an expansive large-scale ridge encompassing much of the West. Along the northern periphery of the deeper midlevel moisture plume, a mix of wet/dry thunderstorms are expected across parts of northern CA into southern/central OR during the afternoon into the evening hours -- aided by inverted-V profiles and 0.80-0.90 inch PW. Given modestly receptive fuels, these storms will pose a risk of isolated lightning-induced ignitions and gusty/erratic outflow winds. Scattered high-based thunderstorms are also expected across much of the Great Basin and the remainder of inland CA, though deeper midlevel moisture and relatively slow storm motions may tend to favor a wetter storm mode over these areas. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Aug 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND PORTIONS OF NEW YORK AND PENNSYLVANIA... ...SUMMARY... A few severe thunderstorms should develop this afternoon and evening across the southern/central High Plains spanning from eastern Colorado into western Oklahoma. Scattered strong to severe thunderstorms are also possible across portions of Pennsylvania and New York. ...Southern/Central High Plains... Elevated thunderstorms are ongoing late this morning across parts of western/southern KS in a northwesterly mid-level flow regime. This activity has generally remained sub-severe, but the stronger cores could be capable of producing occasional hail as they track southeastward this afternoon given the presence of sufficient MUCAPE and deep-layer shear. Modestly enhanced mid-level flow is expected to remain over parts of the central into southern Plains today, generally from eastern WY/CO into western KS/OK and vicinity, between a mid/upper-level anticyclone over the Southwest and mid/upper-level troughing across the Upper Midwest. A surface front extends from northern CO into western KS. This boundary, along with outflow from ongoing convection, may serve as foci for robust thunderstorm development later today. There is still a fair amount of uncertainty regarding convective development and evolution this afternoon/evening across the southern/central High Plains given weak forcing aloft. Modest low-level upslope flow and orographic effects should encourage at least isolated thunderstorms to initially develop over the higher terrain of the central Rockies/Front Range, and subsequently spread southeastward into the High Plains through the evening. The front/outflow boundary draped from northeast CO into southwest KS could also serve as a forcing mechanism to aid parcels in reaching their LFCs. The environment along/south of the front should become moderately unstable with continued daytime heating, with greater low-level moisture present across western KS into the OK/TX Panhandles and western OK. Modest low-level southeasterlies should persist through much of the afternoon/evening along and near the front, which should locally enhance 0-1 km SRH. It appears possible that a supercell or two could develop near the front later today and track south-southeastward in a favorable northwesterly mid-level flow regime. Isolated large hail would probably be the main threat if a supercell can be sustained, with perhaps a tornado also possible where low-level flow can remain backed to southeasterly near the front. Some guidance suggests a cluster or two may eventually emerge this evening across eastern CO and/or southwest KS, but this potential remains highly uncertain. Mesoscale trends will be monitored for a zone of more focused severe potential and possible outlook upgrade. ...New York/Pennsylvania... An amplified upper trough/low over Ontario and extending southward into the Great Lakes/Midwest is forecast to gradually shift eastward today. A related surface cold front will also advance east-southeastward through the period across parts of the Northeast and Mid-Atlantic/OH Valley. Filtered daytime heating of a modestly moist low-level airmass ahead of the front will promote weak to locally moderate instability this afternoon, especially across parts of PA/NY. Current expectations are for thunderstorms to develop along/near the front through the afternoon across western PA/NY. While mid-level lapse rates are forecast to remain poor, which will likely limit updraft strength, sufficient deep-layer shear should be present to support some thunderstorm organization. Loosely organized clusters/cells may pose an isolated threat for damaging winds and perhaps marginally severe hail as they spread eastward across central PA and central/northern NY through early evening. This activity should weaken with eastward extent as it encounters a less unstable airmass. ..Gleason/Moore.. 08/24/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Aug 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND PORTIONS OF NEW YORK AND PENNSYLVANIA... ...SUMMARY... A few severe thunderstorms should develop this afternoon and evening across the southern/central High Plains spanning from eastern Colorado into western Oklahoma. Scattered strong to severe thunderstorms are also possible across portions of Pennsylvania and New York. ...Southern/Central High Plains... Elevated thunderstorms are ongoing late this morning across parts of western/southern KS in a northwesterly mid-level flow regime. This activity has generally remained sub-severe, but the stronger cores could be capable of producing occasional hail as they track southeastward this afternoon given the presence of sufficient MUCAPE and deep-layer shear. Modestly enhanced mid-level flow is expected to remain over parts of the central into southern Plains today, generally from eastern WY/CO into western KS/OK and vicinity, between a mid/upper-level anticyclone over the Southwest and mid/upper-level troughing across the Upper Midwest. A surface front extends from northern CO into western KS. This boundary, along with outflow from ongoing convection, may serve as foci for robust thunderstorm development later today. There is still a fair amount of uncertainty regarding convective development and evolution this afternoon/evening across the southern/central High Plains given weak forcing aloft. Modest low-level upslope flow and orographic effects should encourage at least isolated thunderstorms to initially develop over the higher terrain of the central Rockies/Front Range, and subsequently spread southeastward into the High Plains through the evening. The front/outflow boundary draped from northeast CO into southwest KS could also serve as a forcing mechanism to aid parcels in reaching their LFCs. The environment along/south of the front should become moderately unstable with continued daytime heating, with greater low-level moisture present across western KS into the OK/TX Panhandles and western OK. Modest low-level southeasterlies should persist through much of the afternoon/evening along and near the front, which should locally enhance 0-1 km SRH. It appears possible that a supercell or two could develop near the front later today and track south-southeastward in a favorable northwesterly mid-level flow regime. Isolated large hail would probably be the main threat if a supercell can be sustained, with perhaps a tornado also possible where low-level flow can remain backed to southeasterly near the front. Some guidance suggests a cluster or two may eventually emerge this evening across eastern CO and/or southwest KS, but this potential remains highly uncertain. Mesoscale trends will be monitored for a zone of more focused severe potential and possible outlook upgrade. ...New York/Pennsylvania... An amplified upper trough/low over Ontario and extending southward into the Great Lakes/Midwest is forecast to gradually shift eastward today. A related surface cold front will also advance east-southeastward through the period across parts of the Northeast and Mid-Atlantic/OH Valley. Filtered daytime heating of a modestly moist low-level airmass ahead of the front will promote weak to locally moderate instability this afternoon, especially across parts of PA/NY. Current expectations are for thunderstorms to develop along/near the front through the afternoon across western PA/NY. While mid-level lapse rates are forecast to remain poor, which will likely limit updraft strength, sufficient deep-layer shear should be present to support some thunderstorm organization. Loosely organized clusters/cells may pose an isolated threat for damaging winds and perhaps marginally severe hail as they spread eastward across central PA and central/northern NY through early evening. This activity should weaken with eastward extent as it encounters a less unstable airmass. ..Gleason/Moore.. 08/24/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Aug 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND PORTIONS OF NEW YORK AND PENNSYLVANIA... ...SUMMARY... A few severe thunderstorms should develop this afternoon and evening across the southern/central High Plains spanning from eastern Colorado into western Oklahoma. Scattered strong to severe thunderstorms are also possible across portions of Pennsylvania and New York. ...Southern/Central High Plains... Elevated thunderstorms are ongoing late this morning across parts of western/southern KS in a northwesterly mid-level flow regime. This activity has generally remained sub-severe, but the stronger cores could be capable of producing occasional hail as they track southeastward this afternoon given the presence of sufficient MUCAPE and deep-layer shear. Modestly enhanced mid-level flow is expected to remain over parts of the central into southern Plains today, generally from eastern WY/CO into western KS/OK and vicinity, between a mid/upper-level anticyclone over the Southwest and mid/upper-level troughing across the Upper Midwest. A surface front extends from northern CO into western KS. This boundary, along with outflow from ongoing convection, may serve as foci for robust thunderstorm development later today. There is still a fair amount of uncertainty regarding convective development and evolution this afternoon/evening across the southern/central High Plains given weak forcing aloft. Modest low-level upslope flow and orographic effects should encourage at least isolated thunderstorms to initially develop over the higher terrain of the central Rockies/Front Range, and subsequently spread southeastward into the High Plains through the evening. The front/outflow boundary draped from northeast CO into southwest KS could also serve as a forcing mechanism to aid parcels in reaching their LFCs. The environment along/south of the front should become moderately unstable with continued daytime heating, with greater low-level moisture present across western KS into the OK/TX Panhandles and western OK. Modest low-level southeasterlies should persist through much of the afternoon/evening along and near the front, which should locally enhance 0-1 km SRH. It appears possible that a supercell or two could develop near the front later today and track south-southeastward in a favorable northwesterly mid-level flow regime. Isolated large hail would probably be the main threat if a supercell can be sustained, with perhaps a tornado also possible where low-level flow can remain backed to southeasterly near the front. Some guidance suggests a cluster or two may eventually emerge this evening across eastern CO and/or southwest KS, but this potential remains highly uncertain. Mesoscale trends will be monitored for a zone of more focused severe potential and possible outlook upgrade. ...New York/Pennsylvania... An amplified upper trough/low over Ontario and extending southward into the Great Lakes/Midwest is forecast to gradually shift eastward today. A related surface cold front will also advance east-southeastward through the period across parts of the Northeast and Mid-Atlantic/OH Valley. Filtered daytime heating of a modestly moist low-level airmass ahead of the front will promote weak to locally moderate instability this afternoon, especially across parts of PA/NY. Current expectations are for thunderstorms to develop along/near the front through the afternoon across western PA/NY. While mid-level lapse rates are forecast to remain poor, which will likely limit updraft strength, sufficient deep-layer shear should be present to support some thunderstorm organization. Loosely organized clusters/cells may pose an isolated threat for damaging winds and perhaps marginally severe hail as they spread eastward across central PA and central/northern NY through early evening. This activity should weaken with eastward extent as it encounters a less unstable airmass. ..Gleason/Moore.. 08/24/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Aug 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND PORTIONS OF NEW YORK AND PENNSYLVANIA... ...SUMMARY... A few severe thunderstorms should develop this afternoon and evening across the southern/central High Plains spanning from eastern Colorado into western Oklahoma. Scattered strong to severe thunderstorms are also possible across portions of Pennsylvania and New York. ...Southern/Central High Plains... Elevated thunderstorms are ongoing late this morning across parts of western/southern KS in a northwesterly mid-level flow regime. This activity has generally remained sub-severe, but the stronger cores could be capable of producing occasional hail as they track southeastward this afternoon given the presence of sufficient MUCAPE and deep-layer shear. Modestly enhanced mid-level flow is expected to remain over parts of the central into southern Plains today, generally from eastern WY/CO into western KS/OK and vicinity, between a mid/upper-level anticyclone over the Southwest and mid/upper-level troughing across the Upper Midwest. A surface front extends from northern CO into western KS. This boundary, along with outflow from ongoing convection, may serve as foci for robust thunderstorm development later today. There is still a fair amount of uncertainty regarding convective development and evolution this afternoon/evening across the southern/central High Plains given weak forcing aloft. Modest low-level upslope flow and orographic effects should encourage at least isolated thunderstorms to initially develop over the higher terrain of the central Rockies/Front Range, and subsequently spread southeastward into the High Plains through the evening. The front/outflow boundary draped from northeast CO into southwest KS could also serve as a forcing mechanism to aid parcels in reaching their LFCs. The environment along/south of the front should become moderately unstable with continued daytime heating, with greater low-level moisture present across western KS into the OK/TX Panhandles and western OK. Modest low-level southeasterlies should persist through much of the afternoon/evening along and near the front, which should locally enhance 0-1 km SRH. It appears possible that a supercell or two could develop near the front later today and track south-southeastward in a favorable northwesterly mid-level flow regime. Isolated large hail would probably be the main threat if a supercell can be sustained, with perhaps a tornado also possible where low-level flow can remain backed to southeasterly near the front. Some guidance suggests a cluster or two may eventually emerge this evening across eastern CO and/or southwest KS, but this potential remains highly uncertain. Mesoscale trends will be monitored for a zone of more focused severe potential and possible outlook upgrade. ...New York/Pennsylvania... An amplified upper trough/low over Ontario and extending southward into the Great Lakes/Midwest is forecast to gradually shift eastward today. A related surface cold front will also advance east-southeastward through the period across parts of the Northeast and Mid-Atlantic/OH Valley. Filtered daytime heating of a modestly moist low-level airmass ahead of the front will promote weak to locally moderate instability this afternoon, especially across parts of PA/NY. Current expectations are for thunderstorms to develop along/near the front through the afternoon across western PA/NY. While mid-level lapse rates are forecast to remain poor, which will likely limit updraft strength, sufficient deep-layer shear should be present to support some thunderstorm organization. Loosely organized clusters/cells may pose an isolated threat for damaging winds and perhaps marginally severe hail as they spread eastward across central PA and central/northern NY through early evening. This activity should weaken with eastward extent as it encounters a less unstable airmass. ..Gleason/Moore.. 08/24/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Aug 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND PORTIONS OF NEW YORK AND PENNSYLVANIA... ...SUMMARY... A few severe thunderstorms should develop this afternoon and evening across the southern/central High Plains spanning from eastern Colorado into western Oklahoma. Scattered strong to severe thunderstorms are also possible across portions of Pennsylvania and New York. ...Southern/Central High Plains... Elevated thunderstorms are ongoing late this morning across parts of western/southern KS in a northwesterly mid-level flow regime. This activity has generally remained sub-severe, but the stronger cores could be capable of producing occasional hail as they track southeastward this afternoon given the presence of sufficient MUCAPE and deep-layer shear. Modestly enhanced mid-level flow is expected to remain over parts of the central into southern Plains today, generally from eastern WY/CO into western KS/OK and vicinity, between a mid/upper-level anticyclone over the Southwest and mid/upper-level troughing across the Upper Midwest. A surface front extends from northern CO into western KS. This boundary, along with outflow from ongoing convection, may serve as foci for robust thunderstorm development later today. There is still a fair amount of uncertainty regarding convective development and evolution this afternoon/evening across the southern/central High Plains given weak forcing aloft. Modest low-level upslope flow and orographic effects should encourage at least isolated thunderstorms to initially develop over the higher terrain of the central Rockies/Front Range, and subsequently spread southeastward into the High Plains through the evening. The front/outflow boundary draped from northeast CO into southwest KS could also serve as a forcing mechanism to aid parcels in reaching their LFCs. The environment along/south of the front should become moderately unstable with continued daytime heating, with greater low-level moisture present across western KS into the OK/TX Panhandles and western OK. Modest low-level southeasterlies should persist through much of the afternoon/evening along and near the front, which should locally enhance 0-1 km SRH. It appears possible that a supercell or two could develop near the front later today and track south-southeastward in a favorable northwesterly mid-level flow regime. Isolated large hail would probably be the main threat if a supercell can be sustained, with perhaps a tornado also possible where low-level flow can remain backed to southeasterly near the front. Some guidance suggests a cluster or two may eventually emerge this evening across eastern CO and/or southwest KS, but this potential remains highly uncertain. Mesoscale trends will be monitored for a zone of more focused severe potential and possible outlook upgrade. ...New York/Pennsylvania... An amplified upper trough/low over Ontario and extending southward into the Great Lakes/Midwest is forecast to gradually shift eastward today. A related surface cold front will also advance east-southeastward through the period across parts of the Northeast and Mid-Atlantic/OH Valley. Filtered daytime heating of a modestly moist low-level airmass ahead of the front will promote weak to locally moderate instability this afternoon, especially across parts of PA/NY. Current expectations are for thunderstorms to develop along/near the front through the afternoon across western PA/NY. While mid-level lapse rates are forecast to remain poor, which will likely limit updraft strength, sufficient deep-layer shear should be present to support some thunderstorm organization. Loosely organized clusters/cells may pose an isolated threat for damaging winds and perhaps marginally severe hail as they spread eastward across central PA and central/northern NY through early evening. This activity should weaken with eastward extent as it encounters a less unstable airmass. ..Gleason/Moore.. 08/24/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Aug 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND PORTIONS OF NEW YORK AND PENNSYLVANIA... ...SUMMARY... A few severe thunderstorms should develop this afternoon and evening across the southern/central High Plains spanning from eastern Colorado into western Oklahoma. Scattered strong to severe thunderstorms are also possible across portions of Pennsylvania and New York. ...Southern/Central High Plains... Elevated thunderstorms are ongoing late this morning across parts of western/southern KS in a northwesterly mid-level flow regime. This activity has generally remained sub-severe, but the stronger cores could be capable of producing occasional hail as they track southeastward this afternoon given the presence of sufficient MUCAPE and deep-layer shear. Modestly enhanced mid-level flow is expected to remain over parts of the central into southern Plains today, generally from eastern WY/CO into western KS/OK and vicinity, between a mid/upper-level anticyclone over the Southwest and mid/upper-level troughing across the Upper Midwest. A surface front extends from northern CO into western KS. This boundary, along with outflow from ongoing convection, may serve as foci for robust thunderstorm development later today. There is still a fair amount of uncertainty regarding convective development and evolution this afternoon/evening across the southern/central High Plains given weak forcing aloft. Modest low-level upslope flow and orographic effects should encourage at least isolated thunderstorms to initially develop over the higher terrain of the central Rockies/Front Range, and subsequently spread southeastward into the High Plains through the evening. The front/outflow boundary draped from northeast CO into southwest KS could also serve as a forcing mechanism to aid parcels in reaching their LFCs. The environment along/south of the front should become moderately unstable with continued daytime heating, with greater low-level moisture present across western KS into the OK/TX Panhandles and western OK. Modest low-level southeasterlies should persist through much of the afternoon/evening along and near the front, which should locally enhance 0-1 km SRH. It appears possible that a supercell or two could develop near the front later today and track south-southeastward in a favorable northwesterly mid-level flow regime. Isolated large hail would probably be the main threat if a supercell can be sustained, with perhaps a tornado also possible where low-level flow can remain backed to southeasterly near the front. Some guidance suggests a cluster or two may eventually emerge this evening across eastern CO and/or southwest KS, but this potential remains highly uncertain. Mesoscale trends will be monitored for a zone of more focused severe potential and possible outlook upgrade. ...New York/Pennsylvania... An amplified upper trough/low over Ontario and extending southward into the Great Lakes/Midwest is forecast to gradually shift eastward today. A related surface cold front will also advance east-southeastward through the period across parts of the Northeast and Mid-Atlantic/OH Valley. Filtered daytime heating of a modestly moist low-level airmass ahead of the front will promote weak to locally moderate instability this afternoon, especially across parts of PA/NY. Current expectations are for thunderstorms to develop along/near the front through the afternoon across western PA/NY. While mid-level lapse rates are forecast to remain poor, which will likely limit updraft strength, sufficient deep-layer shear should be present to support some thunderstorm organization. Loosely organized clusters/cells may pose an isolated threat for damaging winds and perhaps marginally severe hail as they spread eastward across central PA and central/northern NY through early evening. This activity should weaken with eastward extent as it encounters a less unstable airmass. ..Gleason/Moore.. 08/24/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Aug 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND PORTIONS OF NEW YORK AND PENNSYLVANIA... ...SUMMARY... A few severe thunderstorms should develop this afternoon and evening across the southern/central High Plains spanning from eastern Colorado into western Oklahoma. Scattered strong to severe thunderstorms are also possible across portions of Pennsylvania and New York. ...Southern/Central High Plains... Elevated thunderstorms are ongoing late this morning across parts of western/southern KS in a northwesterly mid-level flow regime. This activity has generally remained sub-severe, but the stronger cores could be capable of producing occasional hail as they track southeastward this afternoon given the presence of sufficient MUCAPE and deep-layer shear. Modestly enhanced mid-level flow is expected to remain over parts of the central into southern Plains today, generally from eastern WY/CO into western KS/OK and vicinity, between a mid/upper-level anticyclone over the Southwest and mid/upper-level troughing across the Upper Midwest. A surface front extends from northern CO into western KS. This boundary, along with outflow from ongoing convection, may serve as foci for robust thunderstorm development later today. There is still a fair amount of uncertainty regarding convective development and evolution this afternoon/evening across the southern/central High Plains given weak forcing aloft. Modest low-level upslope flow and orographic effects should encourage at least isolated thunderstorms to initially develop over the higher terrain of the central Rockies/Front Range, and subsequently spread southeastward into the High Plains through the evening. The front/outflow boundary draped from northeast CO into southwest KS could also serve as a forcing mechanism to aid parcels in reaching their LFCs. The environment along/south of the front should become moderately unstable with continued daytime heating, with greater low-level moisture present across western KS into the OK/TX Panhandles and western OK. Modest low-level southeasterlies should persist through much of the afternoon/evening along and near the front, which should locally enhance 0-1 km SRH. It appears possible that a supercell or two could develop near the front later today and track south-southeastward in a favorable northwesterly mid-level flow regime. Isolated large hail would probably be the main threat if a supercell can be sustained, with perhaps a tornado also possible where low-level flow can remain backed to southeasterly near the front. Some guidance suggests a cluster or two may eventually emerge this evening across eastern CO and/or southwest KS, but this potential remains highly uncertain. Mesoscale trends will be monitored for a zone of more focused severe potential and possible outlook upgrade. ...New York/Pennsylvania... An amplified upper trough/low over Ontario and extending southward into the Great Lakes/Midwest is forecast to gradually shift eastward today. A related surface cold front will also advance east-southeastward through the period across parts of the Northeast and Mid-Atlantic/OH Valley. Filtered daytime heating of a modestly moist low-level airmass ahead of the front will promote weak to locally moderate instability this afternoon, especially across parts of PA/NY. Current expectations are for thunderstorms to develop along/near the front through the afternoon across western PA/NY. While mid-level lapse rates are forecast to remain poor, which will likely limit updraft strength, sufficient deep-layer shear should be present to support some thunderstorm organization. Loosely organized clusters/cells may pose an isolated threat for damaging winds and perhaps marginally severe hail as they spread eastward across central PA and central/northern NY through early evening. This activity should weaken with eastward extent as it encounters a less unstable airmass. ..Gleason/Moore.. 08/24/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Aug 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND PORTIONS OF NEW YORK AND PENNSYLVANIA... ...SUMMARY... A few severe thunderstorms should develop this afternoon and evening across the southern/central High Plains spanning from eastern Colorado into western Oklahoma. Scattered strong to severe thunderstorms are also possible across portions of Pennsylvania and New York. ...Southern/Central High Plains... Elevated thunderstorms are ongoing late this morning across parts of western/southern KS in a northwesterly mid-level flow regime. This activity has generally remained sub-severe, but the stronger cores could be capable of producing occasional hail as they track southeastward this afternoon given the presence of sufficient MUCAPE and deep-layer shear. Modestly enhanced mid-level flow is expected to remain over parts of the central into southern Plains today, generally from eastern WY/CO into western KS/OK and vicinity, between a mid/upper-level anticyclone over the Southwest and mid/upper-level troughing across the Upper Midwest. A surface front extends from northern CO into western KS. This boundary, along with outflow from ongoing convection, may serve as foci for robust thunderstorm development later today. There is still a fair amount of uncertainty regarding convective development and evolution this afternoon/evening across the southern/central High Plains given weak forcing aloft. Modest low-level upslope flow and orographic effects should encourage at least isolated thunderstorms to initially develop over the higher terrain of the central Rockies/Front Range, and subsequently spread southeastward into the High Plains through the evening. The front/outflow boundary draped from northeast CO into southwest KS could also serve as a forcing mechanism to aid parcels in reaching their LFCs. The environment along/south of the front should become moderately unstable with continued daytime heating, with greater low-level moisture present across western KS into the OK/TX Panhandles and western OK. Modest low-level southeasterlies should persist through much of the afternoon/evening along and near the front, which should locally enhance 0-1 km SRH. It appears possible that a supercell or two could develop near the front later today and track south-southeastward in a favorable northwesterly mid-level flow regime. Isolated large hail would probably be the main threat if a supercell can be sustained, with perhaps a tornado also possible where low-level flow can remain backed to southeasterly near the front. Some guidance suggests a cluster or two may eventually emerge this evening across eastern CO and/or southwest KS, but this potential remains highly uncertain. Mesoscale trends will be monitored for a zone of more focused severe potential and possible outlook upgrade. ...New York/Pennsylvania... An amplified upper trough/low over Ontario and extending southward into the Great Lakes/Midwest is forecast to gradually shift eastward today. A related surface cold front will also advance east-southeastward through the period across parts of the Northeast and Mid-Atlantic/OH Valley. Filtered daytime heating of a modestly moist low-level airmass ahead of the front will promote weak to locally moderate instability this afternoon, especially across parts of PA/NY. Current expectations are for thunderstorms to develop along/near the front through the afternoon across western PA/NY. While mid-level lapse rates are forecast to remain poor, which will likely limit updraft strength, sufficient deep-layer shear should be present to support some thunderstorm organization. Loosely organized clusters/cells may pose an isolated threat for damaging winds and perhaps marginally severe hail as they spread eastward across central PA and central/northern NY through early evening. This activity should weaken with eastward extent as it encounters a less unstable airmass. ..Gleason/Moore.. 08/24/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Aug 24 2025 Valid 241630Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND PORTIONS OF NEW YORK AND PENNSYLVANIA... ...SUMMARY... A few severe thunderstorms should develop this afternoon and evening across the southern/central High Plains spanning from eastern Colorado into western Oklahoma. Scattered strong to severe thunderstorms are also possible across portions of Pennsylvania and New York. ...Southern/Central High Plains... Elevated thunderstorms are ongoing late this morning across parts of western/southern KS in a northwesterly mid-level flow regime. This activity has generally remained sub-severe, but the stronger cores could be capable of producing occasional hail as they track southeastward this afternoon given the presence of sufficient MUCAPE and deep-layer shear. Modestly enhanced mid-level flow is expected to remain over parts of the central into southern Plains today, generally from eastern WY/CO into western KS/OK and vicinity, between a mid/upper-level anticyclone over the Southwest and mid/upper-level troughing across the Upper Midwest. A surface front extends from northern CO into western KS. This boundary, along with outflow from ongoing convection, may serve as foci for robust thunderstorm development later today. There is still a fair amount of uncertainty regarding convective development and evolution this afternoon/evening across the southern/central High Plains given weak forcing aloft. Modest low-level upslope flow and orographic effects should encourage at least isolated thunderstorms to initially develop over the higher terrain of the central Rockies/Front Range, and subsequently spread southeastward into the High Plains through the evening. The front/outflow boundary draped from northeast CO into southwest KS could also serve as a forcing mechanism to aid parcels in reaching their LFCs. The environment along/south of the front should become moderately unstable with continued daytime heating, with greater low-level moisture present across western KS into the OK/TX Panhandles and western OK. Modest low-level southeasterlies should persist through much of the afternoon/evening along and near the front, which should locally enhance 0-1 km SRH. It appears possible that a supercell or two could develop near the front later today and track south-southeastward in a favorable northwesterly mid-level flow regime. Isolated large hail would probably be the main threat if a supercell can be sustained, with perhaps a tornado also possible where low-level flow can remain backed to southeasterly near the front. Some guidance suggests a cluster or two may eventually emerge this evening across eastern CO and/or southwest KS, but this potential remains highly uncertain. Mesoscale trends will be monitored for a zone of more focused severe potential and possible outlook upgrade. ...New York/Pennsylvania... An amplified upper trough/low over Ontario and extending southward into the Great Lakes/Midwest is forecast to gradually shift eastward today. A related surface cold front will also advance east-southeastward through the period across parts of the Northeast and Mid-Atlantic/OH Valley. Filtered daytime heating of a modestly moist low-level airmass ahead of the front will promote weak to locally moderate instability this afternoon, especially across parts of PA/NY. Current expectations are for thunderstorms to develop along/near the front through the afternoon across western PA/NY. While mid-level lapse rates are forecast to remain poor, which will likely limit updraft strength, sufficient deep-layer shear should be present to support some thunderstorm organization. Loosely organized clusters/cells may pose an isolated threat for damaging winds and perhaps marginally severe hail as they spread eastward across central PA and central/northern NY through early evening. This activity should weaken with eastward extent as it encounters a less unstable airmass. ..Gleason/Moore.. 08/24/2025 Read more