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SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0309 PM CDT Fri May 16 2025 Valid 181200Z - 241200Z Critical fire weather conditions are expected to linger over the weekend and into early next week across parts of the southern High Plains. Long-range guidance continues to depict the amplification of an upper trough over the Southwest this weekend before ejecting into the Plains early next week. As this occurs, dry southwesterly flow should overspread much of the Southwest/southern High Plains, which will promote multiple days of fire weather concerns. After the ejection of this wave, ensemble guidance suggests low-amplitude long-wave ridging will become established over the central CONUS. This should promote muted surface pressure gradient winds along with isolated rain chances for most regions with the exception of the Great Basin and Southwest. ...D3/Sunday and D4/Monday - Southern High Plains... Southwesterly flow over the southern/central Rockies will promote lee troughing along the southern High Plains through early next week. To the west of a sharpening dryline, west/southwesterly downslope flow will promote multiple days of dry/windy conditions with afternoon RH values expected to fall into the single digits to low teens with 15-25 mph winds. Widespread elevated to critical fire weather conditions are expected both afternoons as mid-level impulses propagate into the Plains and result in an eastward surge of the dryline. The fire weather threat should be greatest across south-central NM into far West TX where ERCs are currently between the 80th to 95th percentile. With northward and eastward extent, ongoing spring green up should modulate the potential for fire spread. ...D3/Sunday and D4/Monday - Sacramento Valley... Dry northerly winds are expected through the Sacramento Valley both D3/Sun and D4/Mon. Latest deterministic and ensemble guidance suggests winds between 15-20 mph are likely with RH values falling into the 20-30% range. Elevated fire weather conditions are possible, and some fire threat may materialize given ERCs increasing to near the 80th percentile. However, confidence in sustained/widespread critical conditions remains too limited for highlights at this time. ..Moore.. 05/16/2025 ...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 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Fri May 16 2025 Valid 162000Z - 171200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... A regional outbreak of severe thunderstorms is likely this afternoon into tonight across parts of the mid Mississippi, Ohio and Tennessee Valleys. This will include intense supercells with strong, potentially long-track tornadoes and very large hail. The threat for damaging winds in excess of 75 mph will increase into this evening as storms grow into larger clusters. ...20z Update... No changes are needed to the current D1 Convective Outlook. Supercells are ongoing across Missouri producing large hail (up to 3-4 in). These storms will continue eastward through time across the Moderate Risk. The area ahead of these storms is continuing to warm and destabilize rapidly, with some increase in low level shear expected through the evening with an increase in the low level jet. This will support increasing potential for tornadoes, a couple of which may be intense and long-track across eastern Missouri into southern Illinois, southern Indiana, and western Kentucky. See MCD#817 for more information on the short term risk. Elsewhere, a cluster of storms continue across portions of the eastern US from West Virginia to eastern Kentucky which will slowly move into Virginia and North Carolina. See MCD#816 for more information on the short term risk. For more information on the potential risk across southeast Oklahoma into Texas this afternoon/evening, see previous discussion below. ..Thornton/Mosier.. 05/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Fri May 16 2025/ ...Mid MS Valley to the Mid-Atlantic through tonight... An occluded 984 mb cyclone will move slowly eastward toward the upper Great Lakes and fill through tonight, as a trailing cold front progresses across MO/IL/IN/MI. Ongoing thunderstorm clusters will likely persist through the afternoon along the primary moisture/buoyancy gradient into the northern Mid-Atlantic, and with a developing cold pool from TN/KY into VA/NC within the warm sector. MLCAPE increasing to 2000 J/kg or greater, steepening low-level lapse rates, and sufficient deep-layer vertical shear (effective bulk shear of 40-50 kt) will maintain a mix of embedded supercells and bowing segments capable of producing very large hail (2 inch diameter or larger), thunderstorm gusts of 60-75 mph, and a couple of tornadoes. Farther west and in the wake of the ongoing TN/KY storms, rapid recovery is underway across southern MO where moisture advection and strong surface heating will result in rapid destabilization. Visible imagery shows evidence of ascent over northwest AR/southwest MO that will soon interact with the destabilizing warm sector. Supercell development is expected by midday into early afternoon from south central into east central MO, and storms will subsequently expand in coverage while spreading quickly east-northeastward across southern/central IL this afternoon and into IN late this afternoon/evening. The initial storms in MO will likely remain semi-discrete with the potential to producing very large hail (in excess of 3 inches in diameter) and a couple of strong tornadoes given very long hodograph with sufficient low-level shear. Gradual upscale growth into clusters/line segments is expected through storm interactions, with an increase in the potential for swaths of 65-85 mph gusts into this evening. More isolated supercell development may also occur later this afternoon along the modifying outflow boundary into KY, where all hazards are expected. ...Northern IL into Lower MI this afternoon/evening... An embedded speed max and associated zone of ascent now over northern MO will eject quickly east-northeastward toward Lower MI by early tonight. The degree of moistening/destabilization will be modulated by how quickly storms form and how widespread coverage is this afternoon farther to the south from IL into IN. ...AR into southeast OK and northeast/central TX this afternoon... Despite some cloud cover, surface heating in cloud breaks is allowing surface temperatures to warm into the 80s with low-mid 70s boundary-layer dewpoints, beneath midlevel lapse rates in excess of 8 C/km. Scattered thunderstorm development is expected this afternoon along the primary wind shift from AR/southeast OK into northeast and potentially central TX. MLCAPE of 3000-4000 J/kg and long hodographs with strong deep-layer shear will favor supercells capable of producing very large hail (3-4 inches in diameter) with the initial discrete storms, and damaging gusts of 60-75 mph. The tornado threat is less certain given relatively weak low-level shear (as a result of the primary mass response/low-level jet into the TN/OH Valleys), and will likely rely on favorable storm interactions. Read more