Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z An Elevated risk area has been introduced to portions of southeast CA into southern/eastern NV. Latest guidance continues to show high confidence in a corridor of 20-25 mph winds emanating out of the southern Sierra Nevada with RH values in the single digits. Fuel conditions continue to be somewhat marginal across eastern NV, but become increasingly dry with westward extent. Given the high confidence in reaching critical fire weather thresholds, an Elevated risk area has been introduced where the overlap of 20+ mph winds with sub-10% RH and ERCs at/above the 80th percentile is greatest. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0112 AM CDT Thu Aug 15 2024/ ...Synopsis... Friday will be characterized by west-southwesterly mid-level flow across the Western U.S., with a shortwave trough approaching the Oregon/Washington coasts late in the period. This will support some dry/windy conditions across portions of southern Nevada and western Utah, with relative humidity dropping to 10-15% with winds reaching 20-25 MPH. However, these conditions will largely occur over fuels that have received recent wetting rainfall or are only modestly dry, precluding highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z An Elevated risk area has been introduced to portions of southeast CA into southern/eastern NV. Latest guidance continues to show high confidence in a corridor of 20-25 mph winds emanating out of the southern Sierra Nevada with RH values in the single digits. Fuel conditions continue to be somewhat marginal across eastern NV, but become increasingly dry with westward extent. Given the high confidence in reaching critical fire weather thresholds, an Elevated risk area has been introduced where the overlap of 20+ mph winds with sub-10% RH and ERCs at/above the 80th percentile is greatest. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0112 AM CDT Thu Aug 15 2024/ ...Synopsis... Friday will be characterized by west-southwesterly mid-level flow across the Western U.S., with a shortwave trough approaching the Oregon/Washington coasts late in the period. This will support some dry/windy conditions across portions of southern Nevada and western Utah, with relative humidity dropping to 10-15% with winds reaching 20-25 MPH. However, these conditions will largely occur over fuels that have received recent wetting rainfall or are only modestly dry, precluding highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1906 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NEW HAMPSHIRE...VERMONT...INTO MASSACHUSETTS...EASTERN NEW YORK STATE...CONNECTICUT AND RHODE ISLAND
Mesoscale Discussion 1906 NWS Storm Prediction Center Norman OK 1057 AM CDT Thu Aug 15 2024 Areas affected...New Hampshire...Vermont...into Massachusetts...eastern New York State...Connecticut and Rhode island Concerning...Severe potential...Watch unlikely Valid 151557Z - 151830Z Probability of Watch Issuance...5 percent SUMMARY...Increasing thunderstorm development appears probable through 3-5 PM EDT, with widely scattered stronger storms accompanied by a risk for localized, potentially damaging, downbursts and perhaps some small hail. DISCUSSION...Boundary-layer destabilization is underway across much of western New England into the Adirondacks and Catskills, with continuing insolation beneath the western flank of a modest mid-level cold pool associated with a slowly moving mid/upper trough near the Atlantic Seaboard. Forcing for ascent, associated with one or two perturbations pivoting through this regime, has been supporting some thunderstorm activity spreading southward within generally light (10-20 kt) northerly deep-layer mean flow across western Maine, with consolidating surface outflow slowly beginning to spread southwestward into western New England. With further boundary-layer destabilization, which may include CAPE increasing up to 1500+ J/kg, and weakening of mid-level inhibition, model output suggests that the outflow boundary, and orographic forcing along the higher terrain to the west, will provide a focus for increasing thunderstorm development through 19-21Z. Despite the weak nature of the wind fields and shear, modestly steep lower/mid-tropospheric lapse rates evident in forecast soundings may allow for sufficient negative buoyancy in downdrafts to support localized damaging surface gusts in stronger storms. Some small to marginally severe hail might also not be out of the question. ..Kerr/Thompson.. 08/15/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...BTV...ALY... LAT...LON 45807107 44967115 44277135 43307060 42117106 41917201 42197395 43337459 44067379 44887299 45287238 45807107 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTH KS AND NORTH OK... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the central and eastern states on Friday, with localized damaging winds as the primary hazard. A relatively greater concentration of large hail and severe gusts may occur across parts of south Kansas into north Oklahoma on Friday afternoon into the evening. ...Western KS to the Ozarks... At least isolated elevated thunderstorms should be ongoing at 12Z Friday over a part of the central High Plains. This activity may persist and intensify during the day as increasingly pronounced differential heating occurs along an east-southeast oriented baroclinic zone across central/south KS to the Ozarks. Hot temperatures will exist to the south in north OK and the TX Panhandle where full insolation occurs. With moderate to strong effective bulk shear within a west-northwesterly mid to upper flow regime, potential will exist for a few supercells from both elevated convection early to surface-based storms during the afternoon to early evening. With the lack of an appreciable mid/upper-level shortwave impulse and relatively modest low-level warm theta-e advection initially, confidence is below average in terms of diurnal convective evolution as well as the spatial placement for the mesoscale corridor of greater threat. Environmentally though, the setup will favor potential for isolated to scattered large hail to around tennis-ball size and severe gusts to 70 mph. The more robust storms should peak around late afternoon to early evening. ...Great Lakes into the OH/TN Valleys and Mid-South... A mid/upper-level trough will move slowly east across parts of the Upper Midwest/Great Lakes regions. A belt of enhanced mid-level flow (around 40-50 kts at 500 mb) should be present on Friday afternoon across the Lower MO to the OH Valleys. An attendant surface cyclone over WI should drift into Lower MI with a weak cold front extending southwestward across the Mid-MS Valley. Decaying but still extensive convection should be ongoing at 12Z Friday morning across parts of the Mid-South/Lower OH Valley, with more isolated storms possible north into Lower MI. The southern portion of this morning activity may diurnally intensify as the remnant cold pool/outflow shifts southeast into the TN Valley. With decreasing shear to the south and poor mid-level lapse rates, the primary threat should be from sporadic strong gusts producing localized tree damage. Scattered to broken coverage of afternoon thunderstorms is most likely across parts of the southern Great Lakes vicinity from south WI to north OH. Occasional strong to localized severe gusts will be the main threat, especially as multicell clustering occurs later in the afternoon. The threat across the Lower Great Lakes/Upper OH Valley should diminish with eastern extent as convection spreads away from the buoyancy plume. Marginally severe hail will be possible with convection closer to the shortwave trough amid slightly cooler mid-level temperatures. Overall convective potential across the Lower OH/Mid-MS Valleys may be diurnally subdued in the wake of overnight/early morning convection and stronger forcing for ascent remaining to the north. Conditionally, the environment would favor organized storms within the enhanced mid-level jet. ...Northern/central High Plains... Despite low-amplitude, mid-level ridging, an enhanced belt of westerlies could favor transient supercell structures with isolated high-based thunderstorms that develop during the late afternoon. Steepened low to mid-level lapse rates will favor a threat for localized large hail and severe gusts. ..Grams.. 08/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Thu Aug 15 2024 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS AFTERNOON INTO EARLY TONIGHT FROM CENTRAL OK TO THE MID MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Mid MS Valley this afternoon/evening... The remnants of overnight convection, and an associated/lead shortwave trough, are moving across southern MO/IL. Though these storms will likely weaken through midday, a diffuse outflow/differential heating zone may help focus additional thunderstorm development this afternoon. Southern MO to southern IL will be along the southern fringe of the stronger midlevel flow, where a mix of multicell clusters and possibly a supercell or two capable of producing damaging winds (60-70 mph) and isolated large hail (1-1.5 inches in diameter) will be possible later this afternoon/evening. The primary midlevel shortwave trough will progress eastward from NE/SD toward the upper MS Valley by tonight, in conjunction with a surface cold front. Weak, ongoing convection across north central and northeast NE reflects the zone of ascent spreading east-southeastward through the afternoon, toward the destabilizing warm sector in the wake of overnight convection across northern MO/southern IA. Though timing is still a bit uncertain, thunderstorm development appears probable late this afternoon or this evening across eastern NE and especially near the MO/IA border. Relatively long/straight hodographs, midlevel lapse rates near 7.5 C/km and MLCAPE in excess of 2000 J/kg will support supercells capable of producing large hail (1-2 inches in diameter) and damaging gusts (60-75 mph). Some upscale growth into a cluster may also occur as the storms spread east-southeastward toward IL tonight. ...OK this afternoon/evening... Strong surface heating is ongoing across central OK along a weak pre-frontal trough. Mid-upper flow will be weak this far southwest, but deep mixing with surface heating will contribute to steep low-level lapse rates and MLCAPE of 1500 J/kg or greater with minimal convective inhibition. Scattered thunderstorms are expected along this trough by mid-late afternoon, when isolated damaging downburst winds (60-75 mph) will be possible. ...New England this afternoon... To the west of a closed low over Nova Scotia, an embedded shortwave trough is rotating southward over New England with ongoing convection in southwest ME and NH. Surface heating/destabilization on the western/southern fringes of the ongoing storms will likely contribute to additional thunderstorm development this afternoon. Moderate buoyancy and steepening low-level lapse rates, as well as cool midlevel temperatures (-14 to -15 C at 500 mb), will support the potential for isolated wind damage with 45-60 mph gusts and isolated hail approaching 1 inch in diameter with multicell clusters. See MD #1557 for additional information. ...Northern Rockies this afternoon/evening... A midlevel trough will eject east-northeastward over ID/southwest MT/extreme northwest WY through this evening. Steep lapse rates and modest PW (near or less than 0.75 inches) will support high-based thunderstorm development this afternoon in the zone of ascent preceding the midlevel trough. Strong outflow gusts (50-60 mph) will be the main concern. ..Thompson/Weinman.. 08/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Thu Aug 15 2024 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS AFTERNOON INTO EARLY TONIGHT FROM CENTRAL OK TO THE MID MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Mid MS Valley this afternoon/evening... The remnants of overnight convection, and an associated/lead shortwave trough, are moving across southern MO/IL. Though these storms will likely weaken through midday, a diffuse outflow/differential heating zone may help focus additional thunderstorm development this afternoon. Southern MO to southern IL will be along the southern fringe of the stronger midlevel flow, where a mix of multicell clusters and possibly a supercell or two capable of producing damaging winds (60-70 mph) and isolated large hail (1-1.5 inches in diameter) will be possible later this afternoon/evening. The primary midlevel shortwave trough will progress eastward from NE/SD toward the upper MS Valley by tonight, in conjunction with a surface cold front. Weak, ongoing convection across north central and northeast NE reflects the zone of ascent spreading east-southeastward through the afternoon, toward the destabilizing warm sector in the wake of overnight convection across northern MO/southern IA. Though timing is still a bit uncertain, thunderstorm development appears probable late this afternoon or this evening across eastern NE and especially near the MO/IA border. Relatively long/straight hodographs, midlevel lapse rates near 7.5 C/km and MLCAPE in excess of 2000 J/kg will support supercells capable of producing large hail (1-2 inches in diameter) and damaging gusts (60-75 mph). Some upscale growth into a cluster may also occur as the storms spread east-southeastward toward IL tonight. ...OK this afternoon/evening... Strong surface heating is ongoing across central OK along a weak pre-frontal trough. Mid-upper flow will be weak this far southwest, but deep mixing with surface heating will contribute to steep low-level lapse rates and MLCAPE of 1500 J/kg or greater with minimal convective inhibition. Scattered thunderstorms are expected along this trough by mid-late afternoon, when isolated damaging downburst winds (60-75 mph) will be possible. ...New England this afternoon... To the west of a closed low over Nova Scotia, an embedded shortwave trough is rotating southward over New England with ongoing convection in southwest ME and NH. Surface heating/destabilization on the western/southern fringes of the ongoing storms will likely contribute to additional thunderstorm development this afternoon. Moderate buoyancy and steepening low-level lapse rates, as well as cool midlevel temperatures (-14 to -15 C at 500 mb), will support the potential for isolated wind damage with 45-60 mph gusts and isolated hail approaching 1 inch in diameter with multicell clusters. See MD #1557 for additional information. ...Northern Rockies this afternoon/evening... A midlevel trough will eject east-northeastward over ID/southwest MT/extreme northwest WY through this evening. Steep lapse rates and modest PW (near or less than 0.75 inches) will support high-based thunderstorm development this afternoon in the zone of ascent preceding the midlevel trough. Strong outflow gusts (50-60 mph) will be the main concern. ..Thompson/Weinman.. 08/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Thu Aug 15 2024 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS AFTERNOON INTO EARLY TONIGHT FROM CENTRAL OK TO THE MID MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Mid MS Valley this afternoon/evening... The remnants of overnight convection, and an associated/lead shortwave trough, are moving across southern MO/IL. Though these storms will likely weaken through midday, a diffuse outflow/differential heating zone may help focus additional thunderstorm development this afternoon. Southern MO to southern IL will be along the southern fringe of the stronger midlevel flow, where a mix of multicell clusters and possibly a supercell or two capable of producing damaging winds (60-70 mph) and isolated large hail (1-1.5 inches in diameter) will be possible later this afternoon/evening. The primary midlevel shortwave trough will progress eastward from NE/SD toward the upper MS Valley by tonight, in conjunction with a surface cold front. Weak, ongoing convection across north central and northeast NE reflects the zone of ascent spreading east-southeastward through the afternoon, toward the destabilizing warm sector in the wake of overnight convection across northern MO/southern IA. Though timing is still a bit uncertain, thunderstorm development appears probable late this afternoon or this evening across eastern NE and especially near the MO/IA border. Relatively long/straight hodographs, midlevel lapse rates near 7.5 C/km and MLCAPE in excess of 2000 J/kg will support supercells capable of producing large hail (1-2 inches in diameter) and damaging gusts (60-75 mph). Some upscale growth into a cluster may also occur as the storms spread east-southeastward toward IL tonight. ...OK this afternoon/evening... Strong surface heating is ongoing across central OK along a weak pre-frontal trough. Mid-upper flow will be weak this far southwest, but deep mixing with surface heating will contribute to steep low-level lapse rates and MLCAPE of 1500 J/kg or greater with minimal convective inhibition. Scattered thunderstorms are expected along this trough by mid-late afternoon, when isolated damaging downburst winds (60-75 mph) will be possible. ...New England this afternoon... To the west of a closed low over Nova Scotia, an embedded shortwave trough is rotating southward over New England with ongoing convection in southwest ME and NH. Surface heating/destabilization on the western/southern fringes of the ongoing storms will likely contribute to additional thunderstorm development this afternoon. Moderate buoyancy and steepening low-level lapse rates, as well as cool midlevel temperatures (-14 to -15 C at 500 mb), will support the potential for isolated wind damage with 45-60 mph gusts and isolated hail approaching 1 inch in diameter with multicell clusters. See MD #1557 for additional information. ...Northern Rockies this afternoon/evening... A midlevel trough will eject east-northeastward over ID/southwest MT/extreme northwest WY through this evening. Steep lapse rates and modest PW (near or less than 0.75 inches) will support high-based thunderstorm development this afternoon in the zone of ascent preceding the midlevel trough. Strong outflow gusts (50-60 mph) will be the main concern. ..Thompson/Weinman.. 08/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Thu Aug 15 2024 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS AFTERNOON INTO EARLY TONIGHT FROM CENTRAL OK TO THE MID MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Mid MS Valley this afternoon/evening... The remnants of overnight convection, and an associated/lead shortwave trough, are moving across southern MO/IL. Though these storms will likely weaken through midday, a diffuse outflow/differential heating zone may help focus additional thunderstorm development this afternoon. Southern MO to southern IL will be along the southern fringe of the stronger midlevel flow, where a mix of multicell clusters and possibly a supercell or two capable of producing damaging winds (60-70 mph) and isolated large hail (1-1.5 inches in diameter) will be possible later this afternoon/evening. The primary midlevel shortwave trough will progress eastward from NE/SD toward the upper MS Valley by tonight, in conjunction with a surface cold front. Weak, ongoing convection across north central and northeast NE reflects the zone of ascent spreading east-southeastward through the afternoon, toward the destabilizing warm sector in the wake of overnight convection across northern MO/southern IA. Though timing is still a bit uncertain, thunderstorm development appears probable late this afternoon or this evening across eastern NE and especially near the MO/IA border. Relatively long/straight hodographs, midlevel lapse rates near 7.5 C/km and MLCAPE in excess of 2000 J/kg will support supercells capable of producing large hail (1-2 inches in diameter) and damaging gusts (60-75 mph). Some upscale growth into a cluster may also occur as the storms spread east-southeastward toward IL tonight. ...OK this afternoon/evening... Strong surface heating is ongoing across central OK along a weak pre-frontal trough. Mid-upper flow will be weak this far southwest, but deep mixing with surface heating will contribute to steep low-level lapse rates and MLCAPE of 1500 J/kg or greater with minimal convective inhibition. Scattered thunderstorms are expected along this trough by mid-late afternoon, when isolated damaging downburst winds (60-75 mph) will be possible. ...New England this afternoon... To the west of a closed low over Nova Scotia, an embedded shortwave trough is rotating southward over New England with ongoing convection in southwest ME and NH. Surface heating/destabilization on the western/southern fringes of the ongoing storms will likely contribute to additional thunderstorm development this afternoon. Moderate buoyancy and steepening low-level lapse rates, as well as cool midlevel temperatures (-14 to -15 C at 500 mb), will support the potential for isolated wind damage with 45-60 mph gusts and isolated hail approaching 1 inch in diameter with multicell clusters. See MD #1557 for additional information. ...Northern Rockies this afternoon/evening... A midlevel trough will eject east-northeastward over ID/southwest MT/extreme northwest WY through this evening. Steep lapse rates and modest PW (near or less than 0.75 inches) will support high-based thunderstorm development this afternoon in the zone of ascent preceding the midlevel trough. Strong outflow gusts (50-60 mph) will be the main concern. ..Thompson/Weinman.. 08/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Thu Aug 15 2024 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS AFTERNOON INTO EARLY TONIGHT FROM CENTRAL OK TO THE MID MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Mid MS Valley this afternoon/evening... The remnants of overnight convection, and an associated/lead shortwave trough, are moving across southern MO/IL. Though these storms will likely weaken through midday, a diffuse outflow/differential heating zone may help focus additional thunderstorm development this afternoon. Southern MO to southern IL will be along the southern fringe of the stronger midlevel flow, where a mix of multicell clusters and possibly a supercell or two capable of producing damaging winds (60-70 mph) and isolated large hail (1-1.5 inches in diameter) will be possible later this afternoon/evening. The primary midlevel shortwave trough will progress eastward from NE/SD toward the upper MS Valley by tonight, in conjunction with a surface cold front. Weak, ongoing convection across north central and northeast NE reflects the zone of ascent spreading east-southeastward through the afternoon, toward the destabilizing warm sector in the wake of overnight convection across northern MO/southern IA. Though timing is still a bit uncertain, thunderstorm development appears probable late this afternoon or this evening across eastern NE and especially near the MO/IA border. Relatively long/straight hodographs, midlevel lapse rates near 7.5 C/km and MLCAPE in excess of 2000 J/kg will support supercells capable of producing large hail (1-2 inches in diameter) and damaging gusts (60-75 mph). Some upscale growth into a cluster may also occur as the storms spread east-southeastward toward IL tonight. ...OK this afternoon/evening... Strong surface heating is ongoing across central OK along a weak pre-frontal trough. Mid-upper flow will be weak this far southwest, but deep mixing with surface heating will contribute to steep low-level lapse rates and MLCAPE of 1500 J/kg or greater with minimal convective inhibition. Scattered thunderstorms are expected along this trough by mid-late afternoon, when isolated damaging downburst winds (60-75 mph) will be possible. ...New England this afternoon... To the west of a closed low over Nova Scotia, an embedded shortwave trough is rotating southward over New England with ongoing convection in southwest ME and NH. Surface heating/destabilization on the western/southern fringes of the ongoing storms will likely contribute to additional thunderstorm development this afternoon. Moderate buoyancy and steepening low-level lapse rates, as well as cool midlevel temperatures (-14 to -15 C at 500 mb), will support the potential for isolated wind damage with 45-60 mph gusts and isolated hail approaching 1 inch in diameter with multicell clusters. See MD #1557 for additional information. ...Northern Rockies this afternoon/evening... A midlevel trough will eject east-northeastward over ID/southwest MT/extreme northwest WY through this evening. Steep lapse rates and modest PW (near or less than 0.75 inches) will support high-based thunderstorm development this afternoon in the zone of ascent preceding the midlevel trough. Strong outflow gusts (50-60 mph) will be the main concern. ..Thompson/Weinman.. 08/15/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Thu Aug 15 2024 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS AFTERNOON INTO EARLY TONIGHT FROM CENTRAL OK TO THE MID MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Mid MS Valley this afternoon/evening... The remnants of overnight convection, and an associated/lead shortwave trough, are moving across southern MO/IL. Though these storms will likely weaken through midday, a diffuse outflow/differential heating zone may help focus additional thunderstorm development this afternoon. Southern MO to southern IL will be along the southern fringe of the stronger midlevel flow, where a mix of multicell clusters and possibly a supercell or two capable of producing damaging winds (60-70 mph) and isolated large hail (1-1.5 inches in diameter) will be possible later this afternoon/evening. The primary midlevel shortwave trough will progress eastward from NE/SD toward the upper MS Valley by tonight, in conjunction with a surface cold front. Weak, ongoing convection across north central and northeast NE reflects the zone of ascent spreading east-southeastward through the afternoon, toward the destabilizing warm sector in the wake of overnight convection across northern MO/southern IA. Though timing is still a bit uncertain, thunderstorm development appears probable late this afternoon or this evening across eastern NE and especially near the MO/IA border. Relatively long/straight hodographs, midlevel lapse rates near 7.5 C/km and MLCAPE in excess of 2000 J/kg will support supercells capable of producing large hail (1-2 inches in diameter) and damaging gusts (60-75 mph). Some upscale growth into a cluster may also occur as the storms spread east-southeastward toward IL tonight. ...OK this afternoon/evening... Strong surface heating is ongoing across central OK along a weak pre-frontal trough. Mid-upper flow will be weak this far southwest, but deep mixing with surface heating will contribute to steep low-level lapse rates and MLCAPE of 1500 J/kg or greater with minimal convective inhibition. Scattered thunderstorms are expected along this trough by mid-late afternoon, when isolated damaging downburst winds (60-75 mph) will be possible. ...New England this afternoon... To the west of a closed low over Nova Scotia, an embedded shortwave trough is rotating southward over New England with ongoing convection in southwest ME and NH. Surface heating/destabilization on the western/southern fringes of the ongoing storms will likely contribute to additional thunderstorm development this afternoon. Moderate buoyancy and steepening low-level lapse rates, as well as cool midlevel temperatures (-14 to -15 C at 500 mb), will support the potential for isolated wind damage with 45-60 mph gusts and isolated hail approaching 1 inch in diameter with multicell clusters. See MD #1557 for additional information. ...Northern Rockies this afternoon/evening... A midlevel trough will eject east-northeastward over ID/southwest MT/extreme northwest WY through this evening. Steep lapse rates and modest PW (near or less than 0.75 inches) will support high-based thunderstorm development this afternoon in the zone of ascent preceding the midlevel trough. Strong outflow gusts (50-60 mph) will be the main concern. ..Thompson/Weinman.. 08/15/2024 Read more