Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHEASTERN OREGON... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHWESTERN NEVADA... ...Synopsis... A mid-level trough will impinge on the West Coast as upper ridging amplifies over the Rockies into the Plains today. Surface cyclone development is likely to the lee of the Cascades by afternoon, promoting ample buoyancy, lift, and shear for thunderstorms, some of which may be strong. Otherwise, strong downslope and isallobaric flow across the western Great Basin ahead of the upper trough/surface low will promote widespread dry and breezy conditions capable of supporting wildfire spread. ...Along and to the lee of the Cascades - Thunderstorms... By late afternoon, multiple strong thunderstorms should develop amid strong flow aloft. Some of the storms may be high-based, with a couple of dry strikes possible. Of greater concern is the potential for erratic and strong to possibly severe gusts, which may exacerbate ongoing fire concerns, as well as with ignitions from strikes accompanying the storms. Given receptive fuels, isolated dry thunderstorm highlights have been maintained. ...Harney Basin and western Great Basin - Dry/Windy Conditions... By afternoon peak heating, RH is expected to drop into the 15-20 percent range as the boundary layer mixes. When also considering the contribution of isallobaric flow, winds may sustain above 20 mph, particularly over portions of the Harney Basin and in southwestern Nevada, where Critical highlights have been maintained. Otherwise, Elevated highlights remain over a broader area where dry and breezy conditions are expected to overlap with dry fuel beds. ..Squitieri.. 08/17/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHEASTERN OREGON... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHWESTERN NEVADA... ...Synopsis... A mid-level trough will impinge on the West Coast as upper ridging amplifies over the Rockies into the Plains today. Surface cyclone development is likely to the lee of the Cascades by afternoon, promoting ample buoyancy, lift, and shear for thunderstorms, some of which may be strong. Otherwise, strong downslope and isallobaric flow across the western Great Basin ahead of the upper trough/surface low will promote widespread dry and breezy conditions capable of supporting wildfire spread. ...Along and to the lee of the Cascades - Thunderstorms... By late afternoon, multiple strong thunderstorms should develop amid strong flow aloft. Some of the storms may be high-based, with a couple of dry strikes possible. Of greater concern is the potential for erratic and strong to possibly severe gusts, which may exacerbate ongoing fire concerns, as well as with ignitions from strikes accompanying the storms. Given receptive fuels, isolated dry thunderstorm highlights have been maintained. ...Harney Basin and western Great Basin - Dry/Windy Conditions... By afternoon peak heating, RH is expected to drop into the 15-20 percent range as the boundary layer mixes. When also considering the contribution of isallobaric flow, winds may sustain above 20 mph, particularly over portions of the Harney Basin and in southwestern Nevada, where Critical highlights have been maintained. Otherwise, Elevated highlights remain over a broader area where dry and breezy conditions are expected to overlap with dry fuel beds. ..Squitieri.. 08/17/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHEASTERN OREGON... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHWESTERN NEVADA... ...Synopsis... A mid-level trough will impinge on the West Coast as upper ridging amplifies over the Rockies into the Plains today. Surface cyclone development is likely to the lee of the Cascades by afternoon, promoting ample buoyancy, lift, and shear for thunderstorms, some of which may be strong. Otherwise, strong downslope and isallobaric flow across the western Great Basin ahead of the upper trough/surface low will promote widespread dry and breezy conditions capable of supporting wildfire spread. ...Along and to the lee of the Cascades - Thunderstorms... By late afternoon, multiple strong thunderstorms should develop amid strong flow aloft. Some of the storms may be high-based, with a couple of dry strikes possible. Of greater concern is the potential for erratic and strong to possibly severe gusts, which may exacerbate ongoing fire concerns, as well as with ignitions from strikes accompanying the storms. Given receptive fuels, isolated dry thunderstorm highlights have been maintained. ...Harney Basin and western Great Basin - Dry/Windy Conditions... By afternoon peak heating, RH is expected to drop into the 15-20 percent range as the boundary layer mixes. When also considering the contribution of isallobaric flow, winds may sustain above 20 mph, particularly over portions of the Harney Basin and in southwestern Nevada, where Critical highlights have been maintained. Otherwise, Elevated highlights remain over a broader area where dry and breezy conditions are expected to overlap with dry fuel beds. ..Squitieri.. 08/17/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHEASTERN OREGON... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHWESTERN NEVADA... ...Synopsis... A mid-level trough will impinge on the West Coast as upper ridging amplifies over the Rockies into the Plains today. Surface cyclone development is likely to the lee of the Cascades by afternoon, promoting ample buoyancy, lift, and shear for thunderstorms, some of which may be strong. Otherwise, strong downslope and isallobaric flow across the western Great Basin ahead of the upper trough/surface low will promote widespread dry and breezy conditions capable of supporting wildfire spread. ...Along and to the lee of the Cascades - Thunderstorms... By late afternoon, multiple strong thunderstorms should develop amid strong flow aloft. Some of the storms may be high-based, with a couple of dry strikes possible. Of greater concern is the potential for erratic and strong to possibly severe gusts, which may exacerbate ongoing fire concerns, as well as with ignitions from strikes accompanying the storms. Given receptive fuels, isolated dry thunderstorm highlights have been maintained. ...Harney Basin and western Great Basin - Dry/Windy Conditions... By afternoon peak heating, RH is expected to drop into the 15-20 percent range as the boundary layer mixes. When also considering the contribution of isallobaric flow, winds may sustain above 20 mph, particularly over portions of the Harney Basin and in southwestern Nevada, where Critical highlights have been maintained. Otherwise, Elevated highlights remain over a broader area where dry and breezy conditions are expected to overlap with dry fuel beds. ..Squitieri.. 08/17/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Aug 17 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS AND SOUTHEAST... ...SUMMARY... Scattered strong thunderstorms, associated with a severe threat, will be possible on Sunday from the Mid-Atlantic and Carolinas westward into the Southeast, and in parts of the central and northern Plains. ...Mid-Atlantic/Carolinas/Southeast An upper-level trough will move across the Ohio Valley and southern Appalachians on Sunday. At the surface, an associated cold front will approach the Mid Atlantic Seaboard, and move into the Southeast. Ahead of the front, surface dewpoints in the lower to mid 70s F, will contribute to the development of moderate instability by midday. As surface temperatures warm, thunderstorms are expected to form in the higher terrain of the southern and central Appalachians. Additional storms appear likely to develop further to the east near the front and across the moist sector ahead of the front. Current model forecasts suggest that a pocket of moderate instability, with MLCAPE potentially above 2000 J/kg, may develop in parts of the Carolinas. Forecast soundings across eastern North Carolina around 21Z show some directional shear below 850 mb, with speed shear in the mid-levels, resulting in 0-6 km shear in the 25 to 35 knot range. In addition, lapse rates are forecast to become steep, with 0-3 km lapse rates peaking near 8 C/km in the mid afternoon. This should be favorable for an isolated severe threat. The wind profile will favor multicells with isolated wind-damage potential. ...Ozarks/Lower Mississippi Valley... Northwest mid-level flow will be in place on Sunday across the lower to mid Mississippi and Tennessee Valleys. A front is forecast to move southward across the Lower Mississippi Valley and central Gulf Coast States. To the south of the front, surface dewpoints in the lower to mid 70s F will contribute to the development of moderate to strong instability. As low-level convergence increases along and ahead of the front, thunderstorms are expected to form in the early to mid afternoon. Storms will likely expand in coverage, moving southeastward across the Lower Mississippi Valley during the late afternoon. Forecast soundings at 21Z from southern Arkansas southeastward into central Mississippi have MLCAPE reaching the 2500 to 3500 J/kg range, and show 0-6 km shear in the 30 to 35 knot range. 0-3 km lapse-rates are forecast to peak near 8 C/km during the afternoon. This will be favorable for an isolated severe threat, with isolated supercells possible. However, multicell may be the prevalent storm mode. Rotating storms will have potential for isolated large hail. Severe wind gusts will be possible with any cell that can become organized. ...Central and Northern High Plains... An upper-level ridge will be in place on Sunday from the central Rockies into the northern High Plains. An axis of instability is forecast to develop to the east of the ridge from western Kansas north-northwestward into eastern Montana. Although large-scale ascent will be weak, isolated thunderstorms may form as temperatures warm during the day. Model forecasts Sunday afternoon along and near the instability axis have surface dewpoints around 60 F, steep low to mid-level lapse rates, and relatively large surface-dewpoint temperature spreads. This would be favorable for strong outflow gusts with isolated high-based storms in areas with sufficient instability. Hail will also be possible, mainly within rotating cells that come out of higher terrain, where the steepest mid-level lapse rates are forecast. ..Broyles.. 08/17/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Aug 17 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS AND SOUTHEAST... ...SUMMARY... Scattered strong thunderstorms, associated with a severe threat, will be possible on Sunday from the Mid-Atlantic and Carolinas westward into the Southeast, and in parts of the central and northern Plains. ...Mid-Atlantic/Carolinas/Southeast An upper-level trough will move across the Ohio Valley and southern Appalachians on Sunday. At the surface, an associated cold front will approach the Mid Atlantic Seaboard, and move into the Southeast. Ahead of the front, surface dewpoints in the lower to mid 70s F, will contribute to the development of moderate instability by midday. As surface temperatures warm, thunderstorms are expected to form in the higher terrain of the southern and central Appalachians. Additional storms appear likely to develop further to the east near the front and across the moist sector ahead of the front. Current model forecasts suggest that a pocket of moderate instability, with MLCAPE potentially above 2000 J/kg, may develop in parts of the Carolinas. Forecast soundings across eastern North Carolina around 21Z show some directional shear below 850 mb, with speed shear in the mid-levels, resulting in 0-6 km shear in the 25 to 35 knot range. In addition, lapse rates are forecast to become steep, with 0-3 km lapse rates peaking near 8 C/km in the mid afternoon. This should be favorable for an isolated severe threat. The wind profile will favor multicells with isolated wind-damage potential. ...Ozarks/Lower Mississippi Valley... Northwest mid-level flow will be in place on Sunday across the lower to mid Mississippi and Tennessee Valleys. A front is forecast to move southward across the Lower Mississippi Valley and central Gulf Coast States. To the south of the front, surface dewpoints in the lower to mid 70s F will contribute to the development of moderate to strong instability. As low-level convergence increases along and ahead of the front, thunderstorms are expected to form in the early to mid afternoon. Storms will likely expand in coverage, moving southeastward across the Lower Mississippi Valley during the late afternoon. Forecast soundings at 21Z from southern Arkansas southeastward into central Mississippi have MLCAPE reaching the 2500 to 3500 J/kg range, and show 0-6 km shear in the 30 to 35 knot range. 0-3 km lapse-rates are forecast to peak near 8 C/km during the afternoon. This will be favorable for an isolated severe threat, with isolated supercells possible. However, multicell may be the prevalent storm mode. Rotating storms will have potential for isolated large hail. Severe wind gusts will be possible with any cell that can become organized. ...Central and Northern High Plains... An upper-level ridge will be in place on Sunday from the central Rockies into the northern High Plains. An axis of instability is forecast to develop to the east of the ridge from western Kansas north-northwestward into eastern Montana. Although large-scale ascent will be weak, isolated thunderstorms may form as temperatures warm during the day. Model forecasts Sunday afternoon along and near the instability axis have surface dewpoints around 60 F, steep low to mid-level lapse rates, and relatively large surface-dewpoint temperature spreads. This would be favorable for strong outflow gusts with isolated high-based storms in areas with sufficient instability. Hail will also be possible, mainly within rotating cells that come out of higher terrain, where the steepest mid-level lapse rates are forecast. ..Broyles.. 08/17/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Aug 17 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS AND SOUTHEAST... ...SUMMARY... Scattered strong thunderstorms, associated with a severe threat, will be possible on Sunday from the Mid-Atlantic and Carolinas westward into the Southeast, and in parts of the central and northern Plains. ...Mid-Atlantic/Carolinas/Southeast An upper-level trough will move across the Ohio Valley and southern Appalachians on Sunday. At the surface, an associated cold front will approach the Mid Atlantic Seaboard, and move into the Southeast. Ahead of the front, surface dewpoints in the lower to mid 70s F, will contribute to the development of moderate instability by midday. As surface temperatures warm, thunderstorms are expected to form in the higher terrain of the southern and central Appalachians. Additional storms appear likely to develop further to the east near the front and across the moist sector ahead of the front. Current model forecasts suggest that a pocket of moderate instability, with MLCAPE potentially above 2000 J/kg, may develop in parts of the Carolinas. Forecast soundings across eastern North Carolina around 21Z show some directional shear below 850 mb, with speed shear in the mid-levels, resulting in 0-6 km shear in the 25 to 35 knot range. In addition, lapse rates are forecast to become steep, with 0-3 km lapse rates peaking near 8 C/km in the mid afternoon. This should be favorable for an isolated severe threat. The wind profile will favor multicells with isolated wind-damage potential. ...Ozarks/Lower Mississippi Valley... Northwest mid-level flow will be in place on Sunday across the lower to mid Mississippi and Tennessee Valleys. A front is forecast to move southward across the Lower Mississippi Valley and central Gulf Coast States. To the south of the front, surface dewpoints in the lower to mid 70s F will contribute to the development of moderate to strong instability. As low-level convergence increases along and ahead of the front, thunderstorms are expected to form in the early to mid afternoon. Storms will likely expand in coverage, moving southeastward across the Lower Mississippi Valley during the late afternoon. Forecast soundings at 21Z from southern Arkansas southeastward into central Mississippi have MLCAPE reaching the 2500 to 3500 J/kg range, and show 0-6 km shear in the 30 to 35 knot range. 0-3 km lapse-rates are forecast to peak near 8 C/km during the afternoon. This will be favorable for an isolated severe threat, with isolated supercells possible. However, multicell may be the prevalent storm mode. Rotating storms will have potential for isolated large hail. Severe wind gusts will be possible with any cell that can become organized. ...Central and Northern High Plains... An upper-level ridge will be in place on Sunday from the central Rockies into the northern High Plains. An axis of instability is forecast to develop to the east of the ridge from western Kansas north-northwestward into eastern Montana. Although large-scale ascent will be weak, isolated thunderstorms may form as temperatures warm during the day. Model forecasts Sunday afternoon along and near the instability axis have surface dewpoints around 60 F, steep low to mid-level lapse rates, and relatively large surface-dewpoint temperature spreads. This would be favorable for strong outflow gusts with isolated high-based storms in areas with sufficient instability. Hail will also be possible, mainly within rotating cells that come out of higher terrain, where the steepest mid-level lapse rates are forecast. ..Broyles.. 08/17/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Aug 17 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS AND SOUTHEAST... ...SUMMARY... Scattered strong thunderstorms, associated with a severe threat, will be possible on Sunday from the Mid-Atlantic and Carolinas westward into the Southeast, and in parts of the central and northern Plains. ...Mid-Atlantic/Carolinas/Southeast An upper-level trough will move across the Ohio Valley and southern Appalachians on Sunday. At the surface, an associated cold front will approach the Mid Atlantic Seaboard, and move into the Southeast. Ahead of the front, surface dewpoints in the lower to mid 70s F, will contribute to the development of moderate instability by midday. As surface temperatures warm, thunderstorms are expected to form in the higher terrain of the southern and central Appalachians. Additional storms appear likely to develop further to the east near the front and across the moist sector ahead of the front. Current model forecasts suggest that a pocket of moderate instability, with MLCAPE potentially above 2000 J/kg, may develop in parts of the Carolinas. Forecast soundings across eastern North Carolina around 21Z show some directional shear below 850 mb, with speed shear in the mid-levels, resulting in 0-6 km shear in the 25 to 35 knot range. In addition, lapse rates are forecast to become steep, with 0-3 km lapse rates peaking near 8 C/km in the mid afternoon. This should be favorable for an isolated severe threat. The wind profile will favor multicells with isolated wind-damage potential. ...Ozarks/Lower Mississippi Valley... Northwest mid-level flow will be in place on Sunday across the lower to mid Mississippi and Tennessee Valleys. A front is forecast to move southward across the Lower Mississippi Valley and central Gulf Coast States. To the south of the front, surface dewpoints in the lower to mid 70s F will contribute to the development of moderate to strong instability. As low-level convergence increases along and ahead of the front, thunderstorms are expected to form in the early to mid afternoon. Storms will likely expand in coverage, moving southeastward across the Lower Mississippi Valley during the late afternoon. Forecast soundings at 21Z from southern Arkansas southeastward into central Mississippi have MLCAPE reaching the 2500 to 3500 J/kg range, and show 0-6 km shear in the 30 to 35 knot range. 0-3 km lapse-rates are forecast to peak near 8 C/km during the afternoon. This will be favorable for an isolated severe threat, with isolated supercells possible. However, multicell may be the prevalent storm mode. Rotating storms will have potential for isolated large hail. Severe wind gusts will be possible with any cell that can become organized. ...Central and Northern High Plains... An upper-level ridge will be in place on Sunday from the central Rockies into the northern High Plains. An axis of instability is forecast to develop to the east of the ridge from western Kansas north-northwestward into eastern Montana. Although large-scale ascent will be weak, isolated thunderstorms may form as temperatures warm during the day. Model forecasts Sunday afternoon along and near the instability axis have surface dewpoints around 60 F, steep low to mid-level lapse rates, and relatively large surface-dewpoint temperature spreads. This would be favorable for strong outflow gusts with isolated high-based storms in areas with sufficient instability. Hail will also be possible, mainly within rotating cells that come out of higher terrain, where the steepest mid-level lapse rates are forecast. ..Broyles.. 08/17/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Aug 17 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS AND SOUTHEAST... ...SUMMARY... Scattered strong thunderstorms, associated with a severe threat, will be possible on Sunday from the Mid-Atlantic and Carolinas westward into the Southeast, and in parts of the central and northern Plains. ...Mid-Atlantic/Carolinas/Southeast An upper-level trough will move across the Ohio Valley and southern Appalachians on Sunday. At the surface, an associated cold front will approach the Mid Atlantic Seaboard, and move into the Southeast. Ahead of the front, surface dewpoints in the lower to mid 70s F, will contribute to the development of moderate instability by midday. As surface temperatures warm, thunderstorms are expected to form in the higher terrain of the southern and central Appalachians. Additional storms appear likely to develop further to the east near the front and across the moist sector ahead of the front. Current model forecasts suggest that a pocket of moderate instability, with MLCAPE potentially above 2000 J/kg, may develop in parts of the Carolinas. Forecast soundings across eastern North Carolina around 21Z show some directional shear below 850 mb, with speed shear in the mid-levels, resulting in 0-6 km shear in the 25 to 35 knot range. In addition, lapse rates are forecast to become steep, with 0-3 km lapse rates peaking near 8 C/km in the mid afternoon. This should be favorable for an isolated severe threat. The wind profile will favor multicells with isolated wind-damage potential. ...Ozarks/Lower Mississippi Valley... Northwest mid-level flow will be in place on Sunday across the lower to mid Mississippi and Tennessee Valleys. A front is forecast to move southward across the Lower Mississippi Valley and central Gulf Coast States. To the south of the front, surface dewpoints in the lower to mid 70s F will contribute to the development of moderate to strong instability. As low-level convergence increases along and ahead of the front, thunderstorms are expected to form in the early to mid afternoon. Storms will likely expand in coverage, moving southeastward across the Lower Mississippi Valley during the late afternoon. Forecast soundings at 21Z from southern Arkansas southeastward into central Mississippi have MLCAPE reaching the 2500 to 3500 J/kg range, and show 0-6 km shear in the 30 to 35 knot range. 0-3 km lapse-rates are forecast to peak near 8 C/km during the afternoon. This will be favorable for an isolated severe threat, with isolated supercells possible. However, multicell may be the prevalent storm mode. Rotating storms will have potential for isolated large hail. Severe wind gusts will be possible with any cell that can become organized. ...Central and Northern High Plains... An upper-level ridge will be in place on Sunday from the central Rockies into the northern High Plains. An axis of instability is forecast to develop to the east of the ridge from western Kansas north-northwestward into eastern Montana. Although large-scale ascent will be weak, isolated thunderstorms may form as temperatures warm during the day. Model forecasts Sunday afternoon along and near the instability axis have surface dewpoints around 60 F, steep low to mid-level lapse rates, and relatively large surface-dewpoint temperature spreads. This would be favorable for strong outflow gusts with isolated high-based storms in areas with sufficient instability. Hail will also be possible, mainly within rotating cells that come out of higher terrain, where the steepest mid-level lapse rates are forecast. ..Broyles.. 08/17/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Aug 17 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS AND SOUTHEAST... ...SUMMARY... Scattered strong thunderstorms, associated with a severe threat, will be possible on Sunday from the Mid-Atlantic and Carolinas westward into the Southeast, and in parts of the central and northern Plains. ...Mid-Atlantic/Carolinas/Southeast An upper-level trough will move across the Ohio Valley and southern Appalachians on Sunday. At the surface, an associated cold front will approach the Mid Atlantic Seaboard, and move into the Southeast. Ahead of the front, surface dewpoints in the lower to mid 70s F, will contribute to the development of moderate instability by midday. As surface temperatures warm, thunderstorms are expected to form in the higher terrain of the southern and central Appalachians. Additional storms appear likely to develop further to the east near the front and across the moist sector ahead of the front. Current model forecasts suggest that a pocket of moderate instability, with MLCAPE potentially above 2000 J/kg, may develop in parts of the Carolinas. Forecast soundings across eastern North Carolina around 21Z show some directional shear below 850 mb, with speed shear in the mid-levels, resulting in 0-6 km shear in the 25 to 35 knot range. In addition, lapse rates are forecast to become steep, with 0-3 km lapse rates peaking near 8 C/km in the mid afternoon. This should be favorable for an isolated severe threat. The wind profile will favor multicells with isolated wind-damage potential. ...Ozarks/Lower Mississippi Valley... Northwest mid-level flow will be in place on Sunday across the lower to mid Mississippi and Tennessee Valleys. A front is forecast to move southward across the Lower Mississippi Valley and central Gulf Coast States. To the south of the front, surface dewpoints in the lower to mid 70s F will contribute to the development of moderate to strong instability. As low-level convergence increases along and ahead of the front, thunderstorms are expected to form in the early to mid afternoon. Storms will likely expand in coverage, moving southeastward across the Lower Mississippi Valley during the late afternoon. Forecast soundings at 21Z from southern Arkansas southeastward into central Mississippi have MLCAPE reaching the 2500 to 3500 J/kg range, and show 0-6 km shear in the 30 to 35 knot range. 0-3 km lapse-rates are forecast to peak near 8 C/km during the afternoon. This will be favorable for an isolated severe threat, with isolated supercells possible. However, multicell may be the prevalent storm mode. Rotating storms will have potential for isolated large hail. Severe wind gusts will be possible with any cell that can become organized. ...Central and Northern High Plains... An upper-level ridge will be in place on Sunday from the central Rockies into the northern High Plains. An axis of instability is forecast to develop to the east of the ridge from western Kansas north-northwestward into eastern Montana. Although large-scale ascent will be weak, isolated thunderstorms may form as temperatures warm during the day. Model forecasts Sunday afternoon along and near the instability axis have surface dewpoints around 60 F, steep low to mid-level lapse rates, and relatively large surface-dewpoint temperature spreads. This would be favorable for strong outflow gusts with isolated high-based storms in areas with sufficient instability. Hail will also be possible, mainly within rotating cells that come out of higher terrain, where the steepest mid-level lapse rates are forecast. ..Broyles.. 08/17/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Aug 17 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS AND SOUTHEAST... ...SUMMARY... Scattered strong thunderstorms, associated with a severe threat, will be possible on Sunday from the Mid-Atlantic and Carolinas westward into the Southeast, and in parts of the central and northern Plains. ...Mid-Atlantic/Carolinas/Southeast An upper-level trough will move across the Ohio Valley and southern Appalachians on Sunday. At the surface, an associated cold front will approach the Mid Atlantic Seaboard, and move into the Southeast. Ahead of the front, surface dewpoints in the lower to mid 70s F, will contribute to the development of moderate instability by midday. As surface temperatures warm, thunderstorms are expected to form in the higher terrain of the southern and central Appalachians. Additional storms appear likely to develop further to the east near the front and across the moist sector ahead of the front. Current model forecasts suggest that a pocket of moderate instability, with MLCAPE potentially above 2000 J/kg, may develop in parts of the Carolinas. Forecast soundings across eastern North Carolina around 21Z show some directional shear below 850 mb, with speed shear in the mid-levels, resulting in 0-6 km shear in the 25 to 35 knot range. In addition, lapse rates are forecast to become steep, with 0-3 km lapse rates peaking near 8 C/km in the mid afternoon. This should be favorable for an isolated severe threat. The wind profile will favor multicells with isolated wind-damage potential. ...Ozarks/Lower Mississippi Valley... Northwest mid-level flow will be in place on Sunday across the lower to mid Mississippi and Tennessee Valleys. A front is forecast to move southward across the Lower Mississippi Valley and central Gulf Coast States. To the south of the front, surface dewpoints in the lower to mid 70s F will contribute to the development of moderate to strong instability. As low-level convergence increases along and ahead of the front, thunderstorms are expected to form in the early to mid afternoon. Storms will likely expand in coverage, moving southeastward across the Lower Mississippi Valley during the late afternoon. Forecast soundings at 21Z from southern Arkansas southeastward into central Mississippi have MLCAPE reaching the 2500 to 3500 J/kg range, and show 0-6 km shear in the 30 to 35 knot range. 0-3 km lapse-rates are forecast to peak near 8 C/km during the afternoon. This will be favorable for an isolated severe threat, with isolated supercells possible. However, multicell may be the prevalent storm mode. Rotating storms will have potential for isolated large hail. Severe wind gusts will be possible with any cell that can become organized. ...Central and Northern High Plains... An upper-level ridge will be in place on Sunday from the central Rockies into the northern High Plains. An axis of instability is forecast to develop to the east of the ridge from western Kansas north-northwestward into eastern Montana. Although large-scale ascent will be weak, isolated thunderstorms may form as temperatures warm during the day. Model forecasts Sunday afternoon along and near the instability axis have surface dewpoints around 60 F, steep low to mid-level lapse rates, and relatively large surface-dewpoint temperature spreads. This would be favorable for strong outflow gusts with isolated high-based storms in areas with sufficient instability. Hail will also be possible, mainly within rotating cells that come out of higher terrain, where the steepest mid-level lapse rates are forecast. ..Broyles.. 08/17/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Aug 17 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS AND SOUTHEAST... ...SUMMARY... Scattered strong thunderstorms, associated with a severe threat, will be possible on Sunday from the Mid-Atlantic and Carolinas westward into the Southeast, and in parts of the central and northern Plains. ...Mid-Atlantic/Carolinas/Southeast An upper-level trough will move across the Ohio Valley and southern Appalachians on Sunday. At the surface, an associated cold front will approach the Mid Atlantic Seaboard, and move into the Southeast. Ahead of the front, surface dewpoints in the lower to mid 70s F, will contribute to the development of moderate instability by midday. As surface temperatures warm, thunderstorms are expected to form in the higher terrain of the southern and central Appalachians. Additional storms appear likely to develop further to the east near the front and across the moist sector ahead of the front. Current model forecasts suggest that a pocket of moderate instability, with MLCAPE potentially above 2000 J/kg, may develop in parts of the Carolinas. Forecast soundings across eastern North Carolina around 21Z show some directional shear below 850 mb, with speed shear in the mid-levels, resulting in 0-6 km shear in the 25 to 35 knot range. In addition, lapse rates are forecast to become steep, with 0-3 km lapse rates peaking near 8 C/km in the mid afternoon. This should be favorable for an isolated severe threat. The wind profile will favor multicells with isolated wind-damage potential. ...Ozarks/Lower Mississippi Valley... Northwest mid-level flow will be in place on Sunday across the lower to mid Mississippi and Tennessee Valleys. A front is forecast to move southward across the Lower Mississippi Valley and central Gulf Coast States. To the south of the front, surface dewpoints in the lower to mid 70s F will contribute to the development of moderate to strong instability. As low-level convergence increases along and ahead of the front, thunderstorms are expected to form in the early to mid afternoon. Storms will likely expand in coverage, moving southeastward across the Lower Mississippi Valley during the late afternoon. Forecast soundings at 21Z from southern Arkansas southeastward into central Mississippi have MLCAPE reaching the 2500 to 3500 J/kg range, and show 0-6 km shear in the 30 to 35 knot range. 0-3 km lapse-rates are forecast to peak near 8 C/km during the afternoon. This will be favorable for an isolated severe threat, with isolated supercells possible. However, multicell may be the prevalent storm mode. Rotating storms will have potential for isolated large hail. Severe wind gusts will be possible with any cell that can become organized. ...Central and Northern High Plains... An upper-level ridge will be in place on Sunday from the central Rockies into the northern High Plains. An axis of instability is forecast to develop to the east of the ridge from western Kansas north-northwestward into eastern Montana. Although large-scale ascent will be weak, isolated thunderstorms may form as temperatures warm during the day. Model forecasts Sunday afternoon along and near the instability axis have surface dewpoints around 60 F, steep low to mid-level lapse rates, and relatively large surface-dewpoint temperature spreads. This would be favorable for strong outflow gusts with isolated high-based storms in areas with sufficient instability. Hail will also be possible, mainly within rotating cells that come out of higher terrain, where the steepest mid-level lapse rates are forecast. ..Broyles.. 08/17/2024 Read more

MD 1928 CONCERNING SEVERE THUNDERSTORM WATCH 629... FOR PORTIONS OF EXTREME EASTERN OKLAHOMA INTO CENTRAL ARKANSAS
Mesoscale Discussion 1928 NWS Storm Prediction Center Norman OK 1123 PM CDT Fri Aug 16 2024 Areas affected...portions of extreme eastern Oklahoma into central Arkansas Concerning...Severe Thunderstorm Watch 629... Valid 170423Z - 170600Z The severe weather threat for Severe Thunderstorm Watch 629 continues. SUMMARY...The severe threat continues across Severe Thunderstorm Watch 629. Damaging gusts remain the main threat with these storms over the next few hours. DISCUSSION...An MCS has materialized from congealing storms over the last few hours, with strong wind gusts over 50 mph recently reported. Preceding the eastern portion of the MCS is a cooler airmass, characterized by surface temperatures in the upper 70s to low 80s F. However, along the western periphery of the MCS track are warmer surface temperatures between 85-90 F, which also reside beneath the eastern periphery of a modest LLJ and accompanying WAA. As such, the portion of the MCS cold pool propagating into this airmass has the greatest chance for supporting stronger updrafts and corresponding downdrafts, which may penetrate the increasing MLCINH. Here, a few additional strong to severe gusts may occur over the next few hours. ..Squitieri.. 08/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...TSA... LAT...LON 35609511 36009344 36019253 35739224 35359230 35039274 34799328 34689389 34629436 34649475 34829518 35609511 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY/KY...UTAH REGION...AND PARTS OF WESTERN OREGON/SOUTHWEST WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley on Saturday afternoon. Isolated severe thunderstorms are also expected across the Utah region and over parts of western Oregon into southwest Washington. Wind and hail are the primary threats. ...Ohio Valley/KY... Great Lakes/Midwest trough will progress east today and extend from Lower MI-KY by 18/00z. High-level diffluent flow will be noted across the OH Valley into the Mid South which will prove favorable for scattered robust convection, especially by early afternoon as the boundary layer destabilizes with daytime heating. Strength of this feature will encourage a notable synoptic front to advance into OH/western KY by late afternoon, coincident with favorable upper diffluence. Latest model guidance suggests a considerable amount of convection will likely evolve along/ahead the wind shift, concentrated within a zone of stronger instability -- KY/southern OH. While some supercell potential does exist across this region, the majority of storms will likely be multicellular with clusters common. Wind/hail are expected with this activity. ...Utah Region... Well-defined mid-level short-wave trough is lifting north across the lower CO River Valley late this evening. With the upper ridge holding across the southern Rockies, this feature will progress across UT early in the period before shifting into eastern ID/southwest WY by late afternoon. Latest HREF model guidance actually reflects this short wave well with all members exhibiting substantial convection near the mid-level vort over southeast NV at sunrise. This activity will spread/develop northeast across UT during the day within a strongly sheared environment. Though, lapse rates will be seasonally weak given the convective coverage and cloud cover. Even so, robust organized updrafts are expected and wind should be the primary threat with these storms. ...Western OR/Southwest WA... Strong 500mb speed max will round the base of the offshore trough and translate across northern CA into eastern OR by early evening. Left exit region of this feature will aid UVV near the higher terrain and cooling/moistening mid-levels will contribute to modest buoyancy along the cyclonic side of the speed max. Forecast soundings exhibit strongly sheared profiles and isolated supercells are expected to develop, then spread north-northeast as a short-wave trough ejects into southern WA. Hail/wind are possible with these storms. ..Darrow/Squitieri.. 08/17/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY/KY...UTAH REGION...AND PARTS OF WESTERN OREGON/SOUTHWEST WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley on Saturday afternoon. Isolated severe thunderstorms are also expected across the Utah region and over parts of western Oregon into southwest Washington. Wind and hail are the primary threats. ...Ohio Valley/KY... Great Lakes/Midwest trough will progress east today and extend from Lower MI-KY by 18/00z. High-level diffluent flow will be noted across the OH Valley into the Mid South which will prove favorable for scattered robust convection, especially by early afternoon as the boundary layer destabilizes with daytime heating. Strength of this feature will encourage a notable synoptic front to advance into OH/western KY by late afternoon, coincident with favorable upper diffluence. Latest model guidance suggests a considerable amount of convection will likely evolve along/ahead the wind shift, concentrated within a zone of stronger instability -- KY/southern OH. While some supercell potential does exist across this region, the majority of storms will likely be multicellular with clusters common. Wind/hail are expected with this activity. ...Utah Region... Well-defined mid-level short-wave trough is lifting north across the lower CO River Valley late this evening. With the upper ridge holding across the southern Rockies, this feature will progress across UT early in the period before shifting into eastern ID/southwest WY by late afternoon. Latest HREF model guidance actually reflects this short wave well with all members exhibiting substantial convection near the mid-level vort over southeast NV at sunrise. This activity will spread/develop northeast across UT during the day within a strongly sheared environment. Though, lapse rates will be seasonally weak given the convective coverage and cloud cover. Even so, robust organized updrafts are expected and wind should be the primary threat with these storms. ...Western OR/Southwest WA... Strong 500mb speed max will round the base of the offshore trough and translate across northern CA into eastern OR by early evening. Left exit region of this feature will aid UVV near the higher terrain and cooling/moistening mid-levels will contribute to modest buoyancy along the cyclonic side of the speed max. Forecast soundings exhibit strongly sheared profiles and isolated supercells are expected to develop, then spread north-northeast as a short-wave trough ejects into southern WA. Hail/wind are possible with these storms. ..Darrow/Squitieri.. 08/17/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY/KY...UTAH REGION...AND PARTS OF WESTERN OREGON/SOUTHWEST WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley on Saturday afternoon. Isolated severe thunderstorms are also expected across the Utah region and over parts of western Oregon into southwest Washington. Wind and hail are the primary threats. ...Ohio Valley/KY... Great Lakes/Midwest trough will progress east today and extend from Lower MI-KY by 18/00z. High-level diffluent flow will be noted across the OH Valley into the Mid South which will prove favorable for scattered robust convection, especially by early afternoon as the boundary layer destabilizes with daytime heating. Strength of this feature will encourage a notable synoptic front to advance into OH/western KY by late afternoon, coincident with favorable upper diffluence. Latest model guidance suggests a considerable amount of convection will likely evolve along/ahead the wind shift, concentrated within a zone of stronger instability -- KY/southern OH. While some supercell potential does exist across this region, the majority of storms will likely be multicellular with clusters common. Wind/hail are expected with this activity. ...Utah Region... Well-defined mid-level short-wave trough is lifting north across the lower CO River Valley late this evening. With the upper ridge holding across the southern Rockies, this feature will progress across UT early in the period before shifting into eastern ID/southwest WY by late afternoon. Latest HREF model guidance actually reflects this short wave well with all members exhibiting substantial convection near the mid-level vort over southeast NV at sunrise. This activity will spread/develop northeast across UT during the day within a strongly sheared environment. Though, lapse rates will be seasonally weak given the convective coverage and cloud cover. Even so, robust organized updrafts are expected and wind should be the primary threat with these storms. ...Western OR/Southwest WA... Strong 500mb speed max will round the base of the offshore trough and translate across northern CA into eastern OR by early evening. Left exit region of this feature will aid UVV near the higher terrain and cooling/moistening mid-levels will contribute to modest buoyancy along the cyclonic side of the speed max. Forecast soundings exhibit strongly sheared profiles and isolated supercells are expected to develop, then spread north-northeast as a short-wave trough ejects into southern WA. Hail/wind are possible with these storms. ..Darrow/Squitieri.. 08/17/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY/KY...UTAH REGION...AND PARTS OF WESTERN OREGON/SOUTHWEST WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley on Saturday afternoon. Isolated severe thunderstorms are also expected across the Utah region and over parts of western Oregon into southwest Washington. Wind and hail are the primary threats. ...Ohio Valley/KY... Great Lakes/Midwest trough will progress east today and extend from Lower MI-KY by 18/00z. High-level diffluent flow will be noted across the OH Valley into the Mid South which will prove favorable for scattered robust convection, especially by early afternoon as the boundary layer destabilizes with daytime heating. Strength of this feature will encourage a notable synoptic front to advance into OH/western KY by late afternoon, coincident with favorable upper diffluence. Latest model guidance suggests a considerable amount of convection will likely evolve along/ahead the wind shift, concentrated within a zone of stronger instability -- KY/southern OH. While some supercell potential does exist across this region, the majority of storms will likely be multicellular with clusters common. Wind/hail are expected with this activity. ...Utah Region... Well-defined mid-level short-wave trough is lifting north across the lower CO River Valley late this evening. With the upper ridge holding across the southern Rockies, this feature will progress across UT early in the period before shifting into eastern ID/southwest WY by late afternoon. Latest HREF model guidance actually reflects this short wave well with all members exhibiting substantial convection near the mid-level vort over southeast NV at sunrise. This activity will spread/develop northeast across UT during the day within a strongly sheared environment. Though, lapse rates will be seasonally weak given the convective coverage and cloud cover. Even so, robust organized updrafts are expected and wind should be the primary threat with these storms. ...Western OR/Southwest WA... Strong 500mb speed max will round the base of the offshore trough and translate across northern CA into eastern OR by early evening. Left exit region of this feature will aid UVV near the higher terrain and cooling/moistening mid-levels will contribute to modest buoyancy along the cyclonic side of the speed max. Forecast soundings exhibit strongly sheared profiles and isolated supercells are expected to develop, then spread north-northeast as a short-wave trough ejects into southern WA. Hail/wind are possible with these storms. ..Darrow/Squitieri.. 08/17/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY/KY...UTAH REGION...AND PARTS OF WESTERN OREGON/SOUTHWEST WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley on Saturday afternoon. Isolated severe thunderstorms are also expected across the Utah region and over parts of western Oregon into southwest Washington. Wind and hail are the primary threats. ...Ohio Valley/KY... Great Lakes/Midwest trough will progress east today and extend from Lower MI-KY by 18/00z. High-level diffluent flow will be noted across the OH Valley into the Mid South which will prove favorable for scattered robust convection, especially by early afternoon as the boundary layer destabilizes with daytime heating. Strength of this feature will encourage a notable synoptic front to advance into OH/western KY by late afternoon, coincident with favorable upper diffluence. Latest model guidance suggests a considerable amount of convection will likely evolve along/ahead the wind shift, concentrated within a zone of stronger instability -- KY/southern OH. While some supercell potential does exist across this region, the majority of storms will likely be multicellular with clusters common. Wind/hail are expected with this activity. ...Utah Region... Well-defined mid-level short-wave trough is lifting north across the lower CO River Valley late this evening. With the upper ridge holding across the southern Rockies, this feature will progress across UT early in the period before shifting into eastern ID/southwest WY by late afternoon. Latest HREF model guidance actually reflects this short wave well with all members exhibiting substantial convection near the mid-level vort over southeast NV at sunrise. This activity will spread/develop northeast across UT during the day within a strongly sheared environment. Though, lapse rates will be seasonally weak given the convective coverage and cloud cover. Even so, robust organized updrafts are expected and wind should be the primary threat with these storms. ...Western OR/Southwest WA... Strong 500mb speed max will round the base of the offshore trough and translate across northern CA into eastern OR by early evening. Left exit region of this feature will aid UVV near the higher terrain and cooling/moistening mid-levels will contribute to modest buoyancy along the cyclonic side of the speed max. Forecast soundings exhibit strongly sheared profiles and isolated supercells are expected to develop, then spread north-northeast as a short-wave trough ejects into southern WA. Hail/wind are possible with these storms. ..Darrow/Squitieri.. 08/17/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY/KY...UTAH REGION...AND PARTS OF WESTERN OREGON/SOUTHWEST WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley on Saturday afternoon. Isolated severe thunderstorms are also expected across the Utah region and over parts of western Oregon into southwest Washington. Wind and hail are the primary threats. ...Ohio Valley/KY... Great Lakes/Midwest trough will progress east today and extend from Lower MI-KY by 18/00z. High-level diffluent flow will be noted across the OH Valley into the Mid South which will prove favorable for scattered robust convection, especially by early afternoon as the boundary layer destabilizes with daytime heating. Strength of this feature will encourage a notable synoptic front to advance into OH/western KY by late afternoon, coincident with favorable upper diffluence. Latest model guidance suggests a considerable amount of convection will likely evolve along/ahead the wind shift, concentrated within a zone of stronger instability -- KY/southern OH. While some supercell potential does exist across this region, the majority of storms will likely be multicellular with clusters common. Wind/hail are expected with this activity. ...Utah Region... Well-defined mid-level short-wave trough is lifting north across the lower CO River Valley late this evening. With the upper ridge holding across the southern Rockies, this feature will progress across UT early in the period before shifting into eastern ID/southwest WY by late afternoon. Latest HREF model guidance actually reflects this short wave well with all members exhibiting substantial convection near the mid-level vort over southeast NV at sunrise. This activity will spread/develop northeast across UT during the day within a strongly sheared environment. Though, lapse rates will be seasonally weak given the convective coverage and cloud cover. Even so, robust organized updrafts are expected and wind should be the primary threat with these storms. ...Western OR/Southwest WA... Strong 500mb speed max will round the base of the offshore trough and translate across northern CA into eastern OR by early evening. Left exit region of this feature will aid UVV near the higher terrain and cooling/moistening mid-levels will contribute to modest buoyancy along the cyclonic side of the speed max. Forecast soundings exhibit strongly sheared profiles and isolated supercells are expected to develop, then spread north-northeast as a short-wave trough ejects into southern WA. Hail/wind are possible with these storms. ..Darrow/Squitieri.. 08/17/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY/KY...UTAH REGION...AND PARTS OF WESTERN OREGON/SOUTHWEST WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley on Saturday afternoon. Isolated severe thunderstorms are also expected across the Utah region and over parts of western Oregon into southwest Washington. Wind and hail are the primary threats. ...Ohio Valley/KY... Great Lakes/Midwest trough will progress east today and extend from Lower MI-KY by 18/00z. High-level diffluent flow will be noted across the OH Valley into the Mid South which will prove favorable for scattered robust convection, especially by early afternoon as the boundary layer destabilizes with daytime heating. Strength of this feature will encourage a notable synoptic front to advance into OH/western KY by late afternoon, coincident with favorable upper diffluence. Latest model guidance suggests a considerable amount of convection will likely evolve along/ahead the wind shift, concentrated within a zone of stronger instability -- KY/southern OH. While some supercell potential does exist across this region, the majority of storms will likely be multicellular with clusters common. Wind/hail are expected with this activity. ...Utah Region... Well-defined mid-level short-wave trough is lifting north across the lower CO River Valley late this evening. With the upper ridge holding across the southern Rockies, this feature will progress across UT early in the period before shifting into eastern ID/southwest WY by late afternoon. Latest HREF model guidance actually reflects this short wave well with all members exhibiting substantial convection near the mid-level vort over southeast NV at sunrise. This activity will spread/develop northeast across UT during the day within a strongly sheared environment. Though, lapse rates will be seasonally weak given the convective coverage and cloud cover. Even so, robust organized updrafts are expected and wind should be the primary threat with these storms. ...Western OR/Southwest WA... Strong 500mb speed max will round the base of the offshore trough and translate across northern CA into eastern OR by early evening. Left exit region of this feature will aid UVV near the higher terrain and cooling/moistening mid-levels will contribute to modest buoyancy along the cyclonic side of the speed max. Forecast soundings exhibit strongly sheared profiles and isolated supercells are expected to develop, then spread north-northeast as a short-wave trough ejects into southern WA. Hail/wind are possible with these storms. ..Darrow/Squitieri.. 08/17/2024 Read more