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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

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

000
ABPZ20 KNHC 170545
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Fri Aug 16 2024

For the eastern North Pacific...east of 140 degrees west longitude:

Well Offshore of Southwestern Mexico (EP99):
A broad area of low pressure located several hundred miles off the
southwestern coast of Mexico is producing a large area of
disorganized showers and thunderstorms to the west of its center.
Upper-level winds are forecast to become more conducive for gradual
development of this system over the weekend, and a tropical
depression is likely to form early next week while it moves
west-northwestward at about 10 mph across the central portion of the
eastern Pacific.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 7 days...high...80 percent.

Western Portion of the East Pacific:
An area of low pressure could form this weekend or early next week
more than one thousand miles west-southwest of the southern tip of
the Baja California peninsula. Slow development of this system is
anticipated, and a tropical depression will likely form during the
middle part of next week while it moves westward to
west-northwestward across the western portion of the basin and into
the Central Pacific basin. Information on this system's development
can also be found in the Tropical Weather Outlook for the Central
Pacific basin.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...high...70 percent.

Well Southeast of the Hawaiian Islands:
A small area of low pressure has formed well southeast of the
Hawaiian islands. Some development of this system is possible this
weekend into early next week while it moves across the western
portion of the East Pacific and into the Central Pacific basin. By
the middle of next week, the system could merge with a larger system
to the east. Information on this system's development can also be
found in the Tropical Weather Outlook for the Central Pacific basin.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...low...20 percent.

&&
The Tropical Weather Outlook for the Central Pacific basin can be
found under AWIPS header HFOTWOCP and WMO header ACPN50 PHFO and on
the web at hurricanes.gov

$$
Forecaster Kelly

MD 1927 CONCERNING SEVERE THUNDERSTORM WATCH 628... FOR PORTIONS OF EASTERN OKLAHOMA INTO FAR NORTHWESTERN ARKANSAS
Mesoscale Discussion 1927 NWS Storm Prediction Center Norman OK 0921 PM CDT Fri Aug 16 2024 Areas affected...portions of eastern Oklahoma into far northwestern Arkansas Concerning...Severe Thunderstorm Watch 628... Valid 170221Z - 170345Z The severe weather threat for Severe Thunderstorm Watch 628 continues. SUMMARY...The severe threat continues across Severe Thunderstorm Watch 628, with a severe wind/hail threat persisting. Upscale growth into a more organized cluster of storms is possible, and local spatial/temporal extensions of the watch may be needed should this upscale growth occur. DISCUSSION...Multicells and supercells persist across northeast OK with a history of severe wind and hail. These storms are displaced slightly on the cool side of a convective outflow boundary that continues to surge southward in tandem with a leading convective complex in northwestern AR. MLCINH will increase through the evening given nocturnal cooling. However, the rate of MLCINH increase will be gradual given abundant low-level moisture, which is also contributing to 4000 J/kg MUCAPE. Given adequate deep-layer shear also in place, at least a short-term severe threat should persist. However, should storms catch up to and anchor along the leading outflow boundary while also merging cold pools, a more organized MCS could materialize with a persistent severe gust threat, and an occasional instance of large hail also possible. Should an MCS develop, temporal and/or spatial southward extensions of Severe Thunderstorm Watch 628 may be needed. ..Squitieri.. 08/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...TSA...OUN... LAT...LON 35369608 35889652 36499658 36869641 36989592 36959520 36779434 36449384 36149386 35739411 35259441 34839469 34579504 34549519 34959592 35369608 Read more

MD 1926 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PORTIONS OF NORTHWESTERN ARKANSAS
Mesoscale Discussion 1926 NWS Storm Prediction Center Norman OK 0845 PM CDT Fri Aug 16 2024 Areas affected...portions of northwestern Arkansas Concerning...Severe potential...Watch likely Valid 170145Z - 170245Z Probability of Watch Issuance...95 percent SUMMARY...The severe threat is increasing across portions of northwestern AR. Severe gusts are the main threat, though a few instances of large hail are also possible. A WW will be needed soon to address the impending severe threat. DISCUSSION...A robust multicellular cluster (perhaps with embedded transient supercells) continues to rapidly propagate to the southeast. Multiple instances of 70-80 mph gusts and wind damage have been reported with this cluster, and MRMS MESH suggests that at least some marginally severe hail may be falling in the stronger storm cores. Preceding these storms is a thermodynamic airmass characterized by 2000-3000 J/kg MLCAPE amid only slowly increasing MLCINH. Effective bulk shear values are likely exceeding 30 kts per 00Z mesoanalysis, which is sufficient for continued storm organization and intensity given the aforementioned buoyancy. Though MLCINH should ultimately tame severe potential later tonight, at least some concentrated severe wind/hail threat may still materialize over the next couple of hours. A WW issuance will be needed soon to address the near-term severe threat. ..Squitieri/Edwards.. 08/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...TSA... LAT...LON 35459441 36189344 36449288 36229238 35719219 35369230 35039262 34929309 34939366 34999419 35459441 Read more

MD 1925 CONCERNING SEVERE THUNDERSTORM WATCH 628... FOR PORTIONS OF WESTERN OKLAHOMA INTO FAR NORTHWESTERN ARKANSAS
Mesoscale Discussion 1925 NWS Storm Prediction Center Norman OK 0738 PM CDT Fri Aug 16 2024 Areas affected...Portions of western Oklahoma into far northwestern Arkansas Concerning...Severe Thunderstorm Watch 628... Valid 170038Z - 170215Z The severe weather threat for Severe Thunderstorm Watch 628 continues. SUMMARY...The severe threat continues across Severe Thunderstorm Watch 628. Severe wind and hail remain the primary threats over the next few hours. DISCUSSION...A robust uptick in convective coverage and intensity has been noted in north-central Oklahoma to southeast Kansas over the past couple of hours, where severe wind and hail have been observed. Despite weak forcing, thunderstorms have managed to initiate off of multiple converging low-level baroclinic/outflow boundaries. Furthermore, the OUN 00Z observed sounding shows near 3000 J/kg MLCAPE atop a mixed boundary layer, characterized by 30F T/Td spreads. 20-30 F spreads are also evident across eastern OK ahead of the ongoing storms, with 00Z mesoanalysis depicting over 4500 J/kg MLCAPE (given mid 70s F surface dewpoints). Meanwhile, the 00Z OUN sounding, as well as VNX, TLX, and INX VAD profilers show hodographs with modest low-level curvature and mid-level elongation, supporting supercell structures when accounting for the strong to locally extreme buoyancy in place. As such, supercells may persist into northeast OK over the next few hours with a continued severe-wind threat, though large hail is also possible. ..Squitieri.. 08/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...TSA...ICT...OUN... LAT...LON 35209990 36199857 36849753 37039542 36979429 36659377 36289372 36029411 35869555 35629666 35099774 34889843 34939930 35209990 Read more

WW 0628 Status Updates
STATUS REPORT ON WW 628 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SE END TO 20 NE END TO 35 SSE ICT. ..SQUITIERI..08/17/24 ATTN...WFO...TSA...SGF...OUN... STATUS REPORT FOR WS 628 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC007-015-087-143-170340- AR . ARKANSAS COUNTIES INCLUDED ARE BENTON CARROLL MADISON WASHINGTON MOC009-119-145-170340- MO . MISSOURI COUNTIES INCLUDED ARE BARRY MCDONALD NEWTON OKC001-021-035-037-041-071-097-103-105-113-115-117-119-131-143- 145-147-170340- OK . OKLAHOMA COUNTIES INCLUDED ARE ADAIR CHEROKEE CRAIG CREEK DELAWARE KAY Read more

WW 0628 Status Updates
STATUS REPORT ON WW 628 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SE END TO 20 NE END TO 35 SSE ICT. ..SQUITIERI..08/17/24 ATTN...WFO...TSA...SGF...OUN... STATUS REPORT FOR WS 628 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC007-015-087-143-170340- AR . ARKANSAS COUNTIES INCLUDED ARE BENTON CARROLL MADISON WASHINGTON MOC009-119-145-170340- MO . MISSOURI COUNTIES INCLUDED ARE BARRY MCDONALD NEWTON OKC001-021-035-037-041-071-097-103-105-113-115-117-119-131-143- 145-147-170340- OK . OKLAHOMA COUNTIES INCLUDED ARE ADAIR CHEROKEE CRAIG CREEK DELAWARE KAY Read more

WW 0628 Status Updates
STATUS REPORT ON WW 628 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SE END TO 20 NE END TO 35 SSE ICT. ..SQUITIERI..08/17/24 ATTN...WFO...TSA...SGF...OUN... STATUS REPORT FOR WS 628 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC007-015-087-143-170340- AR . ARKANSAS COUNTIES INCLUDED ARE BENTON CARROLL MADISON WASHINGTON MOC009-119-145-170340- MO . MISSOURI COUNTIES INCLUDED ARE BARRY MCDONALD NEWTON OKC001-021-035-037-041-071-097-103-105-113-115-117-119-131-143- 145-147-170340- OK . OKLAHOMA COUNTIES INCLUDED ARE ADAIR CHEROKEE CRAIG CREEK DELAWARE KAY Read more