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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Sat Aug 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CASCADES OF OREGON AND WASHINGTON...CENTRAL KENTUCKY INTO SOUTHERN OHIO...AND UTAH.... ...SUMMARY... Scattered severe thunderstorms are possible today in vicinity of the Cascades of Oregon and Washington, Kentucky, and Utah. Wind and hail are the primary threats. ...CA/OR/WA... Morning water vapor loop shows a strong and fast-moving shortwave trough approaching the coast of northern CA. This feature will rotate inland, affecting the Cascades region this afternoon and evening. Steep mid level lapse rates and pockets of MLCAPE of 500-1000 J/kg will aid in the development of scattered thunderstorms by early afternoon over the mountains and coastal ranges of northern CA, building quickly northward into southern/central OR. Winds aloft will be strenghtening during this period, allowing a few supercell storm structures to likely develop. These storms may pose a threat of large hail and locally damaging wind gusts through the afternoon as they track northward into WA. Other high-based storms capable of gusty/damaging winds may affect parts of the Columbia Basin of northern OR/central WA as well. ...UT... A compact shortwave trough over central NV will continue to rotate around the Four-Corners upper ridge into UT today. Considerable coverage of afternoon thunderstorms will likely accompany this system. Winds aloft will be relatively strong, favoring faster-moving organized multicell or occasional supercell structures capable of damaging winds and hail. One forecast uncertainty is the extent of morning cloudiness and its impact on afternoon destabilization. Regardless, at least isolated severe storms are expected, with some threat spreading into southwest WY by evening. ...Eastern US... A broad upper trough will affect much of the eastern US today, with clusters of thunderstorms from NY/PA across the Appalachians into the Mid South. Any of these clusters may occasionally pose a risk of locally gusty/damaging wind gusts or hail. However, perhaps a more focused area of concern will extend from northern TN into southern OH. The axis of the mid level speed max (~40 knots) will spread across this area during the afternoon. CAM guidance has been consistent on suggesting a higher confidence in a few intense cells in this region. ..Hart/Thornton.. 08/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Sat Aug 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CASCADES OF OREGON AND WASHINGTON...CENTRAL KENTUCKY INTO SOUTHERN OHIO...AND UTAH.... ...SUMMARY... Scattered severe thunderstorms are possible today in vicinity of the Cascades of Oregon and Washington, Kentucky, and Utah. Wind and hail are the primary threats. ...CA/OR/WA... Morning water vapor loop shows a strong and fast-moving shortwave trough approaching the coast of northern CA. This feature will rotate inland, affecting the Cascades region this afternoon and evening. Steep mid level lapse rates and pockets of MLCAPE of 500-1000 J/kg will aid in the development of scattered thunderstorms by early afternoon over the mountains and coastal ranges of northern CA, building quickly northward into southern/central OR. Winds aloft will be strenghtening during this period, allowing a few supercell storm structures to likely develop. These storms may pose a threat of large hail and locally damaging wind gusts through the afternoon as they track northward into WA. Other high-based storms capable of gusty/damaging winds may affect parts of the Columbia Basin of northern OR/central WA as well. ...UT... A compact shortwave trough over central NV will continue to rotate around the Four-Corners upper ridge into UT today. Considerable coverage of afternoon thunderstorms will likely accompany this system. Winds aloft will be relatively strong, favoring faster-moving organized multicell or occasional supercell structures capable of damaging winds and hail. One forecast uncertainty is the extent of morning cloudiness and its impact on afternoon destabilization. Regardless, at least isolated severe storms are expected, with some threat spreading into southwest WY by evening. ...Eastern US... A broad upper trough will affect much of the eastern US today, with clusters of thunderstorms from NY/PA across the Appalachians into the Mid South. Any of these clusters may occasionally pose a risk of locally gusty/damaging wind gusts or hail. However, perhaps a more focused area of concern will extend from northern TN into southern OH. The axis of the mid level speed max (~40 knots) will spread across this area during the afternoon. CAM guidance has been consistent on suggesting a higher confidence in a few intense cells in this region. ..Hart/Thornton.. 08/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Sat Aug 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CASCADES OF OREGON AND WASHINGTON...CENTRAL KENTUCKY INTO SOUTHERN OHIO...AND UTAH.... ...SUMMARY... Scattered severe thunderstorms are possible today in vicinity of the Cascades of Oregon and Washington, Kentucky, and Utah. Wind and hail are the primary threats. ...CA/OR/WA... Morning water vapor loop shows a strong and fast-moving shortwave trough approaching the coast of northern CA. This feature will rotate inland, affecting the Cascades region this afternoon and evening. Steep mid level lapse rates and pockets of MLCAPE of 500-1000 J/kg will aid in the development of scattered thunderstorms by early afternoon over the mountains and coastal ranges of northern CA, building quickly northward into southern/central OR. Winds aloft will be strenghtening during this period, allowing a few supercell storm structures to likely develop. These storms may pose a threat of large hail and locally damaging wind gusts through the afternoon as they track northward into WA. Other high-based storms capable of gusty/damaging winds may affect parts of the Columbia Basin of northern OR/central WA as well. ...UT... A compact shortwave trough over central NV will continue to rotate around the Four-Corners upper ridge into UT today. Considerable coverage of afternoon thunderstorms will likely accompany this system. Winds aloft will be relatively strong, favoring faster-moving organized multicell or occasional supercell structures capable of damaging winds and hail. One forecast uncertainty is the extent of morning cloudiness and its impact on afternoon destabilization. Regardless, at least isolated severe storms are expected, with some threat spreading into southwest WY by evening. ...Eastern US... A broad upper trough will affect much of the eastern US today, with clusters of thunderstorms from NY/PA across the Appalachians into the Mid South. Any of these clusters may occasionally pose a risk of locally gusty/damaging wind gusts or hail. However, perhaps a more focused area of concern will extend from northern TN into southern OH. The axis of the mid level speed max (~40 knots) will spread across this area during the afternoon. CAM guidance has been consistent on suggesting a higher confidence in a few intense cells in this region. ..Hart/Thornton.. 08/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Sat Aug 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CASCADES OF OREGON AND WASHINGTON...CENTRAL KENTUCKY INTO SOUTHERN OHIO...AND UTAH.... ...SUMMARY... Scattered severe thunderstorms are possible today in vicinity of the Cascades of Oregon and Washington, Kentucky, and Utah. Wind and hail are the primary threats. ...CA/OR/WA... Morning water vapor loop shows a strong and fast-moving shortwave trough approaching the coast of northern CA. This feature will rotate inland, affecting the Cascades region this afternoon and evening. Steep mid level lapse rates and pockets of MLCAPE of 500-1000 J/kg will aid in the development of scattered thunderstorms by early afternoon over the mountains and coastal ranges of northern CA, building quickly northward into southern/central OR. Winds aloft will be strenghtening during this period, allowing a few supercell storm structures to likely develop. These storms may pose a threat of large hail and locally damaging wind gusts through the afternoon as they track northward into WA. Other high-based storms capable of gusty/damaging winds may affect parts of the Columbia Basin of northern OR/central WA as well. ...UT... A compact shortwave trough over central NV will continue to rotate around the Four-Corners upper ridge into UT today. Considerable coverage of afternoon thunderstorms will likely accompany this system. Winds aloft will be relatively strong, favoring faster-moving organized multicell or occasional supercell structures capable of damaging winds and hail. One forecast uncertainty is the extent of morning cloudiness and its impact on afternoon destabilization. Regardless, at least isolated severe storms are expected, with some threat spreading into southwest WY by evening. ...Eastern US... A broad upper trough will affect much of the eastern US today, with clusters of thunderstorms from NY/PA across the Appalachians into the Mid South. Any of these clusters may occasionally pose a risk of locally gusty/damaging wind gusts or hail. However, perhaps a more focused area of concern will extend from northern TN into southern OH. The axis of the mid level speed max (~40 knots) will spread across this area during the afternoon. CAM guidance has been consistent on suggesting a higher confidence in a few intense cells in this region. ..Hart/Thornton.. 08/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Sat Aug 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CASCADES OF OREGON AND WASHINGTON...CENTRAL KENTUCKY INTO SOUTHERN OHIO...AND UTAH.... ...SUMMARY... Scattered severe thunderstorms are possible today in vicinity of the Cascades of Oregon and Washington, Kentucky, and Utah. Wind and hail are the primary threats. ...CA/OR/WA... Morning water vapor loop shows a strong and fast-moving shortwave trough approaching the coast of northern CA. This feature will rotate inland, affecting the Cascades region this afternoon and evening. Steep mid level lapse rates and pockets of MLCAPE of 500-1000 J/kg will aid in the development of scattered thunderstorms by early afternoon over the mountains and coastal ranges of northern CA, building quickly northward into southern/central OR. Winds aloft will be strenghtening during this period, allowing a few supercell storm structures to likely develop. These storms may pose a threat of large hail and locally damaging wind gusts through the afternoon as they track northward into WA. Other high-based storms capable of gusty/damaging winds may affect parts of the Columbia Basin of northern OR/central WA as well. ...UT... A compact shortwave trough over central NV will continue to rotate around the Four-Corners upper ridge into UT today. Considerable coverage of afternoon thunderstorms will likely accompany this system. Winds aloft will be relatively strong, favoring faster-moving organized multicell or occasional supercell structures capable of damaging winds and hail. One forecast uncertainty is the extent of morning cloudiness and its impact on afternoon destabilization. Regardless, at least isolated severe storms are expected, with some threat spreading into southwest WY by evening. ...Eastern US... A broad upper trough will affect much of the eastern US today, with clusters of thunderstorms from NY/PA across the Appalachians into the Mid South. Any of these clusters may occasionally pose a risk of locally gusty/damaging wind gusts or hail. However, perhaps a more focused area of concern will extend from northern TN into southern OH. The axis of the mid level speed max (~40 knots) will spread across this area during the afternoon. CAM guidance has been consistent on suggesting a higher confidence in a few intense cells in this region. ..Hart/Thornton.. 08/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Sat Aug 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CASCADES OF OREGON AND WASHINGTON...CENTRAL KENTUCKY INTO SOUTHERN OHIO...AND UTAH.... ...SUMMARY... Scattered severe thunderstorms are possible today in vicinity of the Cascades of Oregon and Washington, Kentucky, and Utah. Wind and hail are the primary threats. ...CA/OR/WA... Morning water vapor loop shows a strong and fast-moving shortwave trough approaching the coast of northern CA. This feature will rotate inland, affecting the Cascades region this afternoon and evening. Steep mid level lapse rates and pockets of MLCAPE of 500-1000 J/kg will aid in the development of scattered thunderstorms by early afternoon over the mountains and coastal ranges of northern CA, building quickly northward into southern/central OR. Winds aloft will be strenghtening during this period, allowing a few supercell storm structures to likely develop. These storms may pose a threat of large hail and locally damaging wind gusts through the afternoon as they track northward into WA. Other high-based storms capable of gusty/damaging winds may affect parts of the Columbia Basin of northern OR/central WA as well. ...UT... A compact shortwave trough over central NV will continue to rotate around the Four-Corners upper ridge into UT today. Considerable coverage of afternoon thunderstorms will likely accompany this system. Winds aloft will be relatively strong, favoring faster-moving organized multicell or occasional supercell structures capable of damaging winds and hail. One forecast uncertainty is the extent of morning cloudiness and its impact on afternoon destabilization. Regardless, at least isolated severe storms are expected, with some threat spreading into southwest WY by evening. ...Eastern US... A broad upper trough will affect much of the eastern US today, with clusters of thunderstorms from NY/PA across the Appalachians into the Mid South. Any of these clusters may occasionally pose a risk of locally gusty/damaging wind gusts or hail. However, perhaps a more focused area of concern will extend from northern TN into southern OH. The axis of the mid level speed max (~40 knots) will spread across this area during the afternoon. CAM guidance has been consistent on suggesting a higher confidence in a few intense cells in this region. ..Hart/Thornton.. 08/17/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 AM CDT Sat Aug 17 2024 Valid 171300Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR CENTRAL KENTUCKY INTO SOUTHERN OHIO...UTAH...AND PARTS OF THE CASCADES OF OREGON AND WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley mainly this afternoon into the early evening. Scattered severe thunderstorms are also forecast for Utah and in the vicinity of the Cascades of Oregon and Washington. Wind and hail are the primary threats. ...Lower Great Lakes into the central/southern Appalachians and OH Valley... A mid-level low and associated trough will slowly move east today and reach the Upper OH Valley/Appalachians tonight as a mid-level anticyclone remains centered over northeast NM. High-level diffluent flow will be noted across the OH Valley into the Mid South and be favorable for scattered thunderstorms developing across much of this region coincident with strong heating. A front will gradually shift east across the OH Valley with this boundary becoming more diffuse in part related to convective outflow across the Mid South/Ozarks. Stronger mid-level flow aiding in storm organization will primarily extend from the Great Smoky Mtns northward into KY/OH/WV. Organized multicells and transient supercells are possible with scattered coverage of severe wind/hail possible with these storms. Observational trends of an MCV over Middle TN moving eastward into the southern Appalachians and the 00z MPAS-NSSL model run data, lend the possibility for a mesoscale corridor of higher thunderstorm coverage and greater damaging-wind potential for the western Carolinas and perhaps into central portions of AL. Limited confidence in this scenario precludes higher severe probabilities at this time. ...Lower MS Valley into north TX... Morning thunderstorms over the OK/AR border associated with low-level WAA may continue into the midday with incipient outflow progressively shunting additional storms/new development farther west and south across eastern OK. Model guidance indicates at least isolated storms potentially developing within an east-west corridor from MS westward into north/northwest TX later today. Forecast soundings indicate severe microbursts will be possible with the more intense cores. Have adjusted low-severe probabilities to trend farther west/southwest based on this forecast scenario. ...Utah Region... Water-vapor imagery this morning shows a northward-moving shortwave trough over southern NV and extrapolation has this feature moving into northern UT by mid afternoon. Scattered to numerous thunderstorms are forecast to begin developing by late morning and spreading north-northeast within a strongly sheared environment. Increasing cloud cover and some limit on the quality of lapse rates will temper overall buoyancy. However, some organization into small clusters yielding severe gusts will be the primary threat with the stronger 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. ..Smith/Mosier.. 08/17/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 AM CDT Sat Aug 17 2024 Valid 171300Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR CENTRAL KENTUCKY INTO SOUTHERN OHIO...UTAH...AND PARTS OF THE CASCADES OF OREGON AND WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley mainly this afternoon into the early evening. Scattered severe thunderstorms are also forecast for Utah and in the vicinity of the Cascades of Oregon and Washington. Wind and hail are the primary threats. ...Lower Great Lakes into the central/southern Appalachians and OH Valley... A mid-level low and associated trough will slowly move east today and reach the Upper OH Valley/Appalachians tonight as a mid-level anticyclone remains centered over northeast NM. High-level diffluent flow will be noted across the OH Valley into the Mid South and be favorable for scattered thunderstorms developing across much of this region coincident with strong heating. A front will gradually shift east across the OH Valley with this boundary becoming more diffuse in part related to convective outflow across the Mid South/Ozarks. Stronger mid-level flow aiding in storm organization will primarily extend from the Great Smoky Mtns northward into KY/OH/WV. Organized multicells and transient supercells are possible with scattered coverage of severe wind/hail possible with these storms. Observational trends of an MCV over Middle TN moving eastward into the southern Appalachians and the 00z MPAS-NSSL model run data, lend the possibility for a mesoscale corridor of higher thunderstorm coverage and greater damaging-wind potential for the western Carolinas and perhaps into central portions of AL. Limited confidence in this scenario precludes higher severe probabilities at this time. ...Lower MS Valley into north TX... Morning thunderstorms over the OK/AR border associated with low-level WAA may continue into the midday with incipient outflow progressively shunting additional storms/new development farther west and south across eastern OK. Model guidance indicates at least isolated storms potentially developing within an east-west corridor from MS westward into north/northwest TX later today. Forecast soundings indicate severe microbursts will be possible with the more intense cores. Have adjusted low-severe probabilities to trend farther west/southwest based on this forecast scenario. ...Utah Region... Water-vapor imagery this morning shows a northward-moving shortwave trough over southern NV and extrapolation has this feature moving into northern UT by mid afternoon. Scattered to numerous thunderstorms are forecast to begin developing by late morning and spreading north-northeast within a strongly sheared environment. Increasing cloud cover and some limit on the quality of lapse rates will temper overall buoyancy. However, some organization into small clusters yielding severe gusts will be the primary threat with the stronger 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. ..Smith/Mosier.. 08/17/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 AM CDT Sat Aug 17 2024 Valid 171300Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR CENTRAL KENTUCKY INTO SOUTHERN OHIO...UTAH...AND PARTS OF THE CASCADES OF OREGON AND WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley mainly this afternoon into the early evening. Scattered severe thunderstorms are also forecast for Utah and in the vicinity of the Cascades of Oregon and Washington. Wind and hail are the primary threats. ...Lower Great Lakes into the central/southern Appalachians and OH Valley... A mid-level low and associated trough will slowly move east today and reach the Upper OH Valley/Appalachians tonight as a mid-level anticyclone remains centered over northeast NM. High-level diffluent flow will be noted across the OH Valley into the Mid South and be favorable for scattered thunderstorms developing across much of this region coincident with strong heating. A front will gradually shift east across the OH Valley with this boundary becoming more diffuse in part related to convective outflow across the Mid South/Ozarks. Stronger mid-level flow aiding in storm organization will primarily extend from the Great Smoky Mtns northward into KY/OH/WV. Organized multicells and transient supercells are possible with scattered coverage of severe wind/hail possible with these storms. Observational trends of an MCV over Middle TN moving eastward into the southern Appalachians and the 00z MPAS-NSSL model run data, lend the possibility for a mesoscale corridor of higher thunderstorm coverage and greater damaging-wind potential for the western Carolinas and perhaps into central portions of AL. Limited confidence in this scenario precludes higher severe probabilities at this time. ...Lower MS Valley into north TX... Morning thunderstorms over the OK/AR border associated with low-level WAA may continue into the midday with incipient outflow progressively shunting additional storms/new development farther west and south across eastern OK. Model guidance indicates at least isolated storms potentially developing within an east-west corridor from MS westward into north/northwest TX later today. Forecast soundings indicate severe microbursts will be possible with the more intense cores. Have adjusted low-severe probabilities to trend farther west/southwest based on this forecast scenario. ...Utah Region... Water-vapor imagery this morning shows a northward-moving shortwave trough over southern NV and extrapolation has this feature moving into northern UT by mid afternoon. Scattered to numerous thunderstorms are forecast to begin developing by late morning and spreading north-northeast within a strongly sheared environment. Increasing cloud cover and some limit on the quality of lapse rates will temper overall buoyancy. However, some organization into small clusters yielding severe gusts will be the primary threat with the stronger 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. ..Smith/Mosier.. 08/17/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 AM CDT Sat Aug 17 2024 Valid 171300Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR CENTRAL KENTUCKY INTO SOUTHERN OHIO...UTAH...AND PARTS OF THE CASCADES OF OREGON AND WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley mainly this afternoon into the early evening. Scattered severe thunderstorms are also forecast for Utah and in the vicinity of the Cascades of Oregon and Washington. Wind and hail are the primary threats. ...Lower Great Lakes into the central/southern Appalachians and OH Valley... A mid-level low and associated trough will slowly move east today and reach the Upper OH Valley/Appalachians tonight as a mid-level anticyclone remains centered over northeast NM. High-level diffluent flow will be noted across the OH Valley into the Mid South and be favorable for scattered thunderstorms developing across much of this region coincident with strong heating. A front will gradually shift east across the OH Valley with this boundary becoming more diffuse in part related to convective outflow across the Mid South/Ozarks. Stronger mid-level flow aiding in storm organization will primarily extend from the Great Smoky Mtns northward into KY/OH/WV. Organized multicells and transient supercells are possible with scattered coverage of severe wind/hail possible with these storms. Observational trends of an MCV over Middle TN moving eastward into the southern Appalachians and the 00z MPAS-NSSL model run data, lend the possibility for a mesoscale corridor of higher thunderstorm coverage and greater damaging-wind potential for the western Carolinas and perhaps into central portions of AL. Limited confidence in this scenario precludes higher severe probabilities at this time. ...Lower MS Valley into north TX... Morning thunderstorms over the OK/AR border associated with low-level WAA may continue into the midday with incipient outflow progressively shunting additional storms/new development farther west and south across eastern OK. Model guidance indicates at least isolated storms potentially developing within an east-west corridor from MS westward into north/northwest TX later today. Forecast soundings indicate severe microbursts will be possible with the more intense cores. Have adjusted low-severe probabilities to trend farther west/southwest based on this forecast scenario. ...Utah Region... Water-vapor imagery this morning shows a northward-moving shortwave trough over southern NV and extrapolation has this feature moving into northern UT by mid afternoon. Scattered to numerous thunderstorms are forecast to begin developing by late morning and spreading north-northeast within a strongly sheared environment. Increasing cloud cover and some limit on the quality of lapse rates will temper overall buoyancy. However, some organization into small clusters yielding severe gusts will be the primary threat with the stronger 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. ..Smith/Mosier.. 08/17/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 AM CDT Sat Aug 17 2024 Valid 171300Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR CENTRAL KENTUCKY INTO SOUTHERN OHIO...UTAH...AND PARTS OF THE CASCADES OF OREGON AND WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley mainly this afternoon into the early evening. Scattered severe thunderstorms are also forecast for Utah and in the vicinity of the Cascades of Oregon and Washington. Wind and hail are the primary threats. ...Lower Great Lakes into the central/southern Appalachians and OH Valley... A mid-level low and associated trough will slowly move east today and reach the Upper OH Valley/Appalachians tonight as a mid-level anticyclone remains centered over northeast NM. High-level diffluent flow will be noted across the OH Valley into the Mid South and be favorable for scattered thunderstorms developing across much of this region coincident with strong heating. A front will gradually shift east across the OH Valley with this boundary becoming more diffuse in part related to convective outflow across the Mid South/Ozarks. Stronger mid-level flow aiding in storm organization will primarily extend from the Great Smoky Mtns northward into KY/OH/WV. Organized multicells and transient supercells are possible with scattered coverage of severe wind/hail possible with these storms. Observational trends of an MCV over Middle TN moving eastward into the southern Appalachians and the 00z MPAS-NSSL model run data, lend the possibility for a mesoscale corridor of higher thunderstorm coverage and greater damaging-wind potential for the western Carolinas and perhaps into central portions of AL. Limited confidence in this scenario precludes higher severe probabilities at this time. ...Lower MS Valley into north TX... Morning thunderstorms over the OK/AR border associated with low-level WAA may continue into the midday with incipient outflow progressively shunting additional storms/new development farther west and south across eastern OK. Model guidance indicates at least isolated storms potentially developing within an east-west corridor from MS westward into north/northwest TX later today. Forecast soundings indicate severe microbursts will be possible with the more intense cores. Have adjusted low-severe probabilities to trend farther west/southwest based on this forecast scenario. ...Utah Region... Water-vapor imagery this morning shows a northward-moving shortwave trough over southern NV and extrapolation has this feature moving into northern UT by mid afternoon. Scattered to numerous thunderstorms are forecast to begin developing by late morning and spreading north-northeast within a strongly sheared environment. Increasing cloud cover and some limit on the quality of lapse rates will temper overall buoyancy. However, some organization into small clusters yielding severe gusts will be the primary threat with the stronger 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. ..Smith/Mosier.. 08/17/2024 Read more

000
ABPZ20 KNHC 171143
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Sat Aug 17 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 showers
and thunderstorms that are beginning to show signs of organization.
Upper-level winds are forecast to be generally conducive for
additional development of this system over the weekend, and a
tropical depression is likely to form by 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...60 percent.
* Formation chance through 7 days...high...90 percent.

Western Portion of the East Pacific:
A broad area of low pressure is expected to form this weekend or
early next week more than one thousand miles west-southwest of the
southern tip of the Baja California peninsula. Thereafter, slow
development of this system is anticipated, and a tropical depression
is 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 located well southeast of the Hawaiian
Islands is associated with some disorganized showers and
thunderstorms. Some development of this system is possible this
weekend into early next week while it moves slowly over the western
portion of the East Pacific or Central Pacific basin. By the middle
of next week, this system could merge with a larger system expected
to develop to its 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 Papin

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sat Aug 17 2024 Valid 201200Z - 251200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... A shortwave ridge over the eastern part of the northern Plains is forecast to deamplify on Tuesday. Further west, the large-scale upper-level ridge is forecast to move eastward across the northern Plains on Tuesday and into the upper Mississippi Valley from Wednesday into Thursday. This feature will move away from a moist axis in the northern Plains, where moderate instability is forecast each afternoon. Thunderstorm development, some with potential for isolated large hail and severe wind gusts, will be possible each day. The greatest severe threat during the mid-week is expected on Wednesday in the Dakotas, where southwest mid-level flow and strong instability is forecast in the wake of the upper-level ridge. ...Friday/Day 7 and Saturday/Day 8... On Friday, some model solutions deepen an upper-level trough over the Intermountain West. In response, the north-central U.S upper-level ridge would move eastward toward the western Great Lakes. Isolated thunderstorms, possibly associated with a severe threat, would be possible within a moist airmass located further to the west from Nebraska into the Dakotas. However, some solutions are slow to move the upper-level trough into the western U.S. This would keep the upper-level ridge further west, negatively impacting the severe potential across the northern Plains. Under this scenario, storm coverage would be more isolated and the severe threat would not be as great. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sat Aug 17 2024 Valid 201200Z - 251200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... A shortwave ridge over the eastern part of the northern Plains is forecast to deamplify on Tuesday. Further west, the large-scale upper-level ridge is forecast to move eastward across the northern Plains on Tuesday and into the upper Mississippi Valley from Wednesday into Thursday. This feature will move away from a moist axis in the northern Plains, where moderate instability is forecast each afternoon. Thunderstorm development, some with potential for isolated large hail and severe wind gusts, will be possible each day. The greatest severe threat during the mid-week is expected on Wednesday in the Dakotas, where southwest mid-level flow and strong instability is forecast in the wake of the upper-level ridge. ...Friday/Day 7 and Saturday/Day 8... On Friday, some model solutions deepen an upper-level trough over the Intermountain West. In response, the north-central U.S upper-level ridge would move eastward toward the western Great Lakes. Isolated thunderstorms, possibly associated with a severe threat, would be possible within a moist airmass located further to the west from Nebraska into the Dakotas. However, some solutions are slow to move the upper-level trough into the western U.S. This would keep the upper-level ridge further west, negatively impacting the severe potential across the northern Plains. Under this scenario, storm coverage would be more isolated and the severe threat would not be as great. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sat Aug 17 2024 Valid 201200Z - 251200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... A shortwave ridge over the eastern part of the northern Plains is forecast to deamplify on Tuesday. Further west, the large-scale upper-level ridge is forecast to move eastward across the northern Plains on Tuesday and into the upper Mississippi Valley from Wednesday into Thursday. This feature will move away from a moist axis in the northern Plains, where moderate instability is forecast each afternoon. Thunderstorm development, some with potential for isolated large hail and severe wind gusts, will be possible each day. The greatest severe threat during the mid-week is expected on Wednesday in the Dakotas, where southwest mid-level flow and strong instability is forecast in the wake of the upper-level ridge. ...Friday/Day 7 and Saturday/Day 8... On Friday, some model solutions deepen an upper-level trough over the Intermountain West. In response, the north-central U.S upper-level ridge would move eastward toward the western Great Lakes. Isolated thunderstorms, possibly associated with a severe threat, would be possible within a moist airmass located further to the west from Nebraska into the Dakotas. However, some solutions are slow to move the upper-level trough into the western U.S. This would keep the upper-level ridge further west, negatively impacting the severe potential across the northern Plains. Under this scenario, storm coverage would be more isolated and the severe threat would not be as great. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sat Aug 17 2024 Valid 201200Z - 251200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... A shortwave ridge over the eastern part of the northern Plains is forecast to deamplify on Tuesday. Further west, the large-scale upper-level ridge is forecast to move eastward across the northern Plains on Tuesday and into the upper Mississippi Valley from Wednesday into Thursday. This feature will move away from a moist axis in the northern Plains, where moderate instability is forecast each afternoon. Thunderstorm development, some with potential for isolated large hail and severe wind gusts, will be possible each day. The greatest severe threat during the mid-week is expected on Wednesday in the Dakotas, where southwest mid-level flow and strong instability is forecast in the wake of the upper-level ridge. ...Friday/Day 7 and Saturday/Day 8... On Friday, some model solutions deepen an upper-level trough over the Intermountain West. In response, the north-central U.S upper-level ridge would move eastward toward the western Great Lakes. Isolated thunderstorms, possibly associated with a severe threat, would be possible within a moist airmass located further to the west from Nebraska into the Dakotas. However, some solutions are slow to move the upper-level trough into the western U.S. This would keep the upper-level ridge further west, negatively impacting the severe potential across the northern Plains. Under this scenario, storm coverage would be more isolated and the severe threat would not be as great. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sat Aug 17 2024 Valid 201200Z - 251200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... A shortwave ridge over the eastern part of the northern Plains is forecast to deamplify on Tuesday. Further west, the large-scale upper-level ridge is forecast to move eastward across the northern Plains on Tuesday and into the upper Mississippi Valley from Wednesday into Thursday. This feature will move away from a moist axis in the northern Plains, where moderate instability is forecast each afternoon. Thunderstorm development, some with potential for isolated large hail and severe wind gusts, will be possible each day. The greatest severe threat during the mid-week is expected on Wednesday in the Dakotas, where southwest mid-level flow and strong instability is forecast in the wake of the upper-level ridge. ...Friday/Day 7 and Saturday/Day 8... On Friday, some model solutions deepen an upper-level trough over the Intermountain West. In response, the north-central U.S upper-level ridge would move eastward toward the western Great Lakes. Isolated thunderstorms, possibly associated with a severe threat, would be possible within a moist airmass located further to the west from Nebraska into the Dakotas. However, some solutions are slow to move the upper-level trough into the western U.S. This would keep the upper-level ridge further west, negatively impacting the severe potential across the northern Plains. Under this scenario, storm coverage would be more isolated and the severe threat would not be as great. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sat Aug 17 2024 Valid 201200Z - 251200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... A shortwave ridge over the eastern part of the northern Plains is forecast to deamplify on Tuesday. Further west, the large-scale upper-level ridge is forecast to move eastward across the northern Plains on Tuesday and into the upper Mississippi Valley from Wednesday into Thursday. This feature will move away from a moist axis in the northern Plains, where moderate instability is forecast each afternoon. Thunderstorm development, some with potential for isolated large hail and severe wind gusts, will be possible each day. The greatest severe threat during the mid-week is expected on Wednesday in the Dakotas, where southwest mid-level flow and strong instability is forecast in the wake of the upper-level ridge. ...Friday/Day 7 and Saturday/Day 8... On Friday, some model solutions deepen an upper-level trough over the Intermountain West. In response, the north-central U.S upper-level ridge would move eastward toward the western Great Lakes. Isolated thunderstorms, possibly associated with a severe threat, would be possible within a moist airmass located further to the west from Nebraska into the Dakotas. However, some solutions are slow to move the upper-level trough into the western U.S. This would keep the upper-level ridge further west, negatively impacting the severe potential across the northern Plains. Under this scenario, storm coverage would be more isolated and the severe threat would not be as great. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Sat Aug 17 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS FROM THE MID-ATLANTIC INTO NORTH CAROLINA...AND ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms, associated with a marginal severe threat, will be possible on Monday in parts of the Mid-Atlantic, North Carolina, and from the central to the northern High Plains. ...Mid-Atlantic/North Carolina... An upper-level trough will move slowly eastward across the southern and central Appalachians on Monday, as a cold front advances southeastward toward the middle Atlantic Coast. Surface dewpoints across most of the Mid-Atlantic into North Carolina are forecast to be in the 60s F, with 70+ surface dewpoints confined to the immediate Atlantic coast. As surface temperatures warm, a pocket of instability will likely develop near and ahead of the front, and in the post-frontal airmass. Scattered thunderstorms are expected to form within these areas as surface temperatures warm during the day. Although low-level lapse rates will become steep in many areas by afternoon, deep-layer shear is forecast to remain relatively weak. The instability could still be strong enough for a marginal severe threat. Isolated strong to severe wind gusts could occur near and around peak heating. ...Central to Northern High Plains... An upper-level ridge is forecast to move across the Central High Plains and northern Plains on Monday. An axis of instability will likely develop during the day to the west of the ridge, from eastern Colorado northward into eastern Montana and western North Dakota. Although large-scale ascent will be weak along this corridor, thunderstorms are expected to form in some areas due to topographical forcing in the central and northern Rockies. More isolated storms will be possible in the lower elevations of the central and northern High Plains. Forecast soundings across the central and northern High Plains have steep low to mid-level lapse rates and sufficient deep-layer shear for a marginal severe threat. Relatively large surface temperature-dewpoint spreads could enhance downdrafts associated with high-based storms. Hail could also accompany the stronger cells, especially further west near the higher terrain. ...Ark-La-Tex... North-northwesterly mid-level flow will be in place across the Ark-La-Tex on Monday. At the surface, a quasi-stationary front is forecast from northeast Texas into Louisiana, where surface dewpoints should be in the lower 70s F. As surface temperatures warm during the day, low-level lapse rates will become steep. This combined with moderate deep-layer shear may support an isolated severe threat. Although there is some uncertainty concerning convective coverage, the forecast environment should be enough for a few marginally severe storms. ..Broyles.. 08/17/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Sat Aug 17 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS FROM THE MID-ATLANTIC INTO NORTH CAROLINA...AND ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms, associated with a marginal severe threat, will be possible on Monday in parts of the Mid-Atlantic, North Carolina, and from the central to the northern High Plains. ...Mid-Atlantic/North Carolina... An upper-level trough will move slowly eastward across the southern and central Appalachians on Monday, as a cold front advances southeastward toward the middle Atlantic Coast. Surface dewpoints across most of the Mid-Atlantic into North Carolina are forecast to be in the 60s F, with 70+ surface dewpoints confined to the immediate Atlantic coast. As surface temperatures warm, a pocket of instability will likely develop near and ahead of the front, and in the post-frontal airmass. Scattered thunderstorms are expected to form within these areas as surface temperatures warm during the day. Although low-level lapse rates will become steep in many areas by afternoon, deep-layer shear is forecast to remain relatively weak. The instability could still be strong enough for a marginal severe threat. Isolated strong to severe wind gusts could occur near and around peak heating. ...Central to Northern High Plains... An upper-level ridge is forecast to move across the Central High Plains and northern Plains on Monday. An axis of instability will likely develop during the day to the west of the ridge, from eastern Colorado northward into eastern Montana and western North Dakota. Although large-scale ascent will be weak along this corridor, thunderstorms are expected to form in some areas due to topographical forcing in the central and northern Rockies. More isolated storms will be possible in the lower elevations of the central and northern High Plains. Forecast soundings across the central and northern High Plains have steep low to mid-level lapse rates and sufficient deep-layer shear for a marginal severe threat. Relatively large surface temperature-dewpoint spreads could enhance downdrafts associated with high-based storms. Hail could also accompany the stronger cells, especially further west near the higher terrain. ...Ark-La-Tex... North-northwesterly mid-level flow will be in place across the Ark-La-Tex on Monday. At the surface, a quasi-stationary front is forecast from northeast Texas into Louisiana, where surface dewpoints should be in the lower 70s F. As surface temperatures warm during the day, low-level lapse rates will become steep. This combined with moderate deep-layer shear may support an isolated severe threat. Although there is some uncertainty concerning convective coverage, the forecast environment should be enough for a few marginally severe storms. ..Broyles.. 08/17/2024 Read more