Aggregator

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 AM CST Tue Dec 19 2023 Valid 191300Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible today across parts of central and northern California. ...DISCUSSION... An upper-level trough will move off the Atlantic Coast today, as an upper-level ridge moves through the Rockies. At the surface, dry and cool air associated with a large surface high in the eastern U.S. will make conditions unfavorable for thunderstorms across most of the continental United States. The only exception will be in central and northern California, where a few thunderstorms will be possible due to an increase of large-scale ascent and mid-level moisture ahead of an eastern Pacific upper-level low. No severe thunderstorms are expected today or tonight. ..Broyles/Thompson.. 12/19/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 AM CST Tue Dec 19 2023 Valid 191300Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible today across parts of central and northern California. ...DISCUSSION... An upper-level trough will move off the Atlantic Coast today, as an upper-level ridge moves through the Rockies. At the surface, dry and cool air associated with a large surface high in the eastern U.S. will make conditions unfavorable for thunderstorms across most of the continental United States. The only exception will be in central and northern California, where a few thunderstorms will be possible due to an increase of large-scale ascent and mid-level moisture ahead of an eastern Pacific upper-level low. No severe thunderstorms are expected today or tonight. ..Broyles/Thompson.. 12/19/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 AM CST Tue Dec 19 2023 Valid 191300Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible today across parts of central and northern California. ...DISCUSSION... An upper-level trough will move off the Atlantic Coast today, as an upper-level ridge moves through the Rockies. At the surface, dry and cool air associated with a large surface high in the eastern U.S. will make conditions unfavorable for thunderstorms across most of the continental United States. The only exception will be in central and northern California, where a few thunderstorms will be possible due to an increase of large-scale ascent and mid-level moisture ahead of an eastern Pacific upper-level low. No severe thunderstorms are expected today or tonight. ..Broyles/Thompson.. 12/19/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 AM CST Tue Dec 19 2023 Valid 191300Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible today across parts of central and northern California. ...DISCUSSION... An upper-level trough will move off the Atlantic Coast today, as an upper-level ridge moves through the Rockies. At the surface, dry and cool air associated with a large surface high in the eastern U.S. will make conditions unfavorable for thunderstorms across most of the continental United States. The only exception will be in central and northern California, where a few thunderstorms will be possible due to an increase of large-scale ascent and mid-level moisture ahead of an eastern Pacific upper-level low. No severe thunderstorms are expected today or tonight. ..Broyles/Thompson.. 12/19/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0655 AM CST Tue Dec 19 2023 Valid 191300Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible today across parts of central and northern California. ...DISCUSSION... An upper-level trough will move off the Atlantic Coast today, as an upper-level ridge moves through the Rockies. At the surface, dry and cool air associated with a large surface high in the eastern U.S. will make conditions unfavorable for thunderstorms across most of the continental United States. The only exception will be in central and northern California, where a few thunderstorms will be possible due to an increase of large-scale ascent and mid-level moisture ahead of an eastern Pacific upper-level low. No severe thunderstorms are expected today or tonight. ..Broyles/Thompson.. 12/19/2023 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CST Tue Dec 19 2023 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance remains in good agreement with the evolution of the upper low expected to be just off the southern CA coast early D4/Friday morning. General expectation for the system to become more progressive, tracking over southern CA/northern Baja and into AZ on D4/Friday, and across the southern High Plains and into the southern/central Plains on D5/Saturday. A moderately warm and moist air mass will likely be in place over the southern Plains, contributing to the potential for showers and thunderstorms as the system moves through. Shear will be strong enough to support organized convection, but whether buoyancy will be large enough to support deep, sustained updrafts remains in question. Another shortwave trough will follow quickly in the wake of the first, with the current expectation taking this system through the Plains on D7/Monday. Guidance suggests colder air will accompany this system, with a strong cold front expected to push across the central and southern Plains on D7/Monday. Some thunderstorms are possible along this front over the southern Plains, although uncertainty regarding the quality of the low-level moisture preceding it limit predictability. Guidance is beginning to suggest this shortwave will continue within the southern stream after D7/Monday, intensifying as it moves across the Southeast during the middle of next week. This intensification, if realized, could lead to some severe potential over the Southeast and Mid-Atlantic during the second half of next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CST Tue Dec 19 2023 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance remains in good agreement with the evolution of the upper low expected to be just off the southern CA coast early D4/Friday morning. General expectation for the system to become more progressive, tracking over southern CA/northern Baja and into AZ on D4/Friday, and across the southern High Plains and into the southern/central Plains on D5/Saturday. A moderately warm and moist air mass will likely be in place over the southern Plains, contributing to the potential for showers and thunderstorms as the system moves through. Shear will be strong enough to support organized convection, but whether buoyancy will be large enough to support deep, sustained updrafts remains in question. Another shortwave trough will follow quickly in the wake of the first, with the current expectation taking this system through the Plains on D7/Monday. Guidance suggests colder air will accompany this system, with a strong cold front expected to push across the central and southern Plains on D7/Monday. Some thunderstorms are possible along this front over the southern Plains, although uncertainty regarding the quality of the low-level moisture preceding it limit predictability. Guidance is beginning to suggest this shortwave will continue within the southern stream after D7/Monday, intensifying as it moves across the Southeast during the middle of next week. This intensification, if realized, could lead to some severe potential over the Southeast and Mid-Atlantic during the second half of next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CST Tue Dec 19 2023 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance remains in good agreement with the evolution of the upper low expected to be just off the southern CA coast early D4/Friday morning. General expectation for the system to become more progressive, tracking over southern CA/northern Baja and into AZ on D4/Friday, and across the southern High Plains and into the southern/central Plains on D5/Saturday. A moderately warm and moist air mass will likely be in place over the southern Plains, contributing to the potential for showers and thunderstorms as the system moves through. Shear will be strong enough to support organized convection, but whether buoyancy will be large enough to support deep, sustained updrafts remains in question. Another shortwave trough will follow quickly in the wake of the first, with the current expectation taking this system through the Plains on D7/Monday. Guidance suggests colder air will accompany this system, with a strong cold front expected to push across the central and southern Plains on D7/Monday. Some thunderstorms are possible along this front over the southern Plains, although uncertainty regarding the quality of the low-level moisture preceding it limit predictability. Guidance is beginning to suggest this shortwave will continue within the southern stream after D7/Monday, intensifying as it moves across the Southeast during the middle of next week. This intensification, if realized, could lead to some severe potential over the Southeast and Mid-Atlantic during the second half of next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CST Tue Dec 19 2023 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance remains in good agreement with the evolution of the upper low expected to be just off the southern CA coast early D4/Friday morning. General expectation for the system to become more progressive, tracking over southern CA/northern Baja and into AZ on D4/Friday, and across the southern High Plains and into the southern/central Plains on D5/Saturday. A moderately warm and moist air mass will likely be in place over the southern Plains, contributing to the potential for showers and thunderstorms as the system moves through. Shear will be strong enough to support organized convection, but whether buoyancy will be large enough to support deep, sustained updrafts remains in question. Another shortwave trough will follow quickly in the wake of the first, with the current expectation taking this system through the Plains on D7/Monday. Guidance suggests colder air will accompany this system, with a strong cold front expected to push across the central and southern Plains on D7/Monday. Some thunderstorms are possible along this front over the southern Plains, although uncertainty regarding the quality of the low-level moisture preceding it limit predictability. Guidance is beginning to suggest this shortwave will continue within the southern stream after D7/Monday, intensifying as it moves across the Southeast during the middle of next week. This intensification, if realized, could lead to some severe potential over the Southeast and Mid-Atlantic during the second half of next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CST Tue Dec 19 2023 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance remains in good agreement with the evolution of the upper low expected to be just off the southern CA coast early D4/Friday morning. General expectation for the system to become more progressive, tracking over southern CA/northern Baja and into AZ on D4/Friday, and across the southern High Plains and into the southern/central Plains on D5/Saturday. A moderately warm and moist air mass will likely be in place over the southern Plains, contributing to the potential for showers and thunderstorms as the system moves through. Shear will be strong enough to support organized convection, but whether buoyancy will be large enough to support deep, sustained updrafts remains in question. Another shortwave trough will follow quickly in the wake of the first, with the current expectation taking this system through the Plains on D7/Monday. Guidance suggests colder air will accompany this system, with a strong cold front expected to push across the central and southern Plains on D7/Monday. Some thunderstorms are possible along this front over the southern Plains, although uncertainty regarding the quality of the low-level moisture preceding it limit predictability. Guidance is beginning to suggest this shortwave will continue within the southern stream after D7/Monday, intensifying as it moves across the Southeast during the middle of next week. This intensification, if realized, could lead to some severe potential over the Southeast and Mid-Atlantic during the second half of next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CST Tue Dec 19 2023 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance remains in good agreement with the evolution of the upper low expected to be just off the southern CA coast early D4/Friday morning. General expectation for the system to become more progressive, tracking over southern CA/northern Baja and into AZ on D4/Friday, and across the southern High Plains and into the southern/central Plains on D5/Saturday. A moderately warm and moist air mass will likely be in place over the southern Plains, contributing to the potential for showers and thunderstorms as the system moves through. Shear will be strong enough to support organized convection, but whether buoyancy will be large enough to support deep, sustained updrafts remains in question. Another shortwave trough will follow quickly in the wake of the first, with the current expectation taking this system through the Plains on D7/Monday. Guidance suggests colder air will accompany this system, with a strong cold front expected to push across the central and southern Plains on D7/Monday. Some thunderstorms are possible along this front over the southern Plains, although uncertainty regarding the quality of the low-level moisture preceding it limit predictability. Guidance is beginning to suggest this shortwave will continue within the southern stream after D7/Monday, intensifying as it moves across the Southeast during the middle of next week. This intensification, if realized, could lead to some severe potential over the Southeast and Mid-Atlantic during the second half of next week. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CST Tue Dec 19 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as the Arizona Lower Desert, on Thursday. ...Synopsis... A low-amplitude shortwave trough is forecast to progress steadily eastward from the southern High Plains through the southern Plains on Thursday. Modest low-level moisture will be in place ahead of this wave, with surface dewpoints likely in the mid to upper 50s across much of TX by Thursday afternoon. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor lapse rates should significantly limit buoyancy. This limited buoyancy will keep updrafts weak and too shallow to produce lightning. Farther west, an upper low is expected to begin the period centered off the southern CA coast. This low is then expected to track southeastward throughout the day, ending the period centered about 200 miles west-southwest of SAN. Strong forcing for ascent and cold mid-level temperatures will help support isolated thunderstorms, with the highest storm coverage anticipated over the immediate coastal areas. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward into the AZ Lower Desert early Friday morning. ..Mosier.. 12/19/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CST Tue Dec 19 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as the Arizona Lower Desert, on Thursday. ...Synopsis... A low-amplitude shortwave trough is forecast to progress steadily eastward from the southern High Plains through the southern Plains on Thursday. Modest low-level moisture will be in place ahead of this wave, with surface dewpoints likely in the mid to upper 50s across much of TX by Thursday afternoon. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor lapse rates should significantly limit buoyancy. This limited buoyancy will keep updrafts weak and too shallow to produce lightning. Farther west, an upper low is expected to begin the period centered off the southern CA coast. This low is then expected to track southeastward throughout the day, ending the period centered about 200 miles west-southwest of SAN. Strong forcing for ascent and cold mid-level temperatures will help support isolated thunderstorms, with the highest storm coverage anticipated over the immediate coastal areas. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward into the AZ Lower Desert early Friday morning. ..Mosier.. 12/19/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CST Tue Dec 19 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as the Arizona Lower Desert, on Thursday. ...Synopsis... A low-amplitude shortwave trough is forecast to progress steadily eastward from the southern High Plains through the southern Plains on Thursday. Modest low-level moisture will be in place ahead of this wave, with surface dewpoints likely in the mid to upper 50s across much of TX by Thursday afternoon. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor lapse rates should significantly limit buoyancy. This limited buoyancy will keep updrafts weak and too shallow to produce lightning. Farther west, an upper low is expected to begin the period centered off the southern CA coast. This low is then expected to track southeastward throughout the day, ending the period centered about 200 miles west-southwest of SAN. Strong forcing for ascent and cold mid-level temperatures will help support isolated thunderstorms, with the highest storm coverage anticipated over the immediate coastal areas. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward into the AZ Lower Desert early Friday morning. ..Mosier.. 12/19/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CST Tue Dec 19 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as the Arizona Lower Desert, on Thursday. ...Synopsis... A low-amplitude shortwave trough is forecast to progress steadily eastward from the southern High Plains through the southern Plains on Thursday. Modest low-level moisture will be in place ahead of this wave, with surface dewpoints likely in the mid to upper 50s across much of TX by Thursday afternoon. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor lapse rates should significantly limit buoyancy. This limited buoyancy will keep updrafts weak and too shallow to produce lightning. Farther west, an upper low is expected to begin the period centered off the southern CA coast. This low is then expected to track southeastward throughout the day, ending the period centered about 200 miles west-southwest of SAN. Strong forcing for ascent and cold mid-level temperatures will help support isolated thunderstorms, with the highest storm coverage anticipated over the immediate coastal areas. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward into the AZ Lower Desert early Friday morning. ..Mosier.. 12/19/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CST Tue Dec 19 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as the Arizona Lower Desert, on Thursday. ...Synopsis... A low-amplitude shortwave trough is forecast to progress steadily eastward from the southern High Plains through the southern Plains on Thursday. Modest low-level moisture will be in place ahead of this wave, with surface dewpoints likely in the mid to upper 50s across much of TX by Thursday afternoon. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor lapse rates should significantly limit buoyancy. This limited buoyancy will keep updrafts weak and too shallow to produce lightning. Farther west, an upper low is expected to begin the period centered off the southern CA coast. This low is then expected to track southeastward throughout the day, ending the period centered about 200 miles west-southwest of SAN. Strong forcing for ascent and cold mid-level temperatures will help support isolated thunderstorms, with the highest storm coverage anticipated over the immediate coastal areas. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward into the AZ Lower Desert early Friday morning. ..Mosier.. 12/19/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CST Tue Dec 19 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as the Arizona Lower Desert, on Thursday. ...Synopsis... A low-amplitude shortwave trough is forecast to progress steadily eastward from the southern High Plains through the southern Plains on Thursday. Modest low-level moisture will be in place ahead of this wave, with surface dewpoints likely in the mid to upper 50s across much of TX by Thursday afternoon. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor lapse rates should significantly limit buoyancy. This limited buoyancy will keep updrafts weak and too shallow to produce lightning. Farther west, an upper low is expected to begin the period centered off the southern CA coast. This low is then expected to track southeastward throughout the day, ending the period centered about 200 miles west-southwest of SAN. Strong forcing for ascent and cold mid-level temperatures will help support isolated thunderstorms, with the highest storm coverage anticipated over the immediate coastal areas. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward into the AZ Lower Desert early Friday morning. ..Mosier.. 12/19/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CST Tue Dec 19 2023 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated lightning flashes are possible along the central and southern California coast and over portions of the Southwest on Wednesday. ...Synopsis... A dry continental air mass is expected to persist across the eastern CONUS on Wednesday, dominating the sensible weather over the region. Some modest air mass modification is anticipated across the southern Plains as a series of low-amplitude shortwave troughs move through the southwestern flow extending from the Southwest into the Plains. Some precipitation is possible in vicinity of these waves over the southern Plains, but thermodynamic conditions are not expected to support lightning production. Deeper convection is possible Wednesday afternoon farther west across portions of AZ and NM, and mid-level temperatures may be cool enough for modest buoyancy. Consequently, some isolated lightning flashes are possible as a shortwave trough moves through. Even farther west, an upper low is forecast to begin the period centered about 285 miles west-southwest of SFO, before then progressing southward/south-southwestward throughout the period. Expectation is for this low to end the period off the southern CA coast, about 250 miles west-southwest of VBG. Persistent southwesterly flow aloft will help keep profiles moist over much of the central and southern CA coast. Mid-level temperatures across this region are expected to cool throughout the day as the upper low move southward. Modest buoyancy associated with these cooling profiles could support isolated lightning flashes within any deeper, more sustained updrafts. ..Mosier.. 12/19/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CST Tue Dec 19 2023 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated lightning flashes are possible along the central and southern California coast and over portions of the Southwest on Wednesday. ...Synopsis... A dry continental air mass is expected to persist across the eastern CONUS on Wednesday, dominating the sensible weather over the region. Some modest air mass modification is anticipated across the southern Plains as a series of low-amplitude shortwave troughs move through the southwestern flow extending from the Southwest into the Plains. Some precipitation is possible in vicinity of these waves over the southern Plains, but thermodynamic conditions are not expected to support lightning production. Deeper convection is possible Wednesday afternoon farther west across portions of AZ and NM, and mid-level temperatures may be cool enough for modest buoyancy. Consequently, some isolated lightning flashes are possible as a shortwave trough moves through. Even farther west, an upper low is forecast to begin the period centered about 285 miles west-southwest of SFO, before then progressing southward/south-southwestward throughout the period. Expectation is for this low to end the period off the southern CA coast, about 250 miles west-southwest of VBG. Persistent southwesterly flow aloft will help keep profiles moist over much of the central and southern CA coast. Mid-level temperatures across this region are expected to cool throughout the day as the upper low move southward. Modest buoyancy associated with these cooling profiles could support isolated lightning flashes within any deeper, more sustained updrafts. ..Mosier.. 12/19/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CST Tue Dec 19 2023 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated lightning flashes are possible along the central and southern California coast and over portions of the Southwest on Wednesday. ...Synopsis... A dry continental air mass is expected to persist across the eastern CONUS on Wednesday, dominating the sensible weather over the region. Some modest air mass modification is anticipated across the southern Plains as a series of low-amplitude shortwave troughs move through the southwestern flow extending from the Southwest into the Plains. Some precipitation is possible in vicinity of these waves over the southern Plains, but thermodynamic conditions are not expected to support lightning production. Deeper convection is possible Wednesday afternoon farther west across portions of AZ and NM, and mid-level temperatures may be cool enough for modest buoyancy. Consequently, some isolated lightning flashes are possible as a shortwave trough moves through. Even farther west, an upper low is forecast to begin the period centered about 285 miles west-southwest of SFO, before then progressing southward/south-southwestward throughout the period. Expectation is for this low to end the period off the southern CA coast, about 250 miles west-southwest of VBG. Persistent southwesterly flow aloft will help keep profiles moist over much of the central and southern CA coast. Mid-level temperatures across this region are expected to cool throughout the day as the upper low move southward. Modest buoyancy associated with these cooling profiles could support isolated lightning flashes within any deeper, more sustained updrafts. ..Mosier.. 12/19/2023 Read more