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SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 PM CST Fri Nov 17 2023 Valid 181200Z - 191200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely today. ...Synopsis... An amplified yet progressive upper-air pattern will exist today across the CONUS. A mean upper trough will develop over the eastern states, with southern and northern stream phasing from New England to FL. The cooling aloft across FL could yield a few showers or thunderstorms grazing the eastern coastal areas, but most of the activity is expected to remain offshore. However, northwest surface winds may enhance convergence immediately along the coast and an isolated cell cannot be ruled out. The greatest chance of thunderstorms will develop throughout the period, from parts of the southwest into the southern and central High Plains. ...Southwest/Southern Plains... Height falls will occur over the Four Corners states during the day as a low-amplitude wave enters the southern High Plains late. Storms will be ongoing over AZ this morning, with additional midlevel moistening and lift spreading over NM. Diurnal heating will lead to a few hundred J/kg MUCAPE during the day, with perhaps 500 J/kg of elevated CAPE into KS/OK/northwest TX overnight as a low-level jet strengthens. Forecast sounding over NM and western TX do show long hodographs and strong deep-layer shear. This may actually reduce damaging gust potential as storm mode trends toward cellular with strong storm relative flow aloft removing potential downdraft material. Assuming a cellular mode, the primary risk typically trends toward hail, but instability will be relatively weak in this case. The end result should be scattered storms capable of perhaps strong gusts or small, non-severe hail, and little severe risk. ..Jewell/Lyons.. 11/18/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 PM CST Fri Nov 17 2023 Valid 181200Z - 191200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely today. ...Synopsis... An amplified yet progressive upper-air pattern will exist today across the CONUS. A mean upper trough will develop over the eastern states, with southern and northern stream phasing from New England to FL. The cooling aloft across FL could yield a few showers or thunderstorms grazing the eastern coastal areas, but most of the activity is expected to remain offshore. However, northwest surface winds may enhance convergence immediately along the coast and an isolated cell cannot be ruled out. The greatest chance of thunderstorms will develop throughout the period, from parts of the southwest into the southern and central High Plains. ...Southwest/Southern Plains... Height falls will occur over the Four Corners states during the day as a low-amplitude wave enters the southern High Plains late. Storms will be ongoing over AZ this morning, with additional midlevel moistening and lift spreading over NM. Diurnal heating will lead to a few hundred J/kg MUCAPE during the day, with perhaps 500 J/kg of elevated CAPE into KS/OK/northwest TX overnight as a low-level jet strengthens. Forecast sounding over NM and western TX do show long hodographs and strong deep-layer shear. This may actually reduce damaging gust potential as storm mode trends toward cellular with strong storm relative flow aloft removing potential downdraft material. Assuming a cellular mode, the primary risk typically trends toward hail, but instability will be relatively weak in this case. The end result should be scattered storms capable of perhaps strong gusts or small, non-severe hail, and little severe risk. ..Jewell/Lyons.. 11/18/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 PM CST Fri Nov 17 2023 Valid 181200Z - 191200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely today. ...Synopsis... An amplified yet progressive upper-air pattern will exist today across the CONUS. A mean upper trough will develop over the eastern states, with southern and northern stream phasing from New England to FL. The cooling aloft across FL could yield a few showers or thunderstorms grazing the eastern coastal areas, but most of the activity is expected to remain offshore. However, northwest surface winds may enhance convergence immediately along the coast and an isolated cell cannot be ruled out. The greatest chance of thunderstorms will develop throughout the period, from parts of the southwest into the southern and central High Plains. ...Southwest/Southern Plains... Height falls will occur over the Four Corners states during the day as a low-amplitude wave enters the southern High Plains late. Storms will be ongoing over AZ this morning, with additional midlevel moistening and lift spreading over NM. Diurnal heating will lead to a few hundred J/kg MUCAPE during the day, with perhaps 500 J/kg of elevated CAPE into KS/OK/northwest TX overnight as a low-level jet strengthens. Forecast sounding over NM and western TX do show long hodographs and strong deep-layer shear. This may actually reduce damaging gust potential as storm mode trends toward cellular with strong storm relative flow aloft removing potential downdraft material. Assuming a cellular mode, the primary risk typically trends toward hail, but instability will be relatively weak in this case. The end result should be scattered storms capable of perhaps strong gusts or small, non-severe hail, and little severe risk. ..Jewell/Lyons.. 11/18/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 PM CST Fri Nov 17 2023 Valid 181200Z - 191200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely today. ...Synopsis... An amplified yet progressive upper-air pattern will exist today across the CONUS. A mean upper trough will develop over the eastern states, with southern and northern stream phasing from New England to FL. The cooling aloft across FL could yield a few showers or thunderstorms grazing the eastern coastal areas, but most of the activity is expected to remain offshore. However, northwest surface winds may enhance convergence immediately along the coast and an isolated cell cannot be ruled out. The greatest chance of thunderstorms will develop throughout the period, from parts of the southwest into the southern and central High Plains. ...Southwest/Southern Plains... Height falls will occur over the Four Corners states during the day as a low-amplitude wave enters the southern High Plains late. Storms will be ongoing over AZ this morning, with additional midlevel moistening and lift spreading over NM. Diurnal heating will lead to a few hundred J/kg MUCAPE during the day, with perhaps 500 J/kg of elevated CAPE into KS/OK/northwest TX overnight as a low-level jet strengthens. Forecast sounding over NM and western TX do show long hodographs and strong deep-layer shear. This may actually reduce damaging gust potential as storm mode trends toward cellular with strong storm relative flow aloft removing potential downdraft material. Assuming a cellular mode, the primary risk typically trends toward hail, but instability will be relatively weak in this case. The end result should be scattered storms capable of perhaps strong gusts or small, non-severe hail, and little severe risk. ..Jewell/Lyons.. 11/18/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0630 PM CST Fri Nov 17 2023 Valid 180100Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered storms are most likely late tonight over central Arizona. ...Discussion... Meager moisture ahead of a cold front has aided sporadic lightning flashes this evening over eastern KY, where diurnal effects have led to a few hundred J/kg MUCAPE. This activity should wane through the evening, as the upper trough passes by and the boundary layer cools. Far to the west, lightning activity has decreased over the ocean, with only a few flashes noted over the past hour. Cold temperatures aloft will however maintain a weakly unstable environment supporting convective showers. Farther south into AZ, a greater threat of thunderstorms is forecast, as the nose of a 70 kt midlevel speed max approaches from the west. Increasing southwest flow with result in both increasing midlevel moisture and lift across the Mogollon Rim. As such, scattered storms are likely after about 08Z. Long hodographs as well as steepening midlevel lapse rates may support cells capable of small/non-severe hail toward morning. ..Jewell.. 11/18/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0630 PM CST Fri Nov 17 2023 Valid 180100Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered storms are most likely late tonight over central Arizona. ...Discussion... Meager moisture ahead of a cold front has aided sporadic lightning flashes this evening over eastern KY, where diurnal effects have led to a few hundred J/kg MUCAPE. This activity should wane through the evening, as the upper trough passes by and the boundary layer cools. Far to the west, lightning activity has decreased over the ocean, with only a few flashes noted over the past hour. Cold temperatures aloft will however maintain a weakly unstable environment supporting convective showers. Farther south into AZ, a greater threat of thunderstorms is forecast, as the nose of a 70 kt midlevel speed max approaches from the west. Increasing southwest flow with result in both increasing midlevel moisture and lift across the Mogollon Rim. As such, scattered storms are likely after about 08Z. Long hodographs as well as steepening midlevel lapse rates may support cells capable of small/non-severe hail toward morning. ..Jewell.. 11/18/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0630 PM CST Fri Nov 17 2023 Valid 180100Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered storms are most likely late tonight over central Arizona. ...Discussion... Meager moisture ahead of a cold front has aided sporadic lightning flashes this evening over eastern KY, where diurnal effects have led to a few hundred J/kg MUCAPE. This activity should wane through the evening, as the upper trough passes by and the boundary layer cools. Far to the west, lightning activity has decreased over the ocean, with only a few flashes noted over the past hour. Cold temperatures aloft will however maintain a weakly unstable environment supporting convective showers. Farther south into AZ, a greater threat of thunderstorms is forecast, as the nose of a 70 kt midlevel speed max approaches from the west. Increasing southwest flow with result in both increasing midlevel moisture and lift across the Mogollon Rim. As such, scattered storms are likely after about 08Z. Long hodographs as well as steepening midlevel lapse rates may support cells capable of small/non-severe hail toward morning. ..Jewell.. 11/18/2023 Read more

No watches are valid as of Fri Nov 17 21:57:01 UTC 2023.

No Mesoscale Discussions are in effect as of Fri Nov 17 21:57:01 UTC 2023.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0335 PM CST Fri Nov 17 2023 Valid 191200Z - 251200Z A strong upper-level trough will dig into the Southwest late this weekend and continue eastward through the Southeast. While ridging aloft will quickly build in the West behind this features, another trough is forecast to take a similar path mid/late next week. At the surface, a cold front will move through the southern Plains early next week with another expected as the second trough moves eastward late next week into the weekend. ...Southern High Plains... With the approach of the trough this weekend, areas of dry and breezy conditions will be possible. Precipitation associated with the trough will occur within parts of the region, but some areas may not receive much rainfall. At present, the driest conditions appear most likely from the Trans-Pecos into the South Plains. Additional dry and windy conditions are possible toward the end of next week with the next trough forecast to move into the region. Given the potential for precipitation and the cooler temperatures behind the initial cold front, the threat of critical fire weather remains low at this time. ...Southern California... Model guidance continues to suggest potential for strong northerly/northeasterly wind even late Sunday into Monday afternoon. Given the upper-level wind support along the western flank of the trough, strong wind gusts will be likely, particularly within the terrain. Even with dry and windy conditions, current fuel information, in addition to the rain expected to occur into this Saturday, suggests fire weather risk with this event does not appear to be high. ..Wendt.. 11/17/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0335 PM CST Fri Nov 17 2023 Valid 191200Z - 251200Z A strong upper-level trough will dig into the Southwest late this weekend and continue eastward through the Southeast. While ridging aloft will quickly build in the West behind this features, another trough is forecast to take a similar path mid/late next week. At the surface, a cold front will move through the southern Plains early next week with another expected as the second trough moves eastward late next week into the weekend. ...Southern High Plains... With the approach of the trough this weekend, areas of dry and breezy conditions will be possible. Precipitation associated with the trough will occur within parts of the region, but some areas may not receive much rainfall. At present, the driest conditions appear most likely from the Trans-Pecos into the South Plains. Additional dry and windy conditions are possible toward the end of next week with the next trough forecast to move into the region. Given the potential for precipitation and the cooler temperatures behind the initial cold front, the threat of critical fire weather remains low at this time. ...Southern California... Model guidance continues to suggest potential for strong northerly/northeasterly wind even late Sunday into Monday afternoon. Given the upper-level wind support along the western flank of the trough, strong wind gusts will be likely, particularly within the terrain. Even with dry and windy conditions, current fuel information, in addition to the rain expected to occur into this Saturday, suggests fire weather risk with this event does not appear to be high. ..Wendt.. 11/17/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0335 PM CST Fri Nov 17 2023 Valid 191200Z - 251200Z A strong upper-level trough will dig into the Southwest late this weekend and continue eastward through the Southeast. While ridging aloft will quickly build in the West behind this features, another trough is forecast to take a similar path mid/late next week. At the surface, a cold front will move through the southern Plains early next week with another expected as the second trough moves eastward late next week into the weekend. ...Southern High Plains... With the approach of the trough this weekend, areas of dry and breezy conditions will be possible. Precipitation associated with the trough will occur within parts of the region, but some areas may not receive much rainfall. At present, the driest conditions appear most likely from the Trans-Pecos into the South Plains. Additional dry and windy conditions are possible toward the end of next week with the next trough forecast to move into the region. Given the potential for precipitation and the cooler temperatures behind the initial cold front, the threat of critical fire weather remains low at this time. ...Southern California... Model guidance continues to suggest potential for strong northerly/northeasterly wind even late Sunday into Monday afternoon. Given the upper-level wind support along the western flank of the trough, strong wind gusts will be likely, particularly within the terrain. Even with dry and windy conditions, current fuel information, in addition to the rain expected to occur into this Saturday, suggests fire weather risk with this event does not appear to be high. ..Wendt.. 11/17/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0335 PM CST Fri Nov 17 2023 Valid 191200Z - 251200Z A strong upper-level trough will dig into the Southwest late this weekend and continue eastward through the Southeast. While ridging aloft will quickly build in the West behind this features, another trough is forecast to take a similar path mid/late next week. At the surface, a cold front will move through the southern Plains early next week with another expected as the second trough moves eastward late next week into the weekend. ...Southern High Plains... With the approach of the trough this weekend, areas of dry and breezy conditions will be possible. Precipitation associated with the trough will occur within parts of the region, but some areas may not receive much rainfall. At present, the driest conditions appear most likely from the Trans-Pecos into the South Plains. Additional dry and windy conditions are possible toward the end of next week with the next trough forecast to move into the region. Given the potential for precipitation and the cooler temperatures behind the initial cold front, the threat of critical fire weather remains low at this time. ...Southern California... Model guidance continues to suggest potential for strong northerly/northeasterly wind even late Sunday into Monday afternoon. Given the upper-level wind support along the western flank of the trough, strong wind gusts will be likely, particularly within the terrain. Even with dry and windy conditions, current fuel information, in addition to the rain expected to occur into this Saturday, suggests fire weather risk with this event does not appear to be high. ..Wendt.. 11/17/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0335 PM CST Fri Nov 17 2023 Valid 191200Z - 251200Z A strong upper-level trough will dig into the Southwest late this weekend and continue eastward through the Southeast. While ridging aloft will quickly build in the West behind this features, another trough is forecast to take a similar path mid/late next week. At the surface, a cold front will move through the southern Plains early next week with another expected as the second trough moves eastward late next week into the weekend. ...Southern High Plains... With the approach of the trough this weekend, areas of dry and breezy conditions will be possible. Precipitation associated with the trough will occur within parts of the region, but some areas may not receive much rainfall. At present, the driest conditions appear most likely from the Trans-Pecos into the South Plains. Additional dry and windy conditions are possible toward the end of next week with the next trough forecast to move into the region. Given the potential for precipitation and the cooler temperatures behind the initial cold front, the threat of critical fire weather remains low at this time. ...Southern California... Model guidance continues to suggest potential for strong northerly/northeasterly wind even late Sunday into Monday afternoon. Given the upper-level wind support along the western flank of the trough, strong wind gusts will be likely, particularly within the terrain. Even with dry and windy conditions, current fuel information, in addition to the rain expected to occur into this Saturday, suggests fire weather risk with this event does not appear to be high. ..Wendt.. 11/17/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Fri Nov 17 2023 Valid 172000Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Discussion... No appreciable change was made to the previous convective outlook. ..Smith.. 11/17/2023 .PREV DISCUSSION... /ISSUED 1031 AM CST Fri Nov 17 2023/ ...Discussion... A long-wave trough will continue advancing eastward across eastern North America today, accompanied by a southeastward surface cold-frontal advance across the eastern half of the country. By late in the period, this front will have cleared most of the southern and eastern U.S., with northerly low-level flow prevailing. Farther west, an upper low off the California coast is forecast to weaken, moving inland as an open wave through the period. Showers will continue over eastern Florida this afternoon near a weak offshore surface low, though most lightning should remain confined to the immediate coastal areas, and offshore. Meanwhile, as the aforementioned cold front advances, showers and possibly a thunderstorm or two will affect portions of the Ohio Valley and central Appalachians today. Overnight, as the front crosses the East Coast states, a few lightning flashes may occur near the North Carolina Outer Banks. Finally, thunder may occur across portions of California and Arizona, ahead of the advancing upper system. In all of these areas, severe weather is not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Fri Nov 17 2023 Valid 172000Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Discussion... No appreciable change was made to the previous convective outlook. ..Smith.. 11/17/2023 .PREV DISCUSSION... /ISSUED 1031 AM CST Fri Nov 17 2023/ ...Discussion... A long-wave trough will continue advancing eastward across eastern North America today, accompanied by a southeastward surface cold-frontal advance across the eastern half of the country. By late in the period, this front will have cleared most of the southern and eastern U.S., with northerly low-level flow prevailing. Farther west, an upper low off the California coast is forecast to weaken, moving inland as an open wave through the period. Showers will continue over eastern Florida this afternoon near a weak offshore surface low, though most lightning should remain confined to the immediate coastal areas, and offshore. Meanwhile, as the aforementioned cold front advances, showers and possibly a thunderstorm or two will affect portions of the Ohio Valley and central Appalachians today. Overnight, as the front crosses the East Coast states, a few lightning flashes may occur near the North Carolina Outer Banks. Finally, thunder may occur across portions of California and Arizona, ahead of the advancing upper system. In all of these areas, severe weather is not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Fri Nov 17 2023 Valid 172000Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Discussion... No appreciable change was made to the previous convective outlook. ..Smith.. 11/17/2023 .PREV DISCUSSION... /ISSUED 1031 AM CST Fri Nov 17 2023/ ...Discussion... A long-wave trough will continue advancing eastward across eastern North America today, accompanied by a southeastward surface cold-frontal advance across the eastern half of the country. By late in the period, this front will have cleared most of the southern and eastern U.S., with northerly low-level flow prevailing. Farther west, an upper low off the California coast is forecast to weaken, moving inland as an open wave through the period. Showers will continue over eastern Florida this afternoon near a weak offshore surface low, though most lightning should remain confined to the immediate coastal areas, and offshore. Meanwhile, as the aforementioned cold front advances, showers and possibly a thunderstorm or two will affect portions of the Ohio Valley and central Appalachians today. Overnight, as the front crosses the East Coast states, a few lightning flashes may occur near the North Carolina Outer Banks. Finally, thunder may occur across portions of California and Arizona, ahead of the advancing upper system. In all of these areas, severe weather is not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Fri Nov 17 2023 Valid 172000Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Discussion... No appreciable change was made to the previous convective outlook. ..Smith.. 11/17/2023 .PREV DISCUSSION... /ISSUED 1031 AM CST Fri Nov 17 2023/ ...Discussion... A long-wave trough will continue advancing eastward across eastern North America today, accompanied by a southeastward surface cold-frontal advance across the eastern half of the country. By late in the period, this front will have cleared most of the southern and eastern U.S., with northerly low-level flow prevailing. Farther west, an upper low off the California coast is forecast to weaken, moving inland as an open wave through the period. Showers will continue over eastern Florida this afternoon near a weak offshore surface low, though most lightning should remain confined to the immediate coastal areas, and offshore. Meanwhile, as the aforementioned cold front advances, showers and possibly a thunderstorm or two will affect portions of the Ohio Valley and central Appalachians today. Overnight, as the front crosses the East Coast states, a few lightning flashes may occur near the North Carolina Outer Banks. Finally, thunder may occur across portions of California and Arizona, ahead of the advancing upper system. In all of these areas, severe weather is not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Fri Nov 17 2023 Valid 172000Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Discussion... No appreciable change was made to the previous convective outlook. ..Smith.. 11/17/2023 .PREV DISCUSSION... /ISSUED 1031 AM CST Fri Nov 17 2023/ ...Discussion... A long-wave trough will continue advancing eastward across eastern North America today, accompanied by a southeastward surface cold-frontal advance across the eastern half of the country. By late in the period, this front will have cleared most of the southern and eastern U.S., with northerly low-level flow prevailing. Farther west, an upper low off the California coast is forecast to weaken, moving inland as an open wave through the period. Showers will continue over eastern Florida this afternoon near a weak offshore surface low, though most lightning should remain confined to the immediate coastal areas, and offshore. Meanwhile, as the aforementioned cold front advances, showers and possibly a thunderstorm or two will affect portions of the Ohio Valley and central Appalachians today. Overnight, as the front crosses the East Coast states, a few lightning flashes may occur near the North Carolina Outer Banks. Finally, thunder may occur across portions of California and Arizona, ahead of the advancing upper system. In all of these areas, severe weather is not expected. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Fri Nov 17 2023 Valid 172000Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Discussion... No appreciable change was made to the previous convective outlook. ..Smith.. 11/17/2023 .PREV DISCUSSION... /ISSUED 1031 AM CST Fri Nov 17 2023/ ...Discussion... A long-wave trough will continue advancing eastward across eastern North America today, accompanied by a southeastward surface cold-frontal advance across the eastern half of the country. By late in the period, this front will have cleared most of the southern and eastern U.S., with northerly low-level flow prevailing. Farther west, an upper low off the California coast is forecast to weaken, moving inland as an open wave through the period. Showers will continue over eastern Florida this afternoon near a weak offshore surface low, though most lightning should remain confined to the immediate coastal areas, and offshore. Meanwhile, as the aforementioned cold front advances, showers and possibly a thunderstorm or two will affect portions of the Ohio Valley and central Appalachians today. Overnight, as the front crosses the East Coast states, a few lightning flashes may occur near the North Carolina Outer Banks. Finally, thunder may occur across portions of California and Arizona, ahead of the advancing upper system. In all of these areas, severe weather is not expected. Read more