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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1021 AM CST Wed Dec 27 2023 Valid 271630Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Mid Atlantic Region... A large upper low remains dominant over the central/eastern CONUS, with a deep warm-conveyor regime over the Mid-Atlantic region. Scattered showers and isolated thunderstorms will be possible this afternoon from eastern NC northward across the Chesapeake Bay area into PA/NJ. A cool and marginally unstable boundary-layer will preclude a risk of severe storms. ...FL Keys... A southern-stream shortwave trough over northern Mexico will track across the Gulf of Mexico and begin affecting the FL Keys after midnight. This may result in isolated thunderstorms over the lower Keys or nearby shelf waters. ...West Coast... A few lightning flashes are possible this afternoon and evening over coastal WA/OR and parts of northern/central CA as a cold front moves ashore. ..Hart/Thornton.. 12/27/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1021 AM CST Wed Dec 27 2023 Valid 271630Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Mid Atlantic Region... A large upper low remains dominant over the central/eastern CONUS, with a deep warm-conveyor regime over the Mid-Atlantic region. Scattered showers and isolated thunderstorms will be possible this afternoon from eastern NC northward across the Chesapeake Bay area into PA/NJ. A cool and marginally unstable boundary-layer will preclude a risk of severe storms. ...FL Keys... A southern-stream shortwave trough over northern Mexico will track across the Gulf of Mexico and begin affecting the FL Keys after midnight. This may result in isolated thunderstorms over the lower Keys or nearby shelf waters. ...West Coast... A few lightning flashes are possible this afternoon and evening over coastal WA/OR and parts of northern/central CA as a cold front moves ashore. ..Hart/Thornton.. 12/27/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 AM CST Wed Dec 27 2023 Valid 271300Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Synopsis/Discussion... In mid/upper levels, the dominant feature over the central/eastern CONUS remains a large synoptic-scale cyclone, initially centered over northwestern MO. Associated cyclonic flow extends from the Four Corners region to the central/southern Appalachians, and from the Upper Great Lakes to northern MX. Its 500-mb low is expected to pivot southward then eastward over southern IL by the end of the period. A broad warm conveyor lingers well east of the low, near the central Atlantic Coast and northward over the central Appalachians region. Weak, elevated buoyancy will decrease northward, with 12Z soundings showing MUCAPE around 600 J/kg at MHX, but less than 300 J/kg at RNK. This may support isolated, episodic thunder in a band of embedded convection moving eastward to northeastward over the area today into this evening. The surface cold front is offshore from the southern Atlantic Coast, though a frontal-wave low -- analyzed at 11Z just offshore from CHS -- should move northeastward near the NC coastline through this evening. However, favorable warm-sector buoyancy/shear for severe is expected to stay over the Atlantic. A temporarily stalled segment of the low-level frontal zone may undergo wave cyclogenesis over the southeastern Gulf this evening and tonight, as a weak southern-stream perturbation approaches from MX. Sufficient lift, elevated instability and moisture should exist over Gulf waters to support thunderstorms over the central/east-central Gulf today and the east-central/southeastern Gulf tonight. Some of this activity may reach portions of the FL Keys before 12Z tomorrow. Farther west, moisture-channel imagery showed a synoptic-scale cyclone over the northeast Pacific, centered near 43N137W. This feature is expected to move northeastward and weaken today, while remaining offshore. However, a basal shortwave trough should pivot northeastward across the coastal Pacific Northwest. Related DCVA/cooling aloft may provide sufficient destabilization, atop weak low/middle-level moisture, to support thunder potential from portions of northern CA up the coast of OR/WA. ..Edwards/Dean.. 12/27/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 AM CST Wed Dec 27 2023 Valid 271300Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Synopsis/Discussion... In mid/upper levels, the dominant feature over the central/eastern CONUS remains a large synoptic-scale cyclone, initially centered over northwestern MO. Associated cyclonic flow extends from the Four Corners region to the central/southern Appalachians, and from the Upper Great Lakes to northern MX. Its 500-mb low is expected to pivot southward then eastward over southern IL by the end of the period. A broad warm conveyor lingers well east of the low, near the central Atlantic Coast and northward over the central Appalachians region. Weak, elevated buoyancy will decrease northward, with 12Z soundings showing MUCAPE around 600 J/kg at MHX, but less than 300 J/kg at RNK. This may support isolated, episodic thunder in a band of embedded convection moving eastward to northeastward over the area today into this evening. The surface cold front is offshore from the southern Atlantic Coast, though a frontal-wave low -- analyzed at 11Z just offshore from CHS -- should move northeastward near the NC coastline through this evening. However, favorable warm-sector buoyancy/shear for severe is expected to stay over the Atlantic. A temporarily stalled segment of the low-level frontal zone may undergo wave cyclogenesis over the southeastern Gulf this evening and tonight, as a weak southern-stream perturbation approaches from MX. Sufficient lift, elevated instability and moisture should exist over Gulf waters to support thunderstorms over the central/east-central Gulf today and the east-central/southeastern Gulf tonight. Some of this activity may reach portions of the FL Keys before 12Z tomorrow. Farther west, moisture-channel imagery showed a synoptic-scale cyclone over the northeast Pacific, centered near 43N137W. This feature is expected to move northeastward and weaken today, while remaining offshore. However, a basal shortwave trough should pivot northeastward across the coastal Pacific Northwest. Related DCVA/cooling aloft may provide sufficient destabilization, atop weak low/middle-level moisture, to support thunder potential from portions of northern CA up the coast of OR/WA. ..Edwards/Dean.. 12/27/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 AM CST Wed Dec 27 2023 Valid 271300Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Synopsis/Discussion... In mid/upper levels, the dominant feature over the central/eastern CONUS remains a large synoptic-scale cyclone, initially centered over northwestern MO. Associated cyclonic flow extends from the Four Corners region to the central/southern Appalachians, and from the Upper Great Lakes to northern MX. Its 500-mb low is expected to pivot southward then eastward over southern IL by the end of the period. A broad warm conveyor lingers well east of the low, near the central Atlantic Coast and northward over the central Appalachians region. Weak, elevated buoyancy will decrease northward, with 12Z soundings showing MUCAPE around 600 J/kg at MHX, but less than 300 J/kg at RNK. This may support isolated, episodic thunder in a band of embedded convection moving eastward to northeastward over the area today into this evening. The surface cold front is offshore from the southern Atlantic Coast, though a frontal-wave low -- analyzed at 11Z just offshore from CHS -- should move northeastward near the NC coastline through this evening. However, favorable warm-sector buoyancy/shear for severe is expected to stay over the Atlantic. A temporarily stalled segment of the low-level frontal zone may undergo wave cyclogenesis over the southeastern Gulf this evening and tonight, as a weak southern-stream perturbation approaches from MX. Sufficient lift, elevated instability and moisture should exist over Gulf waters to support thunderstorms over the central/east-central Gulf today and the east-central/southeastern Gulf tonight. Some of this activity may reach portions of the FL Keys before 12Z tomorrow. Farther west, moisture-channel imagery showed a synoptic-scale cyclone over the northeast Pacific, centered near 43N137W. This feature is expected to move northeastward and weaken today, while remaining offshore. However, a basal shortwave trough should pivot northeastward across the coastal Pacific Northwest. Related DCVA/cooling aloft may provide sufficient destabilization, atop weak low/middle-level moisture, to support thunder potential from portions of northern CA up the coast of OR/WA. ..Edwards/Dean.. 12/27/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 AM CST Wed Dec 27 2023 Valid 271300Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Synopsis/Discussion... In mid/upper levels, the dominant feature over the central/eastern CONUS remains a large synoptic-scale cyclone, initially centered over northwestern MO. Associated cyclonic flow extends from the Four Corners region to the central/southern Appalachians, and from the Upper Great Lakes to northern MX. Its 500-mb low is expected to pivot southward then eastward over southern IL by the end of the period. A broad warm conveyor lingers well east of the low, near the central Atlantic Coast and northward over the central Appalachians region. Weak, elevated buoyancy will decrease northward, with 12Z soundings showing MUCAPE around 600 J/kg at MHX, but less than 300 J/kg at RNK. This may support isolated, episodic thunder in a band of embedded convection moving eastward to northeastward over the area today into this evening. The surface cold front is offshore from the southern Atlantic Coast, though a frontal-wave low -- analyzed at 11Z just offshore from CHS -- should move northeastward near the NC coastline through this evening. However, favorable warm-sector buoyancy/shear for severe is expected to stay over the Atlantic. A temporarily stalled segment of the low-level frontal zone may undergo wave cyclogenesis over the southeastern Gulf this evening and tonight, as a weak southern-stream perturbation approaches from MX. Sufficient lift, elevated instability and moisture should exist over Gulf waters to support thunderstorms over the central/east-central Gulf today and the east-central/southeastern Gulf tonight. Some of this activity may reach portions of the FL Keys before 12Z tomorrow. Farther west, moisture-channel imagery showed a synoptic-scale cyclone over the northeast Pacific, centered near 43N137W. This feature is expected to move northeastward and weaken today, while remaining offshore. However, a basal shortwave trough should pivot northeastward across the coastal Pacific Northwest. Related DCVA/cooling aloft may provide sufficient destabilization, atop weak low/middle-level moisture, to support thunder potential from portions of northern CA up the coast of OR/WA. ..Edwards/Dean.. 12/27/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 AM CST Wed Dec 27 2023 Valid 271300Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Synopsis/Discussion... In mid/upper levels, the dominant feature over the central/eastern CONUS remains a large synoptic-scale cyclone, initially centered over northwestern MO. Associated cyclonic flow extends from the Four Corners region to the central/southern Appalachians, and from the Upper Great Lakes to northern MX. Its 500-mb low is expected to pivot southward then eastward over southern IL by the end of the period. A broad warm conveyor lingers well east of the low, near the central Atlantic Coast and northward over the central Appalachians region. Weak, elevated buoyancy will decrease northward, with 12Z soundings showing MUCAPE around 600 J/kg at MHX, but less than 300 J/kg at RNK. This may support isolated, episodic thunder in a band of embedded convection moving eastward to northeastward over the area today into this evening. The surface cold front is offshore from the southern Atlantic Coast, though a frontal-wave low -- analyzed at 11Z just offshore from CHS -- should move northeastward near the NC coastline through this evening. However, favorable warm-sector buoyancy/shear for severe is expected to stay over the Atlantic. A temporarily stalled segment of the low-level frontal zone may undergo wave cyclogenesis over the southeastern Gulf this evening and tonight, as a weak southern-stream perturbation approaches from MX. Sufficient lift, elevated instability and moisture should exist over Gulf waters to support thunderstorms over the central/east-central Gulf today and the east-central/southeastern Gulf tonight. Some of this activity may reach portions of the FL Keys before 12Z tomorrow. Farther west, moisture-channel imagery showed a synoptic-scale cyclone over the northeast Pacific, centered near 43N137W. This feature is expected to move northeastward and weaken today, while remaining offshore. However, a basal shortwave trough should pivot northeastward across the coastal Pacific Northwest. Related DCVA/cooling aloft may provide sufficient destabilization, atop weak low/middle-level moisture, to support thunder potential from portions of northern CA up the coast of OR/WA. ..Edwards/Dean.. 12/27/2023 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0251 AM CST Wed Dec 27 2023 Valid 301200Z - 041200Z ...DISCUSSION... A mostly dry and stable boundary layer will preclude much thunderstorm activity across the CONUS during the Day 4-8 period. The exception will be around Day 6/Mon. During this time, an upper shortwave trough over the Southwest will eject eastward across the southern Plains and toward the Gulf Coast states. A surface low will develop near the TX coast in response to the approaching upper wave and shift east across the Gulf. Modest moisture return may impinge on parts of the western/central Gulf coast ahead of the surface low and a southeastward-advancing cold front. Isolated thunderstorms may occur, but higher-quality moisture and thermodynamics will likely remain offshore, precluding severe potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0251 AM CST Wed Dec 27 2023 Valid 301200Z - 041200Z ...DISCUSSION... A mostly dry and stable boundary layer will preclude much thunderstorm activity across the CONUS during the Day 4-8 period. The exception will be around Day 6/Mon. During this time, an upper shortwave trough over the Southwest will eject eastward across the southern Plains and toward the Gulf Coast states. A surface low will develop near the TX coast in response to the approaching upper wave and shift east across the Gulf. Modest moisture return may impinge on parts of the western/central Gulf coast ahead of the surface low and a southeastward-advancing cold front. Isolated thunderstorms may occur, but higher-quality moisture and thermodynamics will likely remain offshore, precluding severe potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0251 AM CST Wed Dec 27 2023 Valid 301200Z - 041200Z ...DISCUSSION... A mostly dry and stable boundary layer will preclude much thunderstorm activity across the CONUS during the Day 4-8 period. The exception will be around Day 6/Mon. During this time, an upper shortwave trough over the Southwest will eject eastward across the southern Plains and toward the Gulf Coast states. A surface low will develop near the TX coast in response to the approaching upper wave and shift east across the Gulf. Modest moisture return may impinge on parts of the western/central Gulf coast ahead of the surface low and a southeastward-advancing cold front. Isolated thunderstorms may occur, but higher-quality moisture and thermodynamics will likely remain offshore, precluding severe potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0251 AM CST Wed Dec 27 2023 Valid 301200Z - 041200Z ...DISCUSSION... A mostly dry and stable boundary layer will preclude much thunderstorm activity across the CONUS during the Day 4-8 period. The exception will be around Day 6/Mon. During this time, an upper shortwave trough over the Southwest will eject eastward across the southern Plains and toward the Gulf Coast states. A surface low will develop near the TX coast in response to the approaching upper wave and shift east across the Gulf. Modest moisture return may impinge on parts of the western/central Gulf coast ahead of the surface low and a southeastward-advancing cold front. Isolated thunderstorms may occur, but higher-quality moisture and thermodynamics will likely remain offshore, precluding severe potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0251 AM CST Wed Dec 27 2023 Valid 301200Z - 041200Z ...DISCUSSION... A mostly dry and stable boundary layer will preclude much thunderstorm activity across the CONUS during the Day 4-8 period. The exception will be around Day 6/Mon. During this time, an upper shortwave trough over the Southwest will eject eastward across the southern Plains and toward the Gulf Coast states. A surface low will develop near the TX coast in response to the approaching upper wave and shift east across the Gulf. Modest moisture return may impinge on parts of the western/central Gulf coast ahead of the surface low and a southeastward-advancing cold front. Isolated thunderstorms may occur, but higher-quality moisture and thermodynamics will likely remain offshore, precluding severe potential. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0146 AM CST Wed Dec 27 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible along parts of the northern/central California coast on Friday. ...Synopsis... An upper trough oriented from the Great Lakes to the Gulf of Mexico will progress eastward toward the Atlantic coast on Friday. Meanwhile, the western upper ridge will shift east toward the Rockies and adjacent High Plains vicinity as an upper trough approaches the Pacific coast late in the period. Stable conditions and a dearth of boundary-layer moisture will preclude thunderstorm activity for most of the CONUS. However, deep-layer southwesterly flow ahead of the Pacific trough will support moistening midlevels along the CA coast. Somewhat cool midlevels and modest lapse rates will be sufficient for weak destabilization during the evening and overnight hours. Isolated thunderstorms will be possible along parts of the central/northern CA coastal vicinity, mainly after 00z. ..Leitman.. 12/27/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0146 AM CST Wed Dec 27 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible along parts of the northern/central California coast on Friday. ...Synopsis... An upper trough oriented from the Great Lakes to the Gulf of Mexico will progress eastward toward the Atlantic coast on Friday. Meanwhile, the western upper ridge will shift east toward the Rockies and adjacent High Plains vicinity as an upper trough approaches the Pacific coast late in the period. Stable conditions and a dearth of boundary-layer moisture will preclude thunderstorm activity for most of the CONUS. However, deep-layer southwesterly flow ahead of the Pacific trough will support moistening midlevels along the CA coast. Somewhat cool midlevels and modest lapse rates will be sufficient for weak destabilization during the evening and overnight hours. Isolated thunderstorms will be possible along parts of the central/northern CA coastal vicinity, mainly after 00z. ..Leitman.. 12/27/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0146 AM CST Wed Dec 27 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible along parts of the northern/central California coast on Friday. ...Synopsis... An upper trough oriented from the Great Lakes to the Gulf of Mexico will progress eastward toward the Atlantic coast on Friday. Meanwhile, the western upper ridge will shift east toward the Rockies and adjacent High Plains vicinity as an upper trough approaches the Pacific coast late in the period. Stable conditions and a dearth of boundary-layer moisture will preclude thunderstorm activity for most of the CONUS. However, deep-layer southwesterly flow ahead of the Pacific trough will support moistening midlevels along the CA coast. Somewhat cool midlevels and modest lapse rates will be sufficient for weak destabilization during the evening and overnight hours. Isolated thunderstorms will be possible along parts of the central/northern CA coastal vicinity, mainly after 00z. ..Leitman.. 12/27/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0146 AM CST Wed Dec 27 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible along parts of the northern/central California coast on Friday. ...Synopsis... An upper trough oriented from the Great Lakes to the Gulf of Mexico will progress eastward toward the Atlantic coast on Friday. Meanwhile, the western upper ridge will shift east toward the Rockies and adjacent High Plains vicinity as an upper trough approaches the Pacific coast late in the period. Stable conditions and a dearth of boundary-layer moisture will preclude thunderstorm activity for most of the CONUS. However, deep-layer southwesterly flow ahead of the Pacific trough will support moistening midlevels along the CA coast. Somewhat cool midlevels and modest lapse rates will be sufficient for weak destabilization during the evening and overnight hours. Isolated thunderstorms will be possible along parts of the central/northern CA coastal vicinity, mainly after 00z. ..Leitman.. 12/27/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0146 AM CST Wed Dec 27 2023 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible along parts of the northern/central California coast on Friday. ...Synopsis... An upper trough oriented from the Great Lakes to the Gulf of Mexico will progress eastward toward the Atlantic coast on Friday. Meanwhile, the western upper ridge will shift east toward the Rockies and adjacent High Plains vicinity as an upper trough approaches the Pacific coast late in the period. Stable conditions and a dearth of boundary-layer moisture will preclude thunderstorm activity for most of the CONUS. However, deep-layer southwesterly flow ahead of the Pacific trough will support moistening midlevels along the CA coast. Somewhat cool midlevels and modest lapse rates will be sufficient for weak destabilization during the evening and overnight hours. Isolated thunderstorms will be possible along parts of the central/northern CA coastal vicinity, mainly after 00z. ..Leitman.. 12/27/2023 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Wed Dec 27 2023 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... Cool temperatures and moist fuels across most of the CONUS will limit fire weather concerns on Thursday, as a closed upper low slowly drifts east across the Ohio Valley. ..Bentley.. 12/27/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Wed Dec 27 2023 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... Cool temperatures and moist fuels across most of the CONUS will limit fire weather concerns on Thursday, as a closed upper low slowly drifts east across the Ohio Valley. ..Bentley.. 12/27/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Wed Dec 27 2023 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... Cool temperatures and moist fuels across most of the CONUS will limit fire weather concerns on Thursday, as a closed upper low slowly drifts east across the Ohio Valley. ..Bentley.. 12/27/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more