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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0144 PM CST Thu Nov 21 2024 Valid 212000Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis... A line of convective rain/show showers continues across the Appalachians with occasional lightning flashes. This will persist for a few more hours before weakening late this afternoon as the boundary layer cools and low-level lapse rates weaken. Lightning is expected to remain offshore near the New England coast and the Pacific Northwest coast and therefore, the thunder line has been removed from both areas. ..Bentley.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1029 AM CST Thu Nov 21 2024/ ...Synopsis... A deep midlevel low, characterized by 500-mb temperatures around -32C, will move from the Great Lakes into the Mid-Atlantic through the period. These cold midlevel temperatures and strong height falls accompanying the midlevel low may promote isolated lightning flashes embedded in showers across the central Appalachians this afternoon. Over coastal southern New England, low-level warm advection north of a related occluded surface low will also support isolated thunderstorms, given weak elevated instability. Most of this activity should remain offshore. Isolated thunderstorms are also possible over immediate coastal areas of WA, where forcing for ascent in the left exit region of a jet streak is overlapping deep tropospheric moisture/weak instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0144 PM CST Thu Nov 21 2024 Valid 212000Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis... A line of convective rain/show showers continues across the Appalachians with occasional lightning flashes. This will persist for a few more hours before weakening late this afternoon as the boundary layer cools and low-level lapse rates weaken. Lightning is expected to remain offshore near the New England coast and the Pacific Northwest coast and therefore, the thunder line has been removed from both areas. ..Bentley.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1029 AM CST Thu Nov 21 2024/ ...Synopsis... A deep midlevel low, characterized by 500-mb temperatures around -32C, will move from the Great Lakes into the Mid-Atlantic through the period. These cold midlevel temperatures and strong height falls accompanying the midlevel low may promote isolated lightning flashes embedded in showers across the central Appalachians this afternoon. Over coastal southern New England, low-level warm advection north of a related occluded surface low will also support isolated thunderstorms, given weak elevated instability. Most of this activity should remain offshore. Isolated thunderstorms are also possible over immediate coastal areas of WA, where forcing for ascent in the left exit region of a jet streak is overlapping deep tropospheric moisture/weak instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0144 PM CST Thu Nov 21 2024 Valid 212000Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis... A line of convective rain/show showers continues across the Appalachians with occasional lightning flashes. This will persist for a few more hours before weakening late this afternoon as the boundary layer cools and low-level lapse rates weaken. Lightning is expected to remain offshore near the New England coast and the Pacific Northwest coast and therefore, the thunder line has been removed from both areas. ..Bentley.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1029 AM CST Thu Nov 21 2024/ ...Synopsis... A deep midlevel low, characterized by 500-mb temperatures around -32C, will move from the Great Lakes into the Mid-Atlantic through the period. These cold midlevel temperatures and strong height falls accompanying the midlevel low may promote isolated lightning flashes embedded in showers across the central Appalachians this afternoon. Over coastal southern New England, low-level warm advection north of a related occluded surface low will also support isolated thunderstorms, given weak elevated instability. Most of this activity should remain offshore. Isolated thunderstorms are also possible over immediate coastal areas of WA, where forcing for ascent in the left exit region of a jet streak is overlapping deep tropospheric moisture/weak instability. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Thu Nov 21 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... Mid-level flow across the CONUS is forecast to become more zonal with time as prominent troughing on either coast gradually deamplifies. Ridging over the central CONUS will weaken and shift eastward as the East Coast trough moves offshore. To the west, strong mid-level flow will move inland across the Pacific Northwest and northern Rockies as the upper low cuts off southwest of BC. A weak surface low and cold front will move across the northern Rockies and intensify over the High Plains. High pressure over the eastern US will favor cool, dry and stable offshore flow across the eastern half of the country. ...Northwest and Northern Rockies... As the broad upper-level cyclone over the Pacific Northwest gradually devolves, a lead shortwave trough embedded within the stronger zonal flow will quickly eject eastward over the Northern Rockies. A weak surface low and trailing cold front will also move east with the stronger flow aloft. Area model soundings show weak destabilization is possible over parts of eastern OR and southern ID as forcing for ascent increases and low-level lapse rates steepen ahead of the front. While very limited, enough buoyancy (MUCAPE ~100-200 J/kg) may develop for a few lightning flashes with low-topped, mixed-phase, convective elements. Additionally, low-topped storms may approach near shore areas of OR/WA and northern CA. However, cool inland surface temperatures and weakening large-scale ascent should limit lightning chances inland. ..Lyons.. 11/21/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Thu Nov 21 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... Mid-level flow across the CONUS is forecast to become more zonal with time as prominent troughing on either coast gradually deamplifies. Ridging over the central CONUS will weaken and shift eastward as the East Coast trough moves offshore. To the west, strong mid-level flow will move inland across the Pacific Northwest and northern Rockies as the upper low cuts off southwest of BC. A weak surface low and cold front will move across the northern Rockies and intensify over the High Plains. High pressure over the eastern US will favor cool, dry and stable offshore flow across the eastern half of the country. ...Northwest and Northern Rockies... As the broad upper-level cyclone over the Pacific Northwest gradually devolves, a lead shortwave trough embedded within the stronger zonal flow will quickly eject eastward over the Northern Rockies. A weak surface low and trailing cold front will also move east with the stronger flow aloft. Area model soundings show weak destabilization is possible over parts of eastern OR and southern ID as forcing for ascent increases and low-level lapse rates steepen ahead of the front. While very limited, enough buoyancy (MUCAPE ~100-200 J/kg) may develop for a few lightning flashes with low-topped, mixed-phase, convective elements. Additionally, low-topped storms may approach near shore areas of OR/WA and northern CA. However, cool inland surface temperatures and weakening large-scale ascent should limit lightning chances inland. ..Lyons.. 11/21/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Thu Nov 21 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... Mid-level flow across the CONUS is forecast to become more zonal with time as prominent troughing on either coast gradually deamplifies. Ridging over the central CONUS will weaken and shift eastward as the East Coast trough moves offshore. To the west, strong mid-level flow will move inland across the Pacific Northwest and northern Rockies as the upper low cuts off southwest of BC. A weak surface low and cold front will move across the northern Rockies and intensify over the High Plains. High pressure over the eastern US will favor cool, dry and stable offshore flow across the eastern half of the country. ...Northwest and Northern Rockies... As the broad upper-level cyclone over the Pacific Northwest gradually devolves, a lead shortwave trough embedded within the stronger zonal flow will quickly eject eastward over the Northern Rockies. A weak surface low and trailing cold front will also move east with the stronger flow aloft. Area model soundings show weak destabilization is possible over parts of eastern OR and southern ID as forcing for ascent increases and low-level lapse rates steepen ahead of the front. While very limited, enough buoyancy (MUCAPE ~100-200 J/kg) may develop for a few lightning flashes with low-topped, mixed-phase, convective elements. Additionally, low-topped storms may approach near shore areas of OR/WA and northern CA. However, cool inland surface temperatures and weakening large-scale ascent should limit lightning chances inland. ..Lyons.. 11/21/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Thu Nov 21 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... Mid-level flow across the CONUS is forecast to become more zonal with time as prominent troughing on either coast gradually deamplifies. Ridging over the central CONUS will weaken and shift eastward as the East Coast trough moves offshore. To the west, strong mid-level flow will move inland across the Pacific Northwest and northern Rockies as the upper low cuts off southwest of BC. A weak surface low and cold front will move across the northern Rockies and intensify over the High Plains. High pressure over the eastern US will favor cool, dry and stable offshore flow across the eastern half of the country. ...Northwest and Northern Rockies... As the broad upper-level cyclone over the Pacific Northwest gradually devolves, a lead shortwave trough embedded within the stronger zonal flow will quickly eject eastward over the Northern Rockies. A weak surface low and trailing cold front will also move east with the stronger flow aloft. Area model soundings show weak destabilization is possible over parts of eastern OR and southern ID as forcing for ascent increases and low-level lapse rates steepen ahead of the front. While very limited, enough buoyancy (MUCAPE ~100-200 J/kg) may develop for a few lightning flashes with low-topped, mixed-phase, convective elements. Additionally, low-topped storms may approach near shore areas of OR/WA and northern CA. However, cool inland surface temperatures and weakening large-scale ascent should limit lightning chances inland. ..Lyons.. 11/21/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Thu Nov 21 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... Mid-level flow across the CONUS is forecast to become more zonal with time as prominent troughing on either coast gradually deamplifies. Ridging over the central CONUS will weaken and shift eastward as the East Coast trough moves offshore. To the west, strong mid-level flow will move inland across the Pacific Northwest and northern Rockies as the upper low cuts off southwest of BC. A weak surface low and cold front will move across the northern Rockies and intensify over the High Plains. High pressure over the eastern US will favor cool, dry and stable offshore flow across the eastern half of the country. ...Northwest and Northern Rockies... As the broad upper-level cyclone over the Pacific Northwest gradually devolves, a lead shortwave trough embedded within the stronger zonal flow will quickly eject eastward over the Northern Rockies. A weak surface low and trailing cold front will also move east with the stronger flow aloft. Area model soundings show weak destabilization is possible over parts of eastern OR and southern ID as forcing for ascent increases and low-level lapse rates steepen ahead of the front. While very limited, enough buoyancy (MUCAPE ~100-200 J/kg) may develop for a few lightning flashes with low-topped, mixed-phase, convective elements. Additionally, low-topped storms may approach near shore areas of OR/WA and northern CA. However, cool inland surface temperatures and weakening large-scale ascent should limit lightning chances inland. ..Lyons.. 11/21/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Thu Nov 21 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... Mid-level flow across the CONUS is forecast to become more zonal with time as prominent troughing on either coast gradually deamplifies. Ridging over the central CONUS will weaken and shift eastward as the East Coast trough moves offshore. To the west, strong mid-level flow will move inland across the Pacific Northwest and northern Rockies as the upper low cuts off southwest of BC. A weak surface low and cold front will move across the northern Rockies and intensify over the High Plains. High pressure over the eastern US will favor cool, dry and stable offshore flow across the eastern half of the country. ...Northwest and Northern Rockies... As the broad upper-level cyclone over the Pacific Northwest gradually devolves, a lead shortwave trough embedded within the stronger zonal flow will quickly eject eastward over the Northern Rockies. A weak surface low and trailing cold front will also move east with the stronger flow aloft. Area model soundings show weak destabilization is possible over parts of eastern OR and southern ID as forcing for ascent increases and low-level lapse rates steepen ahead of the front. While very limited, enough buoyancy (MUCAPE ~100-200 J/kg) may develop for a few lightning flashes with low-topped, mixed-phase, convective elements. Additionally, low-topped storms may approach near shore areas of OR/WA and northern CA. However, cool inland surface temperatures and weakening large-scale ascent should limit lightning chances inland. ..Lyons.. 11/21/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1230 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... An Elevated risk area has been introduced for portions of central FL. Latest guidance has trended towards slightly stronger winds along the FL peninsula tomorrow as a secondary cold surge pushes across the region. Gusts up to 15-20 mph will be possible - especially during the late morning hours - with RH reductions into the 25-35% range. Dry/windy conditions today across the area and limited rainfall over the past three days should allow for adequate drying of fine fuels to support a fire concern. ..Moore.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Wed Nov 20 2024/ ...Synopsis... A similar upper-level pattern to Thursday will again be present on Friday. The strong upper low will continue east and a complex surface low evolution will occur off the Mid-Atlantic/New England coast. Fire weather conditions are expected to be minimal for most areas. Northern into central Florida will again be dry. Temperature will be a bit cooler and RH will be a bit higher. Boundary layer mixing will also be less than Thursday, tempering gust potential. With the strongest winds/lowest RH expected over less receptive fuels, highlights will be withheld. Locally elevated conditions can be expected. ...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 1230 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... An Elevated risk area has been introduced for portions of central FL. Latest guidance has trended towards slightly stronger winds along the FL peninsula tomorrow as a secondary cold surge pushes across the region. Gusts up to 15-20 mph will be possible - especially during the late morning hours - with RH reductions into the 25-35% range. Dry/windy conditions today across the area and limited rainfall over the past three days should allow for adequate drying of fine fuels to support a fire concern. ..Moore.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Wed Nov 20 2024/ ...Synopsis... A similar upper-level pattern to Thursday will again be present on Friday. The strong upper low will continue east and a complex surface low evolution will occur off the Mid-Atlantic/New England coast. Fire weather conditions are expected to be minimal for most areas. Northern into central Florida will again be dry. Temperature will be a bit cooler and RH will be a bit higher. Boundary layer mixing will also be less than Thursday, tempering gust potential. With the strongest winds/lowest RH expected over less receptive fuels, highlights will be withheld. Locally elevated conditions can be expected. ...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 1230 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... An Elevated risk area has been introduced for portions of central FL. Latest guidance has trended towards slightly stronger winds along the FL peninsula tomorrow as a secondary cold surge pushes across the region. Gusts up to 15-20 mph will be possible - especially during the late morning hours - with RH reductions into the 25-35% range. Dry/windy conditions today across the area and limited rainfall over the past three days should allow for adequate drying of fine fuels to support a fire concern. ..Moore.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Wed Nov 20 2024/ ...Synopsis... A similar upper-level pattern to Thursday will again be present on Friday. The strong upper low will continue east and a complex surface low evolution will occur off the Mid-Atlantic/New England coast. Fire weather conditions are expected to be minimal for most areas. Northern into central Florida will again be dry. Temperature will be a bit cooler and RH will be a bit higher. Boundary layer mixing will also be less than Thursday, tempering gust potential. With the strongest winds/lowest RH expected over less receptive fuels, highlights will be withheld. Locally elevated conditions can be expected. ...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 1230 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... An Elevated risk area has been introduced for portions of central FL. Latest guidance has trended towards slightly stronger winds along the FL peninsula tomorrow as a secondary cold surge pushes across the region. Gusts up to 15-20 mph will be possible - especially during the late morning hours - with RH reductions into the 25-35% range. Dry/windy conditions today across the area and limited rainfall over the past three days should allow for adequate drying of fine fuels to support a fire concern. ..Moore.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Wed Nov 20 2024/ ...Synopsis... A similar upper-level pattern to Thursday will again be present on Friday. The strong upper low will continue east and a complex surface low evolution will occur off the Mid-Atlantic/New England coast. Fire weather conditions are expected to be minimal for most areas. Northern into central Florida will again be dry. Temperature will be a bit cooler and RH will be a bit higher. Boundary layer mixing will also be less than Thursday, tempering gust potential. With the strongest winds/lowest RH expected over less receptive fuels, highlights will be withheld. Locally elevated conditions can be expected. ...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 1230 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... An Elevated risk area has been introduced for portions of central FL. Latest guidance has trended towards slightly stronger winds along the FL peninsula tomorrow as a secondary cold surge pushes across the region. Gusts up to 15-20 mph will be possible - especially during the late morning hours - with RH reductions into the 25-35% range. Dry/windy conditions today across the area and limited rainfall over the past three days should allow for adequate drying of fine fuels to support a fire concern. ..Moore.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Wed Nov 20 2024/ ...Synopsis... A similar upper-level pattern to Thursday will again be present on Friday. The strong upper low will continue east and a complex surface low evolution will occur off the Mid-Atlantic/New England coast. Fire weather conditions are expected to be minimal for most areas. Northern into central Florida will again be dry. Temperature will be a bit cooler and RH will be a bit higher. Boundary layer mixing will also be less than Thursday, tempering gust potential. With the strongest winds/lowest RH expected over less receptive fuels, highlights will be withheld. Locally elevated conditions can be expected. ...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 1230 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... An Elevated risk area has been introduced for portions of central FL. Latest guidance has trended towards slightly stronger winds along the FL peninsula tomorrow as a secondary cold surge pushes across the region. Gusts up to 15-20 mph will be possible - especially during the late morning hours - with RH reductions into the 25-35% range. Dry/windy conditions today across the area and limited rainfall over the past three days should allow for adequate drying of fine fuels to support a fire concern. ..Moore.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Wed Nov 20 2024/ ...Synopsis... A similar upper-level pattern to Thursday will again be present on Friday. The strong upper low will continue east and a complex surface low evolution will occur off the Mid-Atlantic/New England coast. Fire weather conditions are expected to be minimal for most areas. Northern into central Florida will again be dry. Temperature will be a bit cooler and RH will be a bit higher. Boundary layer mixing will also be less than Thursday, tempering gust potential. With the strongest winds/lowest RH expected over less receptive fuels, highlights will be withheld. Locally elevated conditions can be expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2239 CONCERNING HEAVY SNOW FOR NORTHEAST IL INTO EXTREME NORTHWEST IN
Mesoscale Discussion 2239 NWS Storm Prediction Center Norman OK 0926 AM CST Thu Nov 21 2024 Areas affected...Northeast IL into extreme northwest IN Concerning...Heavy snow Valid 211526Z - 211830Z SUMMARY...Snow rates of around 1 inch per hour are possible through the morning, along with increasingly gusty winds and reductions in visibility. DISCUSSION...Moderate to locally heavy snow is ongoing this morning across southeast WI and far northeast IL, immediately in advance of a midlevel vorticity maximum and compact surface low moving south-southwestward over Lake Michigan. This area of snow will continue to move southward across parts of northeast IL and adjacent parts of northwest IN through the remainder of the morning, in conjunction with stronger ascent attendant to the midlevel vorticity maximum. With initially cold temperatures through a relatively deep column (with 700 mb temps of -10 to -15 C), sufficient ascent through the dendritic growth zone will continue to support heavier snow rates, and 1 inch per hour rates are possible at times through late morning into the early afternoon. In addition, as stronger low-level flow along the western periphery of the compact cyclone over Lake Michigan moves southward, wind gusts in excess of 30 mph will further support reductions in visibility. ..Dean.. 11/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT... LAT...LON 42478835 42488784 42298770 41678732 41278724 41038759 41178802 41518841 41958862 42298866 42418857 42478835 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible along the Pacific Northwest Coast Friday. Severe storms are not expected. ...Synopsis... Amplified mid-level flow is likely over much of the CONUS Friday, with a deep upper low off the East Coast and a similarly deep trough off the West Coast. Between the two lows, a shortwave ridge will slowly migrate eastward over the central Plains. At the surface, a low and trailing cold front will steadily move offshore through the day over the East. High pressure and offshore flow are likely over the central CONUS. While along the West Coast, a pronounced low and onshore flow will continue. As the upper trough continues to shift eastward, cool and stable offshore flow should limit buoyancy and deep convection over the eastern 2/3rds of the CONUS. The only exception to this could be brief, low-topped storms near Cape Cod. A few deeper convective elements embedded within broad stratiform could produce sporadic lightning before stronger offshore flow shifts any lingering buoyancy completely offshore by midday. Across the Pacific Northwest, continuous onshore flow is likely as the cold core of the upper trough (-28 to -30 C 500 mb temps) moves onshore late in the day and overnight. Scattered low-topped convection will be most likely over the ocean overnight, but a few thunderstorms with sporadic lightning could move inland. With very weak MUCAPE (100-200 J/kg) any stronger updrafts will likely be brief. Strong deep-layer shear could briefly overlap with the buoyancy supporting a sporadic strong wind gust near the coast. However, the transient nature of the updrafts should keep the severe risk negligible. ..Lyons.. 11/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible along the Pacific Northwest Coast Friday. Severe storms are not expected. ...Synopsis... Amplified mid-level flow is likely over much of the CONUS Friday, with a deep upper low off the East Coast and a similarly deep trough off the West Coast. Between the two lows, a shortwave ridge will slowly migrate eastward over the central Plains. At the surface, a low and trailing cold front will steadily move offshore through the day over the East. High pressure and offshore flow are likely over the central CONUS. While along the West Coast, a pronounced low and onshore flow will continue. As the upper trough continues to shift eastward, cool and stable offshore flow should limit buoyancy and deep convection over the eastern 2/3rds of the CONUS. The only exception to this could be brief, low-topped storms near Cape Cod. A few deeper convective elements embedded within broad stratiform could produce sporadic lightning before stronger offshore flow shifts any lingering buoyancy completely offshore by midday. Across the Pacific Northwest, continuous onshore flow is likely as the cold core of the upper trough (-28 to -30 C 500 mb temps) moves onshore late in the day and overnight. Scattered low-topped convection will be most likely over the ocean overnight, but a few thunderstorms with sporadic lightning could move inland. With very weak MUCAPE (100-200 J/kg) any stronger updrafts will likely be brief. Strong deep-layer shear could briefly overlap with the buoyancy supporting a sporadic strong wind gust near the coast. However, the transient nature of the updrafts should keep the severe risk negligible. ..Lyons.. 11/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible along the Pacific Northwest Coast Friday. Severe storms are not expected. ...Synopsis... Amplified mid-level flow is likely over much of the CONUS Friday, with a deep upper low off the East Coast and a similarly deep trough off the West Coast. Between the two lows, a shortwave ridge will slowly migrate eastward over the central Plains. At the surface, a low and trailing cold front will steadily move offshore through the day over the East. High pressure and offshore flow are likely over the central CONUS. While along the West Coast, a pronounced low and onshore flow will continue. As the upper trough continues to shift eastward, cool and stable offshore flow should limit buoyancy and deep convection over the eastern 2/3rds of the CONUS. The only exception to this could be brief, low-topped storms near Cape Cod. A few deeper convective elements embedded within broad stratiform could produce sporadic lightning before stronger offshore flow shifts any lingering buoyancy completely offshore by midday. Across the Pacific Northwest, continuous onshore flow is likely as the cold core of the upper trough (-28 to -30 C 500 mb temps) moves onshore late in the day and overnight. Scattered low-topped convection will be most likely over the ocean overnight, but a few thunderstorms with sporadic lightning could move inland. With very weak MUCAPE (100-200 J/kg) any stronger updrafts will likely be brief. Strong deep-layer shear could briefly overlap with the buoyancy supporting a sporadic strong wind gust near the coast. However, the transient nature of the updrafts should keep the severe risk negligible. ..Lyons.. 11/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible along the Pacific Northwest Coast Friday. Severe storms are not expected. ...Synopsis... Amplified mid-level flow is likely over much of the CONUS Friday, with a deep upper low off the East Coast and a similarly deep trough off the West Coast. Between the two lows, a shortwave ridge will slowly migrate eastward over the central Plains. At the surface, a low and trailing cold front will steadily move offshore through the day over the East. High pressure and offshore flow are likely over the central CONUS. While along the West Coast, a pronounced low and onshore flow will continue. As the upper trough continues to shift eastward, cool and stable offshore flow should limit buoyancy and deep convection over the eastern 2/3rds of the CONUS. The only exception to this could be brief, low-topped storms near Cape Cod. A few deeper convective elements embedded within broad stratiform could produce sporadic lightning before stronger offshore flow shifts any lingering buoyancy completely offshore by midday. Across the Pacific Northwest, continuous onshore flow is likely as the cold core of the upper trough (-28 to -30 C 500 mb temps) moves onshore late in the day and overnight. Scattered low-topped convection will be most likely over the ocean overnight, but a few thunderstorms with sporadic lightning could move inland. With very weak MUCAPE (100-200 J/kg) any stronger updrafts will likely be brief. Strong deep-layer shear could briefly overlap with the buoyancy supporting a sporadic strong wind gust near the coast. However, the transient nature of the updrafts should keep the severe risk negligible. ..Lyons.. 11/21/2024 Read more