Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Sep 05 2019 Valid 052000Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes are possible across eastern North Carolina and southeast Virginia through tonight in association with Hurricane Dorian. ...Discussion... The current outlook areas and reasoning continue to reflect the ongoing convective scenario across the U.S., with few changes necessary at this time. Minor adjustments are being made to the risk areas over the Carolinas, to reflect minor progression of Dorian since the prior outlook issuance. Otherwise, no substantive changes appear necessary at this time. ..Goss.. 09/05/2019 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 05 2019/ ...Eastern North Carolina/southeast Virginia... After an active morning for rotating storms/tornadoes across coastal North Carolina, tornado potential will continue and gradually transition north-northeastward this afternoon through tonight in association with a strengthening/spatially transitioning low-level flow field on the periphery of Hurricane Dorian. This tornado threat should also develop northward into coastal southeast Virginia by tonight. ...Oregon and northern portions of California/Nevada... As early-morning cloud cover quickly thins/moves out of the region, a plume of MLCAPE from 500-1000 J/kg is expected by peak heating, particularly across west-central/southern Oregon. An approaching shortwave trough off the northern California coast should support late afternoon thunderstorm development over the Cascades and Sierra Nevada. A deeply mixed and steep low/mid-level lapse rate environment coupled with 30-40 kt effective shear should support isolated severe wind and hail, particularly across Oregon. Some severe-caliber thunderstorm-related wind gusts may occur as far east/southeast as Nevada. ...Upper Midwest... Associated with a fast-moving clipper-type shortwave trough, a few severe storms will remain possible today from eastern Minnesota across northern Wisconsin and parts of the Upper Peninsula of Michigan. Severe hail is the most probable severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Sep 05 2019 Valid 052000Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes are possible across eastern North Carolina and southeast Virginia through tonight in association with Hurricane Dorian. ...Discussion... The current outlook areas and reasoning continue to reflect the ongoing convective scenario across the U.S., with few changes necessary at this time. Minor adjustments are being made to the risk areas over the Carolinas, to reflect minor progression of Dorian since the prior outlook issuance. Otherwise, no substantive changes appear necessary at this time. ..Goss.. 09/05/2019 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 05 2019/ ...Eastern North Carolina/southeast Virginia... After an active morning for rotating storms/tornadoes across coastal North Carolina, tornado potential will continue and gradually transition north-northeastward this afternoon through tonight in association with a strengthening/spatially transitioning low-level flow field on the periphery of Hurricane Dorian. This tornado threat should also develop northward into coastal southeast Virginia by tonight. ...Oregon and northern portions of California/Nevada... As early-morning cloud cover quickly thins/moves out of the region, a plume of MLCAPE from 500-1000 J/kg is expected by peak heating, particularly across west-central/southern Oregon. An approaching shortwave trough off the northern California coast should support late afternoon thunderstorm development over the Cascades and Sierra Nevada. A deeply mixed and steep low/mid-level lapse rate environment coupled with 30-40 kt effective shear should support isolated severe wind and hail, particularly across Oregon. Some severe-caliber thunderstorm-related wind gusts may occur as far east/southeast as Nevada. ...Upper Midwest... Associated with a fast-moving clipper-type shortwave trough, a few severe storms will remain possible today from eastern Minnesota across northern Wisconsin and parts of the Upper Peninsula of Michigan. Severe hail is the most probable severe risk. Read more

WW 0636 Status Updates
STATUS REPORT ON WW 636 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SPC..09/05/19 ATTN...WFO...MHX...RAH... STATUS REPORT FOR WT 636 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC013-031-049-051-055-061-065-079-095-101-103-107-117-127-133- 137-147-163-177-187-191-195-052040- NC . NORTH CAROLINA COUNTIES INCLUDED ARE BEAUFORT CARTERET CRAVEN CUMBERLAND DARE DUPLIN EDGECOMBE GREENE HYDE JOHNSTON JONES LENOIR MARTIN NASH ONSLOW PAMLICO PITT SAMPSON TYRRELL WASHINGTON WAYNE WILSON AMZ131-135-136-137-150-152-154-156-158-170-172-174-176-178-230- 231-052040- CW . ADJACENT COASTAL WATERS INCLUDED ARE ALLIGATOR RIVER PAMLICO SOUND Read more

WW 0636 Status Updates
STATUS REPORT ON WW 636 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SPC..09/05/19 ATTN...WFO...MHX...RAH... STATUS REPORT FOR WT 636 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC013-031-049-051-055-061-065-079-095-101-103-107-117-127-133- 137-147-163-177-187-191-195-052040- NC . NORTH CAROLINA COUNTIES INCLUDED ARE BEAUFORT CARTERET CRAVEN CUMBERLAND DARE DUPLIN EDGECOMBE GREENE HYDE JOHNSTON JONES LENOIR MARTIN NASH ONSLOW PAMLICO PITT SAMPSON TYRRELL WASHINGTON WAYNE WILSON AMZ131-135-136-137-150-152-154-156-158-170-172-174-176-178-230- 231-052040- CW . ADJACENT COASTAL WATERS INCLUDED ARE ALLIGATOR RIVER PAMLICO SOUND Read more

WW 0636 Status Updates
STATUS REPORT ON WW 636 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SPC..09/05/19 ATTN...WFO...MHX...RAH... STATUS REPORT FOR WT 636 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC013-031-049-051-055-061-065-079-095-101-103-107-117-127-133- 137-147-163-177-187-191-195-052040- NC . NORTH CAROLINA COUNTIES INCLUDED ARE BEAUFORT CARTERET CRAVEN CUMBERLAND DARE DUPLIN EDGECOMBE GREENE HYDE JOHNSTON JONES LENOIR MARTIN NASH ONSLOW PAMLICO PITT SAMPSON TYRRELL WASHINGTON WAYNE WILSON AMZ131-135-136-137-150-152-154-156-158-170-172-174-176-178-230- 231-052040- CW . ADJACENT COASTAL WATERS INCLUDED ARE ALLIGATOR RIVER PAMLICO SOUND Read more

WW 636 TORNADO NC CW 051125Z - 052300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 636 NWS Storm Prediction Center Norman OK 725 AM EDT Thu Sep 5 2019 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Eastern North Carolina Coastal Waters * Effective this Thursday morning and evening from 725 AM until 700 PM EDT. * Primary threats include... A few tornadoes likely SUMMARY...Several supercells within outer bands of Hurricane Dorian should shift north from far southern North Carolina across eastern North Carolina through this afternoon. The tornado watch area is approximately along and 90 statute miles east and west of a line from 25 miles southeast of Jacksonville NC to 65 miles north northwest of Cape Hatteras NC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 635... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0.5 inches. Extreme turbulence and surface wind gusts to 50 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 12035. ...Grams Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0130 PM CDT Thu Sep 05 2019 Valid 061200Z - 071200Z ...Portions of Coastal Southern CA... North/northwesterly winds below around 850 mb will increase Friday evening into Saturday morning at the end of the forecast period. This could lead to some localized areas of elevated fire weather potential in Sundowner wind-prone areas. Forecast guidance generally has the surface pressure gradient on the marginal side for strong winds, but gusts between 25-35 mph will be possible. Additionally, RH values will generally be high enough to preclude a critical delineation, with a minimum around 15-20 percent. Given little rain and dry fuels across the area, elevated fire weather potential will exist, mainly across parts of Santa Barbara County and possible into parts of western Ventura County during Friday evening. ..Leitman.. 09/05/2019 .PREV DISCUSSION... /ISSUED 0119 AM CDT Thu Sep 05 2019/ ...Synopsis... Winds will remain light across the western CONUS on Friday which will limit the overall threat for large fire spread. An upper-level trough will move from the Pacific Northwest into the northern Rockies with thunderstorm activity expected. However increasing moisture associated with this trough will lead to more wet storm modes and should limit the threat for additional fire starts. ...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 0130 PM CDT Thu Sep 05 2019 Valid 061200Z - 071200Z ...Portions of Coastal Southern CA... North/northwesterly winds below around 850 mb will increase Friday evening into Saturday morning at the end of the forecast period. This could lead to some localized areas of elevated fire weather potential in Sundowner wind-prone areas. Forecast guidance generally has the surface pressure gradient on the marginal side for strong winds, but gusts between 25-35 mph will be possible. Additionally, RH values will generally be high enough to preclude a critical delineation, with a minimum around 15-20 percent. Given little rain and dry fuels across the area, elevated fire weather potential will exist, mainly across parts of Santa Barbara County and possible into parts of western Ventura County during Friday evening. ..Leitman.. 09/05/2019 .PREV DISCUSSION... /ISSUED 0119 AM CDT Thu Sep 05 2019/ ...Synopsis... Winds will remain light across the western CONUS on Friday which will limit the overall threat for large fire spread. An upper-level trough will move from the Pacific Northwest into the northern Rockies with thunderstorm activity expected. However increasing moisture associated with this trough will lead to more wet storm modes and should limit the threat for additional fire starts. ...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 0130 PM CDT Thu Sep 05 2019 Valid 061200Z - 071200Z ...Portions of Coastal Southern CA... North/northwesterly winds below around 850 mb will increase Friday evening into Saturday morning at the end of the forecast period. This could lead to some localized areas of elevated fire weather potential in Sundowner wind-prone areas. Forecast guidance generally has the surface pressure gradient on the marginal side for strong winds, but gusts between 25-35 mph will be possible. Additionally, RH values will generally be high enough to preclude a critical delineation, with a minimum around 15-20 percent. Given little rain and dry fuels across the area, elevated fire weather potential will exist, mainly across parts of Santa Barbara County and possible into parts of western Ventura County during Friday evening. ..Leitman.. 09/05/2019 .PREV DISCUSSION... /ISSUED 0119 AM CDT Thu Sep 05 2019/ ...Synopsis... Winds will remain light across the western CONUS on Friday which will limit the overall threat for large fire spread. An upper-level trough will move from the Pacific Northwest into the northern Rockies with thunderstorm activity expected. However increasing moisture associated with this trough will lead to more wet storm modes and should limit the threat for additional fire starts. ...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 0130 PM CDT Thu Sep 05 2019 Valid 061200Z - 071200Z ...Portions of Coastal Southern CA... North/northwesterly winds below around 850 mb will increase Friday evening into Saturday morning at the end of the forecast period. This could lead to some localized areas of elevated fire weather potential in Sundowner wind-prone areas. Forecast guidance generally has the surface pressure gradient on the marginal side for strong winds, but gusts between 25-35 mph will be possible. Additionally, RH values will generally be high enough to preclude a critical delineation, with a minimum around 15-20 percent. Given little rain and dry fuels across the area, elevated fire weather potential will exist, mainly across parts of Santa Barbara County and possible into parts of western Ventura County during Friday evening. ..Leitman.. 09/05/2019 .PREV DISCUSSION... /ISSUED 0119 AM CDT Thu Sep 05 2019/ ...Synopsis... Winds will remain light across the western CONUS on Friday which will limit the overall threat for large fire spread. An upper-level trough will move from the Pacific Northwest into the northern Rockies with thunderstorm activity expected. However increasing moisture associated with this trough will lead to more wet storm modes and should limit the threat for additional fire starts. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1240 PM CDT Thu Sep 05 2019 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION...AND THE NORTHEASTERN NORTH CAROLINA/SOUTHEASTERN VIRGINIA COASTAL REGION... ...SUMMARY... A few thunderstorms capable of isolated strong wind gusts will be possible over a portion of the northern Rockies Friday, while a brief tornado may occur during the morning near the northeastern North Carolina/southeastern Virginia coast. ...Synopsis... While upper ridging will prevail over much of the southern U.S., upper troughing will remain just off the West Coast, and will linger over the East even as Hurricane Dorian shifts northeastward across the western Atlantic. Additionally, a smaller, short-wave trough is forecast to shift across the northern Intermountain Region, on the northern periphery of the ridge. At the surface, a weak cool front will cross the upper Midwest and Ohio Valley regions, while an otherwise nondescript surface pattern is expected. ...Northern Intermountain region... A shortwave trough rounding the northern periphery of an upper ridge will shift through the northern Rockies Friday. Daytime heating across the region will support modest CAPE development, within a background kinematic environment featuring 30-35 kt effective bulk shear. Widely scattered high-based storms will likely develop over the higher terrain, and with inverted-V thermodynamic profiles expected, potential exists that a few of the stronger storms will be capable of producing locally strong wind gusts from mid afternoon through mid evening. ...Northeastern North Carolina/southeastern Virginia coasts... Per the latest forecast from the NHC, the center of Dorian is forecast to reside in the vicinity of the North Carolina outer banks at 12Z Friday, and is expected to advance northeastward away from the coast through the day. Given this position, and track, low-level winds inland should veer quickly to a north-of-east orientation with time, lessening any risk for low-level rotation with any onshore convective cells. At this time, will introduce a MRGL risk area, for a small area near the coast, to cover any risk for a brief spin-up during early stages of the period. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 09/05/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1240 PM CDT Thu Sep 05 2019 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION...AND THE NORTHEASTERN NORTH CAROLINA/SOUTHEASTERN VIRGINIA COASTAL REGION... ...SUMMARY... A few thunderstorms capable of isolated strong wind gusts will be possible over a portion of the northern Rockies Friday, while a brief tornado may occur during the morning near the northeastern North Carolina/southeastern Virginia coast. ...Synopsis... While upper ridging will prevail over much of the southern U.S., upper troughing will remain just off the West Coast, and will linger over the East even as Hurricane Dorian shifts northeastward across the western Atlantic. Additionally, a smaller, short-wave trough is forecast to shift across the northern Intermountain Region, on the northern periphery of the ridge. At the surface, a weak cool front will cross the upper Midwest and Ohio Valley regions, while an otherwise nondescript surface pattern is expected. ...Northern Intermountain region... A shortwave trough rounding the northern periphery of an upper ridge will shift through the northern Rockies Friday. Daytime heating across the region will support modest CAPE development, within a background kinematic environment featuring 30-35 kt effective bulk shear. Widely scattered high-based storms will likely develop over the higher terrain, and with inverted-V thermodynamic profiles expected, potential exists that a few of the stronger storms will be capable of producing locally strong wind gusts from mid afternoon through mid evening. ...Northeastern North Carolina/southeastern Virginia coasts... Per the latest forecast from the NHC, the center of Dorian is forecast to reside in the vicinity of the North Carolina outer banks at 12Z Friday, and is expected to advance northeastward away from the coast through the day. Given this position, and track, low-level winds inland should veer quickly to a north-of-east orientation with time, lessening any risk for low-level rotation with any onshore convective cells. At this time, will introduce a MRGL risk area, for a small area near the coast, to cover any risk for a brief spin-up during early stages of the period. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 09/05/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1240 PM CDT Thu Sep 05 2019 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION...AND THE NORTHEASTERN NORTH CAROLINA/SOUTHEASTERN VIRGINIA COASTAL REGION... ...SUMMARY... A few thunderstorms capable of isolated strong wind gusts will be possible over a portion of the northern Rockies Friday, while a brief tornado may occur during the morning near the northeastern North Carolina/southeastern Virginia coast. ...Synopsis... While upper ridging will prevail over much of the southern U.S., upper troughing will remain just off the West Coast, and will linger over the East even as Hurricane Dorian shifts northeastward across the western Atlantic. Additionally, a smaller, short-wave trough is forecast to shift across the northern Intermountain Region, on the northern periphery of the ridge. At the surface, a weak cool front will cross the upper Midwest and Ohio Valley regions, while an otherwise nondescript surface pattern is expected. ...Northern Intermountain region... A shortwave trough rounding the northern periphery of an upper ridge will shift through the northern Rockies Friday. Daytime heating across the region will support modest CAPE development, within a background kinematic environment featuring 30-35 kt effective bulk shear. Widely scattered high-based storms will likely develop over the higher terrain, and with inverted-V thermodynamic profiles expected, potential exists that a few of the stronger storms will be capable of producing locally strong wind gusts from mid afternoon through mid evening. ...Northeastern North Carolina/southeastern Virginia coasts... Per the latest forecast from the NHC, the center of Dorian is forecast to reside in the vicinity of the North Carolina outer banks at 12Z Friday, and is expected to advance northeastward away from the coast through the day. Given this position, and track, low-level winds inland should veer quickly to a north-of-east orientation with time, lessening any risk for low-level rotation with any onshore convective cells. At this time, will introduce a MRGL risk area, for a small area near the coast, to cover any risk for a brief spin-up during early stages of the period. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 09/05/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1240 PM CDT Thu Sep 05 2019 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION...AND THE NORTHEASTERN NORTH CAROLINA/SOUTHEASTERN VIRGINIA COASTAL REGION... ...SUMMARY... A few thunderstorms capable of isolated strong wind gusts will be possible over a portion of the northern Rockies Friday, while a brief tornado may occur during the morning near the northeastern North Carolina/southeastern Virginia coast. ...Synopsis... While upper ridging will prevail over much of the southern U.S., upper troughing will remain just off the West Coast, and will linger over the East even as Hurricane Dorian shifts northeastward across the western Atlantic. Additionally, a smaller, short-wave trough is forecast to shift across the northern Intermountain Region, on the northern periphery of the ridge. At the surface, a weak cool front will cross the upper Midwest and Ohio Valley regions, while an otherwise nondescript surface pattern is expected. ...Northern Intermountain region... A shortwave trough rounding the northern periphery of an upper ridge will shift through the northern Rockies Friday. Daytime heating across the region will support modest CAPE development, within a background kinematic environment featuring 30-35 kt effective bulk shear. Widely scattered high-based storms will likely develop over the higher terrain, and with inverted-V thermodynamic profiles expected, potential exists that a few of the stronger storms will be capable of producing locally strong wind gusts from mid afternoon through mid evening. ...Northeastern North Carolina/southeastern Virginia coasts... Per the latest forecast from the NHC, the center of Dorian is forecast to reside in the vicinity of the North Carolina outer banks at 12Z Friday, and is expected to advance northeastward away from the coast through the day. Given this position, and track, low-level winds inland should veer quickly to a north-of-east orientation with time, lessening any risk for low-level rotation with any onshore convective cells. At this time, will introduce a MRGL risk area, for a small area near the coast, to cover any risk for a brief spin-up during early stages of the period. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 09/05/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Thu Sep 05 2019 Valid 051700Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED LIGHTNING OVER DRY FUELS ACROSS PARTS OF OR/FAR NORTHERN CA AND EXTREME NORTHWEST NV... ...Northern CA...far northwest NV...western ID and much of OR... Latest guidance suggests thunderstorm coverage will increase later this afternoon across the region, and continue into this evening. A deeply mixed boundary layer is evident on forecast soundings. 12z regional RAOBS also indicated a very dry layer atop the nocturnal low level inversion, which when modified with expected afternoon high temperatures shows a similarly mixed boundary layer as that in models soundings. Strong mid-to-upper level flow also will result in fast storm motion, which has already been evident this morning. As a result, wetting rains will be limited despite unusually high PW values per SPC Sounding Climatology values. As a result of expected scattered coverage and low accumulating precip values, have opted to include a critical area for lightning over dry fuels. Strong wind gusts also will be possible with these storms as evaporation processes and steep low level lapse rates aid in downward transport of higher midlevel winds. See the SPC Day 1 Convective Outlook for more details on associated severe thunderstorm concerns. ..Leitman.. 09/05/2019 .PREV DISCUSSION... /ISSUED 0118 AM CDT Thu Sep 05 2019/ ...Synopsis... A potent upper-level trough is moving into the Pacific Northwest this morning with numerous lightning being observed in northern California. Some of these storms are expected to continue into the morning hours today before a brief lull is likely during late morning and early afternoon. Additional thunderstorms are expected during the afternoon as surface temperatures warm. PWAT values across much of the Northwest will be in the 0.75" range which, combined with storm speeds around 30 mph, will support a threat for dry thunderstorms. Otherwise, light winds are expected across much of the dry portions in the western CONUS which will limit the threat for large fire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Thu Sep 05 2019 Valid 051700Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED LIGHTNING OVER DRY FUELS ACROSS PARTS OF OR/FAR NORTHERN CA AND EXTREME NORTHWEST NV... ...Northern CA...far northwest NV...western ID and much of OR... Latest guidance suggests thunderstorm coverage will increase later this afternoon across the region, and continue into this evening. A deeply mixed boundary layer is evident on forecast soundings. 12z regional RAOBS also indicated a very dry layer atop the nocturnal low level inversion, which when modified with expected afternoon high temperatures shows a similarly mixed boundary layer as that in models soundings. Strong mid-to-upper level flow also will result in fast storm motion, which has already been evident this morning. As a result, wetting rains will be limited despite unusually high PW values per SPC Sounding Climatology values. As a result of expected scattered coverage and low accumulating precip values, have opted to include a critical area for lightning over dry fuels. Strong wind gusts also will be possible with these storms as evaporation processes and steep low level lapse rates aid in downward transport of higher midlevel winds. See the SPC Day 1 Convective Outlook for more details on associated severe thunderstorm concerns. ..Leitman.. 09/05/2019 .PREV DISCUSSION... /ISSUED 0118 AM CDT Thu Sep 05 2019/ ...Synopsis... A potent upper-level trough is moving into the Pacific Northwest this morning with numerous lightning being observed in northern California. Some of these storms are expected to continue into the morning hours today before a brief lull is likely during late morning and early afternoon. Additional thunderstorms are expected during the afternoon as surface temperatures warm. PWAT values across much of the Northwest will be in the 0.75" range which, combined with storm speeds around 30 mph, will support a threat for dry thunderstorms. Otherwise, light winds are expected across much of the dry portions in the western CONUS which will limit the threat for large fire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Thu Sep 05 2019 Valid 051700Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED LIGHTNING OVER DRY FUELS ACROSS PARTS OF OR/FAR NORTHERN CA AND EXTREME NORTHWEST NV... ...Northern CA...far northwest NV...western ID and much of OR... Latest guidance suggests thunderstorm coverage will increase later this afternoon across the region, and continue into this evening. A deeply mixed boundary layer is evident on forecast soundings. 12z regional RAOBS also indicated a very dry layer atop the nocturnal low level inversion, which when modified with expected afternoon high temperatures shows a similarly mixed boundary layer as that in models soundings. Strong mid-to-upper level flow also will result in fast storm motion, which has already been evident this morning. As a result, wetting rains will be limited despite unusually high PW values per SPC Sounding Climatology values. As a result of expected scattered coverage and low accumulating precip values, have opted to include a critical area for lightning over dry fuels. Strong wind gusts also will be possible with these storms as evaporation processes and steep low level lapse rates aid in downward transport of higher midlevel winds. See the SPC Day 1 Convective Outlook for more details on associated severe thunderstorm concerns. ..Leitman.. 09/05/2019 .PREV DISCUSSION... /ISSUED 0118 AM CDT Thu Sep 05 2019/ ...Synopsis... A potent upper-level trough is moving into the Pacific Northwest this morning with numerous lightning being observed in northern California. Some of these storms are expected to continue into the morning hours today before a brief lull is likely during late morning and early afternoon. Additional thunderstorms are expected during the afternoon as surface temperatures warm. PWAT values across much of the Northwest will be in the 0.75" range which, combined with storm speeds around 30 mph, will support a threat for dry thunderstorms. Otherwise, light winds are expected across much of the dry portions in the western CONUS which will limit the threat for large fire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Thu Sep 05 2019 Valid 051700Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED LIGHTNING OVER DRY FUELS ACROSS PARTS OF OR/FAR NORTHERN CA AND EXTREME NORTHWEST NV... ...Northern CA...far northwest NV...western ID and much of OR... Latest guidance suggests thunderstorm coverage will increase later this afternoon across the region, and continue into this evening. A deeply mixed boundary layer is evident on forecast soundings. 12z regional RAOBS also indicated a very dry layer atop the nocturnal low level inversion, which when modified with expected afternoon high temperatures shows a similarly mixed boundary layer as that in models soundings. Strong mid-to-upper level flow also will result in fast storm motion, which has already been evident this morning. As a result, wetting rains will be limited despite unusually high PW values per SPC Sounding Climatology values. As a result of expected scattered coverage and low accumulating precip values, have opted to include a critical area for lightning over dry fuels. Strong wind gusts also will be possible with these storms as evaporation processes and steep low level lapse rates aid in downward transport of higher midlevel winds. See the SPC Day 1 Convective Outlook for more details on associated severe thunderstorm concerns. ..Leitman.. 09/05/2019 .PREV DISCUSSION... /ISSUED 0118 AM CDT Thu Sep 05 2019/ ...Synopsis... A potent upper-level trough is moving into the Pacific Northwest this morning with numerous lightning being observed in northern California. Some of these storms are expected to continue into the morning hours today before a brief lull is likely during late morning and early afternoon. Additional thunderstorms are expected during the afternoon as surface temperatures warm. PWAT values across much of the Northwest will be in the 0.75" range which, combined with storm speeds around 30 mph, will support a threat for dry thunderstorms. Otherwise, light winds are expected across much of the dry portions in the western CONUS which will limit the threat for large fire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1139 AM CDT Thu Sep 05 2019 Valid 051630Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes are possible across eastern North Carolina and southeast Virginia through tonight in association with Hurricane Dorian. ...Eastern North Carolina/southeast Virginia... After an active morning for rotating storms/tornadoes across coastal North Carolina, tornado potential will continue and gradually transition north-northeastward this afternoon through tonight in association with a strengthening/spatially transitioning low-level flow field on the periphery of Hurricane Dorian. This tornado threat should also develop northward into coastal southeast Virginia by tonight. ...Oregon and northern portions of California/Nevada... As early-morning cloud cover quickly thins/moves out of the region, a plume of MLCAPE from 500-1000 J/kg is expected by peak heating, particularly across west-central/southern Oregon. An approaching shortwave trough off the northern California coast should support late afternoon thunderstorm development over the Cascades and Sierra Nevada. A deeply mixed and steep low/mid-level lapse rate environment coupled with 30-40 kt effective shear should support isolated severe wind and hail, particularly across Oregon. Some severe-caliber thunderstorm-related wind gusts may occur as far east/southeast as Nevada. ...Upper Midwest... Associated with a fast-moving clipper-type shortwave trough, a few severe storms will remain possible today from eastern Minnesota across northern Wisconsin and parts of the Upper Peninsula of Michigan. Severe hail is the most probable severe risk. ..Guyer/Nauslar.. 09/05/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1139 AM CDT Thu Sep 05 2019 Valid 051630Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes are possible across eastern North Carolina and southeast Virginia through tonight in association with Hurricane Dorian. ...Eastern North Carolina/southeast Virginia... After an active morning for rotating storms/tornadoes across coastal North Carolina, tornado potential will continue and gradually transition north-northeastward this afternoon through tonight in association with a strengthening/spatially transitioning low-level flow field on the periphery of Hurricane Dorian. This tornado threat should also develop northward into coastal southeast Virginia by tonight. ...Oregon and northern portions of California/Nevada... As early-morning cloud cover quickly thins/moves out of the region, a plume of MLCAPE from 500-1000 J/kg is expected by peak heating, particularly across west-central/southern Oregon. An approaching shortwave trough off the northern California coast should support late afternoon thunderstorm development over the Cascades and Sierra Nevada. A deeply mixed and steep low/mid-level lapse rate environment coupled with 30-40 kt effective shear should support isolated severe wind and hail, particularly across Oregon. Some severe-caliber thunderstorm-related wind gusts may occur as far east/southeast as Nevada. ...Upper Midwest... Associated with a fast-moving clipper-type shortwave trough, a few severe storms will remain possible today from eastern Minnesota across northern Wisconsin and parts of the Upper Peninsula of Michigan. Severe hail is the most probable severe risk. ..Guyer/Nauslar.. 09/05/2019 Read more