Severe Storms

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0757 AM CDT Fri Sep 06 2019 Valid 061300Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE NORTHERN INTERMOUNTAIN REGION...NORTHERN/CENTRAL ROCKIES AND ADJACENT HIGH PLAINS... ...SUMMARY... Isolated severe thunderstorm winds and hail are possible this afternoon and evening over parts of the northern Intermountain region, northern/central Rockies and adjacent High Plains. ...Synopsis... In mid/upper levels, an initially strong anticyclone centered over the south-central Rockies will shift southwestward and weaken as a strong shortwave trough crosses the northern Rockies. That trough -- now evident in moisture-channel imagery over western OR and northern CA -- is progged to overtake/absorb lesser vorticity lobes initially to its east across eastern OR/ID. The combined, somewhat stronger perturbation will reach the MT/ID border region and southern ID by 00Z. Thereafter, the trough will pivot eastward and east-southeastward, reaching central MT, western WY and northwestern CO by 12Z. Meanwhile, farther east, shortwave troughs now over the upper Great Lakes and northern MB will move southeastward across the Mid-Atlantic and upper Great Lakes, respectively. In response, Hurricane Dorian has commenced accelerating northeastward over/off the Outer Banks, and should eject away from the Tidewater region through the remainder of the period, per NHC forecasts. With the most thermodynamically and kinematically favorable sector for supercellular tornadoes shifting offshore, and forecast to stay southeast of the Cape Cod/Martha's Vineyard region tonight, unconditional overland tornado probabilities have been dropped. Otherwise, the surface analysis showed a low near GRB with occluded front to southeastern IA, and slow-moving cold front to a weak frontal-wave/lee low over western KS, then extending across parts of southeastern CO. The low should move southeastward across OH overnight and become poorly defined in the broader field of low pressure surrounding Dorian. Meanwhile the front should cross the Ohio Valley and stall across the southern KS/northern OK/ southeastern CO corridor. ...Northern Rockies/Intermountain region to Front Range/central High Plains... Widely scattered to scattered thunderstorms are expected to develop this afternoon into evening in three primary regimes, described below from west to east, each offering isolated severe gusts/hail, with enough spatial overlap to result in a unified outlook area: 1. A "cold-core" regime near the midlevel/500-mb thermal trough, from eastern OR across much of southern ID, potentially forming a quasi-linear band of strong/isolated severe convection over ID before weakening tonight in western WY where regime 2 below will have produced enough convection to stabilize the air mass. Diurnal heating and midlevel cooling should overlap well, steepening low/ middle-level lapse rates considerably, atop 50s F low-elevation surface dew points. This should result in MLCAPE 1000-1500 J/kg atop a well-mixed boundary layer supporting strong/locally severe gusts and survival of hail to ground level. Organization should be tempered somewhat by weakening deep-layer flow with time and proximity to the mid/upper trough, and related lack of shear. However, a conditional cold-pool aggregation potential exists, especially across parts of the Snake River Plain and southern mountains west of I-15. 2. A band of relatively maximized deep-layer ascent shifting eastward from southeastern ID and northern UT across western/central WY. A combination of lift from large-scale DCVA/cooling aloft, frontal forcing near a low-level baroclinic zone preceding that trough, and pre-frontal warm advection will support convection in this area. Buoyancy should be less in both coverage and magnitude than in regime 1, with MLCAPE mainly around 500 J/kg. Still, localized well-mixed boundary layers and marginal deep shear will promote a few strong-severe cells in the broader convective plume. 3. Heating of higher terrain, favorable low-level moisture, and resultant weak MLCINH should foster convection initiation this afternoon over the Front Range, Laramie Range, adjacent foothills, and perhaps the Bighorns. Activity then should move eastward across a diabatically destabilized strip of the central High Plains, offering damaging gusts and isolated hail before weakening. Strong surface heating and deep, strongly mixed boundary layers will support isolated severe potential with this activity before it weakens this evening in a stabilizing boundary layer, at lower elevations. ..Edwards/Smith.. 09/06/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0757 AM CDT Fri Sep 06 2019 Valid 061300Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE NORTHERN INTERMOUNTAIN REGION...NORTHERN/CENTRAL ROCKIES AND ADJACENT HIGH PLAINS... ...SUMMARY... Isolated severe thunderstorm winds and hail are possible this afternoon and evening over parts of the northern Intermountain region, northern/central Rockies and adjacent High Plains. ...Synopsis... In mid/upper levels, an initially strong anticyclone centered over the south-central Rockies will shift southwestward and weaken as a strong shortwave trough crosses the northern Rockies. That trough -- now evident in moisture-channel imagery over western OR and northern CA -- is progged to overtake/absorb lesser vorticity lobes initially to its east across eastern OR/ID. The combined, somewhat stronger perturbation will reach the MT/ID border region and southern ID by 00Z. Thereafter, the trough will pivot eastward and east-southeastward, reaching central MT, western WY and northwestern CO by 12Z. Meanwhile, farther east, shortwave troughs now over the upper Great Lakes and northern MB will move southeastward across the Mid-Atlantic and upper Great Lakes, respectively. In response, Hurricane Dorian has commenced accelerating northeastward over/off the Outer Banks, and should eject away from the Tidewater region through the remainder of the period, per NHC forecasts. With the most thermodynamically and kinematically favorable sector for supercellular tornadoes shifting offshore, and forecast to stay southeast of the Cape Cod/Martha's Vineyard region tonight, unconditional overland tornado probabilities have been dropped. Otherwise, the surface analysis showed a low near GRB with occluded front to southeastern IA, and slow-moving cold front to a weak frontal-wave/lee low over western KS, then extending across parts of southeastern CO. The low should move southeastward across OH overnight and become poorly defined in the broader field of low pressure surrounding Dorian. Meanwhile the front should cross the Ohio Valley and stall across the southern KS/northern OK/ southeastern CO corridor. ...Northern Rockies/Intermountain region to Front Range/central High Plains... Widely scattered to scattered thunderstorms are expected to develop this afternoon into evening in three primary regimes, described below from west to east, each offering isolated severe gusts/hail, with enough spatial overlap to result in a unified outlook area: 1. A "cold-core" regime near the midlevel/500-mb thermal trough, from eastern OR across much of southern ID, potentially forming a quasi-linear band of strong/isolated severe convection over ID before weakening tonight in western WY where regime 2 below will have produced enough convection to stabilize the air mass. Diurnal heating and midlevel cooling should overlap well, steepening low/ middle-level lapse rates considerably, atop 50s F low-elevation surface dew points. This should result in MLCAPE 1000-1500 J/kg atop a well-mixed boundary layer supporting strong/locally severe gusts and survival of hail to ground level. Organization should be tempered somewhat by weakening deep-layer flow with time and proximity to the mid/upper trough, and related lack of shear. However, a conditional cold-pool aggregation potential exists, especially across parts of the Snake River Plain and southern mountains west of I-15. 2. A band of relatively maximized deep-layer ascent shifting eastward from southeastern ID and northern UT across western/central WY. A combination of lift from large-scale DCVA/cooling aloft, frontal forcing near a low-level baroclinic zone preceding that trough, and pre-frontal warm advection will support convection in this area. Buoyancy should be less in both coverage and magnitude than in regime 1, with MLCAPE mainly around 500 J/kg. Still, localized well-mixed boundary layers and marginal deep shear will promote a few strong-severe cells in the broader convective plume. 3. Heating of higher terrain, favorable low-level moisture, and resultant weak MLCINH should foster convection initiation this afternoon over the Front Range, Laramie Range, adjacent foothills, and perhaps the Bighorns. Activity then should move eastward across a diabatically destabilized strip of the central High Plains, offering damaging gusts and isolated hail before weakening. Strong surface heating and deep, strongly mixed boundary layers will support isolated severe potential with this activity before it weakens this evening in a stabilizing boundary layer, at lower elevations. ..Edwards/Smith.. 09/06/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0757 AM CDT Fri Sep 06 2019 Valid 061300Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE NORTHERN INTERMOUNTAIN REGION...NORTHERN/CENTRAL ROCKIES AND ADJACENT HIGH PLAINS... ...SUMMARY... Isolated severe thunderstorm winds and hail are possible this afternoon and evening over parts of the northern Intermountain region, northern/central Rockies and adjacent High Plains. ...Synopsis... In mid/upper levels, an initially strong anticyclone centered over the south-central Rockies will shift southwestward and weaken as a strong shortwave trough crosses the northern Rockies. That trough -- now evident in moisture-channel imagery over western OR and northern CA -- is progged to overtake/absorb lesser vorticity lobes initially to its east across eastern OR/ID. The combined, somewhat stronger perturbation will reach the MT/ID border region and southern ID by 00Z. Thereafter, the trough will pivot eastward and east-southeastward, reaching central MT, western WY and northwestern CO by 12Z. Meanwhile, farther east, shortwave troughs now over the upper Great Lakes and northern MB will move southeastward across the Mid-Atlantic and upper Great Lakes, respectively. In response, Hurricane Dorian has commenced accelerating northeastward over/off the Outer Banks, and should eject away from the Tidewater region through the remainder of the period, per NHC forecasts. With the most thermodynamically and kinematically favorable sector for supercellular tornadoes shifting offshore, and forecast to stay southeast of the Cape Cod/Martha's Vineyard region tonight, unconditional overland tornado probabilities have been dropped. Otherwise, the surface analysis showed a low near GRB with occluded front to southeastern IA, and slow-moving cold front to a weak frontal-wave/lee low over western KS, then extending across parts of southeastern CO. The low should move southeastward across OH overnight and become poorly defined in the broader field of low pressure surrounding Dorian. Meanwhile the front should cross the Ohio Valley and stall across the southern KS/northern OK/ southeastern CO corridor. ...Northern Rockies/Intermountain region to Front Range/central High Plains... Widely scattered to scattered thunderstorms are expected to develop this afternoon into evening in three primary regimes, described below from west to east, each offering isolated severe gusts/hail, with enough spatial overlap to result in a unified outlook area: 1. A "cold-core" regime near the midlevel/500-mb thermal trough, from eastern OR across much of southern ID, potentially forming a quasi-linear band of strong/isolated severe convection over ID before weakening tonight in western WY where regime 2 below will have produced enough convection to stabilize the air mass. Diurnal heating and midlevel cooling should overlap well, steepening low/ middle-level lapse rates considerably, atop 50s F low-elevation surface dew points. This should result in MLCAPE 1000-1500 J/kg atop a well-mixed boundary layer supporting strong/locally severe gusts and survival of hail to ground level. Organization should be tempered somewhat by weakening deep-layer flow with time and proximity to the mid/upper trough, and related lack of shear. However, a conditional cold-pool aggregation potential exists, especially across parts of the Snake River Plain and southern mountains west of I-15. 2. A band of relatively maximized deep-layer ascent shifting eastward from southeastern ID and northern UT across western/central WY. A combination of lift from large-scale DCVA/cooling aloft, frontal forcing near a low-level baroclinic zone preceding that trough, and pre-frontal warm advection will support convection in this area. Buoyancy should be less in both coverage and magnitude than in regime 1, with MLCAPE mainly around 500 J/kg. Still, localized well-mixed boundary layers and marginal deep shear will promote a few strong-severe cells in the broader convective plume. 3. Heating of higher terrain, favorable low-level moisture, and resultant weak MLCINH should foster convection initiation this afternoon over the Front Range, Laramie Range, adjacent foothills, and perhaps the Bighorns. Activity then should move eastward across a diabatically destabilized strip of the central High Plains, offering damaging gusts and isolated hail before weakening. Strong surface heating and deep, strongly mixed boundary layers will support isolated severe potential with this activity before it weakens this evening in a stabilizing boundary layer, at lower elevations. ..Edwards/Smith.. 09/06/2019 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Fri Sep 06 2019 Valid 091200Z - 141200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models are in good agreement on Monday with a shortwave trough and an associated cold front over the northern Plains. The models suggest that thunderstorm development will be possible ahead of the front in parts of Nebraska and the eastern Dakotas on Monday afternoon. Forecast instability and deep-layer shear may be enough for an isolated severe threat. On Tuesday, the models develop an upper-level trough in the western U.S. as a shortwave ridge moves into the northern Plains. Thunderstorms will be possible on Tuesday along a front that is forecast to be from northern parts of the central Plains eastward into the southern Great Lakes region. The models remain in reasonable agreement on Wednesday with an upper-level trough over the western states and southwest mid-level flow in the Great Plains. Thunderstorms will again be possible across parts of the central and northern Plains where the ECMWF, GFS and UKMET show a surface low and a moist airmass. An isolated severe threat will be possible in parts of Nebraska and South Dakota in areas that destabilize the most. ...Thursday/Day 7 to Friday/Day 8... On Thursday and Friday, model solutions are somewhat in agreement concerning an upper-level trough that is forecast to move across the north-central U.S. Both the GFS and ECMWF show a moist and unstable airmass located across the mid Missouri and upper Mississippi Valleys Thursday afternoon. A severe threat will be possible ahead of the upper-level trough in parts of the eastern Dakotas and Minnesota. The potential for severe thunderstorms is forecast to shift into the Great Lakes on Friday as a cold front moves southeastward across the central U.S. Although a conditional severe threat will be possible throughout the day 4 to 8 period across parts of the central and northern U.S, predictability is too low to outlook a threat area at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Fri Sep 06 2019 Valid 091200Z - 141200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models are in good agreement on Monday with a shortwave trough and an associated cold front over the northern Plains. The models suggest that thunderstorm development will be possible ahead of the front in parts of Nebraska and the eastern Dakotas on Monday afternoon. Forecast instability and deep-layer shear may be enough for an isolated severe threat. On Tuesday, the models develop an upper-level trough in the western U.S. as a shortwave ridge moves into the northern Plains. Thunderstorms will be possible on Tuesday along a front that is forecast to be from northern parts of the central Plains eastward into the southern Great Lakes region. The models remain in reasonable agreement on Wednesday with an upper-level trough over the western states and southwest mid-level flow in the Great Plains. Thunderstorms will again be possible across parts of the central and northern Plains where the ECMWF, GFS and UKMET show a surface low and a moist airmass. An isolated severe threat will be possible in parts of Nebraska and South Dakota in areas that destabilize the most. ...Thursday/Day 7 to Friday/Day 8... On Thursday and Friday, model solutions are somewhat in agreement concerning an upper-level trough that is forecast to move across the north-central U.S. Both the GFS and ECMWF show a moist and unstable airmass located across the mid Missouri and upper Mississippi Valleys Thursday afternoon. A severe threat will be possible ahead of the upper-level trough in parts of the eastern Dakotas and Minnesota. The potential for severe thunderstorms is forecast to shift into the Great Lakes on Friday as a cold front moves southeastward across the central U.S. Although a conditional severe threat will be possible throughout the day 4 to 8 period across parts of the central and northern U.S, predictability is too low to outlook a threat area at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Fri Sep 06 2019 Valid 091200Z - 141200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models are in good agreement on Monday with a shortwave trough and an associated cold front over the northern Plains. The models suggest that thunderstorm development will be possible ahead of the front in parts of Nebraska and the eastern Dakotas on Monday afternoon. Forecast instability and deep-layer shear may be enough for an isolated severe threat. On Tuesday, the models develop an upper-level trough in the western U.S. as a shortwave ridge moves into the northern Plains. Thunderstorms will be possible on Tuesday along a front that is forecast to be from northern parts of the central Plains eastward into the southern Great Lakes region. The models remain in reasonable agreement on Wednesday with an upper-level trough over the western states and southwest mid-level flow in the Great Plains. Thunderstorms will again be possible across parts of the central and northern Plains where the ECMWF, GFS and UKMET show a surface low and a moist airmass. An isolated severe threat will be possible in parts of Nebraska and South Dakota in areas that destabilize the most. ...Thursday/Day 7 to Friday/Day 8... On Thursday and Friday, model solutions are somewhat in agreement concerning an upper-level trough that is forecast to move across the north-central U.S. Both the GFS and ECMWF show a moist and unstable airmass located across the mid Missouri and upper Mississippi Valleys Thursday afternoon. A severe threat will be possible ahead of the upper-level trough in parts of the eastern Dakotas and Minnesota. The potential for severe thunderstorms is forecast to shift into the Great Lakes on Friday as a cold front moves southeastward across the central U.S. Although a conditional severe threat will be possible throughout the day 4 to 8 period across parts of the central and northern U.S, predictability is too low to outlook a threat area at this time. Read more

WW 0637 Status Updates
STATUS REPORT ON WW 637 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 NE HSE TO 25 E ECG TO 15 WSW ECG TO 15 W ORF. ..SMITH..09/06/19 ATTN...WFO...MHX...AKQ... STATUS REPORT FOR WT 637 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC029-053-139-143-060840- NC . NORTH CAROLINA COUNTIES INCLUDED ARE CAMDEN CURRITUCK PASQUOTANK PERQUIMANS VAC550-710-740-810-060840- VA . VIRGINIA COUNTIES INCLUDED ARE VIRGINIA INDEPENDENT CITIES INCLUDED ARE CHESAPEAKE NORFOLK PORTSMOUTH VIRGINIA BEACH ANZ633-634-656-658-060840- Read more

WW 637 TORNADO NC VA CW 052215Z - 061100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 637 NWS Storm Prediction Center Norman OK 615 PM EDT Thu Sep 5 2019 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Eastern North Carolina Extreme southeastern Virginia Coastal Waters * Effective this Thursday night and Friday morning from 615 PM until 700 AM EDT. * Primary threats include... A few tornadoes likely SUMMARY...Threat for occasional supercells with tornadoes will persist through tonight within the outer northeastern rain bands of hurricane Dorian. The tornado watch area is approximately along and 65 statute miles east and west of a line from 60 miles northeast of Elizabeth City NC to 25 miles south southeast of New Bern NC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). 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...This tornado watch replaces tornado watch number 636. Watch number 636 will not be in effect after 615 PM EDT. AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 10045. ...Thompson Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Fri Sep 06 2019 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... Marginally severe thunderstorms with strong wind gusts and hail will be possible across parts of the central High Plains Sunday afternoon and evening. ...Central High Plains... An upper-level trough is forecast to move into the central and northern Rockies on Sunday as a shortwave ridge moves across the central and northern Plains. A lee surface trough is forecast to develop in the central High Plains to the east of the Front Range. Surface dewpoints may be able to reach the lower 60s F in parts of eastern Colorado due to upslope easterly flow. This may allow for a pocket of moderate instability to develop by afternoon. Thunderstorms are forecast to develop in the higher terrain and move eastward into the central High Plains during the afternoon. The instability combined with steep mid-level lapse rates and moderate deep-layer shear should be enough for a marginal severe threat. A few of the stronger cells could produce hail and marginally severe wind gusts. ..Broyles.. 09/06/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Fri Sep 06 2019 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... Marginally severe thunderstorms with strong wind gusts and hail will be possible across parts of the central High Plains Sunday afternoon and evening. ...Central High Plains... An upper-level trough is forecast to move into the central and northern Rockies on Sunday as a shortwave ridge moves across the central and northern Plains. A lee surface trough is forecast to develop in the central High Plains to the east of the Front Range. Surface dewpoints may be able to reach the lower 60s F in parts of eastern Colorado due to upslope easterly flow. This may allow for a pocket of moderate instability to develop by afternoon. Thunderstorms are forecast to develop in the higher terrain and move eastward into the central High Plains during the afternoon. The instability combined with steep mid-level lapse rates and moderate deep-layer shear should be enough for a marginal severe threat. A few of the stronger cells could produce hail and marginally severe wind gusts. ..Broyles.. 09/06/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Fri Sep 06 2019 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... Marginally severe thunderstorms with strong wind gusts and hail will be possible across parts of the central High Plains Sunday afternoon and evening. ...Central High Plains... An upper-level trough is forecast to move into the central and northern Rockies on Sunday as a shortwave ridge moves across the central and northern Plains. A lee surface trough is forecast to develop in the central High Plains to the east of the Front Range. Surface dewpoints may be able to reach the lower 60s F in parts of eastern Colorado due to upslope easterly flow. This may allow for a pocket of moderate instability to develop by afternoon. Thunderstorms are forecast to develop in the higher terrain and move eastward into the central High Plains during the afternoon. The instability combined with steep mid-level lapse rates and moderate deep-layer shear should be enough for a marginal severe threat. A few of the stronger cells could produce hail and marginally severe wind gusts. ..Broyles.. 09/06/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Fri Sep 06 2019 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...SUMMARY... Marginally severe thunderstorms with strong wind gusts and hail will be possible across parts of the central High Plains Sunday afternoon and evening. ...Central High Plains... An upper-level trough is forecast to move into the central and northern Rockies on Sunday as a shortwave ridge moves across the central and northern Plains. A lee surface trough is forecast to develop in the central High Plains to the east of the Front Range. Surface dewpoints may be able to reach the lower 60s F in parts of eastern Colorado due to upslope easterly flow. This may allow for a pocket of moderate instability to develop by afternoon. Thunderstorms are forecast to develop in the higher terrain and move eastward into the central High Plains during the afternoon. The instability combined with steep mid-level lapse rates and moderate deep-layer shear should be enough for a marginal severe threat. A few of the stronger cells could produce hail and marginally severe wind gusts. ..Broyles.. 09/06/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Fri Sep 06 2019 Valid 071200Z - 081200Z ...NO CRITICAL AREAS... ...Synopsis... A negatively tilted mid-level shortwave trough will deepen across the far western CONUS throughout the Day 2/Saturday period. A surface trough will become established across the Great Basin region. As such, locally dry, breezy conditions may be observed across far western portions of the Great Basin, mainly along the lee of the Sierra. These conditions are expected to brief and patchy enough to preclude an elevated delineation. Ahead of the surface and mid-level trough axes, deep-layer ascent may encourage isolated to scattered thunderstorms across parts of northern Nevada. Nonetheless, recent accumulated rainfall from previous thunderstorm events raises concerns as to how receptive fuels will be in this area to fire spread, especially given that the forecast Day 2 storms will be predominantly wet in nature, precluding an isolated dry thunderstorm delineation at this time. Otherwise, relatively quiescent fire weather conditions are expected across the western CONUS. ..Squitieri.. 09/06/2019 ...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 0202 AM CDT Fri Sep 06 2019 Valid 071200Z - 081200Z ...NO CRITICAL AREAS... ...Synopsis... A negatively tilted mid-level shortwave trough will deepen across the far western CONUS throughout the Day 2/Saturday period. A surface trough will become established across the Great Basin region. As such, locally dry, breezy conditions may be observed across far western portions of the Great Basin, mainly along the lee of the Sierra. These conditions are expected to brief and patchy enough to preclude an elevated delineation. Ahead of the surface and mid-level trough axes, deep-layer ascent may encourage isolated to scattered thunderstorms across parts of northern Nevada. Nonetheless, recent accumulated rainfall from previous thunderstorm events raises concerns as to how receptive fuels will be in this area to fire spread, especially given that the forecast Day 2 storms will be predominantly wet in nature, precluding an isolated dry thunderstorm delineation at this time. Otherwise, relatively quiescent fire weather conditions are expected across the western CONUS. ..Squitieri.. 09/06/2019 ...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 0202 AM CDT Fri Sep 06 2019 Valid 071200Z - 081200Z ...NO CRITICAL AREAS... ...Synopsis... A negatively tilted mid-level shortwave trough will deepen across the far western CONUS throughout the Day 2/Saturday period. A surface trough will become established across the Great Basin region. As such, locally dry, breezy conditions may be observed across far western portions of the Great Basin, mainly along the lee of the Sierra. These conditions are expected to brief and patchy enough to preclude an elevated delineation. Ahead of the surface and mid-level trough axes, deep-layer ascent may encourage isolated to scattered thunderstorms across parts of northern Nevada. Nonetheless, recent accumulated rainfall from previous thunderstorm events raises concerns as to how receptive fuels will be in this area to fire spread, especially given that the forecast Day 2 storms will be predominantly wet in nature, precluding an isolated dry thunderstorm delineation at this time. Otherwise, relatively quiescent fire weather conditions are expected across the western CONUS. ..Squitieri.. 09/06/2019 ...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 0202 AM CDT Fri Sep 06 2019 Valid 071200Z - 081200Z ...NO CRITICAL AREAS... ...Synopsis... A negatively tilted mid-level shortwave trough will deepen across the far western CONUS throughout the Day 2/Saturday period. A surface trough will become established across the Great Basin region. As such, locally dry, breezy conditions may be observed across far western portions of the Great Basin, mainly along the lee of the Sierra. These conditions are expected to brief and patchy enough to preclude an elevated delineation. Ahead of the surface and mid-level trough axes, deep-layer ascent may encourage isolated to scattered thunderstorms across parts of northern Nevada. Nonetheless, recent accumulated rainfall from previous thunderstorm events raises concerns as to how receptive fuels will be in this area to fire spread, especially given that the forecast Day 2 storms will be predominantly wet in nature, precluding an isolated dry thunderstorm delineation at this time. Otherwise, relatively quiescent fire weather conditions are expected across the western CONUS. ..Squitieri.. 09/06/2019 ...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 0146 AM CDT Fri Sep 06 2019 Valid 061200Z - 071200Z ...Synopsis... A mid-level ridge will break down across the western CONUS, as the first in a series of mid-level shortwave troughs traverses the Pacific Northwest, into the central/northern Rockies regions. Deep-layer ascent associated with the impinging mid-level trough will encourage isolated to scattered thunderstorm development across much of the region, with most of the storms producing wetting rains. Towards the end of the period, as the first trough moves away from the West Coast, modest northerly low-level flow may encourage dry, breezy conditions during the early morning hours across parts of southern California, where modest potential exists for some fire spread. ...Great Basin into the Pacific Northwest, central and northern Rockies regions... Isolated to scattered thunderstorms are expected to develop during the afternoon hours. While many of the storms are expected to be relatively fast-moving and high-based in nature, precipitable water values in the 0.75-1.25 inch range suggests accumulating rainfall should be common with most storms. As such, the density of dry strikes is expected to be low enough to preclude an isolated dry thunderstorm delineation at this time. Still, at least a few dry strikes may occur along the periphery of the storm cores, atop fuels that will be at least modestly receptive to fire spread. Gusty, erratic surface winds may also accompany the stronger storms, worsening the potential for fire spread in localized areas lacking precipitation accumulation, especially in the central Rockies regions. Please see the SPC Day 1 Convective Outlook for more details on severe wind/hail potential. ...Parts of Coastal Southern California... Low-level northerly flow within the 925-850 mb layer will support a modest Sundowner event in the early morning hours across parts of the Santa Ynez mountains. Downslope flow may encourage 15-20 mph sustained northerly surface winds. Surface RH will be on the high side (20-25%) to support a more robust wildfire-spread threat, but dry fuels are in place to support some potential for fire growth, with an elevated area delineated to account for this scenario. ..Squitieri.. 09/06/2019 ...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 0146 AM CDT Fri Sep 06 2019 Valid 061200Z - 071200Z ...Synopsis... A mid-level ridge will break down across the western CONUS, as the first in a series of mid-level shortwave troughs traverses the Pacific Northwest, into the central/northern Rockies regions. Deep-layer ascent associated with the impinging mid-level trough will encourage isolated to scattered thunderstorm development across much of the region, with most of the storms producing wetting rains. Towards the end of the period, as the first trough moves away from the West Coast, modest northerly low-level flow may encourage dry, breezy conditions during the early morning hours across parts of southern California, where modest potential exists for some fire spread. ...Great Basin into the Pacific Northwest, central and northern Rockies regions... Isolated to scattered thunderstorms are expected to develop during the afternoon hours. While many of the storms are expected to be relatively fast-moving and high-based in nature, precipitable water values in the 0.75-1.25 inch range suggests accumulating rainfall should be common with most storms. As such, the density of dry strikes is expected to be low enough to preclude an isolated dry thunderstorm delineation at this time. Still, at least a few dry strikes may occur along the periphery of the storm cores, atop fuels that will be at least modestly receptive to fire spread. Gusty, erratic surface winds may also accompany the stronger storms, worsening the potential for fire spread in localized areas lacking precipitation accumulation, especially in the central Rockies regions. Please see the SPC Day 1 Convective Outlook for more details on severe wind/hail potential. ...Parts of Coastal Southern California... Low-level northerly flow within the 925-850 mb layer will support a modest Sundowner event in the early morning hours across parts of the Santa Ynez mountains. Downslope flow may encourage 15-20 mph sustained northerly surface winds. Surface RH will be on the high side (20-25%) to support a more robust wildfire-spread threat, but dry fuels are in place to support some potential for fire growth, with an elevated area delineated to account for this scenario. ..Squitieri.. 09/06/2019 ...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 0146 AM CDT Fri Sep 06 2019 Valid 061200Z - 071200Z ...Synopsis... A mid-level ridge will break down across the western CONUS, as the first in a series of mid-level shortwave troughs traverses the Pacific Northwest, into the central/northern Rockies regions. Deep-layer ascent associated with the impinging mid-level trough will encourage isolated to scattered thunderstorm development across much of the region, with most of the storms producing wetting rains. Towards the end of the period, as the first trough moves away from the West Coast, modest northerly low-level flow may encourage dry, breezy conditions during the early morning hours across parts of southern California, where modest potential exists for some fire spread. ...Great Basin into the Pacific Northwest, central and northern Rockies regions... Isolated to scattered thunderstorms are expected to develop during the afternoon hours. While many of the storms are expected to be relatively fast-moving and high-based in nature, precipitable water values in the 0.75-1.25 inch range suggests accumulating rainfall should be common with most storms. As such, the density of dry strikes is expected to be low enough to preclude an isolated dry thunderstorm delineation at this time. Still, at least a few dry strikes may occur along the periphery of the storm cores, atop fuels that will be at least modestly receptive to fire spread. Gusty, erratic surface winds may also accompany the stronger storms, worsening the potential for fire spread in localized areas lacking precipitation accumulation, especially in the central Rockies regions. Please see the SPC Day 1 Convective Outlook for more details on severe wind/hail potential. ...Parts of Coastal Southern California... Low-level northerly flow within the 925-850 mb layer will support a modest Sundowner event in the early morning hours across parts of the Santa Ynez mountains. Downslope flow may encourage 15-20 mph sustained northerly surface winds. Surface RH will be on the high side (20-25%) to support a more robust wildfire-spread threat, but dry fuels are in place to support some potential for fire growth, with an elevated area delineated to account for this scenario. ..Squitieri.. 09/06/2019 ...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 0146 AM CDT Fri Sep 06 2019 Valid 061200Z - 071200Z ...Synopsis... A mid-level ridge will break down across the western CONUS, as the first in a series of mid-level shortwave troughs traverses the Pacific Northwest, into the central/northern Rockies regions. Deep-layer ascent associated with the impinging mid-level trough will encourage isolated to scattered thunderstorm development across much of the region, with most of the storms producing wetting rains. Towards the end of the period, as the first trough moves away from the West Coast, modest northerly low-level flow may encourage dry, breezy conditions during the early morning hours across parts of southern California, where modest potential exists for some fire spread. ...Great Basin into the Pacific Northwest, central and northern Rockies regions... Isolated to scattered thunderstorms are expected to develop during the afternoon hours. While many of the storms are expected to be relatively fast-moving and high-based in nature, precipitable water values in the 0.75-1.25 inch range suggests accumulating rainfall should be common with most storms. As such, the density of dry strikes is expected to be low enough to preclude an isolated dry thunderstorm delineation at this time. Still, at least a few dry strikes may occur along the periphery of the storm cores, atop fuels that will be at least modestly receptive to fire spread. Gusty, erratic surface winds may also accompany the stronger storms, worsening the potential for fire spread in localized areas lacking precipitation accumulation, especially in the central Rockies regions. Please see the SPC Day 1 Convective Outlook for more details on severe wind/hail potential. ...Parts of Coastal Southern California... Low-level northerly flow within the 925-850 mb layer will support a modest Sundowner event in the early morning hours across parts of the Santa Ynez mountains. Downslope flow may encourage 15-20 mph sustained northerly surface winds. Surface RH will be on the high side (20-25%) to support a more robust wildfire-spread threat, but dry fuels are in place to support some potential for fire growth, with an elevated area delineated to account for this scenario. ..Squitieri.. 09/06/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more