Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1100 AM CDT Fri Aug 30 2019 Valid 301700Z - 311200Z The primary change with this forecast update was to expand the western edge of the isolated dry thunderstorm area farther west into northeast Utah, southwest Colorado, and extreme southeast Idaho. A few cloud to ground lightning flashes -- generally associated with dry thunderstorms -- are also possible across portions of northeast Oregon and vicinity. However, recent rainfall (locally > 0.5"), relatively marginal precipitable water values (0.8"-1"), and uncertainty regarding thunderstorm coverage precludes the introduction of an isolated dry thunderstorm area. See previous discussion below for more information on today's fire weather forecast. ..Elliott.. 08/30/2019 .PREV DISCUSSION... /ISSUED 0108 AM CDT Fri Aug 30 2019/ ...Synopsis... A upper-level ridge will build across the western CONUS throughout the period, with stronger flow aloft associated with an approaching mid-level shortwave trough glancing the Pacific Northwest. In advance of the developing ridge, small shortwave perturbations embedded in the mid-level flow, combined with afternoon heating and upslope flow across the higher terrain, will promote the development of at least isolated, high-based thunderstorms across portions of the central Rockies. Locally dry, breezy conditions may also occur in terrain favoring locations across northern parts of the Great Basin into the central Rockies, with synoptic forcing to support a more widespread, favorable surface wind/RH parameter space largely absent given the aforementioned mid-level ridging pattern ...Central Rockies... A dry sub-cloud layer extending up to 500 mb, and precipitable water values between 0.50-0.75 inches will support dry strikes associated with high-based thunderstorms during the afternoon hours, where an isolated dry thunderstorm delineation was added. Near critical to critically dry fuels suggest that new ignitions will be possible, despite slower storm motions, especially on the periphery of the storm cores. Otherwise, 20% RH and surface westerly winds locally reaching the 15-20 mph range will be possible by peak afternoon heating, mainly across portions of the Snake River Plain, eastward to portions of the Great Divide Basin in central to southern Wyoming. The patchy nature of these dry, breezy conditions precludes an elevated delineation at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Fri Aug 30 2019 Valid 301300Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE HIGH PLAINS TO SOUTHERN GREAT PLAINS AND SOUTH-CENTRAL MO TO SOUTHWEST OH... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the High Plains into the southern Great Plains, and separately from south-central Missouri to southwest Ohio, mainly through early evening. ...High Plains... Post-frontal upslope flow will be common from northeast NM to eastern WY today, maintaining upper 40s to mid 50s surface dew points at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Confluent mid-level westerlies will generally be confined to the WY portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern WY to northeast CO. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central MO to southern OH... An MCV over west-central MO should drift east towards the Mid-MS Valley before stalling tonight. Ongoing convection ahead of the MCV is decaying, yielding confidence that diabatic surface heating may become adequate for redevelopment later this afternoon. Should this overlap the narrow corridor of enhanced low-level shear/vorticity attendant to the MCV, the risk for a couple supercells capable of a tornado and isolated damaging wind may be realized. Farther east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind. ...Southern Great Plains... Composite outflow/effective front has reached southern OK into the TX Panhandle as a decaying MCS continues to push towards the Ark-La-Tex. Low-level warm advection atop the composite boundary has aided in persistent redevelopment across western OK. Marginally severe hail and wind will be possible with this latter activity, mainly through midday as the low-level jet subsides. Reference MCD 1898 for additional short-term information. Surface-based late afternoon development will probably be confined to the TX Panhandle vicinity near the intersection of the composite outflow/front and dryline. Weakening deep-layer shear across the region will serve to limit the overall threat. ..Grams/Leitman.. 08/30/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Fri Aug 30 2019 Valid 301300Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE HIGH PLAINS TO SOUTHERN GREAT PLAINS AND SOUTH-CENTRAL MO TO SOUTHWEST OH... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the High Plains into the southern Great Plains, and separately from south-central Missouri to southwest Ohio, mainly through early evening. ...High Plains... Post-frontal upslope flow will be common from northeast NM to eastern WY today, maintaining upper 40s to mid 50s surface dew points at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Confluent mid-level westerlies will generally be confined to the WY portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern WY to northeast CO. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central MO to southern OH... An MCV over west-central MO should drift east towards the Mid-MS Valley before stalling tonight. Ongoing convection ahead of the MCV is decaying, yielding confidence that diabatic surface heating may become adequate for redevelopment later this afternoon. Should this overlap the narrow corridor of enhanced low-level shear/vorticity attendant to the MCV, the risk for a couple supercells capable of a tornado and isolated damaging wind may be realized. Farther east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind. ...Southern Great Plains... Composite outflow/effective front has reached southern OK into the TX Panhandle as a decaying MCS continues to push towards the Ark-La-Tex. Low-level warm advection atop the composite boundary has aided in persistent redevelopment across western OK. Marginally severe hail and wind will be possible with this latter activity, mainly through midday as the low-level jet subsides. Reference MCD 1898 for additional short-term information. Surface-based late afternoon development will probably be confined to the TX Panhandle vicinity near the intersection of the composite outflow/front and dryline. Weakening deep-layer shear across the region will serve to limit the overall threat. ..Grams/Leitman.. 08/30/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Fri Aug 30 2019 Valid 301300Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE HIGH PLAINS TO SOUTHERN GREAT PLAINS AND SOUTH-CENTRAL MO TO SOUTHWEST OH... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the High Plains into the southern Great Plains, and separately from south-central Missouri to southwest Ohio, mainly through early evening. ...High Plains... Post-frontal upslope flow will be common from northeast NM to eastern WY today, maintaining upper 40s to mid 50s surface dew points at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Confluent mid-level westerlies will generally be confined to the WY portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern WY to northeast CO. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central MO to southern OH... An MCV over west-central MO should drift east towards the Mid-MS Valley before stalling tonight. Ongoing convection ahead of the MCV is decaying, yielding confidence that diabatic surface heating may become adequate for redevelopment later this afternoon. Should this overlap the narrow corridor of enhanced low-level shear/vorticity attendant to the MCV, the risk for a couple supercells capable of a tornado and isolated damaging wind may be realized. Farther east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind. ...Southern Great Plains... Composite outflow/effective front has reached southern OK into the TX Panhandle as a decaying MCS continues to push towards the Ark-La-Tex. Low-level warm advection atop the composite boundary has aided in persistent redevelopment across western OK. Marginally severe hail and wind will be possible with this latter activity, mainly through midday as the low-level jet subsides. Reference MCD 1898 for additional short-term information. Surface-based late afternoon development will probably be confined to the TX Panhandle vicinity near the intersection of the composite outflow/front and dryline. Weakening deep-layer shear across the region will serve to limit the overall threat. ..Grams/Leitman.. 08/30/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Fri Aug 30 2019 Valid 301300Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE HIGH PLAINS TO SOUTHERN GREAT PLAINS AND SOUTH-CENTRAL MO TO SOUTHWEST OH... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the High Plains into the southern Great Plains, and separately from south-central Missouri to southwest Ohio, mainly through early evening. ...High Plains... Post-frontal upslope flow will be common from northeast NM to eastern WY today, maintaining upper 40s to mid 50s surface dew points at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Confluent mid-level westerlies will generally be confined to the WY portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern WY to northeast CO. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central MO to southern OH... An MCV over west-central MO should drift east towards the Mid-MS Valley before stalling tonight. Ongoing convection ahead of the MCV is decaying, yielding confidence that diabatic surface heating may become adequate for redevelopment later this afternoon. Should this overlap the narrow corridor of enhanced low-level shear/vorticity attendant to the MCV, the risk for a couple supercells capable of a tornado and isolated damaging wind may be realized. Farther east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind. ...Southern Great Plains... Composite outflow/effective front has reached southern OK into the TX Panhandle as a decaying MCS continues to push towards the Ark-La-Tex. Low-level warm advection atop the composite boundary has aided in persistent redevelopment across western OK. Marginally severe hail and wind will be possible with this latter activity, mainly through midday as the low-level jet subsides. Reference MCD 1898 for additional short-term information. Surface-based late afternoon development will probably be confined to the TX Panhandle vicinity near the intersection of the composite outflow/front and dryline. Weakening deep-layer shear across the region will serve to limit the overall threat. ..Grams/Leitman.. 08/30/2019 Read more

MD 1898 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR WESTERN OK
Mesoscale Discussion 1898 NWS Storm Prediction Center Norman OK 0653 AM CDT Fri Aug 30 2019 Areas affected...western OK Concerning...Severe potential...Watch unlikely Valid 301153Z - 301400Z Probability of Watch Issuance...5 percent SUMMARY...Sporadic strong wind gusts and isolated hail near 1 inch are possible for a few hours this morning. A watch is not expected at this time. DISCUSSION...Scattered elevated thunderstorms are ongoing across western OK this morning. This convection is developing in a warm advection regime as a shortwave impulse tracks eastward across KS. A 30 kt southwesterly low level jet is aiding in semi-organized clusters on the edge of steep midlevel lapse rates across the southern and central High Plains. Most recently, a 59 mph gust was observed by the Oklahoma Mesonet site at Weatherford. Other gusts in the region have been sub-severe over the last hour. In addition to gusty winds, isolated hail near 1 inch is possible with the strongest cells. As the low level jet weakens through the morning and the upper shortwave impulse shifts east into MO, isolated severe potential should decrease as well across western OK. ..Leitman/Grams.. 08/30/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN... LAT...LON 35659988 36509964 36809939 36869869 36699801 36319765 35489756 34849806 34629856 34649916 34879962 35399993 35659988 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri Aug 30 2019 Valid 021200Z - 071200Z ...DISCUSSION... Primary features of interest during the extended period are Hurricane Dorian and strong shortwave trough expected to progress quickly through the northern CONUS westerlies from D4/Monday through D6/Wednesday. ...D4/Monday: Northern Plains/Upper Midwest... Air mass across the northern Plains and Upper Midwest is expected to be very moist and buoyant ahead of the approaching shortwave trough and attendant cold front on D4/Monday. Warm temperatures aloft should limit thunderstorm development throughout much of the day with initial convective initiation currently anticipated across the western Dakotas along the cold front. After initiation occurs, the strongly buoyant downstream air mass coupled with a progressive shortwave trough and increasing westerly/northwesterly flow suggest a favorable kinematic and thermodynamic environment for a forward-propagating MCS. ...FL Peninsula/Dorian... Regarding Dorian, current model forecasts and guidance from the National Hurricane Center move the storm into the southern FL Peninsula on D4/Monday. Forward motion is then expected to slow significantly, with the system moving slowly northward across the FL Peninsula on D5/Tuesday and D6/Wednesday. Given the anticipated storm trajectory and motion, an increasingly barotropic atmosphere will limit the overlap between the strong vertical shear and buoyancy. Additionally, the mesoscale details typically needed for TC-related tornadoes are difficult to predict at the medium range. Even so, some TC-related tornado threat is possible and this threat will be addressed in coordination with the National Hurricane Center in the coming days as confidence increases. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri Aug 30 2019 Valid 021200Z - 071200Z ...DISCUSSION... Primary features of interest during the extended period are Hurricane Dorian and strong shortwave trough expected to progress quickly through the northern CONUS westerlies from D4/Monday through D6/Wednesday. ...D4/Monday: Northern Plains/Upper Midwest... Air mass across the northern Plains and Upper Midwest is expected to be very moist and buoyant ahead of the approaching shortwave trough and attendant cold front on D4/Monday. Warm temperatures aloft should limit thunderstorm development throughout much of the day with initial convective initiation currently anticipated across the western Dakotas along the cold front. After initiation occurs, the strongly buoyant downstream air mass coupled with a progressive shortwave trough and increasing westerly/northwesterly flow suggest a favorable kinematic and thermodynamic environment for a forward-propagating MCS. ...FL Peninsula/Dorian... Regarding Dorian, current model forecasts and guidance from the National Hurricane Center move the storm into the southern FL Peninsula on D4/Monday. Forward motion is then expected to slow significantly, with the system moving slowly northward across the FL Peninsula on D5/Tuesday and D6/Wednesday. Given the anticipated storm trajectory and motion, an increasingly barotropic atmosphere will limit the overlap between the strong vertical shear and buoyancy. Additionally, the mesoscale details typically needed for TC-related tornadoes are difficult to predict at the medium range. Even so, some TC-related tornado threat is possible and this threat will be addressed in coordination with the National Hurricane Center in the coming days as confidence increases. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri Aug 30 2019 Valid 021200Z - 071200Z ...DISCUSSION... Primary features of interest during the extended period are Hurricane Dorian and strong shortwave trough expected to progress quickly through the northern CONUS westerlies from D4/Monday through D6/Wednesday. ...D4/Monday: Northern Plains/Upper Midwest... Air mass across the northern Plains and Upper Midwest is expected to be very moist and buoyant ahead of the approaching shortwave trough and attendant cold front on D4/Monday. Warm temperatures aloft should limit thunderstorm development throughout much of the day with initial convective initiation currently anticipated across the western Dakotas along the cold front. After initiation occurs, the strongly buoyant downstream air mass coupled with a progressive shortwave trough and increasing westerly/northwesterly flow suggest a favorable kinematic and thermodynamic environment for a forward-propagating MCS. ...FL Peninsula/Dorian... Regarding Dorian, current model forecasts and guidance from the National Hurricane Center move the storm into the southern FL Peninsula on D4/Monday. Forward motion is then expected to slow significantly, with the system moving slowly northward across the FL Peninsula on D5/Tuesday and D6/Wednesday. Given the anticipated storm trajectory and motion, an increasingly barotropic atmosphere will limit the overlap between the strong vertical shear and buoyancy. Additionally, the mesoscale details typically needed for TC-related tornadoes are difficult to predict at the medium range. Even so, some TC-related tornado threat is possible and this threat will be addressed in coordination with the National Hurricane Center in the coming days as confidence increases. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri Aug 30 2019 Valid 021200Z - 071200Z ...DISCUSSION... Primary features of interest during the extended period are Hurricane Dorian and strong shortwave trough expected to progress quickly through the northern CONUS westerlies from D4/Monday through D6/Wednesday. ...D4/Monday: Northern Plains/Upper Midwest... Air mass across the northern Plains and Upper Midwest is expected to be very moist and buoyant ahead of the approaching shortwave trough and attendant cold front on D4/Monday. Warm temperatures aloft should limit thunderstorm development throughout much of the day with initial convective initiation currently anticipated across the western Dakotas along the cold front. After initiation occurs, the strongly buoyant downstream air mass coupled with a progressive shortwave trough and increasing westerly/northwesterly flow suggest a favorable kinematic and thermodynamic environment for a forward-propagating MCS. ...FL Peninsula/Dorian... Regarding Dorian, current model forecasts and guidance from the National Hurricane Center move the storm into the southern FL Peninsula on D4/Monday. Forward motion is then expected to slow significantly, with the system moving slowly northward across the FL Peninsula on D5/Tuesday and D6/Wednesday. Given the anticipated storm trajectory and motion, an increasingly barotropic atmosphere will limit the overlap between the strong vertical shear and buoyancy. Additionally, the mesoscale details typically needed for TC-related tornadoes are difficult to predict at the medium range. Even so, some TC-related tornado threat is possible and this threat will be addressed in coordination with the National Hurricane Center in the coming days as confidence increases. Read more

MD 1897 CONCERNING SEVERE THUNDERSTORM WATCH 628... FOR SOUTHEAST KS...SOUTHWEST MO AND FAR NORTHEAST OK
Mesoscale Discussion 1897 NWS Storm Prediction Center Norman OK 0231 AM CDT Fri Aug 30 2019 Areas affected...southeast KS...southwest MO and far northeast OK Concerning...Severe Thunderstorm Watch 628... Valid 300731Z - 300900Z The severe weather threat for Severe Thunderstorm Watch 628 continues. SUMMARY...Strong to severe gusts are possible across southeast KS into adjacent portions of northeast OK and southwest MO in the short term. Trends will be monitored and a watch downstream of WW 628 may become necessary soon. DISCUSSION...A line of strong storms moving into southeast KS will continue to shift east/southeast into adjacent portions of southwest MO and northeast OK early this morning. Radar trends continue to fluctuate and surface observations south and east of Wichita KS have reported sub-severe gusts from around 35-48 mph. Further northeast near Emporia KS, several reports of severe gusts from near 70-90 mph were noted in the past hour. These strong gusts likely were facilitated in part by merging outflow boundary in the vicinity of an MCV over Osage County KS. Southward into OK, the Oklahoma Mesonet site at Newkirk reported a 71 mph gust at 0705z. While MLCIN has been increasing slightly, it will remain modest across parts of northeast OK into southwest MO. Surface dewpoints in the low 70s ahead of the bowing complex and steep 2-6 km lapse rates will maintain a reservoir of moderate instability ahead of the line. Additionally, a well established rear-inflow jet has been noted in regional VWP data. While thermodynamic parameters favor a continued downstream severe threat, the low level jet remains west of the bowing complex. As such, longevity and coverage of the severe threat remains in question. Nevertheless, at least a few damaging gusts appear possible in the short term and a new watch may be needed downstream if the recent re-intensification of the line persists. ..Leitman/Grams.. 08/30/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN... LAT...LON 36139524 36419419 36449405 36809362 37329354 37889399 38369449 38839531 38809560 38399566 37859593 37389635 37189712 36809754 36479745 36259689 36119603 36139524 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CDT Fri Aug 30 2019 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not currently expected across the Lower 48 States on Sunday. ...Synopsis... Upper pattern will likely characterized by ridging from the Four Corners into the northern Rockies and troughing over the Great Lakes and OH Valley early Sunday morning. Some enhancement of the northwesterly flow extending from the northern Rockies/northern Plains into the Upper Great Lakes is anticipated, but the overall upper pattern will remain relatively unchanged throughout the day. At surface, expansive ridge centered over the New England, and extending through the Upper Great Lakes and middle OH River Valley, early Sunday is expected to progress northeastward, allowing moisture return into the Upper Midwest and OH Valley. This moisture coupled with broad upper troughing is expected to result in scattered thunderstorms over the middle/upper OH Valley. Depending on destabilization, a few strong storms are possible but limited predictability precludes introducing any risk areas. Isolated thunderstorms are also possible across the Southwest and late Sunday night/early Monday morning across the northern Plains. ...FL Peninsula - Hurricane Dorian... Based on recent model runs and guidance from the National Hurricane Center, Hurricane Dorian is currently expected to be just off the central FL coast by early Monday morning. While some showers and thunderstorms associated with the system are possible across the FL Peninsula on Sunday afternoon/evening, current expectation is for the stronger winds to remain offshore, limiting any tornado threat. A somewhat higher threat is possible early Monday morning as the system gets closer to the coast (particularly in the 00Z ECMWF solution). However, limited buoyancy and low forecast confidence preclude delineating any areas yet. ..Mosier.. 08/30/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CDT Fri Aug 30 2019 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not currently expected across the Lower 48 States on Sunday. ...Synopsis... Upper pattern will likely characterized by ridging from the Four Corners into the northern Rockies and troughing over the Great Lakes and OH Valley early Sunday morning. Some enhancement of the northwesterly flow extending from the northern Rockies/northern Plains into the Upper Great Lakes is anticipated, but the overall upper pattern will remain relatively unchanged throughout the day. At surface, expansive ridge centered over the New England, and extending through the Upper Great Lakes and middle OH River Valley, early Sunday is expected to progress northeastward, allowing moisture return into the Upper Midwest and OH Valley. This moisture coupled with broad upper troughing is expected to result in scattered thunderstorms over the middle/upper OH Valley. Depending on destabilization, a few strong storms are possible but limited predictability precludes introducing any risk areas. Isolated thunderstorms are also possible across the Southwest and late Sunday night/early Monday morning across the northern Plains. ...FL Peninsula - Hurricane Dorian... Based on recent model runs and guidance from the National Hurricane Center, Hurricane Dorian is currently expected to be just off the central FL coast by early Monday morning. While some showers and thunderstorms associated with the system are possible across the FL Peninsula on Sunday afternoon/evening, current expectation is for the stronger winds to remain offshore, limiting any tornado threat. A somewhat higher threat is possible early Monday morning as the system gets closer to the coast (particularly in the 00Z ECMWF solution). However, limited buoyancy and low forecast confidence preclude delineating any areas yet. ..Mosier.. 08/30/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CDT Fri Aug 30 2019 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not currently expected across the Lower 48 States on Sunday. ...Synopsis... Upper pattern will likely characterized by ridging from the Four Corners into the northern Rockies and troughing over the Great Lakes and OH Valley early Sunday morning. Some enhancement of the northwesterly flow extending from the northern Rockies/northern Plains into the Upper Great Lakes is anticipated, but the overall upper pattern will remain relatively unchanged throughout the day. At surface, expansive ridge centered over the New England, and extending through the Upper Great Lakes and middle OH River Valley, early Sunday is expected to progress northeastward, allowing moisture return into the Upper Midwest and OH Valley. This moisture coupled with broad upper troughing is expected to result in scattered thunderstorms over the middle/upper OH Valley. Depending on destabilization, a few strong storms are possible but limited predictability precludes introducing any risk areas. Isolated thunderstorms are also possible across the Southwest and late Sunday night/early Monday morning across the northern Plains. ...FL Peninsula - Hurricane Dorian... Based on recent model runs and guidance from the National Hurricane Center, Hurricane Dorian is currently expected to be just off the central FL coast by early Monday morning. While some showers and thunderstorms associated with the system are possible across the FL Peninsula on Sunday afternoon/evening, current expectation is for the stronger winds to remain offshore, limiting any tornado threat. A somewhat higher threat is possible early Monday morning as the system gets closer to the coast (particularly in the 00Z ECMWF solution). However, limited buoyancy and low forecast confidence preclude delineating any areas yet. ..Mosier.. 08/30/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0146 AM CDT Fri Aug 30 2019 Valid 311200Z - 011200Z ...NO CRITICAL AREAS... ...Synopsis... The developing mid-level ridge on Day 1 will become fully fortified across the western CONUS on Day 2/Saturday. Weaker winds aloft and associated synoptic scale forcing suggest that relatively quiescent fire weather conditions will prevail across much of the western CONUS. The only minor exceptions at this time appear to be around the Snake River Plain/Great Divide Basin areas, where diurnal boundary layer mixing may encourage locally elevated wind/RH conditions across terrain favoring locations, and in parts of northwest New Mexico, where a few dry lightning strikes atop modestly dry fuels may support a few ignitions. ..Squitieri.. 08/30/2019 ...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 0146 AM CDT Fri Aug 30 2019 Valid 311200Z - 011200Z ...NO CRITICAL AREAS... ...Synopsis... The developing mid-level ridge on Day 1 will become fully fortified across the western CONUS on Day 2/Saturday. Weaker winds aloft and associated synoptic scale forcing suggest that relatively quiescent fire weather conditions will prevail across much of the western CONUS. The only minor exceptions at this time appear to be around the Snake River Plain/Great Divide Basin areas, where diurnal boundary layer mixing may encourage locally elevated wind/RH conditions across terrain favoring locations, and in parts of northwest New Mexico, where a few dry lightning strikes atop modestly dry fuels may support a few ignitions. ..Squitieri.. 08/30/2019 ...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 0146 AM CDT Fri Aug 30 2019 Valid 311200Z - 011200Z ...NO CRITICAL AREAS... ...Synopsis... The developing mid-level ridge on Day 1 will become fully fortified across the western CONUS on Day 2/Saturday. Weaker winds aloft and associated synoptic scale forcing suggest that relatively quiescent fire weather conditions will prevail across much of the western CONUS. The only minor exceptions at this time appear to be around the Snake River Plain/Great Divide Basin areas, where diurnal boundary layer mixing may encourage locally elevated wind/RH conditions across terrain favoring locations, and in parts of northwest New Mexico, where a few dry lightning strikes atop modestly dry fuels may support a few ignitions. ..Squitieri.. 08/30/2019 ...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 0146 AM CDT Fri Aug 30 2019 Valid 311200Z - 011200Z ...NO CRITICAL AREAS... ...Synopsis... The developing mid-level ridge on Day 1 will become fully fortified across the western CONUS on Day 2/Saturday. Weaker winds aloft and associated synoptic scale forcing suggest that relatively quiescent fire weather conditions will prevail across much of the western CONUS. The only minor exceptions at this time appear to be around the Snake River Plain/Great Divide Basin areas, where diurnal boundary layer mixing may encourage locally elevated wind/RH conditions across terrain favoring locations, and in parts of northwest New Mexico, where a few dry lightning strikes atop modestly dry fuels may support a few ignitions. ..Squitieri.. 08/30/2019 ...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 0108 AM CDT Fri Aug 30 2019 Valid 301200Z - 311200Z ...Synopsis... A upper-level ridge will build across the western CONUS throughout the period, with stronger flow aloft associated with an approaching mid-level shortwave trough glancing the Pacific Northwest. In advance of the developing ridge, small shortwave perturbations embedded in the mid-level flow, combined with afternoon heating and upslope flow across the higher terrain, will promote the development of at least isolated, high-based thunderstorms across portions of the central Rockies. Locally dry, breezy conditions may also occur in terrain favoring locations across northern parts of the Great Basin into the central Rockies, with synoptic forcing to support a more widespread, favorable surface wind/RH parameter space largely absent given the aforementioned mid-level ridging pattern ...Central Rockies... A dry sub-cloud layer extending up to 500 mb, and precipitable water values between 0.50-0.75 inches will support dry strikes associated with high-based thunderstorms during the afternoon hours, where an isolated dry thunderstorm delineation was added. Near critical to critically dry fuels suggest that new ignitions will be possible, despite slower storm motions, especially on the periphery of the storm cores. Otherwise, 20% RH and surface westerly winds locally reaching the 15-20 mph range will be possible by peak afternoon heating, mainly across portions of the Snake River Plain, eastward to portions of the Great Divide Basin in central to southern Wyoming. The patchy nature of these dry, breezy conditions precludes an elevated delineation at this time. ..Squitieri.. 08/30/2019 ...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 0108 AM CDT Fri Aug 30 2019 Valid 301200Z - 311200Z ...Synopsis... A upper-level ridge will build across the western CONUS throughout the period, with stronger flow aloft associated with an approaching mid-level shortwave trough glancing the Pacific Northwest. In advance of the developing ridge, small shortwave perturbations embedded in the mid-level flow, combined with afternoon heating and upslope flow across the higher terrain, will promote the development of at least isolated, high-based thunderstorms across portions of the central Rockies. Locally dry, breezy conditions may also occur in terrain favoring locations across northern parts of the Great Basin into the central Rockies, with synoptic forcing to support a more widespread, favorable surface wind/RH parameter space largely absent given the aforementioned mid-level ridging pattern ...Central Rockies... A dry sub-cloud layer extending up to 500 mb, and precipitable water values between 0.50-0.75 inches will support dry strikes associated with high-based thunderstorms during the afternoon hours, where an isolated dry thunderstorm delineation was added. Near critical to critically dry fuels suggest that new ignitions will be possible, despite slower storm motions, especially on the periphery of the storm cores. Otherwise, 20% RH and surface westerly winds locally reaching the 15-20 mph range will be possible by peak afternoon heating, mainly across portions of the Snake River Plain, eastward to portions of the Great Divide Basin in central to southern Wyoming. The patchy nature of these dry, breezy conditions precludes an elevated delineation at this time. ..Squitieri.. 08/30/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more