Aggregator

WW 0564 Status Updates
STATUS REPORT ON WW 564 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..COOK..08/09/19 ATTN...WFO...FSD...UNR...ABR... STATUS REPORT FOR WT 564 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS SDC003-005-007-009-015-017-023-035-041-043-049-053-055-059-061- 065-067-069-071-073-075-085-095-107-111-115-117-119-121-123-137- 092340- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE AURORA BEADLE BENNETT BON HOMME BRULE BUFFALO CHARLES MIX DAVISON DEWEY DOUGLAS FAULK GREGORY HAAKON HAND HANSON HUGHES HUTCHINSON HYDE JACKSON JERAULD JONES LYMAN MELLETTE POTTER SANBORN SPINK STANLEY SULLY TODD TRIPP ZIEBACH THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 564 TORNADO SD 091910Z - 100200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 564 NWS Storm Prediction Center Norman OK 210 PM CDT Fri Aug 9 2019 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of South Dakota * Effective this Friday afternoon and evening from 210 PM until 900 PM CDT. * Primary threats include... A few tornadoes likely with a couple intense tornadoes possible Scattered damaging winds and isolated significant gusts to 80 mph likely Scattered large hail and isolated very large hail events to 2 inches in diameter possible SUMMARY...Supercells developing across west-central South Dakota should spread east-southeast across much of the central portion of the state before developing into a cluster towards eastern South Dakota. The tornado watch area is approximately along and 75 statute miles north and south of a line from 65 miles west of Pierre SD to 10 miles north northeast of Mitchell SD. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). 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. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 29030. ...Grams Read more

Wagon Mountain Fire, Missoula Ranger District Location: Located on top of Wagon Mountain, approximately 2 miles northeast of Lolo Pass Visitor Center and east of Highway 12. Not to be confused with the Wagon Mountain Road between Graves Creek and Fish Creek Roads on the west side of Highway 12. Status: The Wagon Mountain Fire was detected on Aug. 5, 2019 at approximately 2:30 p.m. by aircraft responding to the West Fork Lolo 2 Fire. The fire is burning in a previously logged area in new regeneration and also in mature spruce and mixed conifer. The fire is currently staffed as a Type 4 incident. Containment: 100% reached on 8/8/19 at 6:30 p.m. Structures or other values at risk: None at this time. No evacuations are in effect at this time.

An athletic field in Tuscola required three to four waterings per day to keep the field green. news gazette (Champaign, Ill.), Aug. 6, 2019

Unseasonably warm water and low stream flows due to drought have kept pink salmon out of Prince William Sound, lowering salmon harvests. The year-to-date harvest on Aug. 6 was 13.6 million fish, compared to a recent year-to-date odd-year harvest average of 31.2 million fish. Cordova Times (Alaska), Aug. 9, 2019

WW 0564 Status Updates
STATUS REPORT ON WW 564 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..COOK..08/09/19 ATTN...WFO...FSD...UNR...ABR... STATUS REPORT FOR WT 564 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS SDC003-005-007-009-015-017-023-035-041-043-049-053-055-059-061- 065-067-069-071-073-075-085-095-107-111-115-117-119-121-123-137- 092240- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE AURORA BEADLE BENNETT BON HOMME BRULE BUFFALO CHARLES MIX DAVISON DEWEY DOUGLAS FAULK GREGORY HAAKON HAND HANSON HUGHES HUTCHINSON HYDE JACKSON JERAULD JONES LYMAN MELLETTE POTTER SANBORN SPINK STANLEY SULLY TODD TRIPP ZIEBACH THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0565 Status Updates
STATUS FOR WATCH 0565 HAS NOT BEEN ISSUED YET Read more

WW 0565 Status Updates
STATUS FOR WATCH 0565 HAS NOT BEEN ISSUED YET Read more

WW 565 SEVERE TSTM OR 092135Z - 100500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 565 NWS Storm Prediction Center Norman OK 235 PM PDT Fri Aug 9 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southwest and Central Oregon * Effective this Friday afternoon and evening from 235 PM until 1000 PM PDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Scattered thunderstorms will continue to intensify across the watch area through the afternoon and early evening. A few of the storms are expected to become severe, with a risk of hail and damaging wind gusts. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 25 miles west southwest of Klamath Falls OR to 30 miles north northwest of Redmond OR. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 564... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 18030. ...Hart Read more

As topsoil moisture became short in Ohio, crops began showing stress. Corn and soybeans needed rain to enhance their condition and growth. Ohio's Country Journal (Columbus, Ohio), Aug. 5, 2019

Dry weather was causing yield loss in parts of Kentucky, according to Chad Lee, University of Kentucky extension agronomist. The Messenger (Madisonville, Ky.), Aug. 8, 2019

Low flows on the Skagit River meant turning off pumps when minimum flows were not met. A dairy farmer near Mount Vernon was only able to pump one day during a three-week period in July. Skagit Valley Herald (GoSkagit.com) (Wash.), Aug. 3, 2019

MD 1680 CONCERNING TORNADO WATCH 564... FOR SOUTH DAKOTA
Mesoscale Discussion 1680 NWS Storm Prediction Center Norman OK 0343 PM CDT Fri Aug 09 2019 Areas affected...South Dakota Concerning...Tornado Watch 564... Valid 092043Z - 092215Z The severe weather threat for Tornado Watch 564 continues. SUMMARY...The threat for severe wind, hail, and possibly a few tornadoes continues across much of SD. Some upscale growth is possible late this afternoon into the early evening, which would result in an increasing severe wind threat with time. DISCUSSION...One surface-based supercell is ongoing across south-central SD as of 2045Z, with other convection across the area generally near or north of the effective warm front. In the short term, a hail and locally severe wind risk will continue with the ongoing supercell and any semi-discrete cells that evolve out of the convection further north, given the presence of moderate buoyancy (MLCAPE of 1500-2500 J/kg) and effective shear of 40-50 kt. The tornado threat will be contingent on supercell interaction with the effective warm frontal zone. The ongoing supercell across south-central SD has thus far tracked slightly south of the effective boundary, though if it continues to track eastward, it may come in closer proximity to the warm front, which is oriented more northwest/southeast with eastward extent. If any semi-discrete supercells can evolve out of the slightly elevated convection to the north, they would also pose a tornado threat as they propagate east-southeast within a helicity-rich environment. The cells near/north of Pierre as of 2045Z may pose the greatest short-term tornado threat, given their proximity to the front. Otherwise, a tendency for upscale growth is expected with time as convection congeals over central SD, with a southeastward-moving complex capable of potentially more widespread severe wind possible by early evening into a larger portion of south-central/southeast SD. ..Dean.. 08/09/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...ABR...UNR... LAT...LON 43310151 43680195 44560179 44750123 44760006 44659927 44559861 44409810 43879767 43339756 43189787 43179889 43210031 43310151 Read more

The Woodbury is now 100% controlled. State Route 88 Closure: Because of the potential for severe flooding from areas burned in the Woodbury Fire, a 7-mile, unpaved section of State Route 88 (Apache Trail) will remain closed from an area several miles east of Tortilla Flat to just west of the Apache Lake marina turnoff while the Arizona Department of Transportation continues assessing conditions. All inquiries in regards to the closure on State Route 88 (Apache Trail Historic Road) should be directed to ADOT. You can submit questions to ADOT by online form or phone by visiting https://azdot.gov/contact. Tortilla Flat business remain open. Additional information regarding the highway closure can be found at: https://azdot.gov/media/News/news-release/2019/07/29/seven-mile-stretch-of-sr-88-remains-closed-due-to-flooding-risk Forest Closure: For the purposes of public safety, the forest closure extends beyond the fire perimeter. The forest closure includes a portion of the Arizona Trail...

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Aug 09 2019 Valid 092000Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL/EASTERN SD... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF VA AND OR... ...SUMMARY... Scattered severe thunderstorms will likely occur across parts of South Dakota this afternoon and evening. A few tornadoes, some of which may be strong, isolated large hail, and scattered severe winds will all be possible. Other isolated to widely scattered severe thunderstorms will remain possible across parts Oregon and Virginia through this evening. ...20Z Update... 19Z surface analysis shows a weak low over southwestern SD. Low-level convergence to the east of this low has encouraged recent convective development across central SD. A strong baroclinic zone also extends northwest-southeast across SD. The environment along/near this boundary appears increasingly favorable for significant severe weather this afternoon and evening. Supercell thunderstorms are expected to be the dominant storm mode initially given 45-50+ kt of effective bulk shear, with a couple supercell structures observed already. Isolated large hail should occur with these storms. MLCAPE up to 2500 J/kg will likely develop across the warm sector to the southwest of the boundary across parts of western into south-central SD. A very strongly veering low-level wind profile will provide ample effective SRH along the surface boundary, perhaps upwards of 250-450+ m2/s2. The potential for a few tornadoes in this environment with any supercells warrants an increase in tornado probabilities. A strong tornado may also occur if a supercell can move southeastward along the surface boundary given the very favorable low-level shear expected. A small cluster of storms should eventually develop across south-central into southeastern SD and perhaps far northern NE later this evening as a southerly low-level jet strengthens across this area. Scattered severe wind gusts, some potentially significant, will likely occur with these storms through mid to late evening. The Marginal Risk has been expanded westward across western VA into parts of WV to account for thunderstorm development that has occurred this afternoon along a weak front. Both isolated large hail and strong/gusty winds will be possible with these storms as they develop southeastward through the remainder of the afternoon and into the early evening. No changes have been made to the severe probabilities across the northwestern CONUS. ..Gleason.. 08/09/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Aug 09 2019/ ...SD... An embedded shortwave impulse is cresting the midlevel ridge and will move east from eastern WY across SD with an attendant surface cyclone. Elevated convection is ongoing in advance of this impulse across western/central SD and the northern extent of this activity should persist east near the SD/ND border. Surface heating on the southern-western flank of this ongoing convection, within a corridor of 65-70 F boundary-layer dewpoints, will contribute to MLCAPE from 1500-2500 J/kg between 21-00Z across west-central into south-central SD. Surface-based thunderstorm development will become more probable in the next few hours, either emanating from the southwest flank of the elevated convection and/or developing westward towards the surface cyclone. These storms should spread southeast along a pronounced differential heating corridor across central to southeast SD. Backed surface winds east of the cyclone, beneath strengthening low/mid-level flow should yield a rather enlarged hodograph towards early evening in a spatially narrow corridor from around Pierre to Mitchell. If a discrete supercell or two can be maintained through this time frame, the tornado risk may be greater than currently forecast. Otherwise, supercells may evolve into small-scale bows with a risk for significant severe wind. A cluster with severe wind as the primary hazard may progress into southeast SD/northeast NE before waning later in the evening given the dearth of instability with eastern extent in western IA. This area will be monitored for a possible upgrade in the 20Z outlook. ...Eastern VA... A subtle mid-upper speed max will progress east-southeastward from eastern WV across VA. Downstream of the Appalachians, robust diabatic heating is well underway and this will contribute to moderate buoyancy with MLCAPE of 1000-2000 J/kg. A pre-frontal surface trough may help focus storm initiation in the next few hours across central/northeast VA, with storms potentially spreading southeastward into early evening. Straight hodographs with effective bulk shear of 30-35 kt and steep low-level lapse rates will support some transient supercell structures capable of producing damaging gusts and marginally severe hail. ...Northwest... Embedded shortwave impulses will rotate northward from CA to OR around the eastern periphery of a closed low off the northern CA coast. Typically steep lapse rates over the northern Great Basin and interior Northwest, along with sufficient low-midlevel moisture, will support weak-moderate buoyancy later this afternoon across parts of OR, ID, and northern NV. Scattered thunderstorm development is expected to be focused by ascent preceding the ejecting midlevel waves and surface heating over the higher terrain. The more concentrated storms are anticipated over the OR Cascades and the higher terrain in northeastern OR, where isolated severe wind gusts and marginally severe will be possible with high-based storms in an environment supporting clusters and marginal supercells. Locally strong to severe gusts will also be possible farther east-southeast into parts of northern NV and ID. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Aug 09 2019 Valid 092000Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL/EASTERN SD... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF VA AND OR... ...SUMMARY... Scattered severe thunderstorms will likely occur across parts of South Dakota this afternoon and evening. A few tornadoes, some of which may be strong, isolated large hail, and scattered severe winds will all be possible. Other isolated to widely scattered severe thunderstorms will remain possible across parts Oregon and Virginia through this evening. ...20Z Update... 19Z surface analysis shows a weak low over southwestern SD. Low-level convergence to the east of this low has encouraged recent convective development across central SD. A strong baroclinic zone also extends northwest-southeast across SD. The environment along/near this boundary appears increasingly favorable for significant severe weather this afternoon and evening. Supercell thunderstorms are expected to be the dominant storm mode initially given 45-50+ kt of effective bulk shear, with a couple supercell structures observed already. Isolated large hail should occur with these storms. MLCAPE up to 2500 J/kg will likely develop across the warm sector to the southwest of the boundary across parts of western into south-central SD. A very strongly veering low-level wind profile will provide ample effective SRH along the surface boundary, perhaps upwards of 250-450+ m2/s2. The potential for a few tornadoes in this environment with any supercells warrants an increase in tornado probabilities. A strong tornado may also occur if a supercell can move southeastward along the surface boundary given the very favorable low-level shear expected. A small cluster of storms should eventually develop across south-central into southeastern SD and perhaps far northern NE later this evening as a southerly low-level jet strengthens across this area. Scattered severe wind gusts, some potentially significant, will likely occur with these storms through mid to late evening. The Marginal Risk has been expanded westward across western VA into parts of WV to account for thunderstorm development that has occurred this afternoon along a weak front. Both isolated large hail and strong/gusty winds will be possible with these storms as they develop southeastward through the remainder of the afternoon and into the early evening. No changes have been made to the severe probabilities across the northwestern CONUS. ..Gleason.. 08/09/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Aug 09 2019/ ...SD... An embedded shortwave impulse is cresting the midlevel ridge and will move east from eastern WY across SD with an attendant surface cyclone. Elevated convection is ongoing in advance of this impulse across western/central SD and the northern extent of this activity should persist east near the SD/ND border. Surface heating on the southern-western flank of this ongoing convection, within a corridor of 65-70 F boundary-layer dewpoints, will contribute to MLCAPE from 1500-2500 J/kg between 21-00Z across west-central into south-central SD. Surface-based thunderstorm development will become more probable in the next few hours, either emanating from the southwest flank of the elevated convection and/or developing westward towards the surface cyclone. These storms should spread southeast along a pronounced differential heating corridor across central to southeast SD. Backed surface winds east of the cyclone, beneath strengthening low/mid-level flow should yield a rather enlarged hodograph towards early evening in a spatially narrow corridor from around Pierre to Mitchell. If a discrete supercell or two can be maintained through this time frame, the tornado risk may be greater than currently forecast. Otherwise, supercells may evolve into small-scale bows with a risk for significant severe wind. A cluster with severe wind as the primary hazard may progress into southeast SD/northeast NE before waning later in the evening given the dearth of instability with eastern extent in western IA. This area will be monitored for a possible upgrade in the 20Z outlook. ...Eastern VA... A subtle mid-upper speed max will progress east-southeastward from eastern WV across VA. Downstream of the Appalachians, robust diabatic heating is well underway and this will contribute to moderate buoyancy with MLCAPE of 1000-2000 J/kg. A pre-frontal surface trough may help focus storm initiation in the next few hours across central/northeast VA, with storms potentially spreading southeastward into early evening. Straight hodographs with effective bulk shear of 30-35 kt and steep low-level lapse rates will support some transient supercell structures capable of producing damaging gusts and marginally severe hail. ...Northwest... Embedded shortwave impulses will rotate northward from CA to OR around the eastern periphery of a closed low off the northern CA coast. Typically steep lapse rates over the northern Great Basin and interior Northwest, along with sufficient low-midlevel moisture, will support weak-moderate buoyancy later this afternoon across parts of OR, ID, and northern NV. Scattered thunderstorm development is expected to be focused by ascent preceding the ejecting midlevel waves and surface heating over the higher terrain. The more concentrated storms are anticipated over the OR Cascades and the higher terrain in northeastern OR, where isolated severe wind gusts and marginally severe will be possible with high-based storms in an environment supporting clusters and marginal supercells. Locally strong to severe gusts will also be possible farther east-southeast into parts of northern NV and ID. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Aug 09 2019 Valid 092000Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL/EASTERN SD... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF VA AND OR... ...SUMMARY... Scattered severe thunderstorms will likely occur across parts of South Dakota this afternoon and evening. A few tornadoes, some of which may be strong, isolated large hail, and scattered severe winds will all be possible. Other isolated to widely scattered severe thunderstorms will remain possible across parts Oregon and Virginia through this evening. ...20Z Update... 19Z surface analysis shows a weak low over southwestern SD. Low-level convergence to the east of this low has encouraged recent convective development across central SD. A strong baroclinic zone also extends northwest-southeast across SD. The environment along/near this boundary appears increasingly favorable for significant severe weather this afternoon and evening. Supercell thunderstorms are expected to be the dominant storm mode initially given 45-50+ kt of effective bulk shear, with a couple supercell structures observed already. Isolated large hail should occur with these storms. MLCAPE up to 2500 J/kg will likely develop across the warm sector to the southwest of the boundary across parts of western into south-central SD. A very strongly veering low-level wind profile will provide ample effective SRH along the surface boundary, perhaps upwards of 250-450+ m2/s2. The potential for a few tornadoes in this environment with any supercells warrants an increase in tornado probabilities. A strong tornado may also occur if a supercell can move southeastward along the surface boundary given the very favorable low-level shear expected. A small cluster of storms should eventually develop across south-central into southeastern SD and perhaps far northern NE later this evening as a southerly low-level jet strengthens across this area. Scattered severe wind gusts, some potentially significant, will likely occur with these storms through mid to late evening. The Marginal Risk has been expanded westward across western VA into parts of WV to account for thunderstorm development that has occurred this afternoon along a weak front. Both isolated large hail and strong/gusty winds will be possible with these storms as they develop southeastward through the remainder of the afternoon and into the early evening. No changes have been made to the severe probabilities across the northwestern CONUS. ..Gleason.. 08/09/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Aug 09 2019/ ...SD... An embedded shortwave impulse is cresting the midlevel ridge and will move east from eastern WY across SD with an attendant surface cyclone. Elevated convection is ongoing in advance of this impulse across western/central SD and the northern extent of this activity should persist east near the SD/ND border. Surface heating on the southern-western flank of this ongoing convection, within a corridor of 65-70 F boundary-layer dewpoints, will contribute to MLCAPE from 1500-2500 J/kg between 21-00Z across west-central into south-central SD. Surface-based thunderstorm development will become more probable in the next few hours, either emanating from the southwest flank of the elevated convection and/or developing westward towards the surface cyclone. These storms should spread southeast along a pronounced differential heating corridor across central to southeast SD. Backed surface winds east of the cyclone, beneath strengthening low/mid-level flow should yield a rather enlarged hodograph towards early evening in a spatially narrow corridor from around Pierre to Mitchell. If a discrete supercell or two can be maintained through this time frame, the tornado risk may be greater than currently forecast. Otherwise, supercells may evolve into small-scale bows with a risk for significant severe wind. A cluster with severe wind as the primary hazard may progress into southeast SD/northeast NE before waning later in the evening given the dearth of instability with eastern extent in western IA. This area will be monitored for a possible upgrade in the 20Z outlook. ...Eastern VA... A subtle mid-upper speed max will progress east-southeastward from eastern WV across VA. Downstream of the Appalachians, robust diabatic heating is well underway and this will contribute to moderate buoyancy with MLCAPE of 1000-2000 J/kg. A pre-frontal surface trough may help focus storm initiation in the next few hours across central/northeast VA, with storms potentially spreading southeastward into early evening. Straight hodographs with effective bulk shear of 30-35 kt and steep low-level lapse rates will support some transient supercell structures capable of producing damaging gusts and marginally severe hail. ...Northwest... Embedded shortwave impulses will rotate northward from CA to OR around the eastern periphery of a closed low off the northern CA coast. Typically steep lapse rates over the northern Great Basin and interior Northwest, along with sufficient low-midlevel moisture, will support weak-moderate buoyancy later this afternoon across parts of OR, ID, and northern NV. Scattered thunderstorm development is expected to be focused by ascent preceding the ejecting midlevel waves and surface heating over the higher terrain. The more concentrated storms are anticipated over the OR Cascades and the higher terrain in northeastern OR, where isolated severe wind gusts and marginally severe will be possible with high-based storms in an environment supporting clusters and marginal supercells. Locally strong to severe gusts will also be possible farther east-southeast into parts of northern NV and ID. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Aug 09 2019 Valid 092000Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL/EASTERN SD... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF VA AND OR... ...SUMMARY... Scattered severe thunderstorms will likely occur across parts of South Dakota this afternoon and evening. A few tornadoes, some of which may be strong, isolated large hail, and scattered severe winds will all be possible. Other isolated to widely scattered severe thunderstorms will remain possible across parts Oregon and Virginia through this evening. ...20Z Update... 19Z surface analysis shows a weak low over southwestern SD. Low-level convergence to the east of this low has encouraged recent convective development across central SD. A strong baroclinic zone also extends northwest-southeast across SD. The environment along/near this boundary appears increasingly favorable for significant severe weather this afternoon and evening. Supercell thunderstorms are expected to be the dominant storm mode initially given 45-50+ kt of effective bulk shear, with a couple supercell structures observed already. Isolated large hail should occur with these storms. MLCAPE up to 2500 J/kg will likely develop across the warm sector to the southwest of the boundary across parts of western into south-central SD. A very strongly veering low-level wind profile will provide ample effective SRH along the surface boundary, perhaps upwards of 250-450+ m2/s2. The potential for a few tornadoes in this environment with any supercells warrants an increase in tornado probabilities. A strong tornado may also occur if a supercell can move southeastward along the surface boundary given the very favorable low-level shear expected. A small cluster of storms should eventually develop across south-central into southeastern SD and perhaps far northern NE later this evening as a southerly low-level jet strengthens across this area. Scattered severe wind gusts, some potentially significant, will likely occur with these storms through mid to late evening. The Marginal Risk has been expanded westward across western VA into parts of WV to account for thunderstorm development that has occurred this afternoon along a weak front. Both isolated large hail and strong/gusty winds will be possible with these storms as they develop southeastward through the remainder of the afternoon and into the early evening. No changes have been made to the severe probabilities across the northwestern CONUS. ..Gleason.. 08/09/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Aug 09 2019/ ...SD... An embedded shortwave impulse is cresting the midlevel ridge and will move east from eastern WY across SD with an attendant surface cyclone. Elevated convection is ongoing in advance of this impulse across western/central SD and the northern extent of this activity should persist east near the SD/ND border. Surface heating on the southern-western flank of this ongoing convection, within a corridor of 65-70 F boundary-layer dewpoints, will contribute to MLCAPE from 1500-2500 J/kg between 21-00Z across west-central into south-central SD. Surface-based thunderstorm development will become more probable in the next few hours, either emanating from the southwest flank of the elevated convection and/or developing westward towards the surface cyclone. These storms should spread southeast along a pronounced differential heating corridor across central to southeast SD. Backed surface winds east of the cyclone, beneath strengthening low/mid-level flow should yield a rather enlarged hodograph towards early evening in a spatially narrow corridor from around Pierre to Mitchell. If a discrete supercell or two can be maintained through this time frame, the tornado risk may be greater than currently forecast. Otherwise, supercells may evolve into small-scale bows with a risk for significant severe wind. A cluster with severe wind as the primary hazard may progress into southeast SD/northeast NE before waning later in the evening given the dearth of instability with eastern extent in western IA. This area will be monitored for a possible upgrade in the 20Z outlook. ...Eastern VA... A subtle mid-upper speed max will progress east-southeastward from eastern WV across VA. Downstream of the Appalachians, robust diabatic heating is well underway and this will contribute to moderate buoyancy with MLCAPE of 1000-2000 J/kg. A pre-frontal surface trough may help focus storm initiation in the next few hours across central/northeast VA, with storms potentially spreading southeastward into early evening. Straight hodographs with effective bulk shear of 30-35 kt and steep low-level lapse rates will support some transient supercell structures capable of producing damaging gusts and marginally severe hail. ...Northwest... Embedded shortwave impulses will rotate northward from CA to OR around the eastern periphery of a closed low off the northern CA coast. Typically steep lapse rates over the northern Great Basin and interior Northwest, along with sufficient low-midlevel moisture, will support weak-moderate buoyancy later this afternoon across parts of OR, ID, and northern NV. Scattered thunderstorm development is expected to be focused by ascent preceding the ejecting midlevel waves and surface heating over the higher terrain. The more concentrated storms are anticipated over the OR Cascades and the higher terrain in northeastern OR, where isolated severe wind gusts and marginally severe will be possible with high-based storms in an environment supporting clusters and marginal supercells. Locally strong to severe gusts will also be possible farther east-southeast into parts of northern NV and ID. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Fri Aug 09 2019 Valid 101200Z - 111200Z Much of the previous forecast remains on track. Elevated to at least locally critical wind/RH conditions are still expected across eastern Nevada into eastern Idaho. The elevated delineation was expanded southward into southern Nevada, as much of the latest numerical guidance depicts sustained southerly surface winds exceeding 15 mph during the late afternoon hours, amidst critically low RH and fuels that are receptive to fire spread. Locally elevated conditions may also occur along the lee of the northern Sierra across parts of northwest Nevada, but the localized nature of the threat precludes an elevated delineation at this time. Elsewhere, the isolated dry thunderstorm area was expanded into southwestern Idaho, as the most recent convection-allowing models depict discrete convection developing in this area, where a deep, relatively dry sub-cloud layer will be present. Given adequate instability across this particular region, strong, erratic winds are possible with the more intense storms. Across the remainder of the isolated dry thunderstorm area, at least patchy areas of heavier rainfall are expected on Day 1, which may locally temper the wildfire spread threat on Day 2 to a degree. Nonetheless, given the uncertainty associated with pinpointing more exact areas of rainfall, no other changes have been made to the isolated dry thunder area at this time. ..Squitieri.. 08/09/2019 .PREV DISCUSSION... /ISSUED 0126 AM CDT Fri Aug 09 2019/ ...Synopsis... The mid-level trough responsible for D1 fire weather concerns in the West will take on a negative tilt while slowly migrating northeastward over Oregon and vicinity. As this occurs, a belt of enhanced mid-level flow will shift eastward toward eastern Nevada and eastern Idaho. Meanwhile, areas of scattered to widespread thunderstorm activity will once again migrate over inland portions of the Pacific Northwest and northern California. ...Eastern Nevada, far western Utah, and eastern Idaho... Vertical mixing processes beneath the mid-level jet core will encourage development of a belt of relatively strong (15-25 mph) south-southwesterly surface winds during peak heating periods across the region. This region also resides on the western fringe of much of the rainfall over the past month or so, with dry fuels supporting ongoing fires across the region. One lingering uncertainty with regard to the extent of the fire-weather threat in this area will be potential for wetting rainfall over the region on D1/Fri, which may temper fuels in a few areas. However, elevated to locally critical fire weather will likely exist given near-critical RH values expected during the afternoon. Some portions of this region may need a critical upgrade in later outlook updates. ...Washington, Oregon, and northern California for thunderstorms... The continued presence of mid-level moisture and a nearby trough will again foster areas of northeastward-moving clusters of storms across the region. However, the extent of dry thunder potential is a bit less clear compared to prior days due to 1) expected areas of wetting rainfall on D1/Fri, which should temper fuel states on at least a localized basis and 2) the coverage of wetting rainfall during the afternoon and evening, which should further temper fuel states over a much broader area especially in Oregon. CAMS/high-res guidance even depicts upscale growth into linear complex(es) during peak heating hours. Nevertheless, areas that can remain dry will be susceptible to isolated dry lightning strikes outside of heavier thunderstorm cores, and gusty/erratic winds near downdrafts are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Fri Aug 09 2019 Valid 101200Z - 111200Z Much of the previous forecast remains on track. Elevated to at least locally critical wind/RH conditions are still expected across eastern Nevada into eastern Idaho. The elevated delineation was expanded southward into southern Nevada, as much of the latest numerical guidance depicts sustained southerly surface winds exceeding 15 mph during the late afternoon hours, amidst critically low RH and fuels that are receptive to fire spread. Locally elevated conditions may also occur along the lee of the northern Sierra across parts of northwest Nevada, but the localized nature of the threat precludes an elevated delineation at this time. Elsewhere, the isolated dry thunderstorm area was expanded into southwestern Idaho, as the most recent convection-allowing models depict discrete convection developing in this area, where a deep, relatively dry sub-cloud layer will be present. Given adequate instability across this particular region, strong, erratic winds are possible with the more intense storms. Across the remainder of the isolated dry thunderstorm area, at least patchy areas of heavier rainfall are expected on Day 1, which may locally temper the wildfire spread threat on Day 2 to a degree. Nonetheless, given the uncertainty associated with pinpointing more exact areas of rainfall, no other changes have been made to the isolated dry thunder area at this time. ..Squitieri.. 08/09/2019 .PREV DISCUSSION... /ISSUED 0126 AM CDT Fri Aug 09 2019/ ...Synopsis... The mid-level trough responsible for D1 fire weather concerns in the West will take on a negative tilt while slowly migrating northeastward over Oregon and vicinity. As this occurs, a belt of enhanced mid-level flow will shift eastward toward eastern Nevada and eastern Idaho. Meanwhile, areas of scattered to widespread thunderstorm activity will once again migrate over inland portions of the Pacific Northwest and northern California. ...Eastern Nevada, far western Utah, and eastern Idaho... Vertical mixing processes beneath the mid-level jet core will encourage development of a belt of relatively strong (15-25 mph) south-southwesterly surface winds during peak heating periods across the region. This region also resides on the western fringe of much of the rainfall over the past month or so, with dry fuels supporting ongoing fires across the region. One lingering uncertainty with regard to the extent of the fire-weather threat in this area will be potential for wetting rainfall over the region on D1/Fri, which may temper fuels in a few areas. However, elevated to locally critical fire weather will likely exist given near-critical RH values expected during the afternoon. Some portions of this region may need a critical upgrade in later outlook updates. ...Washington, Oregon, and northern California for thunderstorms... The continued presence of mid-level moisture and a nearby trough will again foster areas of northeastward-moving clusters of storms across the region. However, the extent of dry thunder potential is a bit less clear compared to prior days due to 1) expected areas of wetting rainfall on D1/Fri, which should temper fuel states on at least a localized basis and 2) the coverage of wetting rainfall during the afternoon and evening, which should further temper fuel states over a much broader area especially in Oregon. CAMS/high-res guidance even depicts upscale growth into linear complex(es) during peak heating hours. Nevertheless, areas that can remain dry will be susceptible to isolated dry lightning strikes outside of heavier thunderstorm cores, and gusty/erratic winds near downdrafts are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more