Severe Storms

MD 1348 CONCERNING SEVERE THUNDERSTORM WATCH 438... FOR MUCH OF MASSACHUSETTS AND ADJACENT SOUTHERN NEW HAMPSHIRE
Mesoscale Discussion 1348 NWS Storm Prediction Center Norman OK 0535 PM CDT Thu Jun 20 2024 Areas affected...much of Massachusetts and adjacent southern New Hampshire Concerning...Severe Thunderstorm Watch 438... Valid 202235Z - 210030Z The severe weather threat for Severe Thunderstorm Watch 438 continues. SUMMARY...A developing cluster of thunderstorms may still pose increasing risk of producing damaging wind gusts while spreading southeastward across Massachusetts, perhaps including much of the Greater Boston vicinity, by 8-9 PM EDT. DISCUSSION...The boundary layer remains strongly heated (including surface temperatures near 90F) and characterized by seasonably high moisture content supportive of mixed-layer CAPE in excess of 2000 J/kg, along pre-frontal surface troughing inland of the southern New England coast. This is beneath prominent mid/upper ridging, but north of the ridge axis, where deep-layer westerly mean flow may be on the order of 15-20 kt. Aided by southerly low-level inflow of the unstable air, strengthening ongoing storms along a corridor southeast of Albany NY into the Keene NH vicinity may still undergo further intensification and upscale growth during the next hour or two. As this occurs, consolidating southeastward propagating outflow may be accompanied by increasing risk for potentially damaging wind gusts into the 00-01Z time frame. ..Kerr.. 06/20/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...ALY... LAT...LON 42427332 42777227 42807188 42827119 42117069 42037161 41987249 42077327 42427332 Read more

WW 0439 Status Updates
STATUS REPORT ON WW 439 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NNW DEN TO 40 E FCL TO 40 E CYS TO 20 SW BFF TO 15 WSW AIA TO 20 NNE AIA TO 30 ENE CDR TO 35 S PHP. ..WENDT..06/20/24 ATTN...WFO...BOU...CYS...LBF...UNR... STATUS REPORT FOR WS 439 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC075-087-115-123-210040- CO . COLORADO COUNTIES INCLUDED ARE LOGAN MORGAN SEDGWICK WELD NEC007-033-049-069-105-123-161-210040- NE . NEBRASKA COUNTIES INCLUDED ARE BANNER CHEYENNE DEUEL GARDEN KIMBALL MORRILL SHERIDAN 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 439 SEVERE TSTM CO NE SD WY 201920Z - 210100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 439 NWS Storm Prediction Center Norman OK 120 PM MDT Thu Jun 20 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Colorado Nebraska Panhandle Southwest South Dakota Southeast Wyoming * Effective this Thursday afternoon and evening from 120 PM until 700 PM MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...Thunderstorms will intensify this afternoon over southeast Wyoming and northeast Colorado and spread eastward through the early evening. Supercells capable of very large hail and damaging wind gusts are the main concern. An isolated tornado and/or landspout or two is also possible. The severe thunderstorm watch area is approximately along and 95 statute miles north and south of a line from 40 miles northwest of Cheyenne WY to 35 miles east northeast of Alliance NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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 438... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Hart Read more

WW 0440 Status Updates
STATUS REPORT ON WW 440 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1349 ..WENDT..06/20/24 ATTN...WFO...LBF...UNR...FSD... STATUS REPORT FOR WS 440 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC005-009-015-017-031-071-075-089-091-103-113-115-117-149-171- 183-210040- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR BLAINE BOYD BROWN CHERRY GARFIELD GRANT HOLT HOOKER KEYA PAHA LOGAN LOUP MCPHERSON ROCK THOMAS WHEELER SDC007-023-043-053-121-123-210040- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BENNETT CHARLES MIX DOUGLAS GREGORY TODD TRIPP THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE Read more

WW 440 SEVERE TSTM NE SD 202155Z - 210500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 440 NWS Storm Prediction Center Norman OK 455 PM CDT Thu Jun 20 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Nebraska Extreme southern South Dakota * Effective this Thursday afternoon from 455 PM until Midnight CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 3.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...An isolated supercell should persist along a warm front over the northern Sandhills, offering all severe hazards, including a localized tornado threat. In the broader picture, a clustering of severe thunderstorms in the Nebraska Panhandle should move into and across the watch later this evening, posing mainly a hail and severe-wind threat. Isolate severe hail also is possible with later development north of the front. The severe thunderstorm watch area is approximately along and 55 statute miles north and south of a line from 50 miles west of Mullen NE to 15 miles east northeast of Oneill NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). 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 438...WW 439... AVIATION...A few severe thunderstorms with hail surface and aloft to 3.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 26025. ...Edwards Read more

MD 1347 CONCERNING SEVERE THUNDERSTORM WATCH 439... FOR PORTIONS OF NORTHEAST COLORADO INTO THE NEBRASKA PANHANDLE
Mesoscale Discussion 1347 NWS Storm Prediction Center Norman OK 0515 PM CDT Thu Jun 20 2024 Areas affected...Portions of northeast Colorado into the Nebraska Panhandle Concerning...Severe Thunderstorm Watch 439... Valid 202215Z - 202345Z The severe weather threat for Severe Thunderstorm Watch 439 continues. SUMMARY...While large hail and a tornado or two will remain possible, particularly within more favorable mesoscale corridors, the primary hazard over the next few hours will likely be severe gusts associated with a developing MCS in the Nebraska Panhandle. DISCUSSION...A supercell in eastern Wyoming, which was responsible for a few 4.5 in. hail reports, has grown upscale into a linear segment in the western Nebraska. This has occurred as the activity moved into a very well-mixed boundary layer. Given this trend, potential for severe gusts will likely increase with time. This complex recently produced a 61 kt gust at Scottsbluff, NE. Large hail will also remain possible, though very-large hail will be conditional on a supercell mode. Some tornado risk will also remain with the remnant supercell circulation/bookend vortex as well as with any storm favorably interacting with the warm front in northern Nebraska. As a cold pool circulation matures in the Nebraska Panhandle, an increasing low-level jet should promote storm maintenance into the evening farther east. Farther south into the Foothills, storms will likely remain more disorganized due to weaker shear. However, large hail and perhaps a weak tornado (due to ambient low-level vorticity stretched by updrafts) may still occur. ..Wendt.. 06/20/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...BOU...CYS... LAT...LON 40260515 41310442 41780406 42350381 42820258 42660202 41710215 40470323 40130420 40090491 40260515 Read more

WW 0438 Status Updates
STATUS REPORT ON WW 438 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ESE RUT TO 5 ENE LCI TO 20 E PWM. PARTS OF REMAINING VALID PORTION OF WW 438 HAVE OR WILL BE LOCALLY EXTENDED IN TIME. OTHERWISE, A NEW WW IS NOT ANTICIPATED. ..KERR..06/20/24 ATTN...WFO...BOX...GYX...CAR...BTV...ALY... STATUS REPORT FOR WS 438 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MAC009-011-013-015-017-021-023-025-027-210000- MA . MASSACHUSETTS COUNTIES INCLUDED ARE ESSEX FRANKLIN HAMPDEN HAMPSHIRE MIDDLESEX NORFOLK PLYMOUTH SUFFOLK WORCESTER NHC011-015-210000- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE HILLSBOROUGH ROCKINGHAM ANZ230-250-251-210000- CW Read more

WW 438 SEVERE TSTM MA ME NH NY VT CW 201700Z - 210000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 438 NWS Storm Prediction Center Norman OK 100 PM EDT Thu Jun 20 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Massachusetts Central and Western Maine New Hampshire Northeast New York Vermont Coastal Waters * Effective this Thursday afternoon and evening from 100 PM until 800 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...Scattered thunderstorms will develop through the afternoon and spread eastward across the watch area. The strongest cells will pose a risk of locally damaging wind gusts and hail. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 40 miles west southwest of Saranac Lake NY to 25 miles southeast of Bangor ME. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). 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. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 28030. ...Hart Read more

WW 0438 Status Updates
STATUS REPORT ON WW 438 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 S MSS TO 15 WNW SLK TO 5 NE GFL TO 15 E LCI TO 25 S AUG TO 10 SSW BHB. ..KERR..06/20/24 ATTN...WFO...BOX...GYX...CAR...BTV...ALY... STATUS REPORT FOR WS 438 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC031-202340- ME . MAINE COUNTIES INCLUDED ARE YORK MAC009-011-017-027-202340- MA . MASSACHUSETTS COUNTIES INCLUDED ARE ESSEX FRANKLIN MIDDLESEX WORCESTER NHC001-005-011-013-015-017-019-202340- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE BELKNAP CHESHIRE HILLSBOROUGH MERRIMACK ROCKINGHAM STRAFFORD SULLIVAN Read more

MD 1346 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR SANDHILLS VICINITY
Mesoscale Discussion 1346 NWS Storm Prediction Center Norman OK 0442 PM CDT Thu Jun 20 2024 Areas affected...Sandhills Vicinity Concerning...Severe potential...Watch likely Valid 202142Z - 202315Z Probability of Watch Issuance...80 percent SUMMARY...A watch is likely for parts of western/central Nebraska by this evening. Storm coverage with eastern extent may remain quite isolated in the short term, but additional activity will move in from the west. DISCUSSION...Despite rising mid-level heights downstream of a digging trough in the lower Colorado River Valley, an isolated supercell has developed along a warm front in the Sandhills. This appears to be aided be weak warm advection and perhaps a weak shortwave perturbation moving through Nebraska. Sufficient mid-level lapse rates and the supercellular mode should promote a risk of large to potentially very-large hail with this storm. Enhanced low-level SRH near the boundary would also suggest that a low-end tornado threat would exist as well. Visible satellite and KLNX radar suggest other updrafts trying to develop in the nearby vicinity. Some of these updrafts have already merged with the more mature supercell. This activity could further increase tornado potential on the storm scale. The primary uncertainty in this scenario is storm coverage, given the rising heights alluded to earlier. However, this storm will be capable of all severe hazards. Furthermore, storms that are expected to congeal in the Nebraska Panhandle may progress into these areas as the low-level jet strengthens this evening. ..Wendt/Edwards.. 06/20/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...LBF...UNR... LAT...LON 42369849 42139860 41849909 41959999 41980017 42220059 42670075 43050042 43169929 42999857 42369849 Read more

WW 0439 Status Updates
STATUS REPORT ON WW 439 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1347 ..WENDT..06/20/24 ATTN...WFO...BOU...CYS...LBF...UNR... STATUS REPORT FOR WS 439 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC075-087-115-123-202340- CO . COLORADO COUNTIES INCLUDED ARE LOGAN MORGAN SEDGWICK WELD NEC007-013-033-045-049-069-105-123-157-161-165-202340- NE . NEBRASKA COUNTIES INCLUDED ARE BANNER BOX BUTTE CHEYENNE DAWES DEUEL GARDEN KIMBALL MORRILL SCOTTS BLUFF SHERIDAN SIOUX SDC047-102-202340- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE Read more

WW 0440 Status Updates
STATUS FOR WATCH 0440 HAS NOT BEEN ISSUED YET Read more

WW 0438 Status Updates
STATUS REPORT ON WW 438 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SQUITIERI..06/20/24 ATTN...WFO...BOX...GYX...CAR...BTV...ALY... STATUS REPORT FOR WS 438 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC001-005-007-009-011-013-015-017-019-021-023-025-027-031- 202240- ME . MAINE COUNTIES INCLUDED ARE ANDROSCOGGIN CUMBERLAND FRANKLIN HANCOCK KENNEBEC KNOX LINCOLN OXFORD PENOBSCOT PISCATAQUIS SAGADAHOC SOMERSET WALDO YORK MAC009-011-017-027-202240- MA . MASSACHUSETTS COUNTIES INCLUDED ARE ESSEX FRANKLIN MIDDLESEX WORCESTER NHC001-003-005-007-009-011-013-015-017-019-202240- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE Read more

No Mesoscale Discussions are in effect as of Thu Jun 20 21:28:03 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0415 PM CDT Thu Jun 20 2024 Valid 221200Z - 281200Z At least low chances of wetting rains are expected to continue into early this weekend across portions of the Southwest and southern Rockies within a moisture plume associated with the remnants of Alberto. Further west and north across the Great Basin and the rest of the Desert Southwest, hot and dry conditions will be present under a mid to upper-level ridge D3/Saturday. The pattern will begin to shift by D4/Sunday, as a Pacific mid to upper-level shortwave trough and jet max in its base move onshore near northern WA. An associated dry, cold front will traverse WA and OR Sunday. Both a tightening surface pressure gradient and momentum transfer from aloft within subsidence behind the trough axis will lead to breezy, downslope flow developing across the Cascades and into the Columbia Basin. Fuel states are expected to deteriorate within the aforementioned regions. Therefore, at least low critical probabilities remain in the forecast. In addition, if model trends continue to suggest slightly stronger mid-level flow over WA, a small area of 70 percent critical probabilities may be introduced in subsequent forecasts within the lower fuel moisture content of the southwestern Columbia Basin of WA. Ahead of the cold front across the Upper Snake River Plain, warm, dry, and breezy conditions are anticipated within a well-mixed air mass. Fuels across this region are less receptive, but any ignitions may have the opportunity to spread quickly, as sustained speeds at or above 20 mph persist for several hours there in conjunction with single-digits RH. Furthermore, modest flow aloft and a tightening pressure gradient over southern ID behind the cold front D5/Monday will continue to support low critical probabilities within the Upper Snake River Plain. Confidence in the large-scale pattern decreases slightly D6-D8, although hot and dry, fuel-curing conditions appear likely over the Southwest and most of the Great Basin under the influence of upper ridging. Critical probabilities could return to the extended periods mid to late next week, as another north Pacific mid to upper-level low moves onshore. ..Barnes.. 06/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0415 PM CDT Thu Jun 20 2024 Valid 221200Z - 281200Z At least low chances of wetting rains are expected to continue into early this weekend across portions of the Southwest and southern Rockies within a moisture plume associated with the remnants of Alberto. Further west and north across the Great Basin and the rest of the Desert Southwest, hot and dry conditions will be present under a mid to upper-level ridge D3/Saturday. The pattern will begin to shift by D4/Sunday, as a Pacific mid to upper-level shortwave trough and jet max in its base move onshore near northern WA. An associated dry, cold front will traverse WA and OR Sunday. Both a tightening surface pressure gradient and momentum transfer from aloft within subsidence behind the trough axis will lead to breezy, downslope flow developing across the Cascades and into the Columbia Basin. Fuel states are expected to deteriorate within the aforementioned regions. Therefore, at least low critical probabilities remain in the forecast. In addition, if model trends continue to suggest slightly stronger mid-level flow over WA, a small area of 70 percent critical probabilities may be introduced in subsequent forecasts within the lower fuel moisture content of the southwestern Columbia Basin of WA. Ahead of the cold front across the Upper Snake River Plain, warm, dry, and breezy conditions are anticipated within a well-mixed air mass. Fuels across this region are less receptive, but any ignitions may have the opportunity to spread quickly, as sustained speeds at or above 20 mph persist for several hours there in conjunction with single-digits RH. Furthermore, modest flow aloft and a tightening pressure gradient over southern ID behind the cold front D5/Monday will continue to support low critical probabilities within the Upper Snake River Plain. Confidence in the large-scale pattern decreases slightly D6-D8, although hot and dry, fuel-curing conditions appear likely over the Southwest and most of the Great Basin under the influence of upper ridging. Critical probabilities could return to the extended periods mid to late next week, as another north Pacific mid to upper-level low moves onshore. ..Barnes.. 06/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0415 PM CDT Thu Jun 20 2024 Valid 221200Z - 281200Z At least low chances of wetting rains are expected to continue into early this weekend across portions of the Southwest and southern Rockies within a moisture plume associated with the remnants of Alberto. Further west and north across the Great Basin and the rest of the Desert Southwest, hot and dry conditions will be present under a mid to upper-level ridge D3/Saturday. The pattern will begin to shift by D4/Sunday, as a Pacific mid to upper-level shortwave trough and jet max in its base move onshore near northern WA. An associated dry, cold front will traverse WA and OR Sunday. Both a tightening surface pressure gradient and momentum transfer from aloft within subsidence behind the trough axis will lead to breezy, downslope flow developing across the Cascades and into the Columbia Basin. Fuel states are expected to deteriorate within the aforementioned regions. Therefore, at least low critical probabilities remain in the forecast. In addition, if model trends continue to suggest slightly stronger mid-level flow over WA, a small area of 70 percent critical probabilities may be introduced in subsequent forecasts within the lower fuel moisture content of the southwestern Columbia Basin of WA. Ahead of the cold front across the Upper Snake River Plain, warm, dry, and breezy conditions are anticipated within a well-mixed air mass. Fuels across this region are less receptive, but any ignitions may have the opportunity to spread quickly, as sustained speeds at or above 20 mph persist for several hours there in conjunction with single-digits RH. Furthermore, modest flow aloft and a tightening pressure gradient over southern ID behind the cold front D5/Monday will continue to support low critical probabilities within the Upper Snake River Plain. Confidence in the large-scale pattern decreases slightly D6-D8, although hot and dry, fuel-curing conditions appear likely over the Southwest and most of the Great Basin under the influence of upper ridging. Critical probabilities could return to the extended periods mid to late next week, as another north Pacific mid to upper-level low moves onshore. ..Barnes.. 06/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0415 PM CDT Thu Jun 20 2024 Valid 221200Z - 281200Z At least low chances of wetting rains are expected to continue into early this weekend across portions of the Southwest and southern Rockies within a moisture plume associated with the remnants of Alberto. Further west and north across the Great Basin and the rest of the Desert Southwest, hot and dry conditions will be present under a mid to upper-level ridge D3/Saturday. The pattern will begin to shift by D4/Sunday, as a Pacific mid to upper-level shortwave trough and jet max in its base move onshore near northern WA. An associated dry, cold front will traverse WA and OR Sunday. Both a tightening surface pressure gradient and momentum transfer from aloft within subsidence behind the trough axis will lead to breezy, downslope flow developing across the Cascades and into the Columbia Basin. Fuel states are expected to deteriorate within the aforementioned regions. Therefore, at least low critical probabilities remain in the forecast. In addition, if model trends continue to suggest slightly stronger mid-level flow over WA, a small area of 70 percent critical probabilities may be introduced in subsequent forecasts within the lower fuel moisture content of the southwestern Columbia Basin of WA. Ahead of the cold front across the Upper Snake River Plain, warm, dry, and breezy conditions are anticipated within a well-mixed air mass. Fuels across this region are less receptive, but any ignitions may have the opportunity to spread quickly, as sustained speeds at or above 20 mph persist for several hours there in conjunction with single-digits RH. Furthermore, modest flow aloft and a tightening pressure gradient over southern ID behind the cold front D5/Monday will continue to support low critical probabilities within the Upper Snake River Plain. Confidence in the large-scale pattern decreases slightly D6-D8, although hot and dry, fuel-curing conditions appear likely over the Southwest and most of the Great Basin under the influence of upper ridging. Critical probabilities could return to the extended periods mid to late next week, as another north Pacific mid to upper-level low moves onshore. ..Barnes.. 06/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0415 PM CDT Thu Jun 20 2024 Valid 221200Z - 281200Z At least low chances of wetting rains are expected to continue into early this weekend across portions of the Southwest and southern Rockies within a moisture plume associated with the remnants of Alberto. Further west and north across the Great Basin and the rest of the Desert Southwest, hot and dry conditions will be present under a mid to upper-level ridge D3/Saturday. The pattern will begin to shift by D4/Sunday, as a Pacific mid to upper-level shortwave trough and jet max in its base move onshore near northern WA. An associated dry, cold front will traverse WA and OR Sunday. Both a tightening surface pressure gradient and momentum transfer from aloft within subsidence behind the trough axis will lead to breezy, downslope flow developing across the Cascades and into the Columbia Basin. Fuel states are expected to deteriorate within the aforementioned regions. Therefore, at least low critical probabilities remain in the forecast. In addition, if model trends continue to suggest slightly stronger mid-level flow over WA, a small area of 70 percent critical probabilities may be introduced in subsequent forecasts within the lower fuel moisture content of the southwestern Columbia Basin of WA. Ahead of the cold front across the Upper Snake River Plain, warm, dry, and breezy conditions are anticipated within a well-mixed air mass. Fuels across this region are less receptive, but any ignitions may have the opportunity to spread quickly, as sustained speeds at or above 20 mph persist for several hours there in conjunction with single-digits RH. Furthermore, modest flow aloft and a tightening pressure gradient over southern ID behind the cold front D5/Monday will continue to support low critical probabilities within the Upper Snake River Plain. Confidence in the large-scale pattern decreases slightly D6-D8, although hot and dry, fuel-curing conditions appear likely over the Southwest and most of the Great Basin under the influence of upper ridging. Critical probabilities could return to the extended periods mid to late next week, as another north Pacific mid to upper-level low moves onshore. ..Barnes.. 06/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0415 PM CDT Thu Jun 20 2024 Valid 221200Z - 281200Z At least low chances of wetting rains are expected to continue into early this weekend across portions of the Southwest and southern Rockies within a moisture plume associated with the remnants of Alberto. Further west and north across the Great Basin and the rest of the Desert Southwest, hot and dry conditions will be present under a mid to upper-level ridge D3/Saturday. The pattern will begin to shift by D4/Sunday, as a Pacific mid to upper-level shortwave trough and jet max in its base move onshore near northern WA. An associated dry, cold front will traverse WA and OR Sunday. Both a tightening surface pressure gradient and momentum transfer from aloft within subsidence behind the trough axis will lead to breezy, downslope flow developing across the Cascades and into the Columbia Basin. Fuel states are expected to deteriorate within the aforementioned regions. Therefore, at least low critical probabilities remain in the forecast. In addition, if model trends continue to suggest slightly stronger mid-level flow over WA, a small area of 70 percent critical probabilities may be introduced in subsequent forecasts within the lower fuel moisture content of the southwestern Columbia Basin of WA. Ahead of the cold front across the Upper Snake River Plain, warm, dry, and breezy conditions are anticipated within a well-mixed air mass. Fuels across this region are less receptive, but any ignitions may have the opportunity to spread quickly, as sustained speeds at or above 20 mph persist for several hours there in conjunction with single-digits RH. Furthermore, modest flow aloft and a tightening pressure gradient over southern ID behind the cold front D5/Monday will continue to support low critical probabilities within the Upper Snake River Plain. Confidence in the large-scale pattern decreases slightly D6-D8, although hot and dry, fuel-curing conditions appear likely over the Southwest and most of the Great Basin under the influence of upper ridging. Critical probabilities could return to the extended periods mid to late next week, as another north Pacific mid to upper-level low moves onshore. ..Barnes.. 06/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more