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SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Sun Jul 21 2024 Valid 220100Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN ARIZONA... ...SUMMARY... Isolated severe thunderstorms will remain possible this evening across parts of southern Arizona. ...Southern Arizona... Clusters of thunderstorms continue moving south across central/southern AZ early this evening, with isolated reports of measured severe/near severe gusts, or wind damage, received over the past few hours. Storm-scale outflow has surged southward ahead of the higher reflectivity cores across much of the area, and this has tended to limit more widespread severe potential. The presence of a well-mixed boundary layer persisting for a few more hours, combined with subtle ascent with a southward-moving mid-level shortwave trough, will result in isolated severe potential continuing through the early evening. ...Southeast Colorado/Eastern New Mexico... Isolated thunderstorms continue across southeast CO/northeast NM at 01z, within an environment characterized by MLCAPE of 500-1000 J/kg, and modest effective shear of around 25 kts. Although some potential will remain for a stronger storm over the next couple of hours, the overall trend should be for diminishing intensity with time as boundary-layer cooling commences. ..Bunting.. 07/22/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Sun Jul 21 2024 Valid 220100Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN ARIZONA... ...SUMMARY... Isolated severe thunderstorms will remain possible this evening across parts of southern Arizona. ...Southern Arizona... Clusters of thunderstorms continue moving south across central/southern AZ early this evening, with isolated reports of measured severe/near severe gusts, or wind damage, received over the past few hours. Storm-scale outflow has surged southward ahead of the higher reflectivity cores across much of the area, and this has tended to limit more widespread severe potential. The presence of a well-mixed boundary layer persisting for a few more hours, combined with subtle ascent with a southward-moving mid-level shortwave trough, will result in isolated severe potential continuing through the early evening. ...Southeast Colorado/Eastern New Mexico... Isolated thunderstorms continue across southeast CO/northeast NM at 01z, within an environment characterized by MLCAPE of 500-1000 J/kg, and modest effective shear of around 25 kts. Although some potential will remain for a stronger storm over the next couple of hours, the overall trend should be for diminishing intensity with time as boundary-layer cooling commences. ..Bunting.. 07/22/2024 Read more

WW 0558 Status Updates
STATUS REPORT ON WW 558 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 70 NW GBN TO 30 ENE TUS. ..LYONS..07/22/24 ATTN...WFO...PSR...FGZ... STATUS REPORT FOR WS 558 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS AZC013-220240- AZ . ARIZONA COUNTIES INCLUDED ARE MARICOPA 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 0558 Status Updates
STATUS REPORT ON WW 558 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 70 NW GBN TO 30 ENE TUS. ..LYONS..07/22/24 ATTN...WFO...PSR...FGZ... STATUS REPORT FOR WS 558 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS AZC013-220240- AZ . ARIZONA COUNTIES INCLUDED ARE MARICOPA 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 558 SEVERE TSTM AZ 212050Z - 220300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 558 NWS Storm Prediction Center Norman OK 150 PM MST Sun Jul 21 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central and South-Central Arizona * Effective this Sunday afternoon and evening from 150 PM until 800 PM MST. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible SUMMARY...A broken linear cluster of thunderstorms will move southward through the afternoon into the evening across the Watch area. The stronger thunderstorm cores and associated thunderstorm outflow will be potentially capable of 60 to 75 mph gusts as this activity moves into the lower deserts. Marginally severe hail (diameter up to 1 inch) may accompany the stronger thunderstorms this afternoon near the Mogollon Rim. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 55 miles west southwest of Prescott AZ to 95 miles east southeast of Phoenix AZ. 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 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 01015. ...Smith Read more

WW 0558 Status Updates
STATUS REPORT ON WW 558 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 E IGM TO 35 SSW PRC TO 40 NNW SAD. ..LYONS..07/21/24 ATTN...WFO...PSR...FGZ... STATUS REPORT FOR WS 558 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS AZC013-021-025-220040- AZ . ARIZONA COUNTIES INCLUDED ARE MARICOPA PINAL YAVAPAI 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

No Mesoscale Discussions are in effect as of Sun Jul 21 23:45:07 UTC 2024.

MD 1692 CONCERNING SEVERE THUNDERSTORM WATCH 558... FOR PORTIONS OF SOUTH-CENTRAL ARIZONA
Mesoscale Discussion 1692 NWS Storm Prediction Center Norman OK 0520 PM CDT Sun Jul 21 2024 Areas affected...portions of south-central Arizona Concerning...Severe Thunderstorm Watch 558... Valid 212220Z - 212345Z The severe weather threat for Severe Thunderstorm Watch 558 continues. SUMMARY...Scattered thunderstorms over higher terrain could move south and will remain capable of damaging gusts this afternoon and into the evening. DISCUSSION...Radar imagery shows scattered thunderstorms have developed across the higher terrain of central AZ this afternoon. Despite only modest deep-layer shear profiles, large inverted-v thermodynamic profiles have allowed strong downdrafts to develop. These high-based storms have already produced several measured severe gusts within the higher terrain. While the initial cores have moved little and begun to weaken, outflow has moved south/southwest ahead of the initial convection evident in regional surface obs. Damaging gusts will remain possible as the outflow moves into the north/east sides of the Phoenix Metro in the next 1-2 hours. Additional storm development will remain possible along/ahead of the outflow as it encounters upper 50s to low 60s F dewpoints and moderate buoyancy in the lower elevations. Confidence in the exact convective evolution is somewhat low owing to modest flow aloft and chaotic storm interactions, but any storms able to move off the terrain with surging outflow will remain capable of damaging gusts into this evening. ..Lyons.. 07/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...FGZ...PSR...VEF... LAT...LON 33020998 32760987 32710993 32521017 32491052 32541209 32551218 32681324 33451332 34311348 35131332 34211171 33581066 33211015 33020998 Read more

WW 0558 Status Updates
STATUS REPORT ON WW 558 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 E IGM TO 35 SSW PRC TO 40 NNW SAD. ..LYONS..07/21/24 ATTN...WFO...PSR...FGZ... STATUS REPORT FOR WS 558 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS AZC013-021-025-220040- AZ . ARIZONA COUNTIES INCLUDED ARE MARICOPA PINAL YAVAPAI 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 558 SEVERE TSTM AZ 212050Z - 220300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 558 NWS Storm Prediction Center Norman OK 150 PM MST Sun Jul 21 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central and South-Central Arizona * Effective this Sunday afternoon and evening from 150 PM until 800 PM MST. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible SUMMARY...A broken linear cluster of thunderstorms will move southward through the afternoon into the evening across the Watch area. The stronger thunderstorm cores and associated thunderstorm outflow will be potentially capable of 60 to 75 mph gusts as this activity moves into the lower deserts. Marginally severe hail (diameter up to 1 inch) may accompany the stronger thunderstorms this afternoon near the Mogollon Rim. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 55 miles west southwest of Prescott AZ to 95 miles east southeast of Phoenix AZ. 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 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 01015. ...Smith Read more

000
ABPZ20 KNHC 212321
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sun Jul 21 2024

For the eastern North Pacific...east of 140 degrees west longitude:

Western East Pacific:
A large area of disorganized showers and thunderstorms located over
the far western portion of the eastern Pacific is associated with a
trough of low pressure. Environmental conditions are forecast
to be marginally conducive for some slow development during the
next day or so. The disturbance is forecast to move westward at
10 to 15 mph and into the central Pacific basin tonight, and by
midweek, strong upper-level winds are expected to inhibit further
development.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...10 percent.

Central and Western East Pacific:
A tropical wave located about 900 miles south-southwest of the
southern tip of the Baja California Peninsula is producing
disorganized shower and thunderstorm activity. Environmental
conditions could become a little more conducive for some gradual
development of this system over the next several days while it moves
westward to west-northwestward at 10 to 15 mph across the central
and western portions of the basin.
* Formation chance through 48 hours...low... 10 percent.
* Formation chance through 7 days...low...30 percent.

$$
Forecaster Pasch

MD 1691 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEASTERN COLORADO...NORTHEASTERN NEW MEXICO...AND THE WESTERN TEXAS/OKLAHOMA PANHANDLES
Mesoscale Discussion 1691 NWS Storm Prediction Center Norman OK 0310 PM CDT Sun Jul 21 2024 Areas affected...southeastern Colorado...northeastern New Mexico...and the western Texas/Oklahoma Panhandles Concerning...Severe potential...Watch unlikely Valid 212010Z - 212245Z Probability of Watch Issuance...20 percent SUMMARY...Storms are expected to increase in coverage and intensity across the area this afternoon and evening posing an initial threat for hail and eventually evolving into a wind threat. The severe threat appears too marginal and isolated to warrant a severe thunderstorm watch. DISCUSSION...Numerous thunderstorms have already initiated across the area ahead of a southward-moving midlevel shortwave trough. While instability (MLCAPE around 1000 J/kg) and shear (effective bulk shear around 25 knots) are modest, initial multicell modes may support hail (0.75-1.25 in) and convective gusts (45-60 mph). Eventually cold pool mergers are expected to lead to some degree of upscale growth, especially across northeastern New Mexico, where isolated severe gusts (55-65 mph) may be possible if an organized convective cluster develops. A severe thunderstorm watch is unlikely given the isolated and marginal nature of the severe threat. ..Jirak/Smith.. 07/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DDC...GLD...AMA...PUB...BOU...ABQ... LAT...LON 35200520 36190528 37570525 37660523 38350518 38890510 39210483 39250412 38900338 38600278 38130232 37010198 36280186 35480188 35100202 34910237 34730315 34620362 34740493 35200520 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0353 PM CDT Sun Jul 21 2024 Valid 231200Z - 291200Z Fire weather concerns during the extended period will focus on parts of the Northwest, northern Great Basin, and northern Rockies. Dry and windy conditions, as well as dry thunderstorms, are possible ahead of an upper-level trough that will promote some upper-level ridge breakdown in the West. ...Wind/RH Concerns... Winds will begin to increase in the northwest into northern California as the trough approaches on Wednesday. At this time, the strongest winds appear they may remain closer to the terrain/Cascade Gaps. Winds will likely peak on Thursday across the Northwest into northern California/northwest Nevada. Critical fire weather is perhaps most likely Thursday, but there will also be some increase in RH as well. Confidence is not high enough for greater critical fire weather probabilities at this time. By Friday, strong mid-level flow will remain over parts of the northern Rockies. Additionally, a weak tropical low will rejoin the mean westerlies aloft and move into central California and the western Great Basin into the weekend. Strong winds and low RH are possible from the western Great Basin into western/central Montana on Friday and Saturday. However, there are differences between the ECMWF/GFS on the timing and intensity of some key features. When comparing the deterministic models to their counterpart ensembles, it suggests that there is large spread in potential outcomes. This uncertainty precludes introducing highlights. ...Dry Lightning... Mid-level moisture will remain across the northern Great Basin into the adjacent Northwest on Tuesday. Large-scale ascent will be weaker than on previous days and coverage is still somewhat uncertain. Available CAM and global guidance shows some potential for thunderstorms from far northern Nevada into central Idaho. Some of these storms may produce little rainfall. Thunderstorm potential for the northern Great Basin into parts of eastern Oregon, northeast California, and southwest Montana will increase on Wednesday. At least subtle forcing from an approaching trough should support some increase in storm coverage. Slightly faster storm motions should also increase the probability of a few drier storms. Mid-level moisture will shift eastward as the trough progresses. There is a consistent signal in models for thunderstorms from central Idaho into southwest and parts of central Montana. Forcing for ascent will be moderately strong as the trough moves into the region by late afternoon. Between dry sub-cloud layers and fast storm motions, confidence in dry thunderstorms is moderate to high. ..Wendt.. 07/21/2024 ...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 0353 PM CDT Sun Jul 21 2024 Valid 231200Z - 291200Z Fire weather concerns during the extended period will focus on parts of the Northwest, northern Great Basin, and northern Rockies. Dry and windy conditions, as well as dry thunderstorms, are possible ahead of an upper-level trough that will promote some upper-level ridge breakdown in the West. ...Wind/RH Concerns... Winds will begin to increase in the northwest into northern California as the trough approaches on Wednesday. At this time, the strongest winds appear they may remain closer to the terrain/Cascade Gaps. Winds will likely peak on Thursday across the Northwest into northern California/northwest Nevada. Critical fire weather is perhaps most likely Thursday, but there will also be some increase in RH as well. Confidence is not high enough for greater critical fire weather probabilities at this time. By Friday, strong mid-level flow will remain over parts of the northern Rockies. Additionally, a weak tropical low will rejoin the mean westerlies aloft and move into central California and the western Great Basin into the weekend. Strong winds and low RH are possible from the western Great Basin into western/central Montana on Friday and Saturday. However, there are differences between the ECMWF/GFS on the timing and intensity of some key features. When comparing the deterministic models to their counterpart ensembles, it suggests that there is large spread in potential outcomes. This uncertainty precludes introducing highlights. ...Dry Lightning... Mid-level moisture will remain across the northern Great Basin into the adjacent Northwest on Tuesday. Large-scale ascent will be weaker than on previous days and coverage is still somewhat uncertain. Available CAM and global guidance shows some potential for thunderstorms from far northern Nevada into central Idaho. Some of these storms may produce little rainfall. Thunderstorm potential for the northern Great Basin into parts of eastern Oregon, northeast California, and southwest Montana will increase on Wednesday. At least subtle forcing from an approaching trough should support some increase in storm coverage. Slightly faster storm motions should also increase the probability of a few drier storms. Mid-level moisture will shift eastward as the trough progresses. There is a consistent signal in models for thunderstorms from central Idaho into southwest and parts of central Montana. Forcing for ascent will be moderately strong as the trough moves into the region by late afternoon. Between dry sub-cloud layers and fast storm motions, confidence in dry thunderstorms is moderate to high. ..Wendt.. 07/21/2024 ...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 0353 PM CDT Sun Jul 21 2024 Valid 231200Z - 291200Z Fire weather concerns during the extended period will focus on parts of the Northwest, northern Great Basin, and northern Rockies. Dry and windy conditions, as well as dry thunderstorms, are possible ahead of an upper-level trough that will promote some upper-level ridge breakdown in the West. ...Wind/RH Concerns... Winds will begin to increase in the northwest into northern California as the trough approaches on Wednesday. At this time, the strongest winds appear they may remain closer to the terrain/Cascade Gaps. Winds will likely peak on Thursday across the Northwest into northern California/northwest Nevada. Critical fire weather is perhaps most likely Thursday, but there will also be some increase in RH as well. Confidence is not high enough for greater critical fire weather probabilities at this time. By Friday, strong mid-level flow will remain over parts of the northern Rockies. Additionally, a weak tropical low will rejoin the mean westerlies aloft and move into central California and the western Great Basin into the weekend. Strong winds and low RH are possible from the western Great Basin into western/central Montana on Friday and Saturday. However, there are differences between the ECMWF/GFS on the timing and intensity of some key features. When comparing the deterministic models to their counterpart ensembles, it suggests that there is large spread in potential outcomes. This uncertainty precludes introducing highlights. ...Dry Lightning... Mid-level moisture will remain across the northern Great Basin into the adjacent Northwest on Tuesday. Large-scale ascent will be weaker than on previous days and coverage is still somewhat uncertain. Available CAM and global guidance shows some potential for thunderstorms from far northern Nevada into central Idaho. Some of these storms may produce little rainfall. Thunderstorm potential for the northern Great Basin into parts of eastern Oregon, northeast California, and southwest Montana will increase on Wednesday. At least subtle forcing from an approaching trough should support some increase in storm coverage. Slightly faster storm motions should also increase the probability of a few drier storms. Mid-level moisture will shift eastward as the trough progresses. There is a consistent signal in models for thunderstorms from central Idaho into southwest and parts of central Montana. Forcing for ascent will be moderately strong as the trough moves into the region by late afternoon. Between dry sub-cloud layers and fast storm motions, confidence in dry thunderstorms is moderate to high. ..Wendt.. 07/21/2024 ...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 0353 PM CDT Sun Jul 21 2024 Valid 231200Z - 291200Z Fire weather concerns during the extended period will focus on parts of the Northwest, northern Great Basin, and northern Rockies. Dry and windy conditions, as well as dry thunderstorms, are possible ahead of an upper-level trough that will promote some upper-level ridge breakdown in the West. ...Wind/RH Concerns... Winds will begin to increase in the northwest into northern California as the trough approaches on Wednesday. At this time, the strongest winds appear they may remain closer to the terrain/Cascade Gaps. Winds will likely peak on Thursday across the Northwest into northern California/northwest Nevada. Critical fire weather is perhaps most likely Thursday, but there will also be some increase in RH as well. Confidence is not high enough for greater critical fire weather probabilities at this time. By Friday, strong mid-level flow will remain over parts of the northern Rockies. Additionally, a weak tropical low will rejoin the mean westerlies aloft and move into central California and the western Great Basin into the weekend. Strong winds and low RH are possible from the western Great Basin into western/central Montana on Friday and Saturday. However, there are differences between the ECMWF/GFS on the timing and intensity of some key features. When comparing the deterministic models to their counterpart ensembles, it suggests that there is large spread in potential outcomes. This uncertainty precludes introducing highlights. ...Dry Lightning... Mid-level moisture will remain across the northern Great Basin into the adjacent Northwest on Tuesday. Large-scale ascent will be weaker than on previous days and coverage is still somewhat uncertain. Available CAM and global guidance shows some potential for thunderstorms from far northern Nevada into central Idaho. Some of these storms may produce little rainfall. Thunderstorm potential for the northern Great Basin into parts of eastern Oregon, northeast California, and southwest Montana will increase on Wednesday. At least subtle forcing from an approaching trough should support some increase in storm coverage. Slightly faster storm motions should also increase the probability of a few drier storms. Mid-level moisture will shift eastward as the trough progresses. There is a consistent signal in models for thunderstorms from central Idaho into southwest and parts of central Montana. Forcing for ascent will be moderately strong as the trough moves into the region by late afternoon. Between dry sub-cloud layers and fast storm motions, confidence in dry thunderstorms is moderate to high. ..Wendt.. 07/21/2024 ...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 0353 PM CDT Sun Jul 21 2024 Valid 231200Z - 291200Z Fire weather concerns during the extended period will focus on parts of the Northwest, northern Great Basin, and northern Rockies. Dry and windy conditions, as well as dry thunderstorms, are possible ahead of an upper-level trough that will promote some upper-level ridge breakdown in the West. ...Wind/RH Concerns... Winds will begin to increase in the northwest into northern California as the trough approaches on Wednesday. At this time, the strongest winds appear they may remain closer to the terrain/Cascade Gaps. Winds will likely peak on Thursday across the Northwest into northern California/northwest Nevada. Critical fire weather is perhaps most likely Thursday, but there will also be some increase in RH as well. Confidence is not high enough for greater critical fire weather probabilities at this time. By Friday, strong mid-level flow will remain over parts of the northern Rockies. Additionally, a weak tropical low will rejoin the mean westerlies aloft and move into central California and the western Great Basin into the weekend. Strong winds and low RH are possible from the western Great Basin into western/central Montana on Friday and Saturday. However, there are differences between the ECMWF/GFS on the timing and intensity of some key features. When comparing the deterministic models to their counterpart ensembles, it suggests that there is large spread in potential outcomes. This uncertainty precludes introducing highlights. ...Dry Lightning... Mid-level moisture will remain across the northern Great Basin into the adjacent Northwest on Tuesday. Large-scale ascent will be weaker than on previous days and coverage is still somewhat uncertain. Available CAM and global guidance shows some potential for thunderstorms from far northern Nevada into central Idaho. Some of these storms may produce little rainfall. Thunderstorm potential for the northern Great Basin into parts of eastern Oregon, northeast California, and southwest Montana will increase on Wednesday. At least subtle forcing from an approaching trough should support some increase in storm coverage. Slightly faster storm motions should also increase the probability of a few drier storms. Mid-level moisture will shift eastward as the trough progresses. There is a consistent signal in models for thunderstorms from central Idaho into southwest and parts of central Montana. Forcing for ascent will be moderately strong as the trough moves into the region by late afternoon. Between dry sub-cloud layers and fast storm motions, confidence in dry thunderstorms is moderate to high. ..Wendt.. 07/21/2024 ...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 0353 PM CDT Sun Jul 21 2024 Valid 231200Z - 291200Z Fire weather concerns during the extended period will focus on parts of the Northwest, northern Great Basin, and northern Rockies. Dry and windy conditions, as well as dry thunderstorms, are possible ahead of an upper-level trough that will promote some upper-level ridge breakdown in the West. ...Wind/RH Concerns... Winds will begin to increase in the northwest into northern California as the trough approaches on Wednesday. At this time, the strongest winds appear they may remain closer to the terrain/Cascade Gaps. Winds will likely peak on Thursday across the Northwest into northern California/northwest Nevada. Critical fire weather is perhaps most likely Thursday, but there will also be some increase in RH as well. Confidence is not high enough for greater critical fire weather probabilities at this time. By Friday, strong mid-level flow will remain over parts of the northern Rockies. Additionally, a weak tropical low will rejoin the mean westerlies aloft and move into central California and the western Great Basin into the weekend. Strong winds and low RH are possible from the western Great Basin into western/central Montana on Friday and Saturday. However, there are differences between the ECMWF/GFS on the timing and intensity of some key features. When comparing the deterministic models to their counterpart ensembles, it suggests that there is large spread in potential outcomes. This uncertainty precludes introducing highlights. ...Dry Lightning... Mid-level moisture will remain across the northern Great Basin into the adjacent Northwest on Tuesday. Large-scale ascent will be weaker than on previous days and coverage is still somewhat uncertain. Available CAM and global guidance shows some potential for thunderstorms from far northern Nevada into central Idaho. Some of these storms may produce little rainfall. Thunderstorm potential for the northern Great Basin into parts of eastern Oregon, northeast California, and southwest Montana will increase on Wednesday. At least subtle forcing from an approaching trough should support some increase in storm coverage. Slightly faster storm motions should also increase the probability of a few drier storms. Mid-level moisture will shift eastward as the trough progresses. There is a consistent signal in models for thunderstorms from central Idaho into southwest and parts of central Montana. Forcing for ascent will be moderately strong as the trough moves into the region by late afternoon. Between dry sub-cloud layers and fast storm motions, confidence in dry thunderstorms is moderate to high. ..Wendt.. 07/21/2024 ...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 0353 PM CDT Sun Jul 21 2024 Valid 231200Z - 291200Z Fire weather concerns during the extended period will focus on parts of the Northwest, northern Great Basin, and northern Rockies. Dry and windy conditions, as well as dry thunderstorms, are possible ahead of an upper-level trough that will promote some upper-level ridge breakdown in the West. ...Wind/RH Concerns... Winds will begin to increase in the northwest into northern California as the trough approaches on Wednesday. At this time, the strongest winds appear they may remain closer to the terrain/Cascade Gaps. Winds will likely peak on Thursday across the Northwest into northern California/northwest Nevada. Critical fire weather is perhaps most likely Thursday, but there will also be some increase in RH as well. Confidence is not high enough for greater critical fire weather probabilities at this time. By Friday, strong mid-level flow will remain over parts of the northern Rockies. Additionally, a weak tropical low will rejoin the mean westerlies aloft and move into central California and the western Great Basin into the weekend. Strong winds and low RH are possible from the western Great Basin into western/central Montana on Friday and Saturday. However, there are differences between the ECMWF/GFS on the timing and intensity of some key features. When comparing the deterministic models to their counterpart ensembles, it suggests that there is large spread in potential outcomes. This uncertainty precludes introducing highlights. ...Dry Lightning... Mid-level moisture will remain across the northern Great Basin into the adjacent Northwest on Tuesday. Large-scale ascent will be weaker than on previous days and coverage is still somewhat uncertain. Available CAM and global guidance shows some potential for thunderstorms from far northern Nevada into central Idaho. Some of these storms may produce little rainfall. Thunderstorm potential for the northern Great Basin into parts of eastern Oregon, northeast California, and southwest Montana will increase on Wednesday. At least subtle forcing from an approaching trough should support some increase in storm coverage. Slightly faster storm motions should also increase the probability of a few drier storms. Mid-level moisture will shift eastward as the trough progresses. There is a consistent signal in models for thunderstorms from central Idaho into southwest and parts of central Montana. Forcing for ascent will be moderately strong as the trough moves into the region by late afternoon. Between dry sub-cloud layers and fast storm motions, confidence in dry thunderstorms is moderate to high. ..Wendt.. 07/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more