Severe Storms

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0747 PM CDT Thu Jul 17 2025 Valid 180100Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN EASTERN MT TO FAR SOUTHWEST ND... ...SUMMARY... A couple supercells will remain capable of large hail and severe gusts through about midnight across eastern Montana. ...Northern Great Plains... A couple supercells are ongoing over north-central MT with a history of measured severe gusts and severe hail signatures per MRMS MESH. This activity should persist southeastward through at least late evening amid strong effective bulk shear but weak buoyancy and modest mid-level lapse rates per the 00Z GGW sounding. Most guidance outside of the RRFS suggest that convection will remain as discrete supercells before eventually waning as it impinges on minimal surface-based instability near the MT/ND border. With such a cool and dry boundary layer per surface observations across far eastern MT into ND, the overall severe threat should diminish towards midnight. Elevated convection should develop across parts of the Dakotas overnight, with weak MUCAPE marginalizing severe potential. ...Southern High Plains... A slow-moving, loosely organized cluster is ongoing east-southeast of the Sangre de Cristo Mountains in northeast NM. While the boundary layer is climatologically cool, it is moist and moderately unstable (per the 00Z AMA sounding), amid persistent low-level easterlies. This upslope flow regime should support cluster maintenance through late evening before gradually waning overnight. While heavy rain is the primary hazard (per WPC ERO SLGT risk), a few strong to marginal severe gusts and small hail remain possible. ...Northern ME... Convection has largely waned across New England and should continue to do so over the next hour. With some lingering deep convection across northern ME, a moist boundary layer and still sufficient deep-layer shear (per the CBW VWP) may support a weakly rotating storm or two before convection spreads entirely into NB. ...Eastern OK to the Delmarva... A couple microbursts capable of strong gusts may still occur in yet to be overturned areas across a broad swath from the Ozarks to the Mid-Atlantic Coast. With modest deep-layer shear and nocturnal boundary-layer cooling, severe probabilities appear negligible. ..Grams.. 07/18/2025 Read more

WW 0521 Status Updates
STATUS REPORT ON WW 521 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WNW LEB TO 20 SW EFK TO 10 ESE EFK TO 75 NNE EFK. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1703 ..WENDT..07/17/25 ATTN...WFO...CAR...GYX...BTV... STATUS REPORT FOR WS 521 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC003-007-017-021-025-172340- ME . MAINE COUNTIES INCLUDED ARE AROOSTOOK FRANKLIN OXFORD PISCATAQUIS SOMERSET NHC003-007-009-172340- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE CARROLL COOS GRAFTON VTC005-009-017-019-172340- VT . VERMONT COUNTIES INCLUDED ARE CALEDONIA ESSEX ORANGE Read more

WW 0521 Status Updates
STATUS REPORT ON WW 521 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WNW LEB TO 20 SW EFK TO 10 ESE EFK TO 75 NNE EFK. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1703 ..WENDT..07/17/25 ATTN...WFO...CAR...GYX...BTV... STATUS REPORT FOR WS 521 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC003-007-017-021-025-172340- ME . MAINE COUNTIES INCLUDED ARE AROOSTOOK FRANKLIN OXFORD PISCATAQUIS SOMERSET NHC003-007-009-172340- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE CARROLL COOS GRAFTON VTC005-009-017-019-172340- VT . VERMONT COUNTIES INCLUDED ARE CALEDONIA ESSEX ORANGE Read more

WW 0521 Status Updates
STATUS REPORT ON WW 521 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WNW LEB TO 20 SW EFK TO 10 ESE EFK TO 75 NNE EFK. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1703 ..WENDT..07/17/25 ATTN...WFO...CAR...GYX...BTV... STATUS REPORT FOR WS 521 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC003-007-017-021-025-172340- ME . MAINE COUNTIES INCLUDED ARE AROOSTOOK FRANKLIN OXFORD PISCATAQUIS SOMERSET NHC003-007-009-172340- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE CARROLL COOS GRAFTON VTC005-009-017-019-172340- VT . VERMONT COUNTIES INCLUDED ARE CALEDONIA ESSEX ORANGE Read more

WW 0521 Status Updates
STATUS REPORT ON WW 521 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WNW LEB TO 20 SW EFK TO 10 ESE EFK TO 75 NNE EFK. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1703 ..WENDT..07/17/25 ATTN...WFO...CAR...GYX...BTV... STATUS REPORT FOR WS 521 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC003-007-017-021-025-172340- ME . MAINE COUNTIES INCLUDED ARE AROOSTOOK FRANKLIN OXFORD PISCATAQUIS SOMERSET NHC003-007-009-172340- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE CARROLL COOS GRAFTON VTC005-009-017-019-172340- VT . VERMONT COUNTIES INCLUDED ARE CALEDONIA ESSEX ORANGE Read more

WW 0521 Status Updates
STATUS REPORT ON WW 521 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WNW LEB TO 20 SW EFK TO 10 ESE EFK TO 75 NNE EFK. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1703 ..WENDT..07/17/25 ATTN...WFO...CAR...GYX...BTV... STATUS REPORT FOR WS 521 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC003-007-017-021-025-172340- ME . MAINE COUNTIES INCLUDED ARE AROOSTOOK FRANKLIN OXFORD PISCATAQUIS SOMERSET NHC003-007-009-172340- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE CARROLL COOS GRAFTON VTC005-009-017-019-172340- VT . VERMONT COUNTIES INCLUDED ARE CALEDONIA ESSEX ORANGE Read more

MD 1703 CONCERNING SEVERE THUNDERSTORM WATCH 521... FOR PORTIONS OF NORTHERN NEW ENGLAND
Mesoscale Discussion 1703 NWS Storm Prediction Center Norman OK 0543 PM CDT Thu Jul 17 2025 Areas affected...Portions of northern New England Concerning...Severe Thunderstorm Watch 521... Valid 172243Z - 180015Z The severe weather threat for Severe Thunderstorm Watch 521 continues. SUMMARY...Strong/damaging winds will remain possible into perhaps mid evening. A brief tornado could occur in northeast Maine over the next 1-2 hours. DISCUSSION...The KCBW VAD data continues to show large low-level hodographs. Convection in northeast Maine has certainly trended more linear over the past few hours, but a few marginal supercells remain and have shown moderate low-level rotation periodically. These storms will pose a threat for damaging winds and a brief tornado for another 1-2 hours before moving into the Canadian Maritimes. Farther south and west, a line of weak convection has developed along the Vermont/New Hampshire border. With temperatures ahead of this line currently in the mid/upper 80s F (at least in New Hampshire), there is at least some potential for a strong/damaging wind gust to occur. Deep-layer shear has also increased in this area as the shortwave trough has approached late this afternoon. That being said, diurnal cooling will also increase with time. It is unclear how strong this activity will be as it approaches western Maine later this evening. ..Wendt.. 07/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX...BTV...ALY... LAT...LON 43147303 44687274 46486986 47126818 47136772 46306776 45506921 44756976 43107215 43147303 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

WW 521 SEVERE TSTM ME NH NY VT 171825Z - 180100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 521 NWS Storm Prediction Center Norman OK 225 PM EDT Thu Jul 17 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western and Northern Maine Northern and Central New Hampshire Far Northern New York Northern and Central Vermont * Effective this Thursday afternoon and evening from 225 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible A tornado or two possible SUMMARY...Scattered thunderstorms are forecast to develop and intensify this afternoon across the Watch area. A couple of transient supercells are possible as well as a few organized multicells. The primary severe hazard will be strong to severe gusts (50-65 mph) capable of wind damage, but a tornado is possible with the more intense transient supercells. The severe thunderstorm watch area is approximately along and 75 statute miles east and west of a line from 20 miles north northwest of Caribou ME to 15 miles south southwest of Montpelier VT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 55 knots. A few cumulonimbi with maximum tops to 400. Mean storm motion vector 23030. ...Smith Read more

WW 0522 Status Updates
STATUS REPORT ON WW 522 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..07/17/25 ATTN...WFO...TFX...GGW... STATUS REPORT FOR WS 522 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC005-015-027-033-041-051-055-069-071-073-101-105-172340- MT . MONTANA COUNTIES INCLUDED ARE BLAINE CHOUTEAU FERGUS GARFIELD HILL LIBERTY MCCONE PETROLEUM PHILLIPS PONDERA TOOLE VALLEY 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 0521 Status Updates
STATUS REPORT ON WW 521 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WNW LEB TO 20 SW EFK TO 10 ESE EFK TO 75 NNE EFK. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1703 ..WENDT..07/17/25 ATTN...WFO...CAR...GYX...BTV... STATUS REPORT FOR WS 521 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC003-007-017-021-025-172340- ME . MAINE COUNTIES INCLUDED ARE AROOSTOOK FRANKLIN OXFORD PISCATAQUIS SOMERSET NHC003-007-009-172340- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE CARROLL COOS GRAFTON VTC005-009-017-019-172340- VT . VERMONT COUNTIES INCLUDED ARE CALEDONIA ESSEX ORANGE Read more

MD 1703 CONCERNING SEVERE THUNDERSTORM WATCH 521... FOR PORTIONS OF NORTHERN NEW ENGLAND
Mesoscale Discussion 1703 NWS Storm Prediction Center Norman OK 0543 PM CDT Thu Jul 17 2025 Areas affected...Portions of northern New England Concerning...Severe Thunderstorm Watch 521... Valid 172243Z - 180015Z The severe weather threat for Severe Thunderstorm Watch 521 continues. SUMMARY...Strong/damaging winds will remain possible into perhaps mid evening. A brief tornado could occur in northeast Maine over the next 1-2 hours. DISCUSSION...The KCBW VAD data continues to show large low-level hodographs. Convection in northeast Maine has certainly trended more linear over the past few hours, but a few marginal supercells remain and have shown moderate low-level rotation periodically. These storms will pose a threat for damaging winds and a brief tornado for another 1-2 hours before moving into the Canadian Maritimes. Farther south and west, a line of weak convection has developed along the Vermont/New Hampshire border. With temperatures ahead of this line currently in the mid/upper 80s F (at least in New Hampshire), there is at least some potential for a strong/damaging wind gust to occur. Deep-layer shear has also increased in this area as the shortwave trough has approached late this afternoon. That being said, diurnal cooling will also increase with time. It is unclear how strong this activity will be as it approaches western Maine later this evening. ..Wendt.. 07/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX...BTV...ALY... LAT...LON 43147303 44687274 46486986 47126818 47136772 46306776 45506921 44756976 43107215 43147303 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

MD 1702 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST NM INTO SOUTHEAST CO
Mesoscale Discussion 1702 NWS Storm Prediction Center Norman OK 0504 PM CDT Thu Jul 17 2025 Areas affected...Northeast NM into southeast CO Concerning...Severe potential...Watch unlikely Valid 172204Z - 180000Z Probability of Watch Issuance...20 percent SUMMARY...Strong to locally severe storms are possible into early evening. DISCUSSION...Storms are gradually increasing in coverage and intensity late this afternoon from southeast CO into northeast NM. The strongest ongoing activity is occurring near the Sangre de Cristo Range, but some tendency for storm coverage to increase into the lower elevations is expected with time. MLCAPE of up to 1500-2000 J/kg will continue to support occasionally robust convection into the early evening. While deep-layer flow is rather weak, low-level flow is backed across parts of southeast CO into northeast NM, to the north of a quasi-stationary surface front. Weakly veering wind profiles and effective shear of 25-30 kt may support occasionally organized storm structures, and some clustering of storms is possible with time. While midlevel temperatures are rather warm, isolated hail cannot be ruled out with the strongest updrafts into early evening. Strong to locally severe gusts will also be possible, especially if any storm clustering and outflow consolidation occurs with time. ..Dean/Hart.. 07/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GLD...PUB...BOU...ABQ... LAT...LON 35660334 34870354 34510434 34570496 34700530 34820546 35370534 36670527 37860533 38650578 39040462 39070380 38500299 36830307 35830332 35660334 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

MD 1701 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF NORTHERN AND CENTRAL MONTANA
Mesoscale Discussion 1701 NWS Storm Prediction Center Norman OK 0348 PM CDT Thu Jul 17 2025 Areas affected...portions of northern and central Montana Concerning...Severe potential...Watch possible Valid 172048Z - 172245Z Probability of Watch Issuance...60 percent SUMMARY...Isolated to widely scattered thunderstorms are expected this afternoon and evening. A few supercells capable of hail and damaging winds are expected. A WW is possible, although it is uncertain when the severe risk will maximize. DISCUSSION...Afternoon visible and radar imagery show initial thunderstorm development is underway across far northern MT and southern Canada. Aided by synoptic ascent from a shortwave trough within northwesterly flow and heating along a stalled frontal boundary, continued convective development is expected over the next several hours. Modest moisture and somewhat cool surface temperatures have limited boundary-layer destabilization so far this afternoon. Still, with little inhibition, weak MLCAPE (500-700 J/kg) will be sufficient for stronger updrafts. Additional destabilization is expected as low-level warm advection along the boundary increases into this evening. Elongated hodographs owing to enhanced northwesterly flow aloft observed from the 18z TFX RAOB and area VADs will support a supercell storm mode capable of hail and isolated damaging gusts. Despite weaker buoyancy, continued ascent along the stalled front will likely serve as a focus for storm intensification over the next couple of hours. This is supported by recent CAM guidance which shows a few longer-lived supercells into this evening. The exact timing of the severe risk remains unclear as destabilization continues and storms may take some time to mature. However, at least an isolated severe risk should gradually increase over the next few hours. Given the broadly favorable environment for large hail and severe gusts, a WW may be needed. ..Lyons/Smith.. 07/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...GGW...TFX... LAT...LON 49241243 49150908 48360651 47250473 46170558 46080744 46220885 47141104 47711229 48261283 49241243 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

MD 1700 CONCERNING SEVERE THUNDERSTORM WATCH 521... FOR PORTIONS OF VT...NH...AND ME
Mesoscale Discussion 1700 NWS Storm Prediction Center Norman OK 0340 PM CDT Thu Jul 17 2025 Areas affected...Portions of VT...NH...and ME Concerning...Severe Thunderstorm Watch 521... Valid 172040Z - 172245Z The severe weather threat for Severe Thunderstorm Watch 521 continues. SUMMARY...Threat for damaging gusts and/or a brief tornado or two continues across portions of VT, NH, and ME. DISCUSSION...Early afternoon soundings (i.e. 18Z) at CAR and GYX sampled a moist and unstable airmass across the region, with little to no convective inhibition. The CAR sounding also sampled moderate vertical shear (i.e. 0-6 km bulk shear of 43 kt), while notably weaker deep-layer shear (i.e. 0-6 km bulk shear of 25 kt) was sampled farther south at GYX. This variance in shear matches previous expectations and continues to place the greatest severe risk across northern ME. An initially more cellular mode has trended towards a more cell-in-line mode over the last hour or so. Even so, the environmental conditions favor a continued threat for strong to severe storms. Strong downbursts remain the greatest risk, particularly as mid-level flow gradually strengthens. There is enough low-level shear (i.e. 0-1 km 15 to 20 kt) to support a brief tornado as well. ..Mosier.. 07/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX...BTV... LAT...LON 47396939 47456844 47176770 46526776 44617002 43937193 44507307 45477125 46517019 47396939 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

WW 0522 Status Updates
STATUS REPORT ON WW 522 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..07/17/25 ATTN...WFO...TFX...GGW... STATUS REPORT FOR WS 522 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC005-015-027-033-041-051-055-069-071-073-101-105-172340- MT . MONTANA COUNTIES INCLUDED ARE BLAINE CHOUTEAU FERGUS GARFIELD HILL LIBERTY MCCONE PETROLEUM PHILLIPS PONDERA TOOLE VALLEY 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 522 SEVERE TSTM MT 172130Z - 180400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 522 NWS Storm Prediction Center Norman OK 330 PM MDT Thu Jul 17 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Montana * Effective this Thursday afternoon and evening from 330 PM until 1000 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 65 mph possible SUMMARY...Thunderstorms will continue to develop and intensify across north-central Montana this afternoon and track southeastward across the watch area. A few supercells are expected, capable of large hail and damaging wind gusts. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 60 miles north northwest of Great Falls MT to 50 miles southeast of Glasgow MT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). 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 521... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 28030. ...Hart Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0455 PM CDT Thu Jul 17 2025 Valid 191200Z - 251200Z ...Days 3-5/Saturday-Monday... A mid-level trough and attendant dry cold front will move through the Pacific Northwest on Day 3/Saturday. Robust onshore flow will persist across the Cascades, bringing breezy conditions to the Columbia Basin. Despite cooler post-frontal temperatures, sustained west winds of around 15 mph (20 mph in favored Cascade gaps) and relative humidity as low as 15 percent will support a fire weather threat amid dry fuels across the Columbia Basin. Enhanced mid-level flow at the base of the trough overrunning a dry boundary layer in place across southern Idaho will bring stronger winds to the Snake River Plain Day 3/Saturday, raising wildfire spread potential within critically dry fuels. A deepening, positively-tilted trough across the Pacific Northwest and increase in mid-level winds will support a broader area of dry southwesterly flow across the Great Basin, NV and southern ID by Day 4/Sunday, with the fire weather threat shifting southeastward to include northwestern UT by Day 5/Monday. The trough will also aid in pushing residual monsoon moisture and thunderstorm development currently across portions of the Intermountain West along and east of the Continental Divide by early next week, while also mitigating fire weather concerns for the Pacific Northwest as cooler temperatures, cloud cover and higher relative humidity move into the region. ...Days 6-8/Tuesday-Thursday... Long term ensemble guidance indicates some form of mid-level troughing persisting across the Pacific Northwest through the middle of next week, maintaining a dry southwesterly flow over much of the interior of the West. However, relaxing mid-level flow and reduced surface pressure gradients as a subtropical high propagates westward across the southern U.S. should promote lighter winds across the Southwestern U.S., particularly for Days 7-8/Wednesday-Thursday. ..Williams.. 07/17/2025 ...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 0455 PM CDT Thu Jul 17 2025 Valid 191200Z - 251200Z ...Days 3-5/Saturday-Monday... A mid-level trough and attendant dry cold front will move through the Pacific Northwest on Day 3/Saturday. Robust onshore flow will persist across the Cascades, bringing breezy conditions to the Columbia Basin. Despite cooler post-frontal temperatures, sustained west winds of around 15 mph (20 mph in favored Cascade gaps) and relative humidity as low as 15 percent will support a fire weather threat amid dry fuels across the Columbia Basin. Enhanced mid-level flow at the base of the trough overrunning a dry boundary layer in place across southern Idaho will bring stronger winds to the Snake River Plain Day 3/Saturday, raising wildfire spread potential within critically dry fuels. A deepening, positively-tilted trough across the Pacific Northwest and increase in mid-level winds will support a broader area of dry southwesterly flow across the Great Basin, NV and southern ID by Day 4/Sunday, with the fire weather threat shifting southeastward to include northwestern UT by Day 5/Monday. The trough will also aid in pushing residual monsoon moisture and thunderstorm development currently across portions of the Intermountain West along and east of the Continental Divide by early next week, while also mitigating fire weather concerns for the Pacific Northwest as cooler temperatures, cloud cover and higher relative humidity move into the region. ...Days 6-8/Tuesday-Thursday... Long term ensemble guidance indicates some form of mid-level troughing persisting across the Pacific Northwest through the middle of next week, maintaining a dry southwesterly flow over much of the interior of the West. However, relaxing mid-level flow and reduced surface pressure gradients as a subtropical high propagates westward across the southern U.S. should promote lighter winds across the Southwestern U.S., particularly for Days 7-8/Wednesday-Thursday. ..Williams.. 07/17/2025 ...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 0455 PM CDT Thu Jul 17 2025 Valid 191200Z - 251200Z ...Days 3-5/Saturday-Monday... A mid-level trough and attendant dry cold front will move through the Pacific Northwest on Day 3/Saturday. Robust onshore flow will persist across the Cascades, bringing breezy conditions to the Columbia Basin. Despite cooler post-frontal temperatures, sustained west winds of around 15 mph (20 mph in favored Cascade gaps) and relative humidity as low as 15 percent will support a fire weather threat amid dry fuels across the Columbia Basin. Enhanced mid-level flow at the base of the trough overrunning a dry boundary layer in place across southern Idaho will bring stronger winds to the Snake River Plain Day 3/Saturday, raising wildfire spread potential within critically dry fuels. A deepening, positively-tilted trough across the Pacific Northwest and increase in mid-level winds will support a broader area of dry southwesterly flow across the Great Basin, NV and southern ID by Day 4/Sunday, with the fire weather threat shifting southeastward to include northwestern UT by Day 5/Monday. The trough will also aid in pushing residual monsoon moisture and thunderstorm development currently across portions of the Intermountain West along and east of the Continental Divide by early next week, while also mitigating fire weather concerns for the Pacific Northwest as cooler temperatures, cloud cover and higher relative humidity move into the region. ...Days 6-8/Tuesday-Thursday... Long term ensemble guidance indicates some form of mid-level troughing persisting across the Pacific Northwest through the middle of next week, maintaining a dry southwesterly flow over much of the interior of the West. However, relaxing mid-level flow and reduced surface pressure gradients as a subtropical high propagates westward across the southern U.S. should promote lighter winds across the Southwestern U.S., particularly for Days 7-8/Wednesday-Thursday. ..Williams.. 07/17/2025 ...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 0455 PM CDT Thu Jul 17 2025 Valid 191200Z - 251200Z ...Days 3-5/Saturday-Monday... A mid-level trough and attendant dry cold front will move through the Pacific Northwest on Day 3/Saturday. Robust onshore flow will persist across the Cascades, bringing breezy conditions to the Columbia Basin. Despite cooler post-frontal temperatures, sustained west winds of around 15 mph (20 mph in favored Cascade gaps) and relative humidity as low as 15 percent will support a fire weather threat amid dry fuels across the Columbia Basin. Enhanced mid-level flow at the base of the trough overrunning a dry boundary layer in place across southern Idaho will bring stronger winds to the Snake River Plain Day 3/Saturday, raising wildfire spread potential within critically dry fuels. A deepening, positively-tilted trough across the Pacific Northwest and increase in mid-level winds will support a broader area of dry southwesterly flow across the Great Basin, NV and southern ID by Day 4/Sunday, with the fire weather threat shifting southeastward to include northwestern UT by Day 5/Monday. The trough will also aid in pushing residual monsoon moisture and thunderstorm development currently across portions of the Intermountain West along and east of the Continental Divide by early next week, while also mitigating fire weather concerns for the Pacific Northwest as cooler temperatures, cloud cover and higher relative humidity move into the region. ...Days 6-8/Tuesday-Thursday... Long term ensemble guidance indicates some form of mid-level troughing persisting across the Pacific Northwest through the middle of next week, maintaining a dry southwesterly flow over much of the interior of the West. However, relaxing mid-level flow and reduced surface pressure gradients as a subtropical high propagates westward across the southern U.S. should promote lighter winds across the Southwestern U.S., particularly for Days 7-8/Wednesday-Thursday. ..Williams.. 07/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more