378 

FNUS28 KWNS 042202

FWDD38



Day 3-8 Fire Weather Outlook  

NWS Storm Prediction Center Norman OK

0500 PM CDT Thu Jun 04 2026



Valid 061200Z - 121200Z



...Synopsis...

The primary driver of synoptic fire weather risks shifts eastward

entering the weekend. On Day 3/Saturday, a potent upper-level

trough, having advanced from the northern Pacific, will move over

the Pacific Northwest. A cold front associated with this feature

will progress southeastward across the western third of the United

States. This front will introduce a major airmass transition,

dropping daytime temperatures below seasonal normals and temporarily

dampening fire risks across much of WA, OR, and northern CA. By Day

4/Sunday, this initial trough shifts northeastward over the Northern

Rockies. However, the tight surface pressure gradient ahead of the

front, coupled with enhanced mid-level westerly-to-southwesterly

flow, will maximize fire weather concerns across central/southern

portions of the Intermountain West. Broad southwesterly flow

dominates early next week before another potentially stronger,

deeper progressive trough is modeled to impact the western half of

the CONUS by mid-week. However, differing solutions exist as to how

far south this system will dive as it moves across the western

CONUS.



...Great Basin, Southwest, and Rocky Mountains...

...Day 3/Saturday...

As the primary upper-level trough carves into the Pacific Northwest,

a tightening surface pressure gradient will develop across the Great

Basin and Southwest. A mid-level jet max will mix down effectively

to the surface due to deep daytime boundary layer mixing. Sustained

southwest winds of 20 to 30 mph are anticipated. Coincident RH

values will plummet into the single digits and low teens, generally

widespread between 6 and 12 percent. A 70 percent probability of

Critical fire weather conditions has been introduced across portions

of eastern NV, southern UT, and northern AZ where critical

thresholds are expected to be met for multiple consecutive hours.

Surrounding areas of the Great Basin and Four Corners region

maintain a 40 percent Critical probability as fuels continue to dry

rapidly and burn periods lengthen under continued high vapor

pressure deficits. While confidence is not high enough to warrant a

drawn area, portions of southern ID will have some opportunity to

experience a mix of fast moving dry/wet thunderstorms.



...Day 4/Sunday...

The upper-level trough tracks northeastward toward the Northern

Rockies, pushing the trailing cold front further south and east.

Strong mid-level flow continues over the southern tier of the

system. The belt of strongest winds will shift slightly eastward,

impacting eastern UT, northern and eastern AZ, and western CO.

Expect sustained southwest winds of 20 to 25 mph. A dry slot aloft

will keep minimum relative humidity values critically low, between 8

and 15 percent, across the Southern Rockies and Southwest. The 70

percent Critical probability remains highlighted across southern and

eastern UT, northern AZ, and western CO. 40 percent Critical

probabilities encompass the remaining portions of southeast NV,

northwest NM, and central WY where fuels are receptive. While

confidence is not yet high enough to warrant a drawn area, a

non-zero chance of mixed dry/wet thunderstorms over northern UT will

be watched with future forecast guidance.



...Day 5/Monday...

The region enters a temporary synoptic transition phase between the

departing northern Rockies trough and the next approaching Pacific

system. While the core of the mid-level jet weakens slightly and the

surface pressure gradient slackens, broad and persistent

southwesterly flow remains established over the Southwest and Great

Basin. Deep mechanical mixing under clear skies will still generate

localized breezy conditions with 15 to 25 mph gusts alongside

persistent hot and dry air. Given the prolonged absence of moisture

and highly susceptible fine fuels, an additional 70 percent Critical

probability was introduced once again over portions of southern UT,

northern AZ, and nearby far southeastern NV. 40 percent Critical

probabilities encompass the remaining portions of southeast NV,

western CO, and central WY where fuels are receptive.



...Day 6/Tuesday - Day 7/Wednesday...

Medium-range global deterministic models and their respective

ensemble members show strong consensus for a secondary, potentially

more intense trough digging into the western US again by mid-week.

Ahead of this feature, a renewed and amplified pressure gradient

will trigger strong south/southwest surface winds. This will likely

cause continued widespread critical fire weather conditions across a

large swath of the Great Basin and Southwest. Thus, 70 percent

Critical probability was introduced yet again over portions of

southern UT and northern AZ where confidence is highest. The

existing 40 percent Critical probability continues Tuesday and

Wednesday in nearby areas including far eastern NV, western CO, and

portions of central WY. Expect this risk area to be significantly

expanded in spatial coverage and potentially extended later into the

week as forecast guidance converges on the exact timing and track of

this secondary upper level low.



..Stearns.. 06/04/2026



...Please see www.spc.noaa.gov/fire for graphic product...



$$