363
FNUS21 KWNS 251647
FWDDY1
DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1146 AM CDT THU JUN 25 2026
VALID 251700Z - 261200Z
..MORNING UPDATE
GOOD OVERNIGHT HUMIDITY RECOVERIES OCCURRED ACROSS THE GREAT BASIN
AND CENTRAL ROCKIES OWING TO INCREASED MOISTURE ADVECTION AND
WIDESPREAD SHOWERS YESTERDAY AFTERNOON/EVENING. OVERALL, OBSERVED 24
HR PRECIPITATION DOES NOT EXCEED 0.30" (EXCEPT IN A FEW ISOLATED
AREAS) LIKELY DUE TO DEEP SUB-CLOUD LAYER EXTENDING ABOVE 3 KM, AS
SHOWN BY 00Z SOUNDINGS FROM LKN, BOI, SLC, AND GJT. ISOLATED DRY
THUNDERSTORMS ALONGSIDE STRONG/SEVERE OUTFLOW WINDS REMAIN POSSIBLE
THIS AFTERNOON. SEE THE PREVIOUS DISCUSSION AND THE SPC DAY 1
CONVECTIVE OUTLOOK FOR MORE INFORMATION ON SEVERE POTENTIAL.
ACROSS THE COLUMBIA BASIN AND CENTRAL-NORTHERN NV, POOR OVERNIGHT
HUMIDITY RECOVERIES HAVE LED TO RH VALUES OF LESS THAN 25% THIS
MORNING. CURRENT SATELLITE IMAGERY DEPICTS INCREASING CLOUD COVER
OVER PARTS OF WASHINGTON AND OREGON, FORECAST TO EXPAND THIS
AFTERNOON AS A WESTERLY JET AT THE BASE OF AN INCOMING TROUGH MOVES
OVERHEAD. AS A RESULT, RH MAY NOT QUITE REACH WIDESPREAD CRITICAL
THRESHOLDS, AND DAYTIME HIGH TEMPERATURES WILL BE 5-10 DEGREES BELOW
AVERAGE. HOWEVER, SUSTAINED WINDS OF 15-20 MPH (GUSTS OVER 25 MPH)
ATOP RECEPTIVE FUELS WILL MAINTAIN ELEVATED FIRE WEATHER HIGHLIGHTS.
..ELIZALDE-GARCIA.. 06/25/2026
PREV DISCUSSION
/ISSUED 0106 AM CDT THU JUN 25 2026/
..SYNOPSIS
A SUB-TROPICAL MOISTURE PLUME WILL CONTINUE TO PROGRESS EASTWARD
ACROSS THE INTERIOR WEST TODAY. THIS FEATURE WILL PROVIDE A FOCUS
FOR BOTH WET AND DRY THUNDERSTORMS FROM SOUTHEASTERN ID THOUGH THE
WESTERN HALF OF CO AND NORTHWEST NM INTO NORTHEAST AZ AND THE
EASTERN 2/3 OF UT. ON THE WESTERN FRINGE OF THIS POTENTIAL
THUNDERSTORM ACTIVITY, MID-LEVEL WEST/SOUTHWEST FLOW WILL COMBINE
WITH DRIER AIR, LEADING TO A WELL-MIXED BOUNDARY LAYER. FARTHER
NORTH, CLOSER TO THE INCOMING TROUGH OVER THE PACIFIC NORTHWEST, A
COLD FRONT WILL TIGHTEN THE SURFACE PRESSURE GRADIENT LEADING TO
SOUTHWEST FLOW OVER DRY FUELS THERE.
..GREAT BASIN, SOUTHWEST, AND CENTRAL ROCKIES
THUNDERSTORM COVERAGE, PARTICULARLY OVER WESTERN CO, WILL LIKELY BE
GREATER THAN WHAT OCCURRED ON WEDNESDAY WITH SLIGHTLY LESS
PRECIPITABLE WATER AVAILABLE AS MOISTURE PROGRESSES FARTHER INLAND.
HOWEVER, GIVEN OVERNIGHT RAINFALL AND FUELS BECOMING SLIGHTLY LESS
DRY, LIGHTNING IGNITION EFFICIENCY IS LIKELY TO DECREASE GOING INTO
TODAY ACROSS MANY OF THE AREAS COVERED BY THE ISOLATED DRY
THUNDERSTORM RISK. THUS, THE LESS FAVORABLE FUEL CONDITIONS WILL
BALANCE THE SOMEWHAT MORE FAVORABLE ATMOSPHERIC ENVIRONMENT AND
PRECLUDE ANY AREAS OF POTENTIALLY SCATTERED DRY THUNDERSTORMS. GIVEN
THE SLIGHTLY DRIER VERTICAL PROFILES AND REMAINING SUB-CLOUD DRY
LAYER, ANY STORMS THAT DO FORM WILL HAVE POTENTIAL FOR GUSTY OUTFLOW
WINDS. (SEE THE SPC DAY 1 CONVECTIVE OUTLOOK FOR ADDITIONAL
DETAILS.) ADDITIONALLY, PYROCUMULUS DEVELOPMENT REMAINS HIGHLY
POSSIBLE WITH PYROCUMULONIMBUS NOT OUT OF THE QUESTION IF FIRE
ACTIVITY CAN PROVIDE SUFFICIENT SURFACE HEATING.
OVER MUCH OF EASTERN NV AND PORTIONS OF WESTERN UT, SOUTHWEST FLOW
ALOFT OVER HOTTER AND DRIER SURFACE CONDITIONS WILL LEAD TO ELEVATED
WIND/RH CONDITIONS. IN THIS REGION, EXPECT WINDS TO BE SOUTHWEST TO
WESTERLY AT 15-20 MPH AMID MINIMUM RHS RANGING FROM 10-20 PERCENT.
..PACIFIC NORTHWEST
FARTHER NORTHWEST OVER WA AND PORTIONS OF OR EAST OF THE CASCADES,
WEST TO SOUTHWEST FLOW WILL PROMOTE STRONG DOWNSLOPE WINDS AND DRY
CONDITIONS. SOUTHWESTERLY SUSTAINED SURFACE WINDS OF 15-20 MPH WILL
COMBINE WITH 10-15% RH TO SUPPORT ELEVATED FIRE WEATHER CONCERNS
THERE AS WELL. A COLD FRONT WILL PUSH THROUGH THE COLUMBIA BASIN
THIS EVENING INTO THE OVERNIGHT HOURS, BRINGING INCREASED
PRECIPITATION CHANCES AND COOLER TEMPERATURES.
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
CLICK HERE TO GO TO PREVIOUS BULLETINS.
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