858
FNUS21 KWNS 201637
FWDDY1
DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1137 AM CDT FRI JUN 20 2025
VALID 201700Z - 211200Z
..CRITICAL FIRE WEATHER AREA FOR FOUR CORNERS AND GREAT BASIN
NO CHANGES ARE NEEDED TO THE CURRENT D1 FIRE WEATHER OUTLOOK.
MORNING SATELLITE ANALYSIS SHOWS MOSTLY SUNNY SKIES ACROSS THE
CRITICAL AREA, WITH RELATIVE HUMIDITY RANGING FROM 15-20 PERCENT AND
WINDS GUSTING 20-30 MPH. HREF GUIDANCE CONTINUES TO INDICATE THAT
SEVERAL HOURS OF CRITICAL CONDITIONS ARE LIKELY FROM THE GREAT BASIN
TO THE FOUR CORNERS AND INTO PORTIONS OF THE HIGH PLAINS THROUGH
THIS AFTERNOON. SEE PREVIOUS DISCUSSION BELOW FOR MORE INFORMATION.
..THORNTON.. 06/20/2025
PREV DISCUSSION
/ISSUED 0132 AM CDT FRI JUN 20 2025/
..SYNOPSIS
WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY
ACROSS PARTS OF THE GREATER FOUR CORNERS REGION AND THE GREAT BASIN.
EARLY-MORNING WATER VAPOR IMAGERY SHOWS A DOMINANT UPPER RIDGE OVER
THE CENTRAL CONUS WITH SHORTWAVE TROUGHING OVER THE WESTERN GREAT
BASIN AND NORTHEASTERN PACIFIC. THE GREAT BASIN SHORTWAVE IS
FORECAST TO MOVE INTO THE NORTHERN HIGH PLAINS THROUGH THE
AFTERNOON, WHICH WILL FACILITATE SURFACE LOW DEVELOPMENT ACROSS
EASTERN WY BY LATE AFTERNOON. STRENGTHENING LOW-LEVEL WINDS IN
RESPONSE TO THE DEEPENING LOW WILL PROMOTE A WIDESPREAD SWATH OF
20-30 MPH WINDS WITHIN A VERY DRY AIR MASS AND ACROSS A REGION WITH
RECEPTIVE FUELS.
..FOUR CORNERS INTO THE HIGH PLAINS
THE AXIS OF THE MID-LEVEL JET ASSOCIATED WITH THE LEADING SHORTWAVE
IS FORECAST TO RESIDE FROM SOUTHEAST UT INTO SOUTHERN WY BY PEAK
HEATING. THIS WILL MAXIMIZE THE POTENTIAL FOR 20+ MPH WINDS AT THE
SURFACE, AND WILL LIKELY SUPPORT WIND GUSTS BETWEEN 30-45 MPH. RH
VALUES IN THE SINGLE DIGITS TO LOW TEENS COUPLED WITH ANTECEDENT DRY
FUELS (ACTIVE FIRES WERE RECENTLY NOTED ACROSS SOUTHERN UT IN GOES
IR IMAGERY) WILL SUPPORT WIDESPREAD AND PROLONGED CRITICAL
CONDITIONS WITH PERIODS OF EXTREMELY CRITICAL WIND SPEEDS POSSIBLE -
ESPECIALLY ACROSS SOUTH-CENTRAL WY. ELEVATED TO CRITICAL FIRE
WEATHER CONDITIONS WILL LIKELY EXTEND WELL TO THE NORTHEAST INTO THE
CENTRAL HIGH PLAINS, AND POSSIBLY AS FAR EAST AND WESTERN SOUTH
DAKOTA BEHIND AN EASTWARD SURGING DRY LINE. HOWEVER, FUEL CONDITIONS
GENERALLY IMPROVE WITH EASTWARD EXTENT DUE TO RECENT RAINFALL. FIRE
RISK HIGHLIGHTS HAVE BEEN EXPANDED NORTHEAST TO ACCOUNT FOR THE
STRONG WIND/RH SIGNAL, BUT CRITICAL HIGHLIGHTS WERE FOCUSED ACROSS
AREAS WITH DRY, RECEPTIVE FUELS.
..NEVADA INTO ADJACENT PORTIONS OF IDAHO AND UTAH
SOUTHWESTERLY FLOW OVER THE SOUTHERN TO CENTRAL SIERRA NEVADA WILL
INDUCE STRONG DOWNSLOPE FLOW INTO WESTERN AND CENTRAL NV, SPREADING
INTO SOUTHEAST ID AND WESTERN UT BY LATE AFTERNOON. GUIDANCE
CONTINUES TO SHOW A STRONG SIGNAL FOR 20-25 MPH WINDS THROUGH MUCH
OF THE AFTERNOON, AND SINGLE-DIGIT RH VALUES SHOULD SUPPORT
WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS.
..SOUTHERN CALIFORNIA INTO THE SAN JOAQUIN VALLEY
A STRONG ONSHORE PRESSURE GRADIENT WILL SUPPORT INCREASING DOWNSLOPE
WINDS ON THE LEEWARD SIDE/EASTERN SLOPES OF THE COASTAL RANGES
ACROSS SOUTHERN CALIFORNIA THIS AFTERNOON. RELATIVE HUMIDITIES
VALUES FALLING INTO THE TEENS WITHIN THE DOWNSLOPE REGIME, COUPLED
WITH DRY GRASSES, WILL SUPPORT A FIRE WEATHER CONCERN.
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
CLICK HERE TO GO TO PREVIOUS BULLETINS.
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