773
FXUS65 KSLC 211816
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1216 PM MDT SUN JUN 21 2026
KEY MESSAGES
- HIGH PRESSURE WILL BRING A WARMING TREND EARLY THIS WEEK.
DAYTIME TEMPERATURES WILL RUN 5 TO 10 DEGREES ABOVE NORMAL BY
TUESDAY, WITH HOT CONDITIONS CONTINUING THROUGH AT LEAST
THURSDAY. THE POTENTIAL FOR HEAT RELATED ILLNESS WILL INCREASE
ACROSS VALLEY LOCATIONS BY THE MIDDLE OF THE WEEK.
- MOISTURE SPREADING NORTHWARD WILL BRING A CHANCE FOR SHOWERS AND
THUNDERSTORMS WEDNESDAY AND THURSDAY, WITH THE GREATEST CHANCE
FOR PRECIPITATION ACROSS SOUTHERN UTAH. LIGHTNING ASSOCIATED
WITH THESE STORMS MAY RESULT IN NEW FIRE STARTS.
- STRENGTHENING AND DRYING SOUTHWESTERLY FLOW AHEAD OF AN
APPROACHING COLD FRONT WILL BRING THE RETURN OF CRITICAL FIRE
WEATHER CONDITIONS LATE IN THE WEEK.
DISCUSSION
A SLIGHTLY COOLER AND MORE STABLE AIRMASS HAS SPREAD ACROSS MUCH
OF THE FORECAST AREA TODAY IN THE WAKE OF SATURDAY'S COLD FRONT
PASSAGE. AS A RESULT A LIGHTER NORTHWESTERLY LOW LEVEL FLOW WILL
PERSIST THROUGH THIS AFTERNOON AND EARLY EVENING WITH SEASONAL
TEMPERATURES AND SLIGHTLY HIGHER RELATIVE HUMIDITY. THE EXCEPTION
IS FAR SOUTHERN UTAH IN VICINITY OF THE LINGERING SURFACE TROUGH,
WHERE A WESTERLY FLOW AND SLIGHTLY WARMER AIRMASS REMAIN IN PLACE.
MID LEVEL RIDGING WILL BUILD ACROSS THE DESERT SOUTHWEST THROUGH
THE EARLY PORTION OF THE WEEK, ALLOWING FOR A WARMING AND DRYING
TREND ACROSS THE FORECAST AREA. BY TUESDAY MAX TEMPERATURES WILL
ONCE AGAIN RUN 5-10 DEGREES ABOVE CLIMO, WITH LOW-MID 90S ALONG
THE WASATCH FRONT TUESDAY CLIMBING INTO THE MID TO UPPER 90S
WEDNESDAY. LOWER DESERTS OF SOUTHERN UTAH INCLUDING ST GEORGE,
ZION CANYON AND BULLFROG WILL REACH OR EXCEED 105F EACH AFTERNOON.
WITH THESE TEMPERATURES AND ELEVATED OVERNIGHT LOWS, HEATRISK WILL
REACH THE MODERATE CATEGORY ACROSS MOST VALLEYS WITH POCKETS OF
HIGH, AND WILL BE ACCOMPANIED BY AN INCREASED RISK FOR HEAT
RELATED ILLNESSES.
MODEL GUIDANCE IS COMING INTO BETTER AGREEMENT PULLING MOISTURE
NORTHWARD INTO THE DESERT SOUTHWEST AROUND THE PERIPHERY OF THE
UPPER RIDGE, AND SPREADING INTO SOUTHERN UTAH BY WEDNESDAY.
INITIALLY THIS MOISTURE WILL LIKELY BE ELEVATED WITH A DEEPLY
MIXED SUB CLOUD LAYER FAVORING DRY LIGHTNING AND MICROBURST WINDS
WEDNESDAY, WITH PERHAPS A BETTER CHANCE FOR PRECIPITATION BY
THURSDAY.
THERE IS ALSO FAIR AGREEMENT LATE IN THE WEEK HEADING
INTO NEXT WEEKEND BRINGING AN UPPER TROUGH INTO THE PACIFIC
NORTHWEST/NORTHERN GREAT BASIN. THE RESULTANT STRENGTHENING
SOUTHWESTERLY FLOW WOULD ADVECT DRIER AIR BACK INTO THE STATE AND
RESULT IN ANOTHER ROUND OF CRITICAL FIRE WEATHER CONDITIONS FRIDAY
INTO SATURDAY.
AVIATION
KSLC...NORTHWESTERLY WINDS WILL PERSIST THROUGH THE EARLY EVENING,
BECOMING LIGHT AND VARIABLE AFTER ~03-04Z. VFR CONDITIONS WILL
LIKELY PREVAIL, HOWEVER SMOKE FROM NEARBY WILDFIRES COULD PRODUCE
PERIODS OF MVFR VIS, PARTICULARLY AROUND SUNSET/SUNRISE AND AGAIN
MONDAY AFTERNOON.
REST OF UTAH AND SOUTHWEST WYOMING...WINDS WILL REMAIN RELATIVELY
LIGHT AND TERRAIN-DRIVEN ACROSS MUCH OF THE AREA, EXCEPT FOR THE
WESTERN UINTA BASIN WHERE WESTERLY WINDS WILL GUST TO AROUND 20-
25KTS THROUGH ROUGHLY 02Z. ALTHOUGH MANY SITES WILL EXPERIENCE VFR
CONDITIONS, WILDFIRE SMOKE COULD RESULT IN REDUCTIONS IN SLANTWISE
VIS, PARTICULARLY AROUND SUNRISE/SUNSET.
FIRE WEATHER
A SLIGHTLY COOLER AND MORE STABLE AIRMASS HAS
SPREAD ACROSS MUCH OF THE STATE, RESULTING IN A GENERAL
NORTHWESTERLY FLOW AND SEASONAL TEMPERATURES THIS AFTERNOON.
ALTHOUGH RH HAS TRENDED SLIGHTLY HIGHER, VALUES WILL STILL REMAIN
NEAR OR BELOW 20 PERCENT ACROSS MOST LOW AND MID ELEVATIONS INTO
THE EARLY EVENING HOURS. NEAR THE ARIZONA BORDER, THE AIRMASS
REMAIN HOT AND VERY DRY, AND GUSTY WEST WINDS WILL RESULT IN LOCAL
CRITICAL FIRE WEATHER CONDITIONS IN PORTIONS OF ZONES 496 AND 498
THROUGH EARLY EVENING.
HIGH PRESSURE WILL STRENGTHEN ACROSS THE AREA DURING THE FIRST
HALF OF THE WEEK, RESULTING IN A RETURN TO HOT AND VERY DRY
CONDITIONS BY TUESDAY. DAYTIME TEMPERATURES TUESDAY AND WEDNESDAY
WILL RUN 5-10 DEGREES ABOVE NORMAL WITH VERY LOW DAYTIME RH AND
MARGINAL TO POOR OVERNIGHT RECOVERY. HIGH BASED MOISTURE WILL
BEGIN TO INCREASE WEDNESDAY AFTERNOON ACROSS SOUTHERN AND
POTENTIALLY CENTRAL UTAH, BRINGING A CHANCE FOR HIGH BASED SHOWERS
AND DRY THUNDERSTORMS. THIS MOISTURE LOOKS TO INCREASE ON
THURSDAY, BRINGING A MIXTURE OF WET AND DRY THUNDERSTORMS. A DRY
AND STRENGTHENING SOUTHWESTERLY FLOW WILL FOLLOW FRIDAY INTO
SATURDAY AS THIS RIDGE BREAKS DOWN, WHICH WILL LIKELY BRING A
RETURN TO CRITICAL FIRE WEATHER CONDITIONS ACROSS MUCH OF THE
AREA.
SLC WATCHES/WARNINGS/ADVISORIES
UT...NONE.
WY...NONE.
PUBLIC...SEAMAN
AVIATION...CUNNINGHAM
FIRE WEATHER...SEAMAN
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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