165
FXUS65 KSLC 042143
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
343 PM MDT MON AUG 4 2025
SYNOPSIS
A HOT AND VERY DRY SOUTHWEST FLOW WILL SET UP ACROSS
THE REGION THROUGH MUCH OF THE WEEK. A DRY COLD FRONT MAY BRING
SOME RELIEF BY THE WEEKEND.
SHORT TERM (THROUGH 12Z/6AM WEDNESDAY)
SOUTHWESTERLY FLOW IS
SOLIDLY IN PLACE ACROSS UTAH AND SOUTHWEST WYOMING THIS AFTERNOON
WITH HIGH PRESSURE BUILDING TO OUR SOUTHEAST. A WEAK SHORTWAVE
TROUGH GRAZING THE NORTHWEST CORNER OF UTAH HAS PRODUCED A FEW
ISOLATED SHOWERS THIS AFTERNOON OVER THE RAFT RIVER RANGE, BUT
OTHERWISE, CONDITIONS HAVE REMAINED HOT, DRY, AND WINDY STATEWIDE
(SEE FIRE WEATHER SECTION FOR MORE ON CRITICAL FIRE WEATHER
CONDITIONS). THIS WAVE WILL ALSO BUMP TEMPERATURES DOWN BY A FEW
DEGREES ACROSS NORTHERN UTAH BETWEEN TODAY AND TOMORROW, WITH
HIGHS IN THE LOW-90S ALONG THE WASATCH FRONT AND UPPER-80S ACROSS
THE WASATCH BACK. WINDS WILL BE A BIT LIGHTER TUESDAY AFTERNOON
AS THE SHORTWAVE EXITS NORTHEASTWARD AND THE GRADIENT RELAXES,
PARTICULARLY ACROSS NORTHERN UTAH.
LONG TERM (AFTER 12Z/6AM WEDNESDAY), ISSUED 348 AM MDT
CONDITIONS WILL STAY WARM, DRY, AND WINDY WEDNESDAY. A STRONG
RIDGE OF HIGH PRESSURE WILL BE POSITIONED TO THE SOUTHEAST WHILE A
BROAD WEST TO SOUTHWEST SYNOPTIC FLOW STAYS IN PLACE FOR MUCH OF
THE WEST. WINDS WILL BE SIMILAR TO PRIOR IN THE WEEK THROUGHOUT
SOUTHWEST WYOMING AND UTAH, WITH GUSTS GENERALLY RANGING FROM
20-30 MPH MUCH OF THE AFTERNOON. THE ENHANCED SOUTHWEST FLOW WILL
BE DRY, WITH MINIMUM RELATIVE HUMIDITY VALUES IN THE SINGLE DIGITS
TO TEENS. THE COMBINATION OF GUSTY WINDS AND LOW RELATIVE
HUMIDITY WILL BRING HIGH FIRE DANGER. VALLEY HIGH TEMPERATURES
WILL BE IN THE MID OR UPPER 90S FOR MUCH OF UTAH, WITH LOW 100S
AROUND LAKE POWELL AND AROUND 105F FOR LOWER WASHINGTON COUNTY.
MINIMAL CHANGE WILL COME THURSDAY WITH HIGH PRESSURE TO THE
SOUTHEAST. A LONGWAVE TROUGH WILL DIG INTO THE PACNW, WHICH WILL
TRANSITION WINDS A BIT MORE TO THE WEST. TEMPERATURES WILL LIKELY
COOL SLIGHTLY FOR SOUTHWEST WYOMING AND NORTHERN UTAH AND WARM
SLIGHTLY FOR THE REMAINDER OF UTAH.
THE LONGWAVE TROUGH WILL TRACK INTO SOUTHWEST WYOMING AND UTAH
FRIDAY. THERE IS UNCERTAINTY IN PRECISE TIMING, BUT HIGH CONFIDENCE
IN A DRY BAROCLINIC ZONE TRACKING IN FROM THE NORTH. THE LONGWAVE
TROUGH WILL GRAZE TO THE NORTH, WITH THE MOST COOLING FOR SOUTHWEST
WYOMING AND ROUGHLY THE NORTHERN HALF OF UTAH. THAT WILL RESULT IN
COOLER CONDITIONS WITH LIGHTER WINDS FOR LOCATIONS NORTH OF THE
BOUNDARY, WITH MORE DRY, WINDY CONDITIONS FURTHER SOUTH.
VALLEY HIGH TEMPERATURES FOR SATURDAY WILL GENERALLY BE IN THE MID
OR UPPER 80S FOR LOCATIONS WHERE THE FRONT WILL TRACK THROUGH, WHILE
SOUTHERN PORTIONS OF UTAH WILL HAVE HIGH TEMPERATURES IN EXCESS OF
100F.
AVIATION...KSLC
DIFFUSE SMOKE ALOFT WILL CONTINUE TO IMPACT THE
TERMINAL. GUSTY SOUTHERLY WINDS ARE EXPECTED TO SHIFT TO WEST AROUND
22Z, THOUGH WITH HOW STRONG THE SOUTHERLY WINDS ARE, THIS WIND SHIFT
MAY STRUGGLE AND OR VACILLATE ACROSS THE TERMINAL THROUGH THE
EVENING.
REST OF UTAH AND SOUTHWEST WYOMING
DIFFUSE SMOKE ALOFT WILL
IMPACT MUCH OF UTAH FROM VARIOUS WILDFIRES AROUND THE SOUTHWEST.
SURFACE SMOKE MAY BRING REDUCED VISIBILITY TO VALLEY TERMINALS IN THE
VICINITY OF THE MONROE CANYON FIRE DURING THE OVERNIGHT AND MORNING
HOURS. OTHERWISE, WIDESPREAD GUSTY SOUTH TO SOUTHWEST WINDS WILL
IMPACT MOST TERMINALS UNTIL SUNSET THIS EVENING, THEN GRADUALLY
DIMINISH.
FIRE WEATHER
SOUTHWESTERLY FLOW WILL REMAIN IN PLACE ACROSS THE
STATE THROUGH AT LEAST THURSDAY. WINDS ARE EXPECTED TO BE HIGHEST
THIS AFTERNOON AND THURSDAY AFTERNOONS OWING TO WEAK DISTURBANCES
GRAZING NORTHERN UTAH THAT WILL ENHANCE THIS SOUTHWEST FLOW. EVEN
ON TUESDAY AND WEDNESDAY AFTERNOONS, WINDS WILL REMAIN ELEVATED
ABOVE CRITICAL ACROSS ALL BUT NORTHWESTERN UTAH. VERY LOW AFTERNOON
RH WILL CONTINUE THROUGH AT LEAST THURSDAY STATEWIDE, ALBEIT
INCREASING SLIGHTLY TO AS HIGH AS 15-20% ACROSS ISOLATED AREAS OF
THE SOUTHERN MOUNTAINS ON WEDNESDAY. THIS LOW RH COMBINED WITH
THE AFOREMENTIONED WINDS WILL PRODUCE CRITICAL FIRE WEATHER
CONDITIONS ACROSS MUCH OF THE STATE THROUGH AT LEAST THURSDAY,
DESPITE THIS SLIGHT INCREASE IN MOISTURE MID-WEEK. THIS INCREASE
WILL ALSO HELP OVERNIGHT RECOVERIES IMPROVE SLIGHTLY ACROSS MAINLY
THE SOUTHERN MOUNTAINS, SOUTHERN 495, AND WESTERN 498. BY FRIDAY,
FORECAST UNCERTAINTY INCREASES WITH THE POTENTIAL OF A DRY COLD
FRONT CROSSING THE REGION LATE FRIDAY OR SATURDAY. WINDS WILL
LIKELY WEAKEN BEHIND THIS SYSTEM.
SLC WATCHES/WARNINGS/ADVISORIES
UT...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR UTZ478-479.
RED FLAG WARNING UNTIL 9 PM MDT THURSDAY FOR UTZ481>484-488-489-
492>498.
WY...RED FLAG WARNING UNTIL 8 PM MDT FRIDAY FOR WYZ277.
CUNNINGHAM/WILSON/KRUSE
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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