450
FXUS65 KSLC 112157
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
357 PM MDT THU SEP 11 2025
SYNOPSIS
A SLOW MOVING TROUGH SITS WEST OF THE FORECAST AREA
AND WILL DRIVE CONTINUED BUT SPATIALLY LIMITED THUNDERSTORM
POTENTIAL ALONG THE PERIPHERY OF THE FORECAST AREA THROUGH
SATURDAY. BRIEF RIDGING SUNDAY-MONDAY GIVES WAY TO A HIGHER
UNCERTAINTY AND POTENTIALLY ACTIVE PERIOD BY MID NEXT WEEK.
DISCUSSION
RESIDUAL CONVECTION ACROSS EASTERN UTAH AND
SOUTHWEST WYOMING THIS AFTERNOON IS EXPECTED TO DISSIPATE QUICKLY
AFTER SUNSET AS POOR UPPER LEVEL FORCING IS UNABLE TO SUPPORT THE
THERMALLY DRIVEN CONVECTION. WHILE THE TROUGH'S EASTWARD
PROGRESSION REMAINS SLOW AND SITS UPSTREAM OF THE AREA FRIDAY, A
DRY SLOT OVERHEAD IS EXPECTED TO COUNTER ANY IMPROVEMENT IN
UPPER-LEVEL FORCING AND KEEP CONVECTIVE DEVELOPMENT LIMITED TO
PORTIONS OF BOX ELDER COUNTY AND EASTERN UTAH ALONG THE GREEN
RIVER. PROBABILITIES FOR LOW RH WITH GUSTY WINDS DROP OFF
SIGNIFICANTLY STATEWIDE, WITH PORTIONS OF WESTERN UTAH TOPPING OUT
AT < 25% CHANCE OF MEETING CRITICAL FIRE WEATHER CRITERIA.
ENSEMBLES ARE IN FAIRLY GOOD AGREEMENT WITH THE OVERALL EVOLUTION
OF THE PATTERN THROUGH THE WEEKEND, WITH THE TROUGH AXIS SHIFTING
OVERHEAD SATURDAY MORNING AND BRINGING WITH IT A FEW DEGREES OF
COOLING ACROSS THE AREA. A FAIR AMOUNT OF UNCERTAINTY REMAINS AS
FAR AS CONVECTIVE DEVELOPMENT ON SATURDAY, WITH THE COLDER UPPER
LEVEL AIR HELPING TO DESTABILIZE THE ENVIRONMENT, WHILE SYNOPTIC-
SCALE LIFT BEGINS TO DROP OFF. NBM PROBABILITIES WEST OF UTAH'S
CENTRAL MOUNTAIN SPINE CURRENTLY RANGE FROM 0-20% FOR > 0.10",
WHILE SOUTHWEST WYOMING, THE UINTAS, AND THE EASTERN VALLEYS SIT
AROUND 25-50% CHANCES. CONDITIONS ULTIMATELY DRY OUT OVERNIGHT AS
WE MOVE INTO SUNDAY STATEWIDE.
WHILE THE MODELS INDICATE ANOTHER SYSTEM MOVING THROUGH THE
REGION EARLY NEXT WEEK, SIGNIFICANT DIFFERENCES EXIST IN THE DEPTH
AND TIMING OF THE FEATURE. MOST KEEP MONDAY DRY AND HIGHLIGHT
TUESDAY-WEDNESDAY AS THE MOST LIKELY FOR ACTIVE AND WET WEATHER.
HOWEVER, TOTAL AMOUNTS LOOK GENERALLY UNIMPACTFUL, EVEN ON THE
HIGHER END OF THE POTENTIAL OUTCOMES. THIS WILL HOWEVER USHER IN
SOME OF THE COOLEST AIR WE'VE SEEN IN QUITE SOME TIME, AND THE
VERY HIGHEST ELEVATIONS OF THE UINTAS COULD SEE A DUSTING OF SNOW
IN THE COLDEST AND WETTEST SCENARIOS. STILL, NONE OF THE GLOBAL
ENSEMBLES CARRY H700 TEMPS UNDER 0C JUST YET. ACROSS THE ENSEMBLE
SUITE, THIS APPEARS TO BE A FAST-MOVING TROUGH QUICK TO CLEAR THE
AREA, BUT THE PATTERN REMAINS UNSETTLED AND ACTIVE IN ITS WAKE.
AVIATION...KSLC
GUSTY S WINDS BECOME MORE SW LATER THURSDAY
AFTERNOON, WITH A BRIEF PERIOD OF W TO NW POSSIBLE (~40-60% CHANCE)
BETWEEN AROUND 23Z TO 02Z OR SO. THEREAFTER, LIGHTER S WINDS RETURN
OVERNIGHT THROUGH EARLY FRIDAY AFTERNOON. A LOW CHANCE (~10%) OF A
SHOWER OR THUNDERSTORM NEAR THE TERMINAL IS NOTED THROUGH AROUND 03Z
FRIDAY, WITH CHANCES INCREASING SLIGHTLY (~10-20%) FRIDAY AFTERNOON
THROUGH EARLY EVENING.
REST OF UTAH AND SOUTHWEST WYOMING
DEEP SOUTHWESTERLY FLOW AHEAD
OF AN APPROACHING TROUGH IS RESULTING IN SOUTH TO SOUTHWEST WINDS
LARGELY FAVORED AT AREA TERMINALS, WITH FAIRLY WIDESPREAD GUSTS 20
TO 35 KTS OR SO DURING THE DAY. ISOLATED TO SCATTERED CONVECTION
ALONG/EAST OF UTAH'S HIGH TERRAIN WILL WANE IN STRENGTH AND COVERAGE
THROUGH THE EVENING, AND WIND MAGNITUDES WILL DECREASE. WINDS WILL
INCREASE LATE FRIDAY MORNING (THOUGH LESS THAN THAT OF THURSDAY) AND
FAVOR A SOUTHERLY TO DIURNALLY NORMAL DIRECTION. AFTERNOON
CONVECTION CHANCES INCREASE, WITH MORE WIDESPREAD COVERAGE ONCE
AGAIN DEVELOPING ALONG AND EAST OF UTAH'S HIGH TERRAIN.
FIRE WEATHER
WITH THE TROUGH AXIS STILL UPSTREAM OF THE AREA FRIDAY,
UPPER LEVEL SUPPORT FOR GUSTY WINDS AND THUNDERSTORM DEVELOPMENT
REMAINS IN PLACE. HOWEVER, A NOTABLE DRY SLOT SHIFTS OVER THE
STATE AND WILL LIMIT MOST DEVELOPMENT, WITH THE GREATEST
THUNDERSTORM AND LIGHTING POTENTIAL ALONG THE NORTHWESTERN AND
SOUTHEASTERN CORNERS OF THE STATE WHERE SHEAR IS BETTER BALANCED
WITH STABILITY.
BY SATURDAY, THE TROUGH AXIS IS FINALLY OVERHEAD AND SHIFTING
EAST OF THE AREA, USHERING IN A DAY OF SLIGHTLY COOLER TEMPS AND
LIGHTER WINDS STATEWIDE. CANNOT RULE OUT THUNDERSTORMS FOR FAR
EASTERN UTAH AND THE HIGH UINTAS, WITH THE ENVIRONMENT FAVORING
WEAK AND DISORGANIZED CONVECTION RATHER THAN ANY STRONG OR WELL-
ORGANIZED STORMS. SUNDAY WILL SEE A BRIEF PERIOD OF BUILDING HIGH
PRESSURE AND TEMPERATURES INCREASING ONCE AGAIN.
SLC WATCHES/WARNINGS/ADVISORIES
UT...NONE.
WY...NONE.
WESSLER/WARTHEN
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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