798
FXUS65 KSLC 221009
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
409 AM MDT WED OCT 22 2025
SYNOPSIS
A CLOSED LOW SYSTEM WILL SHIFT INTO THE FORECAST AREA
THROUGHOUT THE DAY TODAY, SPREADING INCREASING CLOUD COVER THROUGH
THE DAYLIGHT HOURS AND INCREASING SHOWER COVERAGE ACROSS CENTRAL
AND SOUTHERN UTAH THROUGH THE OVERNIGHT HOURS. THIS LOW WILL
DEPART THE REGION ON THURSDAY EVENING, WITH TEMPORARY HIGH
PRESSURE BUILDING INTO THE REGION BEFORE A COLD TROUGH BEGINS
MAKING IMPACTS ACROSS THE NORTHERN AREA LATE IN THE WEEKEND.
SHORT TERM (THROUGH 12Z/6AM FRIDAY)
MORNING SATELLITE IMAGERY
REVEALS CLEAR SKIES ACROSS A MAJORITY OF UTAH AND SOUTHWEST
WYOMING, WITH CLOUD COVER BUILDING NORTHWARD FROM THE MOJAVE
REGION. CLOUD COVER WILL INCREASE ACROSS THE FORECAST AREA
THROUGHOUT THE DAY AS A CLOSED LOW MOVES INLAND AND SPREADS MID-
LEVEL MOISTURE ACROSS UTAH AND SOUTHWEST WYOMING, APPROACHING
SOUTHERN UTAH BY THE EVENING HOURS. LOWER-LEVEL MOISTURE WILL
INCREASE AS THE CENTER OF THE LOW CREEPS CLOSER TO UTAH, ALLOWING
FOR ANY HIGH-BASED SHOWERS TO BEGIN GENERATING PRECIPITATION AT
THE SURFACE. WHILE GENERALLY ISOLATED AT FIRST, SHOWERS WILL
BECOME MORE SCATTERED IN COVERAGE DURING THE LATE EVENING AND
OVERNIGHT HOURS. ADDITIONALLY, A FEW SHOWERS MAY DEVELOP INTO
ISOLATED THUNDERSTORMS AS THE MID- LEVEL CENTER OF ROTATION MOVES
OVERHEAD FROM EARLY THURSDAY MORNING THROUGH THURSDAY EVENING,
DESTABILIZING THE ENVIRONMENT.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE ANTICIPATED
ACROSS THE SOUTHERN HALF OF UTAH THROUGH MUCH OF THE MORNING AND
AFTERNOON HOURS ON THURSDAY. A FEW ISOLATED LIGHT SHOWERS MAY PUSH
INTO THE SOUTHERN WASATCH AND UINTA BASIN DURING THE MORNING AND
EARLY AFTERNOON HOURS. WHILE NOT A VERY PROBABLE SITUATION,
MODERATE TO HEAVY RAINFALL UNDER ISOLATED THUNDERSTORMS WILL CARRY
A NON- ZERO CHANCE OF PRODUCING FLASH FLOODING FOR NORMALLY PRONE
AREAS (I.E. SLOT CANYONS, DRY WASHES, BURN SCARS, ETC.).
ASIDE FROM THE RAIN, COOLER TEMPERATURES IN THE CORE OF THE LOW
WILL SPREAD OVER THE REGION AND HELP TO BRING COOLER TEMPERATURES
TO THE REGION, MOST NOTABLY ACROSS CENTRAL AND SOUTHERN UTAH.
THE CENTER OF THE LOW DEPARTS THE REGION THROUGH THURSDAY EVENING,
ALLOWING HIGH PRESSURE TO BUILD INTO UTAH AND SOUTHWEST WYOMING
THROUGH THE OVERNIGHT HOURS INTO FRIDAY. AS THIS RIDGE OF HIGH
PRESSURE BUILDS, ANTICIPATE CONDITIONS TO STABILIZE QUITE RAPIDLY.
THAT SAID, A FEW STRAGGLING SHOWERS MAY CONTINUE IN THE HIGHER
TERRAIN OF CENTRAL UTAH BUT WILL BRING LITTLE, IF ANY, IMPACT.
LONG TERM (AFTER 12Z/6AM FRIDAY)
GUIDANCE HAS TRENDED LOWER ON QPF
TOTALS WITH THE UPCOMING STORM AS THE MAJORITY OF GUIDANCE NOW
FAVORS A SLIGHTLY MORE NORTHERLY TRACK THAT WOULD KEEP THE HEAVIEST
PRECIPITATION UP INTO IDAHO. REGARDLESS, THE STORM IS STILL ON TRACK
TO BRING VALLEY RAIN AND MOUNTAIN SNOW TO THE NORTHERN PORTIONS OF
THE CWA ALONG WITH MUCH COOLER AIR (~10F BELOW NORMAL) FOR THE
ENTIRE ZONE STARTING EARLY SUNDAY MORNING.
ADDITIONALLY, THE TRAILING SHORTWAVE THAT LOOKED TO BRING ANOTHER
ROUND OF WIDESPREAD PRECIPITATION TO NORTHERN UTAH/SW WYOMING ON
MONDAY HAS ALSO TRENDED FURTHER NORTH INTO IDAHO. OVERALL, THIS HAS
RESULTED IN STORM TOTAL QPF BEING CUT ROUGHLY IN HALF AS 67% OF
ENSEMBLE MEMBERS NOW FAVOR A MORE NORTHERLY STORM TRACK. MEAN QPF
TOTALS FOR NORTHERN UTAH VALLEYS, PRIMARILY NORTH OF UTAH COUNTY,
ARE BETWEEN 0.25" CLOSER TO SALT LAKE AND TOOELE VALLEYS TO UPWARDS
OF 0.5" ACROSS THE NORTHERN WASATCH AND CACHE VALLEY. MEAN QPF IN
THE NORTHERN MOUNTAINS RANGES FROM 0.50"-1.00" WITH LOW SNOW RATIOS
RESULTING IN SNOW TOTALS ROUGHLY BETWEEN 1-4", AND HIGHER ACROSS THE
BEAR RIVER MOUNTAINS (3-6"). WITH THE MORE NORTHERLY TRACK, H7
TEMPERATURES WILL BE A COUPLE DEGREES WARMER THAN PREVIOUS FORECASTS
IN ADDITION TO MORE WESTERLY FLOW ALOFT. THIS WOULD FAVOR
OROGRAPHICS AND LAKE ENHANCEMENT EAST OF THE GSL, RATHER THAN
SOUTHEAST OF THE GSL, ON MONDAY.
A RIDGE QUICKLY STARTS TO BUILD INTO THE AREA BY TUESDAY AS DRIER
AIR FILTERS IN AND TEMPERATURES RISING CLOSER TO NORMAL BY MIDWEEK.
AVIATION...KSLC
VFR CONDITIONS WILL PERSIST FOR THE KSLC TERMINAL
THROUGH THE PERIOD. DRY CONDITIONS WILL CONTINUE THROUGH MOST OF THE
DAY WITH INCREASING MID LEVEL CLOUDS DURING THE DAY AS A WEAK STORM
CROSSES CENTRAL UTAH. LIGHT SOUTHERLY WINDS WILL TRANSITION TO LIGHT
NORTHERLY WINDS DURING THE DAY.
REST OF UTAH AND SOUTHWEST WYOMING
VFR CONDITIONS WILL PERSIST
FOR THE ENTIRE AIRSPACE THROUGH THE PERIOD. A WEAK STORM WILL BRING
SCATTERED SHOWERS WITH ISOLATED THUNDER INTO THE SOUTHERN AIRSPACE
DURING THE DAY WHILE GRADUALLY SPREADING FURTHER NORTH THROUGH THE
DAY, MISSING THE FAR NORTHERN AIRSPACE. OVERALL, CIGS WILL REMAIN
>8KFT WITH LIGHT RAINFALL RATES. WINDS WILL BE LIGHT AND VARIABLE
ACROSS THE AREA.
SLC WATCHES/WARNINGS/ADVISORIES
UT...NONE.
WY...NONE.
SHORT TERM...WEBBER
LONG TERM/ AVIATION...MAHAN
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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