597
FXUS65 KSLC 221122 CCA
AFDSLC
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
522 AM MDT FRI AUG 22 2025
SYNOPSIS
WITH HIGH PRESSURE CENTERED OVER THE FOUR CORNERS,
MONSOON MOISTURE WILL GRADUALLY SPREAD NORTHWARD INTO UTAH AND
SOUTHWEST WYOMING THROUGH EARLY NEXT WEEK. THIS WILL BRING
INCREASED COVERAGE OF SHOWERS AND THUNDERSTORMS, THE POTENTIAL FOR
FLASH FLOODING, AND GRADUALLY LESS HOT TEMPERATURES.
SHORT TERM (THROUGH 12Z/6AM SUNDAY)
HIGH PRESSURE IS PARKED
OVER THE FOUR CORNERS THIS MORNING, AS IT WILL BE FOR THE NEXT
SEVERAL DAYS. THE RESULTANT SOUTHERLY FLOW IS BRINGING DEEP
MONSOONAL MOISTURE STEADILY NORTHWARD, WITH SATELLITE DERIVED PW
VALUES CURRENTLY IN THE 0.8 TO 1.0 INCH RANGE OVER MUCH OF UTAH
AND SOUTHWEST WYOMING, AND A BIT HIGHER OVER FAR SOUTHERN UTAH.
SEEING SOME SHOWER ACTIVITY CONTINUE INTO THE OVERNIGHT HOURS OVER
NORTHEASTERN UTAH IN ASSOCIATION WITH A PASSING WEAK SHORTWAVE.
THESE SHOWERS WILL REMAIN LIGHT THROUGH MUCH OF THE REMAINDER OF
THE MORNING.
IN THE MOIST AIRMASS, WILL SEE ADDITIONAL CONVECTIVE DEVELOPMENT
THIS AFTERNOON, PRIMARILY FOCUSED OVER THE HIGHER TERRAIN,
PARTICULARLY OVER CENTRAL AND SOUTHERN UTAH, WITH A BIT OF VALLEY
DRIFT. THERE WILL BE A BETTER CHANCE OF WETTING RAINS TODAY BUT
THE MOISTURE, PARTICULARLY OVER NORTHERN PORTIONS OF THE FORECAST
AREA, WILL BE MORE IN THE MID TO UPPER LEVELS, WITH GUSTY AND
ERRATIC WINDS THE MAIN THREAT WITH ANY STORMS THAT DEVELOP.
TEMPERATURES WILL REMAIN ON THE HOT SIDE FOR THIS TIME OF YEAR,
WITH HIGHS EXPECTED TO RUN UP TO 5F ABOVE SEASONAL NORMALS.
THE INCREASE IN MOISTURE WILL SLOW A BIT TOMORROW AS THE CENTER OF
THE LOW SLIDES A BIT WEST, RESULTING IN LIGHT FLOW OVER THE
FORECAST AREA. STILL, THE EXISTING MOISTURE WILL BE MORE THAN
ENOUGH FOR ADDITIONAL CONVECTION, PARTICULARLY FOR SOUTHERN UTAH.
LONG TERM (AFTER 12Z/6AM SUNDAY)
MONSOONAL MOISTURE IS EXPECTED
TO BECOME ESPECIALLY PRONOUNCED ACROSS THE ENTIRETY OF UTAH AND
SOUTHWEST WYOMING ON SUNDAY INTO EARLY NEXT WEEK, WITH PWAT
ANOMALIES PUSHING 150-200% OF NORMAL AREAWIDE. AS SUCH, EXPECT
WIDESPREAD COVERAGE OF SHOWERS AND THUNDERSTORMS EACH DAY, WITH THIS
AMOUNT OF MOISTURE IN THE COLUMN FAVORABLE FOR LOCALLY HEAVY
RAINFALL UNDER STRONGER CORES. THE WEATHER PREDICTION CENTER
CONTINUES TO CARRY A MARGINAL RISK (LEVEL 1 OF 4) FOR EXCESSIVE
RAINFALL ACROSS THE ENTIRE FORECAST AREA THROUGH AT LEAST TUESDAY.
THOSE WITH OUTDOOR PLANS SHOULD CONTINUE TO MONITOR THE FORECAST
GIVEN THE ASSOCIATED RISK FOR FLASH FLOODING. LOCATIONS WITH
GREATEST THREATS FOR FLASH FLOODING INCLUDE SLOT CANYONS, NORMALLY
DRY WASHES, SLICKROCK AREAS, RECENT BURN SCARS, AND URBAN AREAS.
WHILE MOISTURE AVAILABILITY WILL BE PLENTIFUL, THE ONE FACTOR THAT
COULD IMPACT AFTERNOON CONVECTIVE DEVELOPMENT AND EVOLUTION INCLUDES
THE POTENTIAL FOR NOCTURNAL CONVECTION. IF ANY NOCTURNAL CONVECTION
OCCURS AND SKIES REMAIN SUFFICIENTLY CLOUDY, WE COULD SEE MORE
STABLE ATMOSPHERIC CONDITIONS DEVELOP. THIS WOULD INHIBIT THE
DEVELOPMENT OF CONVECTION INTO THE AFTERNOON, INSTEAD FAVORING A
MORE STRATIFORM PRECIP REGIME. WILL BE SOMETHING TO MONITOR AS WE
GET CLOSER.
IN ADDITION TO WIDESPREAD PRECIPITATION, THIS PATTERN WILL BRING A
MUCH-NEEDED GRADUAL COOLING TREND THROUGHOUT THE LONG TERM PERIOD.
TEMPERATURES BEGIN NEAR-AVERAGE ON SUNDAY, DROPPING TO AROUND 5-10F
BELOW SEASONAL AVERAGES BY THE END OF THE WEEK.
AVIATION...KSLC
VFR CONDITIONS TO PERSIST AT KSLC THROUGH THE
PERIOD. AFTERNOON SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
AFTER 18Z, WITH A ROUGHLY 30% CHANCE TO IMPACT THE TERMINAL THROUGH
AROUND 22Z. ANY STORMS THAT DEVELOP WILL BE POSSIBLE OF PRODUCING
GUSTY AND ERRATIC WINDS DURING THIS PERIOD. OTHERWISE, EXPECT WINDS
TO REMAIN GENERALLY LIGHT AND DIURNALLY DRIVEN.
REST OF UTAH AND SOUTHWEST WYOMING
VFR CONDITIONS TO CONTINUE FOR
ALL REGIONAL TERMINALS THROUGH THE PERIOD. WINDS REMAIN GENERALLY
LIGHT AND DIURNALLY DRIVEN. AFTERNOON SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP AGAIN TODAY, WITH GREATEST COVERAGE GENERALLY
SOUTH OF THE I-80 CORRIDOR. STORMS WILL BE CAPABLE OF PRODUCING
GUSTY AND ERRATIC OUTFLOW WINDS THROUGH THIS EVENING.
FIRE WEATHER
THE STATE WILL STAY UNDER SOUTHERLY FLOW OVER THE
NEXT SEVERAL DAYS AS HIGH PRESSURE PARKS ITSELF OVER THE FOUR
CORNERS REGION. THIS WILL ACT TO DRAW MONSOONAL MOISTURE
NORTHWARD. THE INCREASE WILL BE GRADUAL AT FIRST, WITH A MORE
PRONOUNCED SURGE LATE IN THE WEEKEND. THIS WILL BRING INCREASING
RELATIVE HUMIDITY VALUES, DECREASING TEMPERATURES, AND INCREASED
COVERAGE OF SHOWERS AND THUNDERSTORMS. THE MOISTURE WILL INITIALLY
BE HIGH BASED, WITH GUSTY AND ERRATIC WINDS REMAINING THE MAIN
THREAT TODAY BEFORE WETTING RAINS BECOME MORE LIKELY THIS WEEKEND.
MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE MOISTURE WILL PEAK
BY THE MIDDLE OF NEXT WEEK.
SLC WATCHES/WARNINGS/ADVISORIES
UT...EXTREME HEAT WARNING UNTIL 9 PM MDT THIS EVENING FOR UTZ123-124.
WY...NONE.
SHORT TERM/FIRE WEATHER...TRAPHAGAN
LONG TERM/AVIATION...WHITLAM
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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