118
FXUS65 KSLC 132135
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
335 PM MDT SAT SEP 13 2025
SYNOPSIS
AFTER ANOTHER ACTIVE DAY DUE TO A BROAD SLOW MOVING
SYSTEM, HIGH PRESSURE WILL BRIEFLY RETURN FOR SUNDAY. A GRAZING
SYSTEM WILL THEN QUICKLY SLIDE THROUGH, BRINGING COOLER WEATHER
AND A CHANCE OF LIGHT PRECIPITATION TO AREAS IN THE NORTH.
SHORT TERM (THROUGH 12Z/6AM MONDAY)
A BROAD SLOW MOVING TROUGH IS
CURRENTLY CENTERED MORE OR LESS ATOP THE FORECAST REGION THIS
AFTERNOON AS IT CONTINUES TO SLOWLY TRANSLATE EASTWARD. SYNOPTIC
FORCING FROM THE TROUGH IN COMBINATION WITH ANALYZED PWAT VALUES
AROUND 0.5" TO 0.7" AND SBCAPE 500-1500 J/KG HAVE RESULTED IN THE
DEVELOPMENT OF CONVECTION THROUGH THE MORNING ON INTO THE
AFTERNOON, ESPECIALLY ACROSS EASTERN UTAH. INITIALLY SLOW MOVEMENT
AND GOOD MOISTURE TRANSPORT RESULTED IN SOME NEAR STATIONARY
STORMS, WHICH IN A FEW INSTANCES RESULTED IN RADAR RAINFALL
ESTIMATES UPWARDS OF 2-3". BASED ON RADAR TRENDS, AT LEAST SEEING
WHAT IS LIKELY SOME COLD POOL PROPAGATION HELPING STORMS MOVE
ALONG A BIT MORE NOW. THAT SAID, AS A GOOD REMINDER, EVEN IF A
STORM PRODUCED ABUNDANT RAINFALL SOMEWHERE MANY MILES AWAY, THE
WATER MAY STILL BE WORKING ITS WAY DOWN DRAINAGE... BEST TO
CONTINUE TO AVOID PLACES LIKE TYPICALLY DRY WASHES/LOW WATER
CROSSINGS, SLOT CANYONS, ETC. WHILE RAIN IS EITHER ONGOING OR
FLOOD WATERS COULD STILL BE DRAINING. ALSO SEEING A BIT OF
CONVECTIVE DEVELOPMENT AT SOME AREAS ACROSS NORTHERN UTAH,
PRIMARILY ALONG/EAST OF HIGH TERRAIN, BUT MOST OF THIS ACTIVITY
HAS BEEN FAIRLY PULSEY IN NATURE. EXPECTING THE CESSATION OF
DAYTIME HEATING THROUGH THE EVENING TO RESULT IN
COVERAGE/INTENSITY OF ANY REMAINING SHOWERS AND THUNDERSTORMS TO
DECREASE.
OVERNIGHT INTO SUNDAY THE TROUGH DEPARTS AND GIVES WAY TO A
MODEST SHORTWAVE RIDGE. WITH THE SUBSIDENT EFFECTS OF THE RIDGE,
PRECIPITATION CHANCES WILL BE VERY LIMITED ACROSS THE AREA, AND
AFTERNOON TEMPERATURES WILL INCREASE A A FEW DEGREES OR SO. THIS
RIDGE WILL BE QUITE TRANSIENT IN NATURE THOUGH AND QUICKLY GIVE
WAY TO A SHORTWAVE IMPULSE APPROACHING THE AREA. THIS GRAZING
IMPULSE WILL BEGIN TO SHOVE A COLD FRONT SOUTHWARD OVERNIGHT,
BRINGING SOME LOW END CHANCES (~10-30%) OF SOME LIGHT
PRECIPITATION TO NORTHERN UTAH AND SOUTHWEST WYOMING.
LONG TERM (AFTER 12Z MONDAY), ISSUED 400 AM MDT
A QUINTESSENTIAL FALL PATTERN WILL SET UP DURING THE LONG TERM
PERIOD. A WEAKENING SHORTWAVE TROUGH WILL GRAZE NORTHERN UTAH
MONDAY AND TUESDAY BRINGING A SLIGHT CHANCE FOR PRECIPITATION
ALONG WITH A COOLER AIRMASS. MOISTURE WILL BE LIMITED WITH THIS
WEAKLY FORCED WAVE. ONLY ~30% OF ENSEMBLE MEMBERS HAVE
PRECIPITATION, WHICH IS CONFINED TO THE FAR NORTHERN AND EASTERN
PORTION OF THE CWA. TEMPERATURES WILL BE RUNNING JUST A FEW
DEGREES BELOW NORMAL ON MONDAY AND TUESDAY ACROSS THE NORTH THANKS
TO THIS FRONTAL PASSAGE. THIS AIRMASS DOESN'T PUSH INTO CENTRAL
AND SOUTHERN UTAH WHICH WILL KEEP TEMPERATURES NEAR TO SLIGHTLY
ABOVE NORMAL.
A RIDGE STARTS TO BUILD INTO THE GREAT BASIN REGION BY MIDWEEK.
THIS WILL RESULT IN A WARMING TREND WITH TEMPERATURES NEAR TO
SLIGHTLY ABOVE NORMAL. SOUTHERLY FLOW WILL MAKE A RETURN TOWARDS
THE END OF THE WEEK WHICH WILL ADVECT MOISTURE UP INTO THE AREA.
DIURNAL CONVECTION WILL BE POSSIBLE FRIDAY AND SATURDAY, BUT AN
APPROACHING TROUGH INTO THE PNW COULD BRING SOME ENHANCED LIFT TO
THE AREA AS THE POTENTIAL FOR SOME EJECTING SHORTWAVES OUT AHEAD
OF THE TROUGH COULD BRING SOME ENHANCED LIFT ALLOWING FOR BETTER
COVERAGE IN CONVECTION. ROUGHLY 50% OF ENSEMBLE MEMBERS HAVE
ENOUGH MOISTURE TO RESULT IN MEASURABLE QPF, WHILE THE REMAINING
50% KEEP CONDITIONS ON THE DRIER SIDE.
AVIATION...KSLC
VFR CONDITIONS WILL PERSIST FOR THE KSLC TERMINAL
THROUGH THE PERIOD. MOSTLY DRY CONDITIONS WITH SOME MID LEVEL
CLOUDS AND LIGHT NORTHERLY WILL CONTINUE. SOUTHEAST WINDS MAY MAKE
AN EARLY APPEARANCE AROUND 02Z DUE TO PASSING SHOWERS, WITH ~10%
CHANCE OF AN ISOLATED VICINITY THUNDERSTORM INTO EARLY EVENING.
REST OF UTAH AND SOUTHWEST WYOMING
VFR CONDITIONS WILL PERSIST
FOR THE ENTIRE AIRSPACE THROUGH THE PERIOD. VICINITY STORMS
CURRENTLY IMPACTING NORTHERN TERMINALS AND BCE ARE EXPECTED TO BE
EAST OF THE TERMINALS BY 00Z, POSSIBLY PERSISTING AT LGU AND EVW
INTO EARLY EVENING.
FIRE WEATHER
SLOW MOVING SYSTEM RESPONSIBLE FOR SEVERAL DAYS OF
UNSETTLED WEATHER WILL FINALLY DEPART THE AREA AND GIVE WAY TO A
BRIEF PERIOD OF HIGH PRESSURE SUNDAY. THIS HIGH PRESSURE WILL
PROVIDE DRY CONDITIONS IN ADDITION TO SLIGHT WARMUP. A LOW
PRESSURE SYSTEM, SOMEWHAT GRAZING IN NATURE, WILL THEN BRUSH BY
SUNDAY NIGHT THROUGH MONDAY AND PUSH AN ASSOCIATED COLD FRONTAL
BOUNDARY SOUTHWARD THROUGH UTAH. THIS WILL BRING A SLIGHT CHANCE
OF SOME LIGHT PRECIPITATION TO NORTHERN UTAH, AS WELL AS COOL
TEMPERATURES BACK DOWN A BIT AT AREAS BEHIND THE FRONT. THEREAFTER
INTO THE MIDDLE OF THE WEEK WILL SEE A WARMING AND DRYING TREND,
WITH WIDESPREAD AFTERNOON MINIMUM HUMIDITY VALUES IN THE TEENS.
SLC WATCHES/WARNINGS/ADVISORIES
UT...NONE.
WY...NONE.
SHORT TERM...WARTHEN
LONG TERM...MAHAN
AVIATION...VERZELLA
FIRE WEATHER...WARTHEN
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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