948
FXUS65 KSLC 130415
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1015 PM MDT SUN APR 12 2026
KEY MESSAGES
- A COOL SPRING SYSTEM WILL CONTINUE TO MOVE THROUGH THE AREA AND
BRING PERIODS OF VALLEY RAIN AND ACCUMULATING MOUNTAIN SNOW
THROUGH TUESDAY. THE HIGHEST CHANCE OF IMPACTFUL ACCUMULATIONS
IS NOTED IN THE SOUTHERN AND CENTRAL MOUNTAINS, WITH THE HIGHEST
RATES EXPECTED SUNDAY AND MONDAY NIGHT.
- A COLDER SYSTEM IS EXPECTED TO IMPACT THE AREA ROUGHLY THURSDAY
INTO EARLY SATURDAY. IT IS ANTICIPATED TO BRING ADDITIONAL
MOUNTAIN SNOW ACCUMULATIONS, AND POTENTIAL FOR LOW ELEVATION
SNOW FOLLOWING PASSAGE OF AN ASSOCIATED COLD FRONT.
- THERE IS APPROXIMATELY A 50-70% CHANCE OF FREEZING TEMPERATURES
ALONG UTAH'S URBAN CORRIDOR THURSDAY NIGHT AND FRIDAY NIGHT,
AND A GREATER THAN 80% CHANCE OF FREEZING TEMPERATURES ELSEWHERE
(EXCLUDING LOWER WASHINGTON COUNTY/LOWER ZION).
DISCUSSION
EVENING SATELLITE MID LEVEL WATER VAPOR LOOP SHOWS THE
CORE OF A BROAD PACIFIC TROUGH SHIFTING EASTWARD INTO NEVADA.
SURFACE OBSERVATIONS SHOW AN ASSOCIATED COLD FRONTAL BOUNDARY
CONTINUING TO GRADUALLY ADVANCE SOUTHEASTWARD THROUGH UTAH, WITH
SCATTERED SHOWERS NOTED BOTH AHEAD AND BEHIND THE FRONT. GUSTY
SOUTHWESTERLY WINDS AHEAD OF THE FRONT WILL CONTINUE TO DECREASE,
AND FURTHER TAPER OFF AND SHIFT NORTHWESTERLY IN THE HOURS
FOLLOWING FRONTAL PASSAGE.
IN TERMS OF THE FORECAST WITH THIS SYSTEM, THINGS LARGELY REMAIN
ON TRACK. THE COOLER AIR WILL RESULT IN SNOW LEVELS GRADUALLY
DROPPING DOWN TO AROUND 6000-6500 FEET BY MONDAY MORNING, AND
BRING BELOW NORMAL TEMPERATURES BACK INTO THE REGION. PERIODS OF
VALLEY RAIN AND MOUNTAIN SNOW SHOWERS WILL PERSIST THROUGH TUESDAY
AS THE TROUGH TRACKS EAST, WITH TIMING AND LOCATION OF HIGHER
PRECIPITATION RATES ASSOCIATED WITH WHEN/WHERE EXACTLY SHORTWAVE
IMPULSES EMBEDDED WITHIN THE BROADER (AND SOMEWHAT MESSY)
CIRCULATION OF THE TROUGH PIVOT. MODELS HAVE CONTINUED TRENDING TO
A SLIGHTLY MORE SOUTHERLY TRACK, WITH FORCING AND WATER/SNOW
AMOUNTS ACCORDINGLY FAVORING SOUTHERN TO CENTRAL UTAH. GIVEN THE
SLOW MOVEMENT OF THE TROUGH, FURTHER LOCALLY HIGHER AMOUNTS WILL
BE POSSIBLE IN ANY DEFORMATION AXIS NEAR THE SYSTEMS CORE, THOUGH
PINPOINTING WHERE SUCH AN AXIS SETS UP IS A BIT NEBULOUS.
CURRENTLY, FAVORED TIMING FOR THESE HIGHER RATE PERIODS IN
SOUTHERN TO CENTRAL UTAH SEEM TO BE SUNDAY NIGHT, AND ESPECIALLY
MONDAY NIGHT INTO TUESDAY MORNING. FOR NORTHERN MOUNTAINS, LATEST
FORECAST NOW ONLY CARRIES A BROAD 2-6" OF SNOW. EVEN FOR FAVORED
AREAS SUCH AS THE UPPER COTTONWOODS THE PROBABILITY OF EXCEEDING
6" HAS DROPPED DRAMATICALLY TO AROUND 20-30%, THOUGH SUSPECT ANY
MORE CONVECTIVELY ENHANCED SHOWERS DURING THE DAY COULD RESULT IN
BRIEFLY HIGHER RATES. ACROSS THE SOUTHERN AND CENTRAL MOUNTAINS,
FORECAST TOTALS HAVE TRENDED UPWARD, WITH NOW A GENERAL 3-8" OF
SNOW ACCUMULATION. THESE AMOUNTS ARE LOCALLY HIGHER ESPECIALLY IN
AREAS OF THE TUSHARS, BRIAN HEAD AREA MOUNTAINS, AND TO A LESSER
EXTENT THE MANTI-LA SAL SKYLINE. IN THESE LOCATIONS, THERE IS
AROUND A 40-60% CHANCE OF ACCUMULATIONS IN EXCESS OF 12",
ESPECIALLY IN THE TUSHARS. WHILE LONGER DURATION AND SPORADIC IN
NATURE, THE POTENTIAL FOR HIGHER RATE PERIODS ALONG WITH THE
OVERALL TRENDS SEEMS WORTHY OF WINTER WEATHER ADVISORY HEADLINES.
IN TERMS OF IMPACTS, THIS IS FURTHERED GIVEN THE LATER SEASONAL
ASPECT TO THE SYSTEM, AND THE INFREQUENCY OF SNOW ACROSS THE
SOUTHERN HALF OF UTAH THIS SEASON. GIVEN THE SNOW LEVELS,
ANTICIPATE MOST TRAVEL IMPACTS TO LARGELY BE CONFINED TO HIGHER
MOUNTAIN AND SEASONAL ROUTES THAT ARE OPEN (ESPECIALLY ABOVE 7500
FEET OR SO), AND ESPECIALLY DURING THOSE HIGHER RATE PERIODS.
AFTER A BRIEF LULL, MODELS CONTINUE TO REMAIN IN GOOD AGREEMENT
IN AN EVEN COLDER SYSTEM SWEEPING THROUGH THE REGION ROUGHLY IN
THE THURSDAY TO SATURDAY TIME FRAME. TIMING CURRENTLY FAVORS LATE
THURSDAY FOR THE INITIAL FRONTAL PASSAGE WITH THIS SYSTEM. TO
GIVE AN IDEA OF JUST HOW COLD THE ASSOCIATED AIRMASS IS PROGGED,
700 MB TEMPS AHEAD OF THE FRONT ARE FORECAST AROUND 1C TO 3C,
FALLING QUICKLY TO AROUND -8C TO -12C FOLLOWING FRONTAL PASSAGE.
IN TURN, THE PRESSURE GRADIENT ALONG THE BAROCLINIC ZONE COULD BE
QUITE SHARP, BRINGING A GUSTY FRONTAL PASSAGE ALONG WITH A BROADER
FORCED BAND OF PRECIP. WITHIN THE BROADER POST-FRONTAL CYCLONIC
FLOW, SHOWERY PRECIPITATION WOULD LIKELY CONTINUE INTO LATE FRIDAY
AND TAPER OFF OVERNIGHT INTO THE WEEKEND. AS CURRENTLY FORECAST,
NOT ONLY WOULD THIS SYSTEM BRING ANOTHER ROUND OF ACCUMULATING
MOUNTAIN SNOW, BUT ALSO FAVORABLE ODDS FOR SNOW LEVELS BELOW
VALLEY FLOORS, AND NON-ZERO CHANCES OF LIGHT VALLEY SNOW
ACCUMULATIONS. IN FACT, CURRENT NBM GUIDANCE CARRIES A GREATER
THAN 70% CHANCE FOR 0.1" OR MORE SNOW FOR NORTHERN VALLEYS, AND
EVEN AROUND A 30-50% CHANCE OF 1" OR MORE. GRANTED, THE WARM
GROUND TEMPERATURES WOULD LIKELY DO A NUMBER ON MELTING ANYTHING
OFF THAT DOESN'T COME IN WITH HEAVY RATES.
ASIDE FROM THE SNOW POTENTIAL, THE VERY COLD TEMPERATURES BEHIND
THE FRONT WOULD POSE A THREAT TO EARLY SEASON AGRICULTURE WITH
FREEZING POTENTIAL. AS OF NOW, THERE IS APPROXIMATELY A 50-70%
CHANCE OF FREEZING TEMPERATURES ALONG UTAH'S URBAN CORRIDOR
THURSDAY NIGHT AND FRIDAY NIGHT, AND A GREATER THAN 80% CHANCE OF
FREEZING TEMPERATURES ELSEWHERE (EXCLUDING LOWER WASHINGTON
COUNTY/LOWER ZION).
AVIATION...KSLC
RAIN SHOWERS AND INTERMITTENT MOUNTAIN
OBSCURATION WILL CONTINUE THROUGH THE EVENING, ENDING BY 09-10Z
OR SO. WHILE CONDITIONS THUS FAR HAVE REMAINED VFR, THERE IS
AROUND A 40% CHANCE OF MVFR CIGS/VIS BETWEEN 04-08Z. ADDITIONALLY,
THERE IS LOW CONFIDENCE IN WIND DIRECTION AFTER 02Z WITH THESE
SHOWERS, WITH WINDS BECOMING VARIABLE AT TIMES. SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS MAY REDEVELOP MONDAY AFTERNOON AFTER
~19Z, THOUGH KSLC WILL BE ON THE NORTHERN PERIPHERY OF THESE
SHOWERS.
REST OF UTAH AND SOUTHWEST WYOMING
SOUTHWESTERLY WINDS WILL
CONTINUE TO WEAKEN INTO THE EVENING, PARTICULARLY ACROSS THE
NORTHERN THIRD OF UT AND SW-WY WHERE A DIFFUSE COLD FRONT HAS
ALREADY PUSHED THROUGH. WEAK SHOWERS WILL LIKELY CONTINUE ACROSS
MOSTLY WESTERN AND NORTHERN UT THROUGH THE EVENING, GRADUALLY
DIMINISHING BETWEEN 08-11Z. WITH THESE SHOWERS, THERE IS A 40-50%
CHANCE OF MVFR VIS/CIGS AS WELL AS PERIODS OF VARIABLE WINDS.
WEAK, ISOLATED SHOWERS MAY EVEN LINGER INTO THE EARLY MORNING
ACROSS THE SOUTHERN THIRD OF UT. SCATTERED SHOWERS AND
THUNDERSTORMS WILL REDEVELOP MONDAY AFTERNOON, LARGELY SOUTH OF
I-80.
SLC WATCHES/WARNINGS/ADVISORIES
UT...WINTER WEATHER ADVISORY UNTIL 3 PM MDT TUESDAY FOR UTZ117-125.
WY...NONE.
PUBLIC...WARTHEN
AVIATION...CUNNINGHAM
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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