019
FXUS65 KSLC 050958
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
258 AM MST MON JAN 5 2026
KEY MESSAGES
- VALLEY RAIN AND MOUNTAIN SNOW WILL PERSIST THROUGH THIS MORNING
BEFORE QUICKLY TAPERING OFF THIS AFTERNOON. HEAVY MOUNTAIN
SNOWFALL WILL RESULT IN TRAVEL IMPACTS ALONG MOUNTAIN ROUTES
THIS MORNING.
- A COLDER STORM SYSTEM WILL IMPACT THE AREA LATE WEDNESDAY INTO
EARLY FRIDAY, BRINGING THE POTENTIAL FOR ACCUMULATING SNOW TO
THE NORTHERN VALLEYS, AS WELL AS SIGNIFICANT MOUNTAIN SNOW
ACCUMULATIONS.
- HIGH PRESSURE WILL LIKELY RESULT IN VALLEY INVERSIONS BECOMING
ESTABLISHED THIS WEEKEND, AND REMAINING IN PLACE THROUGH MUCH OF
NEXT WEEK.
DISCUSSION
A SHORTWAVE TROUGH EMBEDDED WITHIN A MILD
SOUTHWESTERLY FLOW ALOFT IS CURRENTLY LIFTING THROUGH THE GREAT
BASIN, AND WILL CROSS THE FORECAST AREA THIS MORNING. AHEAD OF
THIS TROUGH, MODEST LARGE SCALE ASCENT COUPLED WITH OROGRAPHIC
FORCING CONTINUES TO RESULT IN VALLEY RAIN AND HIGH ELEVATION
SNOW ACROSS THE MOUNTAINS OF NORTHERN UTAH WITH SNOW LEVELS
GENERALLY AROUND 7000 FEET. SWE RATES ARE EXCEEDING .20"/HOUR AT
TIMES, AND CONVECTIVE ELEMENTS WITHIN THIS PRECIPITATION ARE
RESULTING IN GRAUPEL MIXING IN OR AT TIMES FALLING AS THE
PREDOMINANT PRECIP TYPE BASED ON WEB CAMS AROUND NORTHERN UTAH.
THE LOW-MID LEVEL TROUGH AXIS AND ASSOCIATED COLD FRONT ARE NOTED
LIFTING INTO FAR NORTHWEST UTAH AS OF 09Z, RESULTING IN A BAND OF
HEAVIER PRECIPITATION. THE PASSAGE OF THIS TROUGH AXIS ACROSS
NORTHERN UTAH/SOUTHWEST WYOMING WILL ENHANCE PRECIPITATION RATES
THROUGH MID MORNING, PARTICULARLY ACROSS THE HIGHER TERRAIN. MODEL
GUIDANCE HAS TRENDED FASTER LIFTING THIS TROUGH OUT OF THE AREA BY
EARLY AFTERNOON, WITH AN AMPLIFYING SHORTWAVE RIDGE QUICKLY
BUILDING INTO THE GREAT BASIN. THE RESULTING SUBSIDENCE AND
RELATIVELY UNFAVORABLE WSW FLOW ALOFT WILL RESULT IN PRECIP
QUICKLY TAPERING OFF THIS AFTERNOON ACROSS THE AREA, AND GOING
WINTER WX HEADLINES MAY BE ABLE TO BE CANCELLED EARLY AS THIS
PRECIP WINDS DOWN.
FURTHER SOUTH, AN UPPER JET MAX SPREADING ACROSS SOUTHWEST UTAH
EARLY THIS MORNING IS ALLOWING FOR AN ORGANIZED AREA OF VALLEY
RAIN/MOUNTAIN SNOW. THIS WILL LAST FOR A FEW MORE HOURS, BUT AGAIN
THE MODELS HAVE TRENDED A LITTLE QUICKER MOVING THIS FORCING OUT
OF THE AREA, AND LINGERING PRECIP WILL LIKELY BEGIN TO WIND DOWN
BY MID MORNING.
THE AFOREMENTIONED SHORTWAVE RIDGE WILL BRING A TEMPORARY LULL IN
PRECIPITATION TUESDAY, WITH ONLY A FEW SHOWERS EXPECTED OVER THE
NORTHERN MOUNTAINS. THE AIRMASS WILL REMAIN MILD ACROSS THE
FORECAST AREA TUESDAY, WITH VALLEY TEMPERATURES IN THE MID-UPPER
40S (LOW-MID 50S IN LOWER WASHINGTON COUNTY/ZION CANYON) RUNNING
AROUND 10F ABOVE CLIMO. MODEL GUIDANCE IS TRENDING TOWARD THIS
BREAK BETWEEN STORM SYSTEMS PERSISTING THROUGH MUCH OF WEDNESDAY
AS A MORE ZONAL WESTERLY FLOW OVERSPREADS THE AREA, IN ADVANCE OF
AN APPROACHING UPPER TROUGH. IF THIS TREND CONTINUES TEMPERATURES
WILL LIKELY REMAIN AROUND 10F ABOVE CLIMO, WITH POPS NOT TRENDING
UP SIGNIFICANTLY UNTIL LATE WEDNESDAY OR WEDNESDAY NIGHT AT THE
EARLIEST.
THE CONSENSUS IN MODEL GUIDANCE BRINGS THE NEXT (AND LIKELY LAST
FOR AWHILE) UPPER TROUGH INTO THE GREAT BASIN LATE WEDNESDAY
THROUGH THURSDAY, WITH THE ASSOCIATED COLD FRONT SURGING THROUGH
THE FORECAST AREA WEDNESDAY NIGHT (NORTH) THROUGH EARLY THURSDAY
(SOUTH). MUCH COLDER AIR BEHIND THIS FRONT WILL DROP SNOW LEVELS
TO MOST VALLEY FLOORS EXCLUDING THE ST GEORGE AREA. WHAT IS LESS
CERTAIN IS THE EVOLUTION OF THIS UPPER TROUGH, AND THE RESULTING
EFFECT ON SNOWFALL DISTRIBUTION AND DURATION ACROSS THE FORECAST
AREA. THUS, ALTHOUGH THE POTENTIAL EXISTS FOR THE FIRST
SUBSTANTIAL VALLEY SNOW OF THE WINTER ACROSS MOST VALLEYS
INCLUDING THE WASATCH FRONT, WE'LL NEED TO LIKELY WAIT A LITTLE
LONGER BEFORE HONING IN ON THE DETAILS.
ENSEMBLE GUIDANCE IS IN VERY GOOD AGREEMENT WHICH YIELDS HIGH
CONFIDENCE IN A STRONG MID LEVEL RIDGE BECOMING ESTABLISHED BY
NEXT WEEKEND ACROSS MUCH OF THE WESTERN CONUS, AND PERSISTING
WELL INTO THE FOLLOWING WEEK. THIS WOULD SIGNAL A HIGH LIKELIHOOD
FOR A POTENTIALLY PROLONGED VALLEY INVERSION EVENT, PARTICULARLY
IF APPRECIABLE SNOW DOES OCCUR WITH THE LATE WEEK TROUGH.
AVIATION...KSLC
SOUTHERLY WINDS WILL PERSIST THROUGH AROUND 20Z
BEFORE THE LAKE BREEZE CLOCKS WINDS TO NORTHWESTERLY. OCCASIONAL
GUSTS TO 25KTS MAY PERSIST THROUGH THE MORNING HOURS. SCATTERED RAIN
SHOWERS ARE EXPECTED TO COME TO A HALT AROUND 15Z, KEEPING
CONDITIONS DRY FOR THE REMAINDER OF THE PERIOD. OTHERWISE, VFR
CONDITIONS WITH THE EXCEPTION OF MOUNTAIN OBSCURATIONS WILL PERSIST
THROUGH THE PERIOD.
REST OF UTAH AND SOUTHWEST WYOMING
WIDESPREAD PRECIPITATION AND
ASSOCIATED CLOUD COVER WILL IMPACT ALL SITES THROUGH THE TAF PERIOD.
MOST SITES CAN EXPECT TO SEE MOUNTAIN OBSCURATIONS AT MOST, THOUGH
KEVW AND KHCR WILL SEE PERIODS OF MVFR CIGS TODAY AS A SYSTEM PUSHES
THROUGH. ADDITIONALLY, HIGH RATES OF SNOWFALL MAY RESULT IN BRIEF
PERIODS OF IFR VSBYS AND PERHAPS IFR CEILINGS THROUGH THE MORNING
HOURS. CONDITIONS WILL GRADUALLY IMPROVE ACROSS ALL SITES THROUGH
THE AFTERNOON HOURS.
SLC WATCHES/WARNINGS/ADVISORIES
UT...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR
UTZ110>113.
WINTER WEATHER ADVISORY UNTIL 2 PM MST THIS AFTERNOON FOR
UTZ125.
WY...NONE.
PUBLIC...SEAMAN
AVIATION...WORSTER
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page