857
FXUS65 KSLC 121057
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
357 AM MST SUN JAN 12 2025
SYNOPSIS
A COLD AIRMASS WILL REMAIN IN PLACE ACROSS THE REGION
THROUGH AT LEAST MIDWEEK.
SHORT TERM (THROUGH 12Z/5AM TUESDAY)
A COLD NORTHERLY FLOW
PREVAILS ACROSS THE FORECAST EARLY THIS MORNING, AND WILL REMAIN
IN PLACE THROUGH THE SHORT TERM PERIOD. A SUBTLE WAVE IS NOTED IN
WV/IR IMAGERY DROPPING SOUTH ACROSS NORTHERN UTAH, AND WITH LOW
STATIC STABILITY OWING TO -30C 500MB TEMPS, IS RESPONDING FAIRLY
WELL GENERATING BURSTS OF MODERATE TO HEAVY SNOWFALL. THIS IS
BEING AIDED BY THE RELATIVELY WARM WATERS OF THE GSL AND -10C
TEMPS AT 700MB, RESULTING IN SUFFICIENT LOW LEVEL INSTABILITY TO
SUPPORT LAKE ENHANCEMENT. PICKED UP A QUICK 2" OF LOW DENSITY SNOW
AS ONE OF THESE BANDS PASSED OVER THE OFFICE EARLIER. EXPECT THIS
WINDOW TO PERSIST THROUGH ABOUT SUNRISE AS THE AFOREMENTIONED
WAVE CONTINUES TO SLOWLY TRANSLATE SOUTHWARD INTO CENTRAL UTAH.
WITH COLD TEMPERATURES ALOFT REMAINING IN PLACE, SCATTERED SNOW
SHOWERS WILL REMAIN POSSIBLE OVER THE HIGHER TERRAIN THROUGH THE
DAY TODAY. AFTERNOON TEMPS WILL ONLY REACH THE LOW-MID 30S ACROSS
MOST WESTERN VALLEYS FROM THE WASATCH FRONT TO CEDAR CITY...A GOOD
5F BELOW CLIMO FOR THE NORTH AND 10F BELOW CLIMO ACROSS THE
SOUTH. THIS COLD AIRMASS WILL REMAIN IN PLACE THROUGH MONDAY WITH
SIMILAR DAYTIME TEMPERATURES.
LONG TERM (AFTER 12Z/5AM TUESDAY)
A REX BLOCK WILL BE IN PLACE
MUCH OF THE WEEK. THIS PATTERN WILL BE AS A RIDGE OFF THE PACIFIC
COAST IS POSITIONED NORTH OF A CLOSED LOW OFF THE CALIFORNIA AND
BAJA CALIFORNIA COASTS. SOUTHWEST WYOMING AND UTAH WILL BE DRY FROM
TUESDAY THROUGH LATER IN THE WEEK OR THE WEEKEND UNTIL A SYNOPTIC
CHANGE EITHER BREAKS DOWN THAT BLOCKING PATTERN OR PUSHES IT MORE
WEST. TEMPERATURES WILL WARM SLIGHTLY THROUGH THE WEEK, BUT BUILDING
VALLEY INVERSIONS ARE LIKELY WITH LIMITED MIXING.
ENSEMBLES ARE IN GOOD AGREEMENT ON THE REX BLOCK RETROGRADING
SLIGHTLY THROUGH LATER IN THE WEEK. THAT COULD ALLOW FOR TROUGHS TO
TRACK DOWN THE EASTERN PERIPHERY OF THE AFOREMENTIONED RIDGE. THERE
IS GENERAL AGREEMENT ON THAT, BUT DIFFERENCES IN TIMING AND TRACK OF
A TROUGH LATE IN THE WEEK INTO THE WEEKEND.
THE MAIN STORM TRACKS REPRESENTED BY ENSEMBLE MEMBERS ARE ONE WHERE
THE TROUGH DIGS NEAR AND ALONG THE EASTERN EDGE OF THE ROCKY
MOUNTAINS AND WHERE THE TROUGH DIG FURTHER WEST, WHICH WOULD BRING
COLDER CONDITIONS AND LIKELY MORE SNOW TO SOUTHWEST WYOMING AND
UTAH. THE EASTERN TRACK IS REPRESENTED BY MOST GEFS MEMBERS, WHILE
MOST EPS AND CANADIAN MEMBERS BRING THE TROUGH FURTHER WEST.
CONFIDENCE IS LOW ON TIMING, WITH A RANGE FROM FRIDAY TO SATURDAY.
CONFIDENCE WILL INCREASE WITH MORE CONFIDENCE ON THE POSITION OF THE
REX BLOCK AROUND THEN.
AVIATION...KSLC
THERE IS AROUND A 20% CHANCE FOR SNOW SHOWERS
CAPABLE OF MVFR CONDITIONS THROUGH THE MORNING. DRY CONDITIONS ARE
LIKELY THROUGH THE AFTERNOON. CLOUDS WILL DIMINISH THROUGH THE
AFTERNOON, WITH MOSTLY CLEAR CONDITIONS BY AROUND 03Z. LIGHT
NORTHWEST WINDS WILL PREVAIL THROUGH AROUND 05Z.
REST OF UTAH AND SOUTHWEST WYOMING
ISOLATED TO SCATTERED SNOW
SHOWERS PRIMARILY SOUTH OF I-80 WILL TAPER OFF FROM NORTH TO SOUTH
THROUGH THE DAY. SNOW SHOWERS WILL BE CAPABLE OF MVFR OR IFR
CONDITIONS. WINDS WILL PREVAIL FROM THE NORTHWEST TO NORTHEAST
THROUGHOUT, WITH GUSTS AROUND 20 KNOTS FOR MUCH OF SOUTHERN UTAH.
SLC WATCHES/WARNINGS/ADVISORIES
UT...NONE.
WY...NONE.
SEAMAN/WILSON
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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