754
FXUS65 KSLC 161043
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
343 AM MST SUN FEB 16 2025
SYNOPSIS
A SERIES OF WEATHER DISTURBANCES WILL MOVE ACROSS
NORTHERN UTAH AND SOUTHWEST WYOMING TODAY THROUGH TUESDAY,
BRINGING PERIODS OF PRECIPITATION, PRIMARILY SNOW. ANOTHER STORM
SYSTEM IS EXPECTED TO FOLLOW LATE IN THE WEEK.
SHORT TERM (THROUGH 00Z WEDNESDAY)
HIGH PRESSURE IS CENTERED
NEAR THE UTAH/NEVADA THIS MORNING, THOUGH IT IS FLATTENING AS A
PACIFIC NORTHWEST TROUGH MOVES ONSHORE. EJECTING SHORTWAVE ENERGY
FROM THIS SYSTEM HAS MOVED INTO NORTHERN NEVADA, MAKING ITS WAY
EAST INTO NORTHERN UTAH, ALONG WITH SOME MOISTURE IN THE WARM
ADVECTION. CLOUDS ARE STARTING TO INCREASE AND SOME LIGHT SHOWERS
WILL FILL IN OVER FAR NORTHERN UTAH DURING THE MORNING,
PARTICULARLY FOR AREAS NEAR THE UTAH/IDAHO BORDER.
THE FIRST DISTURBANCE WILL CROSS NORTHERN UTAH DURING THE
AFTERNOON, ALLOWING VALLEY RAIN AND MOUNTAIN SNOW TO SPREAD ACROSS
THE NORTHERN HALF OF THE FORECAST AREA. THE EXIT OF THIS
DISTURBANCE MAY ALLOW FOR A BRIEF RELATIVE LULL LATE IN THE
EVENING, BUT ANOTHER PIECE OF THE SYSTEM WILL FOLLOW FOR TONIGHT
INTO EARLY MONDAY, WHICH COULD BRING THE HEAVIEST SNOW OF THE
EVENT. THE ASSOCIATED COLD AIR IS EXPECTED TO BRING THE SNOW LEVEL
DOWN TO AT LEAST MOST VALLEY FLOORS MONDAY MORNING. ADDITIONAL
WAVES WILL FOLLOW ALLOWING THE SNOW, GENERALLY LIGHT TO CONTINUE
INTO TUESDAY MORNING, TAPERING OFF DURING THE AFTERNOON.
ACCUMULATIONS WILL BE ENOUGH TO CAUSE TRAVEL DIFFICULTIES FOR THE
MOUNTAINS OF NORTHERN UTAH FOR THE REMAINDER OF THE HOLIDAY
WEEKEND, SO GOING WINTER WEATHER ADVISORY COVERS THIS THREAT WELL.
LONG TERM (AFTER 00Z WEDNESDAY)
A TRANSIENT RIDGE CROSSING
UTAH TUESDAY NIGHT INTO WEDNESDAY MORNING WILL BRING A PERIOD OF
DRY AND STABLE CONDITIONS TO THE AREA. HOWEVER, THIS WILL BE
SHORT- LIVED, AS THE NEXT SHORTWAVE TROUGH WILL IMPACT THE AREA
WEDNESDAY THROUGH AT LEAST THURSDAY. SOME UNCERTAINTY REMAINS IN
PLACE REGARDING THE TIMING AND EVOLUTION OF THIS STORM, WITH
SOLUTIONS VARYING REGARDING WHETHER THE TROUGH PINCHES INTO A
CLOSED LOW BEFORE REACHING UTAH AS WELL AS THE EXTENT TO WHICH IT
CARVES BACK INTO THE DESERT SOUTHWEST. BASED ON CLUSTER ANALYSIS
OF GLOBAL ENSEMBLES, 37% OF MEMBERS FAVOR A LESS CARVED-OUT
SOLUTION. NEVERTHELESS, THERE IS GOOD MODEL AGREEMENT THAT AT
LEAST NORTHERN AND CENTRAL UTAH WILL SEE A PERIOD OF PRECIPITATION
BY LATE WEDNESDAY AFTERNOON AND CONTINUING THROUGH AT LEAST
THURSDAY AFTERNOON.
WARM ADVECTION AT H7 TAKING PLACE ON WEDNESDAY ACROSS NORTHERN UTAH
WILL ALLOW THE AIRMASS TO WARM WHILE MOISTURE INCREASES OVER THE
AREA. DEPENDING ON HOW QUICKLY PRECIPITATION DEVELOPS ACROSS
NORTHERN UTAH, VALLEYS MAY SEE PRECIPITATION BEGIN AS SNOW OR A
RAIN/SNOW MIX, BUT SNOW LEVELS ARE EXPECTED TO RISE ABOVE MOST
VALLEY FLOORS BY LATE WEDNESDAY, ALTHOUGH IT MAY TAKE LONGER TO DO
SO ALONG THE IDAHO BORDER WHERE COLDER AIR MAY REMAIN TRAPPED. BY
WEDNESDAY NIGHT (OR THURSDAY ON SOME OF THE SLOWER SOLUTIONS), A
TRANSITION TO COLD ADVECTION WILL THEN BRING SNOW LEVELS BACK DOWN
TO THE VALLEY FLOORS WHILE SPREADING PRECIPITATION INTO CENTRAL AND
POTENTIALLY SOUTHERN UTAH.
GIVEN THE FLUCTUATING SNOW LEVELS, THE LOWER VALLEYS ARE NOT
EXPECTED TO SEE SIGNIFICANT SNOW ACCUMULATIONS. THE 25TH-75TH
PERCENTILE OF THE NBM HAS A RANGE OF TRACE-3 INCHES ON THE VALLEY
FLOORS ACROSS NORTHERN AND CENTRAL UTAH, WITH LOCALLY UP TO 4 INCHES
ON THE BENCHES. MORE SIGNIFICANT ACCUMULATIONS WILL BE POSSIBLE IN
THE NORTHERN UTAH MOUNTAINS, WHERE THE 25TH-75TH PERCENTILE HAS A
RANGE OF 10-27 INCHES IN THE UPPER COTTONWOODS AND 5-18 INCHES
ELSEWHERE. ACROSS THE CENTRAL UTAH MOUNTAINS, AMOUNTS ARE LOWER, AT
2-9 INCHES. LOOKING AT THE PROBABILITIES, THE NORTHERN UTAH
MOUNTAINS ARE LIKELY TO SEE AT LEAST 6 INCHES OF SNOW AND A 40-70%
CHANCE OF SEEING AT LEAST 9 INCHES. ACROSS THE CENTRAL MOUNTAINS,
THERE IS LESS THAN A 50% CHANCE OF AT LEAST 6 INCHES OF SNOW.
PRECIPITATION IS EXPECTED TO LARGELY END BY LATE THURSDAY NIGHT,
ALTHOUGH THE SLOWER SOLUTIONS SUGGEST LINGERING LIGHT PRECIPITATION
INTO FRIDAY. THEREAFTER, A RIDGE BUILDING INTO THE AREA OVER THE
WEEKEND WILL BRING A RETURN TO DRIER AND GRADUALLY WARMING
CONDITIONS.
AVIATION...KSLC
SOUTH WINDS WILL INCREASE THIS MORNING, WITH A
LATE SHIFT (~21-22Z) TO A LIGHT NORTHWEST. HOWEVER, THERE IS A 40%
CHANCE THAT WINDS WILL REMAIN SOUTHERLY THROUGHOUT THE DAY. CIGS ARE
EXPECTED TO GRADUALLY LOWER IN THE AFTERNOON TO BELOW 7KFT AS
PRECIPITATION DEVELOPS IN THE AREA, WITH THE MOST LIKELY WINDOW FOR
PRECIPITATION AT THE TERMINAL BEING THE 22-02Z TIMEFRAME. SINCE
PRECIPITATION WILL LIKELY BE IN THE FORM OF RAIN, CONDITIONS SHOULD
REMAIN VFR, BUT CANNOT COMPLETELY RULE OUT BRIEF PERIODS OF MVFR
CONDITIONS, ESPECIALLY IF PRECIPITATION DEVELOPS EARLIER AND SNOW
MAY MIX WITH RAIN.
REST OF UTAH AND SOUTHWEST WYOMING
PRECIPITATION WILL FILL IN
ACROSS NORTHERN UTAH DURING THE DAY, THEN CONTINUING INTO THE
NIGHTTIME HOURS WHILE BECOMING INCREASINGLY CONFINED TO THE
MOUNTAINS. VALLEY LOCATIONS (BELOW 5.5-6KFT) MAY SEE PRECIPITATION
BEGIN AS SNOW OR A RAIN/SNOW MIX, WITH RAIN BECOMING MORE LIKELY
THROUGH THE AFTERNOON AND EARLY EVENING HOURS AS SNOW LEVELS RISE.
LOCAL MVFR TO IFR CONDITIONS CAN BE EXPECTED WHERE SNOW EXISTS,
WHILE WIDESPREAD MOUNTAIN TOP OBSCURATIONS WILL BE LIKELY. ACROSS
SOUTHERN UTAH, GENERALLY DRY CONDITIONS WILL REMAIN IN PLACE WITH
HIGH CLOUDS. A SOUTHWEST TO WESTERLY FLOW CAN BE EXPECTED ACROSS
MOST OF THE AREA TODAY.
SLC WATCHES/WARNINGS/ADVISORIES
UT...WINTER WEATHER ADVISORY FROM NOON TODAY TO NOON MST TUESDAY FOR
UTZ110>112.
WY...NONE.
SHORT TERM...TRAPHAGAN
LONG TERM/AVIATION...CHENG
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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