058
FXUS65 KSLC 201150
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
449 AM MST THU FEB 20 2025
SYNOPSIS
WIDESPREAD PRECIPITATION WILL CONTINUE OVER NORTHERN AND
PORTIONS OF CENTRAL UTAH THROUGH THE DAY. EXPECT IMPACTS TO THE
THURSDAY MORNING COMMUTE. THE REMAINDER OF THE WEEK WILL CONSIST OF
DRY CONDITIONS WITH WARMING TEMPERATURES.
SHORT TERM (THROUGH 12Z SATURDAY)
AN UPPER TROUGH CURRENTLY OVER
WESTERN UTAH WILL CONTINUE MAKING ITS WAY ACROSS THE STATE THROUGH
THE DAY. WITHIN THIS TROUGH, LATEST SATELLITE IMAGERY IS INDICATING
A CLOSED LOW DEVELOPING OVER NORTHWEST UTAH. PRECIPITATION FILLED IN
OVER NORTHERN AND CENTRAL UTAH OVERNIGHT IN A MOIST SOUTHWEST TO
WEST FLOW AS UPPER DIFFLUENCE INCREASED AHEAD OF THE APPROACHING
STORM. NORTHERN AND PORTIONS OF CENTRAL UTAH WILL CONTINUE TO SEE
PRECIPITATION THROUGH EARLY AFTERNOON BEFORE GRADUALLY TAPERING OFF
FROM THE NORTH THIS AFTERNOON AND EVENING. PRECIPITATION WILL BE
MORE LIMITED IN SOUTHERN UTAH AND NOT LIKELY TO REACH WASHINGTON OR
KANE COUNTIES.
PRECIPITATION IN THE LOWER VALLEYS HAS BEEN IN THE FORM OF
SNOW NORTH OF OGDEN, WHILE SOUTH OF OGDEN, IT HAS THUS FAR BEEN
MOSTLY RAIN OR MIXED PHASE. HOWEVER, AS THE FLOW BECOMES MORE
NORTHWEST ON THE BACKSIDE OF THE LOW AND COLD ADVECTION CONTINUES,
SNOW WILL BECOME MORE LIKELY OVER THE NEXT FEW HOURS. ADDITIONALLY,
ANY HEAVIER BURSTS OF PRECIPITATION WILL LIKELY CHANGE PRECIPITATION
OVER TO SNOW.
DUE TO PRECIPITATION TYPE ISSUES OVERNIGHT, VALLEYS FROM OGDEN
SOUTHWARD ARE OFF TO A SLOW START IN TERMS OF SNOW ACCUMULATIONS. AS
SUCH, HAVE TRENDED STORM TOTAL ACCUMULATIONS DOWNWARD IN THESE
AREAS. HOWEVER, THE EXPECTATION IS THAT SNOW WILL FILL IN MORE ALONG
THE WASATCH FRONT DURING THE MORNING HOURS, WITH THE BEST
ACCUMULATIONS TO OCCUR FROM AROUND THE MORNING COMMUTE TIME INTO THE
EARLY AFTERNOON HOURS. GIVEN POTENTIAL IMPACTS, GOING WINTER WEATHER
HIGHLIGHTS REMAIN IN PLACE, WITH THE ONLY CHANGE WITH THE MORNING
FORECAST PACKAGE BEING THE ADDITION OF A WINTER WEATHER ADVISORY IN
THE BEAR LAKE AND BEAR RIVER VALLEY. THAT SAID, WOULD NOT BE
SURPRISED IF THE CACHE VALLEY OR EVEN PORTIONS OF EASTERN BOX ELDER
COUNTY END UP WITH OVER 6 INCHES, REACHING WARNING CRITERIA.
PRECIPITATION IS EXPECTED TO LARGELY WIND DOWN BY LATE TONIGHT.
HOWEVER, THE AREA WILL REMAIN IN A COOL AND CYCLONIC FLOW ALOFT. ONE
FINAL EMBEDDED DISTURBANCE WILL ROTATE INTO EASTERN NEVADA AND
WESTERN UTAH TOMORROW, BUT LIMITED MOISTURE SHOULD RESULT IN VERY
LOW CHANCES FOR PRECIPITATION.
LONG TERM (AFTER 12Z/5AM MST SATURDAY)
* HIGH CONFIDENCE IN AN EXTENDED PERIOD OF ABOVE AVERAGE
TEMPERATURES AND BELOW AVERAGE PRECIPITATION FROM THIS WEEKEND
THROUGH NEXT WEEK, WITH THE STRONGEST WARM/DRY SIGNAL ACROSS
SOUTHERN UTAH.
AT THE BEGINNING OF THE LONG TERM PORTION OF THE FORECAST PERIOD ON
SATURDAY, MODEL SUITE IS IN GOOD AGREEMENT IN THEIR COLLECTIVE
DEPICTIONS OF MID-LEVEL RIDGING NOSING ACROSS UTAH AND SW WYOMING,
BRINGING DRY CONDITIONS TO THE AREA. TEMPERATURES HAVE COOLED
SLIGHTLY COMPARED TO FORECASTS FROM 24 HOURS AGO ACROSS THE FAR
NORTHERN VALLEYS, POTENTIALLY OWING TO THE ANTICIPATED LINGERING
SNOWPACK HERE, ESPECIALLY ACROSS THE CACHE AND BEAR RIVER VALLEYS AS
WELL AS EASTERN BOX ELDER COUNTY, WHERE HIGH TEMPERATURES SATURDAY
ARE NOW EXPECTED TO BE NEAR TO SLIGHTLY BELOW NORMAL FOR LATE
FEBRUARY. ACROSS THE SOUTHERN HALF OF UTAH, HIGHS ARE EXPECTED TO BE
5F TO 10F ABOVE NORMAL. A GRAZING TROUGH REMAINS ON TRACK TO
PROPAGATE EASTWARD ACROSS THE NORTHERN ROCKIES LATE SATURDAY AND
INTO SUNDAY, WITH ABOUT 10-20% OF THE ENSEMBLE MEMBERSHIP INDICATING
A PERIOD OF LIGHT SNOW SHOWERS ACROSS THE NORTHERN MOUNTAINS ON
SUNDAY. TRENDS HAVE NUDGED EVER SO SLIGHTLY IN THE DRIER DIRECTION
WHEN COMPARED TO 24 HOURS AGO DURING THIS TIME. LITTLE CHANGE
EXPECTED IN TEMPERATURES ACROSS THE NORTH SUNDAY, WITH A MODEST
WARMING TREND CONTINUING ACROSS THE SOUTH.
HIGH CONFIDENCE EXISTS IN MID-LEVEL RIDGING IN PLACE MONDAY AND
EARLY TUESDAY ACROSS THE FORECAST AREA, WITH A MINORITY OF SOLUTIONS
SHOWING ANOTHER GRAZING TROUGH SWINGING THROUGH THE NORTHERN ROCKIES
ON TUESDAY AND INTO WEDNESDAY, BRINGING LOW-END (10-20%) CHANCES FOR
SNOW SHOWERS TO THE NORTHERN MOUNTAINS ONCE AGAIN DURING THIS
PERIOD, WHILE ALSO FLATTENING THE NORTHERN PERIPHERY OF THE RIDGE.
THROUGH THE MIDDLE OF NEXT WEEK, THERE IS VIRTUALLY NO CHANCE OF
PRECIPITATION ACROSS SOUTHERN UTAH. TUESDAY IS FORECAST TO BE THE
WARMEST DAY ACROSS THE ENTIRETY OF THE REGION, WITH HIGH
TEMPERATURES ~10F ABOVE NORMAL ACROSS NORTHERN UTAH AND SW WYOMING,
AND 10F-20F ABOVE NORMAL ACROSS SOUTHERN UTAH. IN ADVANCE OF THE
TROUGH, THERE EXISTS A SCENARIO WHERE THE COMBINATION OF SUFFICIENT
INSOLATION AND SOUTHERLY DOWNSLOPING RESULTS IN HIGH TEMPERATURES
ACROSS THE WASATCH FRONT SURGING INTO THE 60S ON TUESDAY, AS
REPRESENTED BY THE NBM 75TH PERCENTILE (OR 10% CHANCE OF
OCCURRENCE). BRIEF, ALBEIT SHORT-LIVED, MODEST COOLING ON WEDNESDAY
ACROSS THE NORTH WILL BUILD IN BEHIND THE WEAK WAVE. MAJORITY OF THE
ENSEMBLE SOLUTION SPACE DEPICTS ANOTHER RIDGE AXIS BUILDING INTO THE
REGION IN THE THURSDAY TO FRIDAY TIMEFRAME NEXT WEEK, WITH AN
ATTENDANT REBOUND IN TEMPERATURES ACROSS THE NORTH AND MAINTENANCE
OF SPRING-LIKE TEMPERATURES ACROSS THE SOUTH. EFI VALUES AND ANOMALY
PLOTS SUPPORT THE CONTINUATION OF THE ABOVE-NORMAL TEMPERATURES,
WITH THE DEGREE OF THE ANOMALIES INCREASING FROM NORTH TO SOUTH.
MAGNITUDE OF EFI SUGGEST MOST RECORDS SHOULD BE SAFE, BUT CAN'T RULE
OUT THE OCCASIONAL RECORD HIGH TEMPERATURE OR RECORD WARM OVERNIGHT
LOW TEMPERATURE. RETURN INTERVAL PLOTS SUGGESTS THE MILD PERIOD IN
THIS FORECAST SHOULD OCCUR ABOUT ONCE EVERY 10 YEARS IN LATE
FEBRUARY.
FINALLY, MAJORITY OF DETERMINISTIC AND MANY ENSEMBLE MEMBERS NOW
DEPICT A CLOSED LOW DRIFTING THROUGH SOUTHERN CALIFORNIA INTO
ARIZONA NEXT WEEKEND. THIS LOW DOES NOT APPEAR TO PRESENT AS A
PARTICULARLY STRONG ONE, SO IMPACTS APPEAR TO BE LIMITED TO AN
INCREASE IN CLOUD COVER ACROSS SOUTHERN UTAH.
AVIATION...KSLC
CHALLENGING FORECAST WITH RESPECT TO
PRECIPITATION TYPE EARLY IN THE PERIOD, AS PRECIPITATION HAS
REMAINED MAINLY RAIN OVERNIGHT. WE DID SEE THE REDUCTION IN CIGS TO
THE MVFR TO OCCASIONALLY IFR CATEGORY, HOWEVER. MOST LIKELY SCENARIO
AS WE GO THROUGH THE DAY SUGGESTS INCREASING ODDS FOR SNOW IN THE 12-
14Z RANGE, WITH SNOW SHOWERS THEN CONTINUING THROUGH 22Z-00Z
FOLLOWED BY IMPROVING CONDITIONS. EXPECT CIG/VIS IN THE MVFR TO IFR
RANGE THROUGH THIS PERIOD. INCREASINGLY NORTHERLY GRADIENT WILL
FORCE A WIND SHIFT TO THE NW BETWEEN 12-14Z, WITH NW WINDS
CONTINUING THROUGH THE DAY, GUSTY AT TIMES. SPEEDS WILL DECREASE
AFTER SUNSET. MAJORITY OF SOLUTIONS SUGGEST SOME FLAVOR OF N SFC
WINDS CONTINUING TONIGHT, HOWEVER THERE IS NOW ~40% CHANCE SFC WINDS
WILL TURN BACK TO A TRADITIONAL SSE DIRECTION AROUND 06Z TONIGHT.
REST OF UTAH AND SOUTHWEST WYOMING
STEADY, OCCASIONALLY MODERATE
SNOWFALL ACROSS NORTHERN UT AND SW WYOMING WILL CONTINUE THROUGH THE
MORNING AND EARLY AFTERNOON, BEFORE GRADUALLY DIMINISHING FROM NORTH
TO SOUTH LATE THIS AFTERNOON. IFR TO OCCASIONALLY LIFR CONDITIONS
HAVE BEEN OBSERVED AT TIMES IN THE HEAVIEST SNOW. SOUTHERN EDGE OF
SNOW WILL EXPAND ACROSS CENTRAL UTAH LATER THIS MORNING. BY THIS
EVENING, REMAINING SNOW SHOWERS WILL BE LARGELY TIED TO TERRAIN
EXCEPT ACROSS THE NORTHEAST CORNER OF THE STATE CLOSER TO THE AREA
OF LOW PRESSURE. ALL SNOW EXPECTED TO COME TO AN END BY LATE
TONIGHT, LEAVING PATCHY FOG IN SOME NORTHERN VALLEYS ALONG WITH
STRATUS CLINGING TO TERRAIN.AIN DRY WITH VFR CONDITIONS PREVAILING
THROUGH THE PERIOD.
SLC WATCHES/WARNINGS/ADVISORIES
UT...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR UTZ102-
103-105-107>109.
WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR UTZ104.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR
UTZ110>113-117.
WY...WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ021.
CHENG/DESMET
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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