632
FXUS65 KSLC 191006
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
306 AM MST WED FEB 19 2025
SYNOPSIS
A PACIFIC NORTHWEST STORM SYSTEM WILL BRING ADDITIONAL
PRECIPITATION TO NORTHERN AND CENTRAL UTAH WEDNESDAY AFTERNOON
THROUGH THURSDAY. HIGH PRESSURE WILL BRING A DRIER PATTERN
THEREAFTER.
SHORT TERM (AFTER 12Z/5 AM MST FRIDAY)
CURRENTLY SEEING MOSTLY
CLEAR AND DRY CONDITIONS OVER UTAH AND SOUTHWEST WYOMING THIS
MORNING WITH HIGH PRESSURE CENTERED OVER THE GREAT BASIN. HIGH
CLOUDS, HOWEVER, ARE ALREADY STARTING TO MOVE INTO FAR WESTERN
UTAH AHEAD OF A TROUGH MAKING ITS WAY ONSHORE ALONG THE PACIFIC
NORTHWEST COAST. DURING THE AFTERNOON, WILL START TO SEE THE
DEVELOPMENT OF SNOW OVER THE MOUNTAINS OF NORTHERN UTAH IN A
SOMEWHAT MOIST WARM ADVECTION REGIME AHEAD OF THE MAIN TROUGH,
WITH ACCUMULATIONS STAYING LIGHT AT THIS POINT.
THE FRONT END OF THE TROUGH AND THE ASSOCIATED COLD FRONT ARE ON
TRACK TO MOVE ACROSS NORTHERN AND CENTRAL UTAH THIS EVENING INTO
EARLY THURSDAY, BRINGING THE HEAVIEST PERIOD OF PRECIPITATION WITH
THE SYSTEM. THIS PRECIPITATION WILL BE SNOW FOR THE MOUNTAINS,
WHERE 25TH-75TH PERCENTILE SNOW ACCUMULATION NUMBERS ARE IN THE
FOUR TO EIGHT INCH RANGE FOR THE MAJORITY OF THE NORTHERN AND
CENTRAL MOUNTAINS, A BIT BELOW THE CRITERIA FOR A WINTER WEATHER
ADVISORY, THOUGH TIMING OF THE HEAVIEST SNOW COULD HAVE SOME
IMPACT ON THOSE USING MOUNTAIN ROUTES FOR THEIR MORNING COMMUTE.
THE PRECIPITATION TYPE FORECAST FOR MOST NORTHERN UTAH VALLEY
LOCATIONS IS A BIT MORE PROBLEMATIC, WITH VALLEYS FROM OGDEN
NORTHWARD SEEING A HIGH CHANCE OF LIGHT ACCUMULATING SNOW. FOR
VALLEYS SOUTH OF OGDEN, ACCUMULATIONS ON VALLEY FLOORS LOOK LESS
LIKELY WITH THE CURRENT GUIDANCE TRENDING JUST SLIGHTLY WARMER,
THOUGH BELIEVE THERE'S A HIGH CHANCE OF AT LEAST SEEING SOME
FLAKES IN THE AIR, AND BENCH LOCATIONS SHOULD SEE LIGHT
ACCUMULATIONS. THUS, DESPITE TIMING OF THE HEAVIEST PRECIPITATION
BEING JUST AHEAD OF THE MORNING COMMUTE, HAVE OPTED NOT TO ISSUE
ANY HEADLINES AT THIS TIME AND SEE IF THE DAY SHIFT CAN FIND SOME
BETTER CONFIDENCE IN THE DAYTIME GUIDANCE.
IN COLD POOL INSTABILITY WITH THE MAIN TROUGH, WILL SEE
PRECIPITATION, PRIMARILY SNOW, LINGER OVER NORTHERN AND CENTRAL
UTAH THROUGHOUT THURSDAY, BECOMING INCREASINGLY FOCUSED OVER THE
HIGHER TERRAIN. AS THE TROUGH TRACKS SOUTHEAST OF THE AREA, WILL
SEE ASSOCIATED PRECIPITATION DIMINISH SIGNIFICANTLY THURSDAY
NIGHT BEFORE TAPERING OFF EARLY FRIDAY.
LONG TERM (AFTER 12Z/5 AM MST FRIDAY)
* HIGH CONFIDENCE IN A 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
FRIDAY MORNING, MODEL CONSENSUS DEPICTS LINGERING CYCLONIC FLOW
ACROSS UTAH IN THE WAKE OF A DEPARTING STORM SYSTEM, WITH
TEMPERATURES BRIEFLY NEAR TO SLIGHTLY ABOVE NORMAL FOR THE TIME OF
YEAR. ROUGHLY 15% OF THE ENSEMBLE MEMBERSHIP HANGS ON TO SNOW
SHOWERS ACROSS NORTHERN UTAH (PRIMARILY ACROSS THE NORTHERN SLOPES
OF THE UINTAS) THROUGH THE FIRST HALF OF THE DAY. MID-LEVEL HEIGHT
RISES WILL BEGIN IN EARNEST ACROSS THE AREA THIS WEEKEND, WITH AN
ATTENDANT WARMING TREND. THE WARMING TREND WILL BE MOST PRONOUNCED
ACROSS SOUTHERN UTAH, WHERE HIGH TEMPERATURES WILL INCREASE 10F-15F
BETWEEN FRIDAY AND SUNDAY. A GRAZING TROUGH FORECAST TO PROPAGATE
EASTWARD ACROSS THE NORTHERN ROCKIES WILL TEMPER THE WARMING TREND
SLIGHTLY ACROSS NORTHERN UTAH AND SW WYOMING, WITH ABOUT 15-20% OF
THE ENSEMBLE MEMBERSHIP INDICATING A PERIOD OF SNOW SHOWERS ACROSS
THE NORTHERN MOUNTAINS ON SUNDAY. EVEN ACROSS NORTHERN UTAH,
TEMPERATURES ARE FORECAST TO WARM ~10F BETWEEN FRIDAY AND SUNDAY.
HIGH CONFIDENCE EXISTS IN MID-LEVEL RIDGING REMAINING IN PLACE
THROUGH 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.
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 REGION, WITH HIGH TEMPERATURES ~10F ABOVE
NORMAL ACROSS NORTHERN UTAH AND SW WYOMING, AND 10F-20F ABOVE NORMAL
ACROSS SOUTHERN UTAH. 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. EFI VALUES AND ANOMALY PLOTS SUPPORT
THE ABOVE-NORMAL TEMPERATURES, WITH THE DEGREE OF THE ANOMALIES
INCREASING FROM NORTH TO SOUTH. MAGNITUDE OF EFIS 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.
AVIATION...KSLC
WEAK WARM FRONT MOVING THROUGH THE AREA THIS
AFTERNOON WILL BRING A 30-40% CHANCE OF RAIN AND SNOW SHOWERS ALONG
WITH MOUNTAIN OBSCURATION. MOST LIKELY CIGS WILL DROP DOWN TO AROUND
5KFT BETWEEN ROUGHLY 20Z-03Z, WITH A BRIEF LULL AFTER THIS. HIGH-RES
MODEL CONSENSUS THEN DEPICTS EITHER SNOW SHOWERS OR A SOLID,
PERSISTENT AREA OF SNOW BETWEEN ROUGHLY 09Z THROUGH MUCH OF THE
AFTERNOON BEFORE DIMINISHING. CIG/VIS TRENDS WILL BE MODULATED BY
THE STRENGTH OF THIS ACTIVITY, WITH A 50% CHANCE FOR MVFR CIGS
DURING THIS PERIOD AND A 15% CHANCE OF IFR CONDITIONS. OFFICIAL
FORECAST IS LEANING A BIT MORE ON THE PESSIMISTIC SIDE. HIGH
CONFIDENCE IN SOUTHERLY SFC WINDS THROUGH LATE, WITH INCREASING
TRENDS FOR VARIABLE TO EVENTUALLY STRONGER SIGNAL FOR NW WINDS BY
AROUND 09Z. LOWER CONFIDENCE IN WIND DIRECTION DURING AND PROCEEDING
POTENTIAL SHOWERY PERIODS FROM LATE AFTERNOON THROUGH EARLY EVENING.
REST OF UTAH AND SOUTHWEST WYOMING
WEAK WARM FRONT MOVING THROUGH
THE AREA THIS AFTERNOON WILL BRING A 30-40% CHANCE OF RAIN AND SNOW
SHOWERS ALONG WITH MOUNTAIN OBSCURATION TO THE WASATCH FRONT, WITH
MUCH HIGHER SNOW CHANCES ACROSS NORTHERN MOUNTAINS AND THE CACHE.
WHILE SNOW SHOWERS WILL CONTINUE THROUGH THE EVENING ACROSS NORTHERN
MOUNTAINS, SW WYOMING AND AREAS NEAR THE IDAHO BORDER, BRIEF LULL IN
THE ACTION EXPECTED ACROSS THE WASATCH FRONT. STRONGER SIGNAL FOR
SNOW SHOWERS ACROSS MUCH OF NORTHERN UTAH BUILDING IN AFTER 06Z,
EXPANDING SOUTHWARD ACROSS CENTRAL UTAH THROUGH THE MORNING HOURS
THURSDAY. SNOW SHOWERS THEN BECOME INCREASINGLY TIED TO TERRAIN BY
LATE THURSDAY AFTERNOON BEFORE GRADUALLY DIMINISHING. STRONGER SNOW
SHOWERS WILL BRING MEDIUM TO HIGH POTENTIAL FOR IFR CIGS/VIS. BEST
CHANCES FOR MOST WIDESPREAD REDUCTIONS FROM PRE-DAWN HOURS THURSDAY
MORNING INTO EARLY THURSDAY AFTERNOON. VFR CONDITIONS EXPECTED
ACROSS SOUTHERN UTAH.
SLC WATCHES/WARNINGS/ADVISORIES
UT...NONE.
WY...NONE.
SHORT TERM...TRAPHAGAN
LONG TERM/AVIATION...ADESMET
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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