006
FXUS65 KSLC 091033
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
333 AM MST TUE DEC 9 2025
KEY MESSAGES
- AN ATMOSPHERIC RIVER WILL PRIMARILY AFFECT THE PACIFIC NORTHWEST
THROUGH WEDNESDAY. SOUTHWEST WYOMING AND FAR NORTHERN UTAH WILL
BE ON THE SOUTHERN PERIPHERY OF THIS TUESDAY AND WEDNESDAY, WITH
GUSTY WINDS AND LIGHT MOUNTAIN SNOW.
- HIGH PRESSURE WILL BE IN PLACE THURSDAY THROUGH THE WEEKEND,
WITH DRY CONDITIONS AND TEMPERATURES AROUND 10-15F WARMER THAN
NORMAL. STRENGTHENING VALLEY INVERSIONS CAN BE EXPECTED, ESPECIALLY
BY THE WEEKEND.
DISCUSSION
UTAH REMAINS UNDER A NORTHWESTERLY FLOW ALOFT THIS
MORNING DOWNSTREAM OF A RIDGE OVER THE EASTERN PACIFIC. A LANDFALLING
ATMOSPHERIC RIVER IS CURRENTLY NOTED OVER THE PACNW, WITH MOISTURE
STREAMING INTO MONTANA AND NORTHERN IDAHO. THE POSITION OF THE UPPER
JET WELL NORTH OF UTAH WILL KEEP THE BULK OF THE MOISTURE TO THE
NORTH. HOWEVER, THE NORTHWEST FLOW WILL PULL SOME REMNANT MOISTURE
INTO NORTHERN UTAH TODAY INTO TOMORROW. THIS MOISTURE IS EXPECTED TO
REMAIN FAIRLY LIMITED, WITH THE NBM 25TH PERCENTILE QPF AMOUNTS
REMAINING AT 0, WHILE THE 75TH PERCENTILE AMOUNTS RANGE FROM LESS
THAN 0.1 INCHES ACROSS THE CENTRAL WASATCH AND WESTERN UINTA
MOUNTAINS TO UP TO 0.15 INCHES IN THE NORTHERN WASATCH AND AROUND
0.4 INCHES IN THE BEAR RIVER RANGE. IT SHOULD BE NOTED, HOWEVER,
THAT THE HREF AMOUNTS ARE HIGHER, WITH ENSEMBLE MEANS OF UP TO 0.30
INCHES IN THE WASATCH/UINTAS AND LOCALLY OVER 1 INCH IN THE BEAR
RIVER RANGE. THESE MODELS LAND ON THE VERY HIGH END OF THE NBM
PROBABILISTIC FORECAST AND THUS CONSIDERED VERY LIKELY, BUT CANNOT
BE COMPLETELY RULED OUT. NONETHELESS, SNOW LEVELS WILL BE HIGH (NEAR
7000 FT TODAY RISING TO NEAR 9000 FT TOMORROW) AND SNOW DENSITIES
WILL BE LOW, SO SNOW ACCUMULATIONS ARE NOT EXPECTED TO BE
SIGNIFICANT EVEN IF THE STORM DOES OVERPERFORM.
ENHANCED WINDS ARE NOTED ACROSS SOUTHWEST WYOMING AND PORTIONS OF
FAR NORTHEAST UTAH THIS MORNING, AND THESE WINDS WILL INCREASE
THROUGH THE DAY AND CONTINUE INTO TOMORROW AS A TROUGH OVER SOUTHERN
BRITCOL TRACKS SOUTHEAST BEFORE GRAZING NORTHEAST WYOMING THIS
EVENING. MODELS CONTINUE TO INDICATE H7 WINDS OF UP TO 55KT ACROSS
SOUTHWEST WYOMING ALONG WITH A WESTERLY SURFACE GRADIENT. HOWEVER,
THE PROBABILITY OF REACHING HIGH WIND WARNING CRITERIA IN BOTH THE
NBM AND THE HREF REMAINS GENERALLY UNDER 15%. GIVEN THIS
PROBABILISTIC INFORMATION, ALONG WITH THE TROUGH POSITION WELL TO THE
EAST AND MODEL SOUNDINGS NOT EVEN MIXING UP TO THE H7 LEVEL, IT
SEEMS REASONABLE TO GO WITHOUT ANY WIND HIGHLIGHTS.
DRY AND ABOVE NORMAL TEMPERATURES CAN BE EXPECTED THURSDAY THROUGH
THE WEEKEND AS THE UPSTREAM RIDGE BUILDS AND VERY SLOWLY SHIFTS
INLAND. AS THE FLOW WEAKENS, ESPECIALLY OVER THE WEEKEND, EXPECT
INVERSION CONDITIONS TO STRENGTHEN, ALTHOUGH THE LACK OF BOTH SNOW
COVER AND PRE-EXISTING COLD AIR WILL HELP MODERATE THIS SOMEWHAT.
FOR THOSE LOOKING FOR THE NEXT STORM, GLOBAL DETERMINISTICS ARE ALL
TRENDING TOWARDS A RELATIVELY WEAK TROUGH NEXT TUESDAY. THIS
SOLUTION REMAINS IN THE MINORITY BASED ON CLUSTER ANALYSIS OF GLOBAL
ENSEMBLES, BUT IT'S...SOMETHING.
AVIATION...KSLC
VFR CONDITIONS WILL PERSIST FOR THE KSLC TERMINAL
THROUGH THE PERIOD. DRY CONDITIONS WILL CONTINUE WITH MID LEVEL
CLOUDS INCREASING DURING THE DAY. LIGHT SOUTHERLY WINDS WILL
TRANSITION TO LIGHT NORTHERLY WINDS DURING THE AFTERNOON.
REST OF UTAH AND SOUTHWEST WYOMING
VFR CONDITIONS WILL PERSIST
FOR THE ENTIRE AIRSPACE THROUGH THE PERIOD. MID LEVEL CLOUDS WILL
INCREASE ACROSS THE NORTHERN AIRSPACE WITH SOME LIGHT MOUNTAIN
SHOWERS IN THE EVENING ACROSS THE FAR NORTHERN MOUNTAINS. ELSEWHERE,
CONDITIONS WILL REMAIN DRY WITH LIGHT AND DIURNALLY DRIVEN WINDS
WITH STRONGER WINDS ACROSS THE HIGHER TERRAIN IN THE NORTHEAST.
SLC WATCHES/WARNINGS/ADVISORIES
UT...NONE.
WY...NONE.
CHENG/MAHAN
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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