Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 231225
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
525 AM MST SUN NOV 23 2014

.SYNOPSIS...A WEATHER DISTURBANCE MOVING SOUTH THROUGH NORTHERN
UTAH WILL BRING SNOW TO MUCH OF NORTHERN AND CENTRAL UTAH THIS
MORNING. THE LAST PIECE OF THIS WEEKENDS STORMS WILL ARRIVE OVER
NORTHERN UTAH FOR LATE TONIGHT THROUGH MONDAY. HIGH PRESSURE WILL
BUILD INTO THE REGION BY MIDWEEK.

&&

.SHORT TERM (UNTIL 00Z THURSDAY)...A SHORT WAVE CROSSING THE IDAHO
BORDER AT TIME IS GENERATING A FAIRLY ACTIVE AREA OF CONVECTIVE
SNOWS ACROSS SOUTHEAST IDAHO SOUTHWARD ALONG THE WASATCH MOUNTAINS
AND WASATCH FRONT. THE COLDEST AIR OF THIS WEEKENDS STORMS WILL
ACCOMPANY THIS FEATURE THROUGH NORTHERN UTAH THIS MORNING. THE
COMBINATION OF DEEP LAYER MOISTURE/INSTABILITY AND WEAK DYNAMIC
LIFT WILL MAINTAIN CONVECTIVE SNOWFALL THROUGH AT LEAST MID-
MORNING. SNOW SHOWERS WILL LINGER BEHIND THE PASSING SHORTWAVE
THROUGH AT LEAST MID-AFTERNOON AS COLD AIR INSTABILITY AND
SUFFICIENT MOISTURE REMAIN OVER NORTHERN UTAH AND SOUTHWEST
WYOMING.

THE LAST PIECE OF THIS WEEKENDS WINTER STORM CURRENTLY ALONG THE
BRITCOL COAST WILL DIG SOUTHEAST THROUGH THE NORTHERN ROCKIES AND
NORTHERN GREAT BASIN LATER TONIGHT THROUGH MONDAY. THIS DIGGING
WILL BE IN RESPONSE TO STRONG RIDGING TAKING PLACE OVER THE
EASTERN PACIFIC WEST OF 130W BEGINNING LATER TODAY. A SUBTLE
DIFFERENCE EXISTS BETWEEN THE LATEST GFS AND ECMWF IN TERMS OF THE
TRAJECTORY OF THIS NEXT SHORTWAVE. BOTH MODELS REMAIN CONSISTENT
WITH THE GFS TAKING A MORE DIRECT PATH THROUGH NORTHERN
UTAH...WHILE THE ECMWF IS SLIGHTLY FURTHER EAST THROUGH WESTERN
WYOMING AND NORTHEAST UTAH.

BASED IN PART ON THE STRONG AND FAIRLY RAPID RIDGING OVER THE
EASTERN PACIFIC...WILL FOLLOW THE ECMWF SOLUTION FOR THE END OF
THE STORM CYCLE. WILL CONCENTRATE THE BEST THREAT FOR HEAVIER
SNOWS ACROSS THE NORTHERN AND CENTRAL WASATCH RANGE...THEN EAST
INTO THE UINTA MOUNTAINS. THE NORTHERN AND CENTRAL WASATCH FRONT
ALONG WITH THE CACHE VALLEY WILL ALSO DO QUITE WELL LATE TONIGHT
THROUGH EARLY MONDAY AFTERNOON.

WILL LEAVE ALL MOUNTAIN WARNING/ADVISORIES IN PLACE WITH THE EARLY
MORNING FORECAST PACKAGE. HAVE DROPPED THE ADVISORY FOR SOUTHWEST
WYOMING AS A FAIRLY LONG BREAK IN SIGNIFICANT SNOWFALL IS
EXPECTED. WILL LIKELY NEED TO ISSUE ADDITIONAL ADVISORIES FOR THE
URBAN AREAS OF NORTHERN UTAH AND AGAIN FOR SOUTHWEST WYOMING IN
SUBSEQUENT FORECAST UPDATES.

BUILDING HEIGHTS BEGINNING LATE MONDAY WILL DRIVE THE LAST OF THE
SNOW OUT OF THE AREA MONDAY NIGHT. A MOIST AND FAIRLY DEEP LAYER
ANTICYCLONIC WARM ADVECTION PATTERN SETTING ON TUESDAY WILL BRING
PLENTY OF CLOUDS AND SOME LIGHT PRECIP TO THE FAR NORTH WHERE THE
WARM ADVECTION IS STRONGEST LATE TUESDAY THROUGH TUESDAY NIGHT.
CONTINUED BUILDING OF HEIGHTS SHOULD NUDGE ANY PRECIP NORTH OF THE
STATE FOR WEDNESDAY.

&&

.LONG TERM (AFTER 00Z THURSDAY)...A RIDGE WILL DOMINATE THE
REGION FROM THURSDAY INTO SATURDAY. TEMPERATURES ARE EXPECTED TO
BE ABOVE NORMAL AS A COUPLE OF CLOUDY NIGHTS LEADING UP TO
THURSDAY SHOULD KEEP THE INVERSION FROM BECOMING ENTRENCHED AND
THEREFORE REASONABLE MIXING CAN EASILY GET OUR TEMPS ABOUT 5 TO 10
DEGREES ABOVE NORMAL THROUGHOUT THE CWA.

A WEAK SYSTEM IS EXPECTED TO MOVE INTO THE GREAT BASIN SATURDAY
NIGHT INTO SUNDAY ACCORDING THE 00Z GFS...BUT THE EC DID NOT SHOW
THIS. THE LATEST 06Z GFS HAS BACKED OFF AND SO THE VERY LOW POPS
L0OKS TO BE THE RIGHT DIRECTION AT THIS TIME.

&&

.AVIATION...AT THE SLC TERMINAL...ISOLATED TO SCATTERED SNOW
SHOWERS ARE EXPECTED THROUGH ABOUT 16-17Z. TEMPORARY REDUCTION TO
MVFR CONDITIONS ARE POSSIBLE IN ANY OF THESE SHOWERS. WINDS WILL
BE NORTHERLY AT UNDER 10 MPH...EXCEPT COULD GUST TO 20 MPH WHEN
ANY SNOW SHOWER IS NEARBY. CIGS SHOULD EXCEED 7K FT AGL AFTER 17Z
WITH A 20 PERCENT CHANCE OF LINGERING THROUGH 19Z.


.SLC WATCHES/WARNINGS/ADVISORIES...
UT...WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR UTZ006-010.

     WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR UTZ007>009.

     WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR UTZ517.

WY...NONE.
&&

$$

SHORT TERM...CONGER
LONG TERM/AVIATION...STRUTHWOLF

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)

FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)



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