FXUS65 KSLC 251154
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
454 AM MST FRI DEC 25 2009

.SYNOPSIS...A COLD NORTHERLY FLOW WILL CONTINUE ACROSS UTAH
THROUGH EARLY SATURDAY. HIGH PRESSURE ALOFT WILL SETTLE ACROSS
THE NORTHERN ROCKIES THROUGH NORTHERN GREAT BASIN THIS WEEKEND. 

&&

.DISCUSSION...THE HIGH AMPLITUDE UPPER RIDGE ALONG THE WEST COAST
AND THE MASSIVE UPPER LOW OVER THE CNTRL CONUS HAS PRODUCED A COLD
CYCLONIC NORTHERLY FLOW ACROSS THE INTERIOR WEST THIS MORNING.
WEAK DYNAMIC LIFT GENERATED FROM EMBEDDED SHEAR VORTICITY LOBES
WORKING WITH ADEQUATE LOW/MID-LEVEL MOISTURE WILL PRODUCE
ORGANIZED CLOUD BANDS ACROSS NRN/CNTRL UTAH TODAY. COULD SEE SOME
VERY LIGHT SNOW IN THESE CLOUD BANDS...BUT ONLY A MINIMAL THREAT
OF MEASURABLE PRECIP THROUGH EARLY THIS EVENING.

HEAVY SNOW COVER FROM THE LAST STORM ALONG WITH CLEAR SKIES AND
LIGHT WINDS HAS ALLOWED DENSE FOG TO DEVELOP IN THE CNTRL VALLEYS
OVERNIGHT. THIS FOG MAY STRUGGLE TO CLEAR OUT THIS MORNING WITH A
STRATOCUMULUS CLOUD DECK MOVING THROUGH THE AREA. EXPECTING SOME
IMPROVEMENT BY AFTERNOON...THOUGH DENSE FOG WILL LIKELY RETURN
ACROSS THE SAME AREAS AGAIN TONIGHT.

THE UPPER RIDGE WILL DRIFT EAST INTO THE NRN ROCKIES/WRN GREAT
BASIN BY EARLY THIS WEEKEND. THE WESTERLIES ARE EXPECTED TO
UNDERCUT THE RIDGE THIS WEEKEND...LEAVING A HIGH CENTER OVER SRN
CANADA AND MUCH OF THE NRN/CNTRL GREAT BASIN UNDER A WEAK FLOW
ZONE THROUGH EARLY NEXT WEEK. RESIDUAL MOIST OVER UTAH WILL HAVE
NO WHERE TO GO...SO LOOKING AT SOME FORM OF CLOUD COVER THE NEXT
SEVERAL DAYS. DECAYING SHORTWAVES OFF THE ERN PACIFIC MAY BE ABLE
TO GENERATE LIGHT PRECIP...BUT THE THREAT OF THIS LOOKS LOW
THROUGH EARLY NEXT WEEK.

THE NEXT BEST THREAT FOR PRECIP WILL COME AROUND THE MIDDLE OF
NEXT WEEK. BUILDING HEIGHTS OVER THE ERN PACIFIC WILL DRIVE
SHORTWAVES SE INTO AND THROUGH THE GREAT BASIN. GENERALLY WEAK
DYNAMIC LIFT ALONG WITH MODEST THERMAL ADVECTION SHOULD BE ABLE TO
GENERATE THE NECESSARY LIFT FOR PRECIP LATE TUESDAY/WEDNESDAY. THE
ERN PACIFIC RIDGE WILL PROGRESS EASTWARD...AND SETTLE ACROSS THE
AREA LATE IN THE WEEK. PLENTY OF MOISTURE WILL BE EMBEDDED IN THE
RIDGE...BUT THE THREAT OF PRECIP WILL BE LIMITED AND CONFINED
MAINLY TO THE FAR NORTH WHERE WARM ADVECTION COULD GENERATE ENOUGH
LIFT FOR PRECIP.
 
&&

.AVIATION...VFR CONDITIONS ARE EXPECTED AT THE SLC TERMINAL 
THROUGHOUT THE DAY. THERE IS A 30 PERCENT CHANCE OF FLURRIES 
DEVELOPING IN THE VICINITY OF THE TERMINAL...WHICH WILL
TEMPORARILY LOWER CEILINGS TO 6000 FT AGL OR BELOW FOR A PERIOD
THIS MORNING. LIGHT WINDS ARE EXPECTED TO BECOME NORTHWESTERLY
BETWEEN 17Z AND 19Z.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...DENSE FOG ADVISORY UNTIL 9 AM FRIDAY FOR UTZ014.

WY...NONE.

&&

$$

PUBLIC...CONGER
AVIATION...TRAPHAGAN

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
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