FXUS65 KSLC 240505
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1005 PM MST WED DEC 23 2009

.SYNOPSIS...A COLD NORTHERLY FLOW WILL BE OVER THE AREA INTO THE
WEEKEND. 

&&

.DISCUSSION...A SHARP HI AMPLITUDE RIDGE IS CENTERED JUST OFF THE
WEST COAST THIS EVE WITH A STRONG NORTHERLY FLOW ALOFT OVER OUR
AREA. A COLD LOW IS DIVING SOUTH INTO THE PLAINS THIS EVE AND IS
HELPING SET THE STAGE FOR THE BIG MIDWEST SNOW STORM OVER THE
NEXT SEVERAL DAYS. COLD AIR ASSOCIATED WITH THIS LOW HAS MADE IT
WEST OF THE DIVIDE AND IS SPILLING INTO THE CWA. THIS LIKELY
PROVIDED SOME EXTRA LIFT FOR THE STRATUS IN PLACE ALONG THE
UPWIND SLOPES OF THE NRN AND CENTRAL MTNS LATE IN THE AFTN THRU
THIS EVE AND RESULTED IN AREAS OF LIGHT SNOW ALONG THE WASATCH
FRONT. 

THE LOWER LEVELS ARE FORECAST TO GRADUALLY DRY LATER TONIGHT THRU
THU BUT THE AIRMASS REMAINS COOL SO INVERSIONS WILL BE SLOWER TO
STRENGTHEN. ANOTHER WEAK WAVE IS FORECAST TO BRING AN INCREASE IN
LOW LEVEL MOISTURE AGAIN ON FRI TO MAINLY THE NERN 1/4 OF THE CWA. 

THE RIDGE PINCHES OFF INTO A CLOSED HIGH OVER SWRN CANADA BY SAT
AND WE WILL START TO SEE WEAKENING SYSTEMS BREAKING THRU UNDER THE
RIDGE INTO THE WESTERN STATES LATER IN THE WEEKEND AND EARLY NEXT
WEEK. 

FOR TONIGHT...EXPECT FOG WILL BE ISOLATED TO THE COLDEST NRN
VALLEYS AND PROBABLY WONT DEVELOP ALONG THE WASATCH FRONT MUCH
SOUTH OF BRIGHAM CITY. DONT EXPECT IT IN THE SOUTH AND EAST AS
THERE HAS BEEN TOO MUCH MIXING THROUGH THE AFTERNOON AND EVE DUE
TO BRISK NORTH WINDS. THESE WINDS ARE CONTINUING INTO THE NIGHT
BUT SHOULD RELAX TOWARDS MORNING. THE GAP WINDS IN DIXIE SHOULD
REMAIN SUB ADVISORY. 

UPDATED EARLIER TO INCREASE CLOUD COVER AND THE MENTION OF LIGHT
SNOW ACROSS THE NORTH FOR THE EVE AND ADJUST FOG COVERAGE
OVERNIGHT. NO ADDITIONAL UPDATES PLANNED. 

&&

.AVIATION...VFR CONDITIONS EXPECTED TO CONTINUE AT THE SLC TERMINAL 
THROUGH TOMORROW. ENOUGH WIND AND CLOUDS TO KEEP FOG FROM FORMING 
TONIGHT. WINDS SHOULD REMAIN LIGHT AND VARIABLE THROUGH AROUND 04Z 
TO 05Z THEN BECOME LIGHT SOUTHEASTERLY.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.

&&

$$

WILENSKY/YOUNG

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HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)