FXUS65 KSLC 152301
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
401 PM MST TUE DEC 15 2009
.SYNOPSIS...A MOIST WESTERLY FLOW ALOFT WILL BRING A SERIES OF
WEAK STORM SYSTEMS ACROSS NORTHERN UTAH THROUGH THURSDAY. HIGH
PRESSURE ALOFT WILL FOLLOW FOR THE COMING WEEKEND.
&&
.DISCUSSION...A MOIST LOW-AMPLITUDE WESTERLY FLOW ALOFT WILL SET
UP ACROSS NRN UTAH AND POINTS NORTH THROUGH THURSDAY. PRECIP WILL
FOR THE MOST PART BE ON THE LIGHT SIDE AS THE MOST OF THE EMBEDDED
SHORTWAVE ENERGY REMAINS OVER THE NRN ROCKIES/FAR NRN GREAT BASIN.
FOR TONIGHT LOW-LEVEL WARM ADVECTION WITH SLIGHT MID-LEVEL COOLING
SHOULD SUPPLY ENOUGH LIFT FOR LIGHT PRECIP NEAR THE UT/ID BORDER.
COLD AIR TRAPPED IN THE FAR NRN VALLEYS SHOULD KEEP THE PRECIP TYPE
SNOW...WITH A BRIEF RAIN/SNOW MIX POSSIBLE ALONG THE NRN WASATCH
FRONT THIS EVENING WHERE THE COLD AIR MIXED OUT A BIT TODAY.
A LITTLE BETTER THREAT FOR PRECIP MAY COME ON WEDNESDAY NIGHT
AS A MORE ENERGETIC SHORTWAVE MOVES EAST ALONG THE UT/ID BORDER
REGION. MODEST COLD ADVECTION...WEAK DYNAMIC LIFT...AND DEEP
LAYER MOISTURE MORE THAN SUFFICIENT TO PRODUCE PRECIP ACROSS THE
FAR NORTH WEDNESDAY NIGHT. SNOW STILL LOOKS TO BE THE DOMINATE PRECIP
TYPE...THOUGH SOME AREAS OF THE NRN WASATCH FRONT MAY AGAIN SEE
SOME RAIN WITH THE SNOW.
HEIGHTS BEGINNING TO BUILD WEST OF UTAH ON THURSDAY...WITH THE
UPPER RIDGE REMAINING THE DOMINATE FEATURE TO OUR WEST THROUGH THE
COMING WEEKEND. THE LATEST GFS MODEL NOW LINING UP WITH THE
ECMWF/CANADIAN MODELS FOR SATURDAY NIGHT/SUNDAY. THE GFS NO LONGER
BRINGS A DIGGING SHORTWAVE THROUGH NRN UTAH...BUT RATHER PUSHES IT
FURTHER NORTH INTO THE NRN ROCKIES AS IT TRACKS SE. COULD STILL
SEE CLOUDS AND SOME LIGHT PRECIP...BUT NOT AS MUCH AS EARLIER
INDICATED IN THE GFS MODEL.
THE UPPER RIDGE LOOKS TO HOLD FIRM THROUGH MONDAY NIGHT. LONG
RANGE GUIDANCE AGAIN DIVERGE...THOUGH THE GENERAL IDEA OF COLDER
TEMPS WITH AN INCREASING THREAT OF PRECIP MIDWEEK APPEARS IN ALL
OF THE GUIDANCE. THE ECMWF/CANADIAN SOLUTIONS ARE CLEARLY THE
COLDER MODELS...DRAWING COLD AIR DUE SOUTH OUT OF NRN CANADA. THE
GFS IS RELATIVELY MILDER...THOUGH IT STILL TAPS SOME OF THAT COLD
AIR AS IT BRING A TROUGH EAST OUT OF THE PACIFIC NW TUESDAY/WEDNESDAY.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED AT THE SLC TERMINAL THROUGH
TONIGHT...WITH A 30 PERCENT CHANCE THAT CIGS WILL DROP BELOW 6000
FT AGL AFTER 04Z. SOUTHERLY WINDS ARE EXPECTED TO CONTINUE
THROUGH THE OVERNIGHT HOURS.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&
$$
PUBLIC...CONGER
AVIATION...TRAPHAGAN
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
