FXUS65 KSLC 082249
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
349 PM MST TUE DEC 8 2009
.SYNOPSIS..A WEAK AND RATHER COLD WEATHER DISTURBANCE WILL ENTER
NORTHERN UTAH FROM THE NORTHWEST LATE TONIGHT...FOLLOWED BY A VERY
COLD NORTHERLY FLOW ALOFT WEDNESDAY. COLD TEMPERATURES WILL REMAIN
ACROSS UTAH THROUGH THE BALANCE OF THE WEEK.
&&
.DISCUSSION...SNOW SHOWERS ARE DISSIPATING RAPIDLY THIS AFTERNOON
AS THE MASSIVE STORM SYSTEM THAT BROUGHT WIDESPREAD SNOW TO THE
GREAT BASIN MOVES OUT INTO THE CNTRL PLAINS STATES. HAVE DROPPED
ALL WEATHER HIGHLIGHTS THIS AFTERNOON...BUT WILL LEAVE A MENTION
OF SHOWERS OVER THE HIGH TERRAIN THROUGH EARLY EVENING. THE COLD
UPPER TROUGH MOVING SOUTH THROUGH OREGON AT TIME WILL TURN SE
SHORTLY...AND THEN RACE THROUGH NRN UTAH LATE TONIGHT/WEDNESDAY
MORNING. ENOUGH DYNAMIC LIFT AND MID-LEVEL COLD AIR TO OFFSET AN
INCREASINGLY STABLE LOW-LEVEL AIRMASS TO GENERATE SOME LIGHT
SNOW INTO EARLY WEDNESDAY.
A BITTERLY COLD NORTHERLY FLOW ALOFT WILL DEVELOP WEDNESDAY IN THE
WAKE OF TONIGHTS TROUGH PASSAGE. THE BULK OF THE COLD AIR WILL
STAY ON THE EAST SIDE OF THE DIVIDE...THOUGH ENOUGH WILL TRICKLE
INTO NRN UT/SW WY TO HAVE AN IMPACT. THE COMBINATION OF FRESH/DEEP
SNOW AND GENERALLY CLEAR SKIES WILL KEEP TEMPS MUCH BELOW NORMAL
THROUGH AT LEAST THURSDAY.
THE WESTERLIES ARE PROGGED TO BREAK THROUGH FROM THE ERN PACIFIC
BY FRIDAY. SUBSTANTIAL WARMING ALOFT WILL COME WITH THIS CHANGE
THURSDAY NIGHT...STRENGTHENING VALLEY INVERSIONS AND POSSIBLY
LEADING TO A NOTABLE INCREASE IN VALLEY FOG. VALLEY TEMPS WILL
REMAIN COLD...ESPECIALLY ACROSS ERN UTAH...WITH MOUNTAIN LOCATIONS
MODERATING SOMEWHAT.
INCREASING PACIFIC MOISTURE ACCOMPANIED BY A SERIES OF EMBEDDED
DISTURBANCES WILL CROSS THE WRN CONUS SATURDAY THROUGH MONDAY. THE
FEATURE OF MOST INTEREST WILL BE THE ONE SCHEDULED TO ARRIVE SUNDAY.
MOIST WARM ADVECTION AHEAD OF THIS FEATURE COULD GENERATE A NICE
OVERRUNNING PRECIP EVENT WITH ALL THE COLD AIR DOMED IN THE
VALLEYS. MODEST DYNAMIC LIFT AND THERMAL ADVECTION WILL ACCOMPANY
THE TROUGH THROUGH UTAH SUNDAY/SUNDAY NIGHT. PRECIP SHOULD SHUT
DOWN FAIRLY QUICKLY AS HEIGHTS BUILD RAPIDLY TO OUR WEST EARLY
NEXT WEEK. TEMPS WILL REBOUND NICELY AT THE HIGHER ELEVATIONS...
WITH VALLEYS TYPICALLY SLOW TO RESPOND WITH THIS MUCH SNOW COVER
AND LOW SUN ANGLE.
&&
.AVIATION...ONLY EXPECTING ISOLATED SNOW FLURRIES AT THE SLC TERMINAL
EARLY THIS EVENING...AND AGAIN LATE TONIGHT. VFR CONDITIONS ARE NOW
EXPECTED TO REMAIN THROUGH THE FORECAST PERIOD. A 20 PERCENT
CHANCE OF MVFR CONDITIONS WITH SNOW SQUALLS OFF THE LAKE IS
POSSIBLE. WINDS WILL REMAIN OUT OF THE NORTHWEST UNTIL 02Z-03Z
WHEN SOUTHEAST DRAINAGE DEVELOPS.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&
$$
PUBLIC...CONGER
AVIATION...YOUNG
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
