FXUS65 KSLC 241154
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
454 AM MST THU DEC 24 2009
.SYNOPSIS...STRONG HIGH PRESSURE ALOFT ALONG THE WEST COAST WILL
SLIDE EAST INTO THE INTERIOR WEST THIS WEEKEND.
&&
.DISCUSSION...THE HIGH AMPLITUDE UPPER RIDGE ALONG THE WEST COAST
PRODUCING A LONG NORTHERLY CYCLONIC FLOW INTO THE GREAT BASIN.
SHEAR VORTICITY LOBES MOVING THROUGH THE FLOW WILL OFFER LITTLE
THREAT FOR SNOW AS THERMAL ADVECTION WEAK AT BEST AND THE LOW-
LEVELS REMAIN RATHER COLD AND STABLE. THE ONLY REAL WEATHER ISSUES
THE NEXT SEVERAL DAYS WILL BE THE COLD VALLEYS TEMPS AND THE
DEVELOPMENT OF SOME FOG AND URBAN HAZE HEADING INTO AND THROUGH
THE COMING WEEKEND.
LONG RANGE GUIDANCE MATCHING UP REASONABLY WELL DURING THE EARLY
AND MIDDLE PORTIONS OF NEXT WEEK. THE HIGH AMPLITUDE RIDGE IS
SCHEDULED TO PINCH OFF THE NRN PORTION OVER SRN CANADA/NRN ROCKIES
WITH THE WESTERLIES UNDERCUTTING ACROSS THE SRN GREAT BASIN. A
COUPLE OF DECAYING SHORTWAVES EMBEDDED WITHIN THE WESTERLIES WILL
MOVE THROUGH THE BASIN LATE IN THE WEEKEND. WEAK DYNAMIC LIFT AND
MINIMAL THERMAL ADVECTION SUGGEST THAT ANY PRECIP THAT DEVELOPS
WILL BE ON THE LIGHT SIDE WITH LIMITED COVERAGE. A MORE ENERGETIC
SYSTEM WILL REACH THE COAST AND SPLIT EARLY NEXT WEEK. THE BULK
OF THE ENERGY WILL DIVE SOUTHEAST INTO NRN MEXICO...AND WILL BE
FAR REMOVED FROM EVEN SRN UTAH. HAVE KEPT A MENTION OF PRECIP FOR
MONDAY/TUESDAY...BUT SUSPECT THAT NRN UTAH WILL END UP DRY AND SRN
UTAH WILL SEE SPOTTY PRECIP AT BEST AS THIS FEATURE PASSES WELL TO
THE SOUTH.
&&
.AVIATION...VFR CONDITIONS EXPECTED TO PERSIST AT KSLC THROUGH THE
PERIOD WITH A 10 PERCENT CHANCE OF TEMPORARY MVFR CIGS THROUGH 16Z.
OTHERWISE CURRENT STRATUS DECK IN THE 4-5KFT RANGE SHOULD SCATTER
OUT BY 18Z...WITH A 20 PERCENT CHANCE THIS LAYER HOLDS TOGETHER
THROUGH 21Z. SURFACE WINDS TO REMAIN LIGHT THROUGH THE PERIOD.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&
$$
PUBLIC...CONGER
AVIATION...SEAMAN
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
