FXUS65 KGJT 031016
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
316 AM MST THU DEC 3 2009

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT...

VERY COLD AIR WILL CONTINUE SPREADING ACROSS EASTERN UT AND WESTERN
CO TODAY AS AN UPPER TROUGH SINKS ACROSS THE REGION.  TROUGH AXIS
EXPECTED TO SLIDE OVERHEAD THIS AFTERNOON...WITH THE TROUGH TO THE
EAST AND SOUTH BY FRI MORNING. WEAK UPPER DIVERGENCE AND 500 MB PVA
ACROSS THE 4-CORNERS AND SW CO THIS MORNING WITH THE NOSE OF THE
NEXT JET/VORT MAX...AND SOME SHALLOW UPSLOPE ON THE NORTH SIDE OF
THE HIGHER TERRAIN IN NW CO AND NE UT ABOUT THE ONLY FORCING.
SCARCITY OF MOISTURE CONTINUES WITH ONLY SCATTERED LIGHT SNOW SHOWERS
MAINLY NEAR THE DIVIDE.

CLEAR SKIES AND DRY AIR WILL FAVOR RADIATIONAL COOLING TONIGHT IN
ADDITION TO THE ALREADY COLD AIRMASS...FOR EVEN COLDER TEMPERATURES
FRI MORNING THEN THIS MORNING. FRIDAY WILL BE ANOTHER STABLE DAY WITH
THE COLD AIR ENTRENCHED IN THE VALLEYS AS WARM ADVECTION COMMENCES
ALOFT. THIS OCCURS AS AN ENERGETIC SHORTWAVE DROPS INTO THE PACNW/NRN
ROCKIES BY FRI EVE...BACKING WINDS ALOFT TO THE W-SW. THIS WILL
ALSO RESULT IN QUITE STABLE CONDITIONS FRI. SHOULD SEE SOME HIGH
CLOUDS MOVE ACROSS FRI AFTERNOON AHEAD OF THIS DIGGING SHORTWAVE
TROUGH. LOOK FOR A LITTLE WARMER TEMPS FRI NIGHT.

.LONG TERM...SATURDAY THROUGH WEDNESDAY...

MAJOR PATTERN CHANGE EXPECTED THROUGH THIS PERIOD AS LOW PRESSURE
DROPS SOUTH OUT OF CANADA AND SETTLES INTO THE PACNW. INITIALLY...
MOISTURE WILL BE LIMITED...WITH THE FORECAST STARTING OFF ON THE
DRY SIDE SATURDAY. FLOW ALOFT TRANSITIONS TO A MORE WESTERLY
COMPONENT BY SATURDAY NIGHT AS BROAD TROUGHING DEVELOPS TO OUR
NORTH. THIS WILL BRING A GRADUAL INCREASE OF PACIFIC MOISTURE
STARTING SATURDAY NIGHT AND PERSISTING THROUGH TUESDAY. EXPECT
A SERIES OF SHRTWVS TO MOVE THROUGH THE FORECAST AREA IN VERY MOIST
WESTERLY FLOW. VERY FAVORABLE PATTERN FOR SIGNIFICANT PRECIPITATION
OVER MUCH EASTERN UTAH AND WESTERN COLORADO...INCLUDING MANY OF THE
VALLEYS. AT THIS POINT...IT APPEARS THE BEST CHANCE FOR SIGNIFICANT
SNOWFALL WILL ARRIVE MONDAY AND MONDAY NIGHT AS THE PACNW LOW
SLIDES SLOWLY EAST WITH TROUGH PASSAGE EXPECTED TUESDAY AFTERNOON.
THIS WILL RESULT IN A PROLONGED PERIOD OF SNOWFALL OVER OUR AREA...
WITH THE HEAVIEST SNOW EXPECTED OVER OUR CENTRAL AND SOUTHERN
MOUNTAINS ATTM. PRECIP WINDS DOWN BY TUESDAY NIGHT WITH FLAT
RIDGING SLIDING IN FOR WEDNESDAY.  TEMPS WILL REMAIN COLD...ALTHOUGH
SOME MODERATION EXPECTED WITH INCREASED MOISTURE AND CLOUD COVER AS
WE START OFF THE NEW WEEK.

&&

.AVIATION...
VFR CONDITIONS EXPECTED ACROSS EASTERN UTAH AND WESTERN COLORADO
THROUGH FRIDAY AS SHRTWV RIDGING BUILDS OVER THE AREA.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...NONE.
UT...NONE.

&&

$$

SHORT TERM...JAD
LONG TERM....JDC
AVIATION.....TGJT