FXUS65 KGJT 302242
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
342 PM MST MON NOV 30 2009
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...
DRY WEATHER WILL CONTINUE FOR ANOTHER 24 HOURS AS UPPER LEVEL FLOW
TRANSITIONS TO A MORE NORTHWESTERLY COMPONENT. THIS WILL EVENTUALLY
OPEN THE GATES FOR SHORTWAVE ENERGY OVER WESTERN CANADA TO DIVE
SOUTH ALONG THE SPINE OF THE ROCKIES ON TUESDAY. THIS SYSTEM WILL BE
DRAGGING A STRONG SFC FRONT WITH IT...WHICH WILL PASS THROUGH THE
FORECAST AREA TUESDAY NIGHT AND WEDNESDAY. H7 TEMPS WILL DROP A GOOD
5 TO 10 DEGREES ACROSS THE BOARD...WITH READINGS BOTTOMING OUT
AROUND -15C OVER THE CENTRAL PORTIONS OF OUR FORECAST AREA.
WILL BE INCREASING POPS ALONG THE DIVIDE...GENERALLY NORTH OF
INTERSTATE 70 FOR TUESDAY NIGHT AND WEDNESDAY AS THE STRONG CAA
KICKS IN. OROGRAPHICS ARE NOT ALL THAT IMPRESSIVE AT THIS POINT AND
MOISTURE WILL BE LIMITED...BUT STRENGTH OF THE CAA AND FORCING
ALONG THE FRONT WILL BE ENOUGH TO GET SOME LIGHT SNOW GOING ALONG
THE DIVIDE. AT THIS TIME WILL KEEP AMOUNTS UNDER 3 INCHES FROM VAIL
PASS NORTH TO THE PARK RANGE FOR TUESDAY NIGHT AND WEDNESDAY.
SCATTERED SNOW SHOWERS WILL ALSO BE POSSIBLE OVER THE REMAINDER OF
THE MOUNTAINS THROUGH THIS PERIOD...ALTHOUGH ACCUMULATIONS WILL NOT
BE WIDESPREAD. LITTLE CHANGE IN TEMPS EXPECTED ON TUESDAY WITH
PERSISTENCE A GOOD CHOICE. HOWEVER...THAT CHANGES TUESDAY NIGHT AND
WEDNESDAY...WITH DAYTIME HIGHS ON WEDNESDAY EXPECTED TO RUN 10
DEGREES COOLER IN MANY AREAS...WITH THE COLDEST AIR IMPACTING OUR
EASTERN ZONES...FROM CRAIG SOUTH TO ASPEN.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
...COLD AND GENERALLY DRY THIS WEEK...
...NEXT POTENTIAL WINTER STORM NOW TIMED TO START SUNDAY NIGHT...
A TROUGH OF LOW PRESSURE...EXTENDING TO THE SW FROM HUDSON BAY...
WILL DEEPEN THROUGH THURSDAY. THE TROUGH SHIFTS EAST ON FRIDAY AND
ALLOWS TRANSIENT HIGH PRESSURE TO BUILD IN FROM THE WEST. THIS
WEEKEND THE PACIFIC RELOADS WITH THE FAVORED EC/CANADIAN KEEPING
MOST OF THIS ENERGY IN THE NORTHERN ROCKIES. FINALLY SUNDAY NIGHT-
MONDAY A TROUGH DIGS DOWN THE WEST COAST AND CLOSES. THIS IS
CURRENTLY PROGGED TO TAP SOME MOISTURE FROM THE SW...WITH AN
ASSOCIATED COLD FRONT PASSING LATE MONDAY.
WEDNESDAY NIGHT-THURSDAY NIGHT: THE GFS IS COLDER BUT BOTH MODELS
ARE KEEPING THE -36C COLD CORE ON THE EAST SIDE OF THE DIVIDE.
STILL COLD ADVECTION IS IMPRESSIVE IN OUR EASTERN CWA WITH 700 TEMPS
DROPPING TO -18 OR EVEN -20C THURSDAY NIGHT. LOWERED TEMPERATURES
FOR THESE PERIODS WITH THE EASTERN MTNS AND VALLEYS POSSIBLY DROPPING
BELOW ZERO F THURSDAY NIGHT. MOISTURE COMES FROM THE NW WITH THIS
SYSTEM SO IT IS QUITE MOISTURE STARVED. SNOW SHOWERS WILL FAVOR THE
CONTINENTAL DIVIDE AND LOOK TO BE LIGHT.
FRIDAY-SUNDAY: LOWERED POPS TO ZERO FOR FRIDAY UNDER THE RIDGE OF
HIGH PRESSURE. SATURDAY...THE FAVORED EC/CANADIAN DIGS A LOW TO JUST
OFF THE OREGON COAST WITH A DEFORMATION ZONE STRETCHED DUE EAST
ACROSS THE NORTHERN ROCKIES. THIS KEEPS OUR FORECAST AREA SOUTH OF
THE MOISTURE AND FORCING. IN DEFERENCE TO THE DEEPER GFS...HAVE
KEPT ISOLATED POPS IN THE NORTHERN MTNS.
SUNDAY NIGHT-MONDAY: MODELS COME BACK INTO AGREEMENT FOR THE
DEEPENING AND THEN PROGRESSIVE PACIFIC LOW. THE GFS...THAT SEEMS
OVER-COLD IN THE SHORT TERM...IS PUSHING A -30C COLD CORE TO CENTRAL
UTAH ON MONDAY WITH THE ASSOCIATED COLD FRONT INTO THE NORTHERN CWA
MONDAY AFTERNOON.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL OVER THE FORECAST AREA THROUGH TUESDAY
WITH DRY NORTHWEST FLOW ALOFT IN PLACE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JDC
LONG TERM....JOE
AVIATION.....JDC
