FXUS65 KGJT 262236
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
336 PM MST THU NOV 26 2009

.SHORT TERM...TONIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE WILL REMAIN OVER THE AREA TONIGHT AND MOVE
EAST FRIDAY. SOUNDINGS AND MODELS SHOW THE WEST COAST TROUGH
SLOWING CONSIDERABLY OVER PREVIOUS RUNS...WITH A GOOD CLOSED LOW
FORMING OVER SOUTHERN CA FRIDAY. THIS PUTS A SIGNIFICANT DRAG ON THE
NORTHERN PORTION OF THE SYSTEM...RESULTING IN A 12+ HOUR DELAY IN
CLOUDS AND MOISTURE REACHING THE AREA. HAVE ELIMINATED ALL CLOUDS
FOR TONIGHT AND MUCH OF FRIDAY. HAVE DECREASED CLOUDS AND POPS FRIDAY
AND FRIDAY NIGHT...AND MADE SIGNIFICANT ADJUSTMENTS FOR SATURDAY. IT
APPEARS NOW THIS STORM WILL HIT THE SOUTHERN PART OF THE FORECAST
AREA FIRST AND HARDER...SO HAVE EMPHASIZED WEATHER OVER THE SOUTHWEST
THIRD OF THE AREA SATURDAY. EVEN THOUGH ITS ONLY 4 PERIODS AWAY...
UNCERTAINTY REMAINS HIGH FOR SATURDAYS WEATHER.

.LONG TERM...SATURDAY THROUGH THURSDAY...
ANOTHER COMPLEX SPLITTING SYSTEM FOR THE MODELS TO RESOLVE. MODELS
ARE NOW IN FAIRLY GOOD AGREEMENT WITH A SPLITTING TROUGH. THE
NORTHERN PART OF THE TROUGH MOVES EAST OVER THE NORTHERN PLAINS WITH
THE SOUTHERN EDGE SKIRTING THE PARK RANGE SATURDAY NIGHT AND EARLY
SUNDAY. BY SATURDAY NIGHT THE SOUTHERN PART OF THE TROUGH...IS A
CLOSED LOW OVER SOUTHERN CA MOVING INTO NORTHERN BAJA. THE SOUTHERN
LOW PULLS MOISTURE OVER THE SOUTHERN THIRD OF THE FORECAST AREA IN
SOUTHWESTERLY FLOW. BETWEEN THE TWO PARTS A DEFORMATION ZONE TRACKS
OVER THE REGION. AN ASSOCIATED COLD FRONT WILL ALSO TRACK OVER THE
SOUTHERN PAR OF THE CWA AND SHOULD EXIT THE SOUTHERN BORDER BY EARLY
SUNDAY. SHIFTED PRECIPITATION CHANCES MORE SOUTH WITH THIS SOLUTION.
KEEPING SNOW OVER THE NORTHERN MOUNTAINS OF WESTERN CO BECAUSE OF THE
SOUTHERN EDGE OF THE NORTHERN TROUGH AND THE ASSOCIATED JET. CLEAR
OUT THE SHOWERS FOR MOST AREAS BY SUNDAY EVENING WITH DRYER NORTHERLY
FLOW. A FEW SHOWERS WILL LINGER OVER THE SOUTH CENTRAL AND SAN JUAN
MOUNTAINS.

A RIDGE BUILDS OVER THE GREAT BASIN FOR MONDAY INTO TUESDAY. THEN
THE MODELS DIVERGE AGAIN. THE NEW GFS NO LONGER BRINGS A VERY COLD
CANADIAN TROUGH INTO THE CENTRAL ROCKIES BUT KEEPS IT ALONG THE
NORTHERN US BORDER WITH A CLOSED PAC LOW MAKING LAND FALL OVER
CENTRAL CA. THE EC CONTINUES THE TREND OF DIGGING A TROUGH SOUTH
OVER THE ROCKIES BY MID WEEK...ALTHOUGH THE TIMING IS SLIGHTLY
SLOWER. BIASED TOWARD THE EC SOLUTION WITH COLDER TEMPERATURES AND
INCREASED PRECIPITATION CHANCES FOR THE NORTHERN MOUNTAINS AND
ALONG THE DIVIDE BY MID WEEK.

&&

.AVIATION...
VFR CONDITIONS TO CONTINUE FOR NEXT 24 HOURS.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM.....CJC
LONG TERM......AS
AVIATION.......TGJT