Area Forecast Discussion
Issued by NWS Grand Junction, CO

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000
FXUS65 KGJT 141027
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
427 AM MDT MON APR 14 2014

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 403 AM MDT MON APR 14 2014

THE FREEZE WARNING FOR THE GRAND VALLEY AND THE DELTA/MONTROSE AREAS
REMAINS IN EFFECT UNTIL 8 AM THIS MORNING.

SATELLITE WATER VAPOR IMAGES SHOWED THE UPPER TROUGH OVER ERN CO AND
HEADED INTO THE PLAINS EARLY THIS MORNING. 4AM METAR OBSERVATIONS
AND CDOT WEBCAMS INDICATED SNOW PERSISTED NEARER THE CONTINENTAL
DIVIDE IN NW OROGRAPHIC FLOW BEHIND THE TROUGH. THIS WILL CONTINUE
TO EXHIBIT A DECREASING TREND OVER THE NEXT SEVERAL HOURS AS LARGE-
SCALE SUBSIDENCE AND DRIER AIR CONTINUE TO MOVE IN BEHIND THE UPPER
TROUGH. SUNNY SKIES WILL PREVAIL ACROSS THE ENTIRE FORECAST AREA BY
NOON.

HIGH PRESSURE SLIDES OVER THE FORECAST AREA TONIGHT. DRY AIR AND
CLEAR SKIES TO START TONIGHT WILL PROMOTE RADIATIONAL COOLING...AND
FREEZING TEMPS ARE EXPECTED TONIGHT FOR ALL BUT SE UT. BUT WARM
ADVECTION AT 700 MB AFTER MIDNIGHT AND SOME HIGH CLOUDS MOVING
INTO NE UT/NW CO BY SUNRISE ADDS SOME UNCERTAINTY FOR A HARD
FREEZE IN THE FRUIT AREAS OF THE GRAND VALLEY AND DELTA/MONTROSE
AREAS. THEREFORE...WILL ISSUE A FREEZE WATCH FOR THESE AREAS
(ZONES 6 AND 11) TONIGHT AND GIVE THE DAY SHIFT ANOTHER CHANCE TO
EVALUATE.

HIGH PRESSURE WEAKENS TUESDAY AS THE NEXT PACIFIC TROUGH MOVES
INLAND TO WRN WY BY LATE IN THE DAY. HIGH TEMPS WILL BE WARMER WHILE
CLOUDS INCREASE FROM THE NW. A FEW ISOLATED SHOWERS ARE POSSIBLE
OVER THE EASTERN UINTA AND THE ELKHEAD MTNS IN THE FAR NORTH LATE IN
THE DAY.


.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 403 AM MDT MON APR 14 2014

THE WEAK RIDGE OVER THE WESTERN U.S. WILL BE FLATTENED BY A
SHORTWAVE TROUGH AND MODERATELY STRONG COLD FRONT BEGINNING TUE
NIGHT IN BOTH THE GFS AND ECMWF. BOTH MODELS SHOW A MOST OF THE
ENERGY AND COLD AIR PLUNGING DOWN THE FRONT RANGE THE COLD FRONT
PROGRESSING N TO S THROUGH WESTERN CO AND EASTERN UT TUE NGT
THROUGH WED NGT. PASSAGE OF THE FRONT SHOULD BRING 6 TO 10
DEGREES OF COOLING WED...WITH SCATTERED TO NUMEROUS SHOWERS OVER
NE UT AND NW AND CENTRAL CO...WHILE ISOLD TO SCATTERED SHOWERS
AFFECT SE UT AND SW CO.

ANOTHER GREAT BASIN RIDGE WILL BUILD IN THU MORNING AND PUSH THE
MOISTURE AND PRECIP QUICKLY EAST. THIS RIDGE SHARPENS THROUGH
FRI...THEN TWO TROUGHS WILL APPROACH FROM THE WEST...AN OLD LOW
OVER THE BAJA COAST AND AN OPEN WAVE MOVING OUT OF THE PACNW. THE
GFS KEEPS THESE FEATURES RELATIVELY LOW AMPLITUDE AND FAST-MOVING.
IT HAS THESE FEATURES BREEZING THROUGH THE AREA LATE FRI AFTERNOON
AND SAT. THE GFS LEAVES A DEFORMATION ZONE AND AREAS PRECIP OVER
THE AREA THROUGH THE WEEKEND. THE ECMWF DEVELOPS STRONGER TROUGHS...
WHICH COME INTO PHASE AND COMBINE INTO A SINGLE CLOSED LOW OVER
THE WESTERN GREAT BASIN AND SOUTHERN CA FRI AFTERNOON. THE EC
KEEPS MORE SIGNIFICANT PRECIP AND CLOUDS OVER THE AREA THROUGH
THE WEEKEND. SO UNCERTAINTY REMAINS HIGH FOR THE SITUATION AT THE
END OF THE WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 403 AM MDT MON APR 14 2014

SNOW SHOWERS WITH ISOLD MVFR/IFR CONDITIONS AND MOUNTAIN
OBSCURATIONS WILL DISSIPATE QUICKLY THIS MORNING...CLEARING THE
AREA BY ABOUT 16Z.

MOSTLY CLEAR SKIES AND VFR CONDITIONS WILL PREVAIL THIS AFTERNOON
THROUGH TUE MORNING.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
     COZ006-011.

     FREEZE WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ006-011.

UT...NONE.
&&

$$

SHORT TERM...JAD
LONG TERM...CC
AVIATION...CC



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