Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 120605
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1205 AM MDT SAT JUL 12 2014

.UPDATE...
ISSUED AT 1200 AM MDT SAT JUL 12 2014

CONVECTION IS CONTINUING EARLY THIS MORNING IN THREE AREAS. FIRST
IS ALONG A PERSISTENT LINE EXTENDING FROM THE EASTERN UT PORTION
OF THE TAVAPUTS PLATEAU TO NW MOFFAT COUNTY IN NW CO. SECOND IS
ALONG ANOTHER PERSISTENT LINE EXTENDING FROM DELTA...CO TO THE
NORTHEAST OVER THE GRAND MESA AND THE COLORADO RIVER VALLEY OVER
EAGLE AND VAIL. AND THE THIRD AREA BEING THE SAN JUAN MOUNTAINS
AND SE UTAH...WHERE WEAKENING THUNDERSTORMS ARE PUSHING A BROAD
OUTFLOW BOUNDARY TO THE WEST...ACROSS MUCH OF SW CO AND INTO SE
UT. THESE AREAS WILL REMAIN ACTIVE THROUGH ABOUT 4 AM...THOUGH
CONVECTION AND RAINFALL WILL SLOWLY DECREASE THROUGH THAT TIME.

&&

.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 251 PM MDT FRI JUL 11 2014

STARTING TO SOUND LIKE A BROKEN RECORD WITH AFTERNOON/EVENING
SHOWERS AND STORMS FORECASTED YET AGAIN. MODELS HAVE PICKED UP ON
BEST DIVERGENCE ALOFT OVER CONTINENTAL DIVIDE AND NORTHERN UT/CO WHICH
IS ALSO WHERE A PV LOBE IS PROGGED TO MOVE OVER THIS EVENING.
BEHIND THIS PV LOBE...WATER VAPOR IMAGERY SHOWS PLENTY OF DRIER
AIR MOVING INTO THE AREA WHICH SHOWS UP IN LESS COVERAGE TOMORROW.
FOR THE REMAINDER OF TODAY INTO TONIGHT...ISOLD/SCT STORMS WILL
CONTINUE WITH SOME HEAVY RAINERS POSSIBLE AS PWATS REMAIN VERY
HIGH OVER THE CWA.

AS PREVIOUSLY MENTIONED...WATER VAPOR IMAGERY INDICATES
DRIER AIR MOVING INTO THE REGION THIS EVENING WHILE TOMORROW...H7
WINDS WILL BECOME MORE WESTERLY AND THEN NORTHERLY WHICH WILL
LIMIT...SOMEWHAT...AVAILABLE MOISTURE. HOWEVER...ENOUGH MOISTURE
WILL REMAIN TRAPPED UNDER THE HIGH PRESSURE TO ALLOW ANOTHER DAY
OF CONVECTION THOUGH STORMS SHOULD BE LIMITED TO THE SAN JUANS
WITH WEAK CELLS POPPING OVER THE REMAINING HIGHER TERRAIN. DO NOT
ANTICIPATE MUCH PRECIP IN THE VALLEYS BUT LEFT CHC TO SCHC IN
FORECAST IN THE OFF CHANCE A STRAY SHOWER OR STORM MAKES IT OFF
THE HIGHER TERRAIN.

NO BIG SWINGS IN TEMPERATURES EXPECTED STAYING NEAR NORMAL INTO
THE WEEKEND.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 251 PM MDT FRI JUL 11 2014

THE PERSISTENT UPPER HIGH STRENGTHENS OVER THE GREAT BASIN EARLY
NEXT WEEK. THE RESULTING NW FLOW ALOFT ERODES MOISTURE
SLIGHTLY... TO LESS THAN ONE INCH PWAT VALUES FOR ALL BUT THE
SOUTHERN MOST ZONES. SO THE DAILY THUNDERSTORM GENERATION WILL
FAVOR THE SOUTH FIRST OVER THE MOUNTAINS MOVING OVER THE VALLEYS
LATE IN THE AFTERNOON AND INTO THE EVENING HOURS. IMPORTANT
DISTURBANCES ARE NEARLY IMPOSSIBLE TO DEFINE THIS FAR OUT. ONE
SIGNIFICANT IMPULSE WILL DROP DOWN THE EAST SIDE OF THE HIGH ON
WEDNESDAY PROVIDING SOME UPPER JET DYNAMICS. NW GRADIENT WINDS
WILL INCREASE ON TUESDAY AND WEDNESDAY.

THURSDAY-FRIDAY THERE IS LESS CERTAINTY WITH THE LARGE SCALE
PATTERN. THE GFS REBOUNDS THE RIDGE OVER THE ROCKIES...WHILE THE
EC FLATTENS THE RIDGE INTO THE DESERT SW. BOTH MODELS CONTINUE TO
PRODUCE DIURNAL SHOWERS.

TEMPERATURES WILL BE NEAR NORMAL FOR THESE PERIODS FOR THIS THE
CLIMATOLOGICALLY HOTTEST PERIOD OF THE YEAR.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1034 PM MDT FRI JUL 11 2014

A WEAK DISTURBANCE CONTINUED TO BRING SCATTERED SHOWERS AND
THUNDERSTORMS TO WESTERN COLORADO. A BAND OF ACTIVITY STRETCHING
FROM NORTH OF KEGE TO 5NW KAJZ WILL CONTINUE TO SWEEP SLOWLY
EASTWARD THROUGH 09Z BRINGING A HIGH PROBABLY FOR BRIEF HEAVY RAIN
AND IFR VSBY TO BOTH KEGE AND KASE. MEANWHILE...TO THE SOUTH AN
AREA OF SHOWERS WAS OVER KDRO AND MAY CONTINUE TO BRING LIGHT RAIN
THROUGH 07Z. HOWEVER...INTENSITY SHOULD REMAIN LIGHT SO VFR
CONDITIONS SHOULD PERSIST.

THUNDERSTORMS WILL WEAKEN LATE EARLY THIS MORNING WITH A FEW
SHOWERS POSSIBLY LINGERING LATE TONIGHT. TAF IMPACTS WILL BE
MINIMAL WITH VFR CONDITIONS EXPECTED ACROSS THE REGION THROUGH
18Z/SATURDAY. A BIT LESS MOISTURE INDICATED FOR SATURDAY AFTERNOON
SO EXPECT THUNDERSTORM COVERAGE WILL BE REDUCED.


&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&

$$

UPDATE...CC
SHORT TERM...TGR
LONG TERM...JOE
AVIATION...NL


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