Area Forecast Discussion
Issued by NWS Grand Junction, CO

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000
FXUS65 KGJT 252113 AAA
AFDGJT

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
313 PM MDT SAT JUL 25 2015

CORRECTED ERROR IN FIRE WX SECTION

.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 312 PM MDT SAT JUL 25 2015

ATYPICAL JULY AFTERNOON IN A COUPLE OF WAYS...NO CONVECTIVE STORMS
AS OF 19Z. HRRR AND RAP INDICATE THAT A STORM OR TWO WILL POP OVER
THE SAN JUANS LATER THIS AFTERNOON AND PROMPTLY MOVE EAST.
CONVECTIVE ACTIVITY HAS DOMINATED THIS JULY...SO THE LACK OF
STORMS SEEMS OUT OF PLACE. ABUNDANT SUNSHINE PREVAILS TODAY BUT
HARDLY A SCORCHER. OUTSIDE OF MONUMENT VALLEY...NO TEMP SENSOR
HAVE REACHED 90F BY 1 PM. THE DRY SOUTHWEST FLOW WITH HIGH
PRESSURE CENTERED OVER THE SRN PLAINS HAS PROVIDED OUR FORECAST
AREA WITH A COMFORTABLE AND QUIET SUMMER DAY.

MOISTURE INCREASES FROM THE SOUTH EARLY SUNDAY MORNING RESULTING
IN CLOUD COVER INCREASING ACROSS SOUTHWEST COLORADO. SHOWERS ARE
EXPECTED TO BEGIN DEVELOPING BY NOON AND INCREASE IN COVERAGE AND
INTENSITY THROUGHOUT THE DAY SUNDAY AS 500 MB VORTICITY STREAMS
SOUTHWEST TO NORTHEAST ACROSS AN AREA FAIRLY SIMILAR TO YESTERDAY
BUT THE MOISTURE SHIELD REACHING FURTHER NORTH. THIS PLUME OF
MOISTURE LOOKS TO MOVE OFF TO THE EAST AND DISSIPATE ON SUNDAY
EVENING AS DRIER AIR PROTRUDES INTO WESTERN COLORADO FROM THE
GREAT BASIN. NORTHWEST COLORADO AND NORTHEAST UTAH WILL REMAIN DRY
AND BREEZY WITH THE ACTIVITY TO THE SOUTH AND A 60 KT JET
OVERHEAD.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 312 PM MDT SAT JUL 25 2015

A BURLY PACIFIC NORTHWEST TROUGH WILL PUSH EAST ACROSS THE
INTERMOUNTAIN WEST BEGINNING ON MONDAY AND BRUSH ALONG THE
WY/UT/CO BORDER MONDAY EVENING INTO TUESDAY. WINDS AHEAD OF THE
TROUGH ON MONDAY WILL BE ENHANCED WITH VERY GUSTY WINDS ALONG THE
NORTHERN UT/CO BOUNDARIES THANKS TO THE INCREASE PRESSURE GRADIENT
AND A 60 KT JET ALOFT. ASSUMING RELATIVE HUMIDITY VALUES CAN DRY
OUT ENOUGH IN THE AFTERNOON AS FORECAST MODELS HAVE BEEN SHOWING
FOR DAYS...WINDY AND DRY CONDITIONS DO LOOK PROBABLE IN NE UTAH
AND NW COLORADO. MOISTURE ON MONDAY WILL HUG THE SAN JUANS AND
SOUTHERN COLORADO DIVIDE MOUNTAINS SO SHOWERS AND A FEW ISOLATED
TSTORMS ARE POSSIBLE IN THESE AREAS.

THE NAM IS BRINGING A SOLID ELONGATED VORT MAX TO THE WY/UT/CO
BORDER ON TUESDAY LINED UP WITH THE ULJ WHILE THE GFS AND EC ARE
KEEPING THIS ENERGY A BIT FURTHER NORTH. THIS ENERGY STAYS IN
WYOMING BUT MAY KEEP CONDITIONS BREEZY ALONG THE WY/UT/CO BORDER.
500 MB HIGH PRESSURE BEGINS TO BACK TO THE WEST OVER THE FOUR
CORNERS LATER IN THE DAY ON TUESDAY. THIS HIGH PRESSURE WILL BE
CENTERED OVER THE SOUTHWEST AND GREAT BASIN BY THURSDAY AND
THROUGH SATURDAY. 700 MB ISOBARS SHOW CENTER OF HIGH PRESSURE AT
THAT LEVEL OVER WESTERN KS...WESTERN OK...AND THE PANHANDLE OF TX
WHICH WOULD STREAM MOISTURE INTO THE FOUR CORNERS FROM THE GULF.
SIGNAL LOOKS SLIGHTLY MONSOONAL AT THE END OF NEXT WEEK AS THIS
HIGH PRESSURE PATTERN SETS UP.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1125 AM MDT SAT JUL 25 2015

ISOLATED -TSRA/-SHRA WILL DEVELOP OVER THE SWRN COLORADO MOUNTAINS
THIS AFTERNOON BETWEEN 20Z-01Z. ANY STORMS WILL BE SHORT LIVED AND
MOVE EASTWARD. OTHERWISE NO WEATHER RELATED AVIATION HAZARDS ARE
EXPECTED THROUGH THE FORECAST PERIOD.


&&

.FIRE WEATHER...
ISSUED AT 312 PM MDT SAT JUL 25 2015

RED FLAG WARNING IN EFFECT FOR FIRE ZONE 200 NOW UNTIL 8PM DUE TO
BREEZY AND DRY CONDITIONS CONTINUING THERE TODAY. WINDS WILL ERODE
THIS EVENING.

ISSUED FIRE WEATHER WATCH FOR SUNDAY FOR FIRE ZONE 200 WITH 60 KT
UPPER LEVEL JET SUPPORT IN PLACE AND DRY AIR REMAINING OVER NE
UTAH AND NW COLORADO WHILE MAINLY STRATIFORM RAIN IS EXPECTED IN
WEST CENTRAL AND SOUTHWEST COLORADO WITH SOME CONVECTIVE ELEMENT
IN THE AFTERNOON. ALREADY GUSTY WINDS MAY BE ENHANCED BY OUTFLOW
ORIGINATING FROM WELL SOUTH OF MOFFAT COUNTY. ALSO ISSUED A WATCH
FOR MONDAY FOR FIRE ZONES 200 201 202 AND 203 AFTER GOOD RUN TO
RUN CONSISTENCIES ON FORECAST WINDS AND LOW RH FOR MONDAY AS A
TROUGH BRUSHES BY THE WY/UT/CO BORDER. ON MONDAY CERTAIN PARTS OF
THE WATCH AREA MAY POTENTIALLY BE BATTLING WITH TOO MUCH MOISTURE
FROM SUNDAYS SHOWERS BUT FORECAST MODELS HAVE BEEN CONSISTENT ON
QUITE BREEZY CONDITIONS AND THIS SHOULD DRY CONDITIONS OUT PRETTY
QUICKLY. SINCE ITS JUST A WATCH DECIDED TO ERR ON THE SIDE OF
CAUTION WITH SUCH A DEFINED FEATURE AFFECTING THE AREA.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
     FOR COZ200>203.

     RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ200.

     FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
     FOR COZ200.

UT...NONE.
&&

$$

SHORT TERM...PF/JAM
LONG TERM...JAM
AVIATION...PF
FIRE WEATHER...JAM



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