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000
FXUS65 KGJT 231001
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
401 AM MDT THU MAY 23 2013

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM MDT THU MAY 23 2013

WINDY AND WARMER TODAY AS A LARGE UPPER LOW PARKED OVER WA/OR
MAINTAINS DRY SOUTHWEST FLOW ALOFT ACROSS THE AREA. SEE THE FIRE
WEATHER SECTION BELOW FOR IMPACTS. A COLD FRONT WAS BUTTED UP
AGAINST THE WESTERN SIDE OF THE UTAH MTNS EARLIER AND SHOULD
REMAIN TO OUR NORTHWEST TODAY AS THE SOUTHWEST FLOW WILL PROVIDE
LITTLE EASTWARD PUSH.

AN UPPER JET MAX ROTATING AROUND THE UPPER LOW WILL MOVE ACROSS NWRN
UT TODAY AND ENHANCE WINDS ALOFT OVER ERN UT/WRN CO. LAST EVENING/S
SOUNDING AT GRAND JCT SHOWED DEEP MIXING UP TO 500 MB AND SEE NO
REASON WHY DEEP MIXING WON/T OCCUR AGAIN TODAY WITH STRONG SURFACE
HEATING...RESULTING IN GUSTY WINDS AGAIN THIS AFTERNOON AND A BIT
STRONGER THAN YESTERDAY. WIND GUSTS OF 35-40 MPH WILL BECOME COMMON
ACROSS ERN UT AND MUCH OF WRN CO THIS AFTERNOON...AND SOME ISOLATED
LOCATIONS IN ERN UT AND NW CO COULD FLIRT WITH GUSTS UP TO 45 MPH.

GUSTY WINDS WILL PERSIST UNTIL AROUND MIDNIGHT AS THE UPPER JET MAX MOVES
INTO SOUTHEAST IDAHO...THOUGH ONCE THE DIURNAL INPUT SUBSIDES
AROUND SUNSET...WIND STRENGTH WILL BEGIN TO DIMINISH. HOWEVER
SOME GUSTINESS WILL PERSIST UNTIL AROUND MIDNIGHT AS AN ASSOCIATED
COLD FRONT MOVES WEST-EAST ACROSS WY AND BRUSHES OUR NORTHERN
BORDER. THE AREA WILL SEE ANOTHER WARM NIGHT MOST LOCATIONS WITH
LOWS 0-2 DEGREES COOLER THAN WED NIGHT`S.

THE GRADIENT RELAXES A LITTLE ON FRIDAY. HOWEVER THE LARGE-SCALE
PATTERN REMAINS IN PLACE AS THE FORECAST AREA SITS BETWEEN THE
NORTHWEST LOW AND HIGH PRESSURE OVER THE PLAINS STATES. THEREFORE
GUSTY WINDS ARE AGAIN EXPECTED TO MIX TO THE SURFACE BY THE
AFTERNOON. WITHOUT THE SHORTWAVE ENERGY OF THE PREVIOUS
DAY...WINDS ARE NOT EXPECTED TO BE QUITE AS STRONG. BUT THE
POTENTIAL WILL AGAIN DEVELOP FOR CRITICAL FIRE WEATHER CONCERNS
WHERE FUELS ARE DRY. TEMPERATURES REMAIN A FEW DEGREES LOWER THAN
THOSE ON THU.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM MDT THU MAY 23 2013

LITTLE CHANGE TO THE DRY...WARM AND GUSTY CONDITIONS AS STRONG
SOUTHWEST FLOW REMAINS ENTRENCHED OVER THE FORECAST AREA THROUGH
SATURDAY. THE LARGE SCALE PATTERN ONLY GRADUALLY EVOLVES AS THE
LOW PRESSURE TROUGH REMAINS OVER THE WEST COAST AND HIGH PRESSURE
SITS TO OUR EAST. AGAIN GUSTY WINDS WILL MIX TO THE SURFACE BY
SATURDAY AFTERNOON. TEMPERATURES WILL REMAIN WARM WITH HIGHS 7-10
DEGREES ABOVE NORMAL...AND LOWS CLOSER TO NORMAL VALUES.

THE CLOSED LOW OVER THE PAC NW LIFTS INTO WRN CANADA SAT NIGHT AND
SUNDAY...BUT UPSTREAM PACIFIC ENERGY LOOKS TO MAINTAIN AN UPPER
TROUGH OVER THE WEST THROUGH THE FIRST HALF OF NEXT WEEK. MODEL
DIFFERENCES GROW...HOWEVER. THE ECMWF KEEPS THE TROUGH CLOSER TO
THE WEST COAST AND IS SLOWER TO PROGRESS IT EASTWARD FOR MOSTLY
DRY WEATHER...WHILE THE GFS LIFTS A SHORTWAVE TROUGH ACROSS THE 4
CORNERS BY WED FOR A BIT BETTER CHANCE OF SHOWERS BY MIDWEEK.
WARMER THAN NORMAL TEMPERATURES SHOULD CONTINUE THROUGH THE FIRST
PART OF NEXT WEEK.


&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 400 AM MDT THU MAY 23 2013

VFR CONDITIONS WILL REMAIN IN PLACE ACROSS EASTERN UTAH AND WESTERN
COLORADO TODAY AND TONIGHT. GUSTY SOUTHWEST WINDS WILL AGAIN BE
PRESENT THIS AFTERNOON WHEN GUSTS OF 25-35 KTS ARE LIKELY. PRIOR
TO 18Z...LOCAL LOW LEVEL WIND SHEAR WILL BE POSSIBLE DUE TO
MORNING DOWN VALLEY FLOW AT THE SURFACE AND SOUTHWEST WINDS AT
RIDGE TOPS. WINDS WILL DECREASE AFTER 03Z THIS EVENING.

&&

.FIRE WEATHER...
ISSUED AT 400 AM MDT THU MAY 23 2013

SOUTHWEST FLOW WILL STRENGTHEN TODAY AS THE AREA SITS BETWEEN A HIGH
PRESSURE RIDGE TO OUR EAST...AND A STRONG LOW PRESSURE SYSTEM OVER
THE PACIFIC NORTHWEST. A DISTURBANCE ROTATING AROUND THE PACIFIC
NORTHWEST LOW WILL BRUSH THE FORECAST AREA THIS AFTERNOON AND ENHANCE THE
ALREADY STRONG FLOW. DEEP MIXING IN THE AFTERNOON WILL ALLOW THE
STRONG SOUTHWEST WINDS TO MIX TO THE SURFACE. RELATIVE HUMIDITY
VALUES WILL DROP INTO THE SINGLE DIGITS ACROSS THE LOWER SOUTHWEST
AND WEST CENTRAL VALLEYS. WHERE FUELS ARE DRY...WIND GUSTS 25-40 MPH
IN THE LOWER ELEVATIONS WILL COMBINE WITH THE DRY CONDITIONS TO
PRODUCE CRITICAL FIRE WEATHER CONDITIONS THIS AFTERNOON AND EVENING.
THEREFORE A RED FLAG WARNING WILL CONTINUE TO BE IN EFFECT FOR THE
LOWER ELEVATIONS OF CO FIRE ZONES 207...290 AND 292 WHERE FUELS ARE
CRITICALLY DRY.

THE STRONG FLOW ALOFT WILL CONTINUE INTO EARLY NEXT WEEK WITH ONLY A
GRADUAL MODIFICATION TO THE LARGE SCALE PATTERN. THEREFORE THE
POTENTIAL WILL CONTINUE FOR CRITICAL FIRE WEATHER CONDITIONS TO
DEVELOP EACH AFTERNOON AS THESE WINDS ALOFT MIX TO THE SURFACE. IN
ADDITION...THE WARM AND DRY CONDITIONS WILL PERSIST. A FIRE WEATHER
WATCH FOR FRIDAY AFTERNOON AND EVENING WILL REMAIN IN EFFECT FOR THE
ABOVE MENTIONED ZONES.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
     COZ207-290-292.

     FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING
     FOR COZ207-290-292.

UT...NONE.
&&

$$

SHORT TERM...EH/JAD
LONG TERM...EH/JAD
AVIATION...JAD
FIRE WEATHER...EH