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000
FXUS65 KGJT 232146
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
346 PM MDT THU MAY 23 2013

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 345 PM MDT THU MAY 23 2013

AMPLIFIED TROF-RIDGE-TROF PATTERN CONTINUES TO DOMINATE THE NORTHERN
2/3 OF NOAM WITH WEAKER WESTERLY FLOW ACROSS THE SOUTHERN STATES
AND MEXICO. MOISTURE FOR PRECIPITATION IS PUSHED UP AGAINST THE
FRONT RANGE IN THE RETURN FLOW AROUND STRONG HIGH PRESSURE OVER
THE UPPER MIDWEST...WITH VERY DRY AIR ACROSS WESTERN COLORADO BACK
TO THE PACIFIC. THE GRADIENT BETWEEN SHORT WAVE RIDGING OVER THE
CENTRAL ROCKIES AND THE LARGE PACIFIC NORTHWEST SYSTEM INCREASED
WINDS ALOFT OVERNIGHT. STRONG HEATING...AND MAINLY CLEAR SKIES ARE
HELPING BRING THESE STRONGER WINDS ALOFT TO THE SURFACE. MANY
AREAS ARE SEEING GUSTS OVER 30 MPH WITH 40 TO 50 MPH GUSTS OVER
PORTIONS OF FAR WESTERN COLORADO AND EASTERN UTAH.

A SUBTLE WAVE IS SEEN MOVING THROUGH EASTERN NEW MEXICO LATE THIS
AFTERNOON AND WILL MAINLY INTERACT WITH MOISTURE EAST OF THE
DIVIDE...THOUGH A STRAY SHOWER MAY BE POSSIBLE JUST WEST OF THIS
TEARRAIN BOUNDARY THROUGH SUNSET. EXPECT A DROP OFF OF THE WINDS
WITH SUNSET AND THE DRY AIR WILL HELP DEVELOP SHALLOW LOW LEVEL
INVERSIONS. THERE WILL BE SOME WINDS REMAINING IN THE HIGH COUNTRY
OVERNIGHT WITH LEE DOWN-SLOPING WINDS AND WINDWARD RIDGE-TOP
WINDS KEEPING THINGS MIXED AT TIMES. AS A RESULT LOCALLY CRITICAL
FIRE WEATHER CONCERNS WILL REMAIN IN AREAS OF THE SOUTHERN CWA
WHERE FUELS REMAIN DRY AND RH RECOVERY WILL BE MINIMAL. SFC LOW
PRESSURE BE LIFTING NORTH OVERNIGHT AS THE JET ROUNDS THE TROF TO
THE WEST. THIS SLACKENS THE GRADIENT ACROSS THE WESTERN SLOPE AND
WEAKENING DOWN VALLEY WINDS...WITH SLIGHTLY COOLER MINIMUMS WILL
RESULT.

AS THE UPPER LOW TO THE NORTHWEST ABSORBS THE JET AND VORT LOBE IT
WILL BE RE-ORIENTING EAST TO WEST...WITH A REDUCTION IN THE MID
LEVEL GRADIENT ALOFT. THIS SHOULD NEGATE THE CHANCES OF ADVISORY
LEVEL WINDS BUT STRONG HEATING AND AFTERNOON MIXING WILL BE ENOUGH
TO KEEP A THREAT OF CRITICAL FIRE WEATHER CONDITIONS IN PLACE
ACROSS SOUTHWEST COLORADO AS WINDS GUSTS OVER 25 MPH. H7 TEMPS
WILL TAKE A SLIGHT DIP TOMORROW AND HIGHS MAY BE A ONE OR TWO
DEGREES COOLER IN PLACES BUT STILL RUNNING WELL ABOVE NORMAL UNDER
MAINLY CLEAR SKIES. AGAIN EXPECT WINDS TO QUICKLY TAKE A DOWN TURN
NEAR AROUND SUNSET TOMORROW EVENING WITH LOWS DROPPING OFF TO NEAR
OR SLIGHTLY ABOVE NORMAL IN THIS WARM REGIME.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 PM MDT THU MAY 23 2013

THE ELONGATED TROUGH REMAINS NEAR THE WEST COAST THROUGH THE
WEEKEND. DRY...WARM CONDITIONS COMBINE WITH GUSTY SW WINDS INTO
MEMORIAL DAY. DAYTIME TEMPERATURES EXPECTED TO STAY 7-10 DEGREES
ABOVE NORMAL THROUGH THE WEEKEND. TEMPERATURES ARE FORECAST TO LOWER
TO NEAR NORMAL BY MEMORIAL DAY BUT THIS SEEMS OVERLY FAST.

THE MODELS ARE IN BETTER AGREEMENT FOR THE TROUGH PROGRESSION EARLY
NEXT WEEK...THOUGH THE FAVORED EC IS STILL SLOWER. CHANCES OF
SHOWERS START AS EARLY AS TUESDAY AS THE NEGATIVELY TILTED IS
ORIENTED FROM OREGON INTO SOUTHERN ARIZONA. PRECIPITABLE WATER
VALUES INCREASE TO NEAR 0.6 INCHES. THE TROUGH APPROACHES THE REGION
ON WEDNESDAY FOR INCREASING MOISTURE AND COOLER TEMPERATURES WITH A
WEAK COLD FRONTAL PASSAGE TIMED FOR WEDNESDAY OR THURSDAY. ACCEPTED
SLIGHT CHANCE POPS THROUGH THESE PERIODS IN THIS FORECAST PACKAGE
BUT WILL RAISE THEM SIGNIFICANTLY TOMORROW IF MODEL TIMING IS
CONSISTENT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 345 PM MDT THU MAY 23 2013

DRY...WARM AND WINDY CONDITIONS WILL BE IN PLACE OVER THE NEXT
24 HOURS. WITH ONLY HIGH TO MID LEVEL CLOUDS EXPECTED VFR
CONDITIONS WILL HOLD AT AREA FORECAST TERMINALS. SOUTH TO
SOUTHWEST WINDS MAY BE AN ISSUE TO FLIGHT OPERATIONS AS GUSTS OF
40 TO 50 MPH ARE EXPECTED THROUGH EARLY THIS EVENING AND MAY
PERSIST ACROSS THE RIDGE TOPS OF HIGHER TERRAIN THROUGH THE
OVERNIGHT HOURS...WHERE MECHANICAL TURBULENCE COULD BE AN ISSUE.
WIND GUSTS DO NOT LOOK AS STRONG FRIDAY AFTERNOON BUT COULD STILL
BE IN THE 25 TO 35 MPH RANGE IN THE LATE AFTERNOON OVER THE LOWER
VALLEY REGIONS OF WESTERN COLORADO AND EASTERN UTAH.

&&

.FIRE WEATHER...
ISSUED AT 345 PM MDT THU MAY 23 2013

STRONG SW GRADIENT WINDS WERE REALIZED TODAY AND WILL CONTINUE
TONIGHT. SURFACE BASED INVERSIONS WILL BE WEAK AND WILL BREAK AT
TIMES ESPECIALLY IN THE MID-SLOPE THERMAL BELT AND ALONG THE
NORTH-FACING SLOPES. THEREFORE THE RED FLAG WARNINGS FOR COLORADO
FIRE ZONES 291 AND 207 HAVE BEEN EXTENDED THROUGH THE NIGHT AND
FRIDAY. CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE AGAIN ON
SATURDAY SO A FIRE WEATHER WATCH WAS ISSUED FOR ZONES 291 AND 207.
BY SUNDAY THE CRITICAL WIND THRESHOLD OF 25 MPH MAY NOT BE MET SO
FORECAST CERTAINTY DIMINISHES SOMEWHAT. OVERALL THOUGH ABOVE NORMAL
TEMPERATURES...BELOW NORMAL RH...AND GUSTY SW WINDS CONTINUE INTO
MEMORIAL DAY.

NEXT WEEK THE WEST COAST TROUGH OF LOW PRESSURE BEGINS TO PUSH
ACROSS THE INTER-MOUNTAIN WEST. THIS WILL BRING A COOLING TREND AND
A CHANCE OF SHOWERS ON TUESDAY THROUGH THURSDAY.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR COZ001-002.

     RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ290-292.

     RED FLAG WARNING UNTIL 9 PM MDT FRIDAY FOR COZ207-291.

     FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
     EVENING FOR COZ207-291.

UT...WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR UTZ022-027-029.

&&

$$

SHORT TERM...15
LONG TERM...JOE
AVIATION...15
FIRE WEATHER...JOE