Wind Advisory 4, NWS Grand Junction, CO

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
222 PM MDT MON APR 5 2010

CORRECTED HIGHLIGHT SUMMARY AT THE END

.SHORT TERM...TONIGHT THROUGH WEDNESDAY...
STRONG GUSTY WINDS HAVE DEVELOPED AS A BROAD SURFACE LOW COVERS MUCH
OF UTAH AND THE WESTERN SLOPE.  WITH MID LEVEL LEVEL MOISTURE ON THE
INCREASE...PCPN IS INCREASING ON THE WINDWARD SLOPES OVER THE NRN
AND CENTRAL MOUNTAINS.  EXPECT THE STRONGEST WINDS TO OCCUR MID TO
LATE AFTERNOON AS THE SURFACE FRONT BEGINS TO CROSS ERN UTAH.  PCPN
COVERAGE EXPANDS RAPIDLY WITH FRONTAL PASSAGE AND WITH THE POST
FRONTAL AIR MASS.  SNOW LEVELS WILL FALL AND LOWER TO VALLEY BOTTOMS
AFTER MIDNIGHT.  WITH THE TRACK OF THE 700 MB CYCLONE CROSSING
WYOMING...THE HEAVIEST SNOW WILL OCCUR OVER THE NRN MOUNTAINS.  WITH
DEEP POTENTIAL INSTABILITY...CONTINUED COLD ADVECTION INTO
TUESDAY...AND COMBINED WITH MODERATELY STRONG NORTHWEST FLOW WILL
BRING SIGNIFICANT SNOW ACCUMULATIONS TO THE CENTRAL MOUNTAINS AND
PERHAPS AS FAR SOUTH AS THE SILVERTON VICINITY IN THE SAN JUAN
MOUNTAINS.

TUESDAY NIGHT AND WEDNESDAY...PRECIPITABLE WATER WILL BE
CONSIDERABLY LOWER AND POTENTIAL INSTABILITY WILL GRADUALLY
SHRINKING AS THE COLDEST AIR SHIFTS EAST.  BROAD CYCLONIC FLOW AND
MOUNTAIN TOP TEMPS WITHIN THE IDEAL DENDRITIC GROWTH RANGE...EXPECT
SNOW TO PERSIST OVER THE HIGH COUNTRY.  BUT DRIER WEATHER ACROSS ERN
UTAH WILL SPREAD ACROSS THE WESTERN SLOPE ON WEDNESDAY.  THE FLOW
BECOMES ANTICYCLONIC WITH SIGNIFICANT WARMING ALOFT AND THIS WILL
END SNOW SHOWER ACTIVITY EXCEPT FOR FLURRIES OVER THE HIGHEST
MOUNTAIN PASSES AND RIDGES.  TEMPERATURES WILL BE COOL FOR THE NEXT
TWO DAYS...BUT SOME RECOVERY IS EXPECTED ON WEDNESDAY.  FROSTY NIGHT
EXPECTED TUESDAY NIGHT.

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...

A FEW SNOW SHOWERS MAY LINGER NEAR THE DIVIDE WED EVENING IN DRYING
N-NW FLOW ALOFT. DRY WEATHER WITH WARMER TEMPS EXPECTED THU-SAT AS A
RIDGE OF HIGH PRESSURE SLIDES EAST ACROSS THE REGION. FRI-SAT LOOK
LIKE THE WARMEST DAYS WITH HIGH TEMPS NEAR OR ABOVE NORMAL AND
ABUNDANT SUNSHINE. WESTERLY WINDS ALOFT ON BECOME SOUTHWESTERLY FRI
AND SAT...AS THE NEXT PACIFIC TROUGH APPROACHES THE WEST COAST. THIS
COULD LEAD TO SOME BREEZY AFTERNOON WINDS THIS WEEKEND. MODEL
DIFFERENCES THEN GROW SUN-MON WITH THE INLAND PROGRESSION OF THAT
PACIFIC TROUGH. ALL SHOW A LESSER TENDENCY TO CLOSE OFF AN UPPER
LOW IN THE BASE OF THE TROUGH THEN PREVIOUS RUNS...AS IT MOVES ACROSS
THE GREAT BASIN/SOUTHWEST USA. THIS MORNING/S GFS THE SYSTEM ACROSS
OUR REGION MIDDAY MONDAY...WHILE THE ECWMF IS 18-24 HRS SLOWER.
LEANED TOWARD THE 12Z HPC GUIDANCE FOR SKY/POPS MON...WITH A CHANCE
OF SHOWERS IN THE MTNS AND A SLIGHT CHANCE VALLEYS.

&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED FOR VALLEY LOCATIONS TODAY...WITH
AREAS OF MVFR AND LOCAL IFR OVER THE HIGH MOUNTAIN PASSES DUE TO
SNOWFALL...WITH MVFR CONDITIONS BECOMING WIDESPREAD BY THIS
EVENING OVER THE VALLEYS WITH IFR CONDS OVER THE MOUNTAINS. STRONG
SOUTHWEST WINDS TODAY WILL RESULT IN TURBULENT CONDITIONS OVER ALL
OF WESTERN COLORADO AND EASTERN UTAH...DIMINISHING AFTER 03Z THIS
EVENING.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR ZONES
          006-007-011-020>023.
     WINTER STORM WARNING FROM NOON TODAY TO 6 AM MDT WEDNESDAY FOR
          ZONES 003>005-009-010-012-013.
     WIND ADVISORY UNTIL 6 PM MDT FOR ZONES 001-002-017>019.
     WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 AM MDT
          WEDNESDAY FOR ZONES 001-002-018-019.
     WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM MDT
          WEDNESDAY FOR ZONE 017.
UT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM MDT TUESDAY FOR
          ZONE 025.
     WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR ZONES
          022-027-029.
     WINTER STORM WARNING UNTIL 6 AM MDT TUESDAY FOR ZONE 023.
     WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR ZONE 028.

&&

SHORT TERM...PF
LONG TERM....JAD
AVIATION.....JDC