Area Forecast Discussion
Issued by NWS Grand Junction, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS65 KGJT 201121
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
421 AM MST THU NOV 20 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 420 AM MST THU NOV 20 2014

THE HIGH PRESSURE RIDGE THAT HAS DOMINATED THE WEST DURING THE
LAST SEVERAL DAYS WILL CONTINUE TO WEAKEN AND SHIFT EAST AS A LOW
PRESSURE TROUGH PASSES OVER OUR FORECAST AREA TODAY. THE SENSIBLE
WEATHER ASSOCIATED WITH THIS WAVE WILL BE LIMITED AS IT WORKS
AGAINST THE UPPER RIDGE. A FEW MOUNTAIN SNOW SHOWERS WILL BE
POSSIBLE THIS AFTERNOON AND EARLY EVENING...OTHERWISE INCREASED
CLOUDS WILL BE THE NORM. FOLLOWING CLOSELY BEHIND THIS WAVE IS THE
NEXT SPLITTING TROUGH THAT WILL MOVE OVER NORTHERN CALIFORNIA
TODAY. THE BASE OF THIS TROUGH WILL THEN DROP INTO SOUTHERN
ARIZONA ON FRIDAY. THE BEST ENERGY/PRECIPITATION WILL STAY SOUTH
OF OUR FORECAST AREA...BUT A FEW AFTERNOON SHOWERS MAY DEVELOP
OVER THE SOUTHERN MOUNTAINS.

HIGH TEMPERATURES SHOULD BE CLOSE TO NORMAL TODAY AND ON FRIDAY.
NIGHTTIME LOWS WILL CONTINUE TO MODERATE DUE TO WEAKER INVERSIONS
AND EXTENSIVE CLOUD COVER.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 420 AM MST THU NOV 20 2014

SPLIT TROUGH PASSES EAST OF THE FORECAST AREA LATE FRIDAY NIGHT
AND MODELS ALL DRY AT SUNRISE SATURDAY MORNING. HOWEVER...APPEARS
DRY WEATHER WILL BE SHORT LIVED AS A MOIST PACIFIC TROUGH PUSHES
INTO THE EASTERN UINTA MOUNTAINS BY MIDDAY SATURDAY. COLD FRONT
ASSOCIATED WITH THIS SYSTEM ARRIVES OVER NORTHEAST UTAH/NORTHWEST
COLORADO LATE IN THE DAY. TEMPERATURES RELATIVELY MILD AHEAD OF
THE FRONT SO SNOW LARGELY CONFINED TO THE MOUNTAINS SATURDAY
AFTERNOON. MOISTURE SPREADS INTO THE NORTHERN AND CENTRAL COLORADO
MOUNTAINS DURING THE AFTERNOON BRINGING LIGHT TO MODERATE SNOWFALL
ACROSS THOSE AREAS.

THE FRONT SWEEPS ACROSS THE AREA SATURDAY NIGHT BRINGING SNOW
LEVELS DOWN TO VALLEY FLOORS. STEEP LAPSE RATES...DEEP MOISTURE...
OROGRAPHIC LIFT AND JET DIVERGENCE FAVOR PERIODS OF MOUNTAIN
SNOWFALL THROUGH SUNDAY AFTERNOON. A BIT OF LULL INDICATED SUNDAY
EVENING...ESPECIALLY OVER THE SOUTHERN MOUNTAINS...BUT MODELS
INDICATED MOIST NORTHWEST FLOW WILL BE REINFORCED MONDAY RESULTING
IN PROLONGED PERIODS OF SNOW OVER THE COLORADO DIVIDE MOUNTAINS
WHICH MAY PERSIST THROUGH TUESDAY NIGHT. ECMWF MOVES OUT OF PHASE
WITH THE GFS WEDNESDAY DROPPING A TROUGH INTO THE PACIFIC
NORTHWEST AND LEAVING THE MOISTURE TAP OPEN ACROSS THE NORTHERN
MOUNTAINS. IN CONTRAST...THE GFS40 DEVELOPS A RIDGE OVER THE WEST
AND MAINTAINS A DRY NORTHWEST FLOW ACROSS THE AREA ON WEDNESDAY.
GIVEN DIFFERENCES DEFERRED TO THE BLENDED MODEL SOLUTION.

TEMPERATURES TURN CONSIDERABLY COLDER BEHIND THE FRONT SUNDAY AND
STAY BELOW NORMAL THROUGH THE COMING WEEK.

THE ANTICIPATED PROLONGED PERIOD OF SNOWFALL SHOULD LEAD TO
SIGNIFICANT SNOWFALL ACCUMULATIONS...ESPECIALLY ACROSS THE
NORTHERN AND CENTRAL COLORADO MOUNTAINS. SINCE THE ACTION DOESN/T
BEGIN UNTIL LATE IN THE FIFTH PERIOD...WILL HOLD OFF ON WATCH FOR
THE TIME BEING. PERHAPS LATER RUNS WILL CLARIFY THE END OF THE
STORM.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 420 AM MST THU NOV 20 2014

A WEAK DISTURBANCE WILL CONTINUE TO SPREAD MID AND HIGH LEVEL
CLOUDS ACROSS THE REGION. ISOLATED LIGHT SNOW SHOWERS WILL IMPACT
THE MOUNTAINS THIS AFTERNOON AND EVENING RESULTING IN SOME
MOUNTAIN OBSCURATION. TAF SITES ARE UNLIKELY TO BE IMPACTED BY
THIS ACTIVITY AND SHOULD CONTINUE TO HAVE VFR CONDITIONS
THROUGHOUT THE NEXT 24 HOURS.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...NONE.
UT...NONE.

&&

$$

SHORT TERM...NL/EH
LONG TERM...NL
AVIATION...NL


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.