National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KGJT 101024
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
324 AM MST WED FEB 10 2010

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT...

THE WELL-DEFINED UPPER LOW ALONG THE SRN CA COAST EARLY THIS MORNING
IS EXPECTED TO SWING INLAND TODAY AND TRACK ACROSS EXTREME NRN MEXICO
TONIGHT-THU. SHORTWAVE OVER ERN NV/WRN UT LAST EVENING IS SHEARING
APART IN THE DEFORMATION ZONE NE OF THE LOW CENTER. SOME LIGHT PRECIP
HAS OBSERVED FROM SRN NV TO SW CO UNDERNEATH THIS AREA. GFS/ECWMF/NAM
MODELS KEEP A 300 MB DEFORMATION AREA ACROSS THE S THROUGH TODAY...
SO WILL KEEP THE HIGHEST CHANCE POPS THERE ALTHOUGH ANY SNOW
ACCUMULATIONS SHOULD BE LIGHT. BEST MOISTURE AND FORCING WILL REMAIN
ACROSS AZ AND NM TODAY.

ONCE THIS LOW AND ASSOCIATED TROUGH MOVE PAST TONIGHT...FOCUS FOR
SNOW SHIFTS TO THE NRN MOUNTAINS THU-THU NIGHT.  MOIST WNW TO NW
OROGRAPHIC FLOW BECOMES ESTABLISHED WITH A SHORTWAVE BRUSHING THE N
THU NIGHT. FLOW LOOKS TO HAVE PRETTY STABLE LAPSE RATES...BUT BUFKIT
SOUNDINGS ARE VERY MOIST IN THE LOW LEVELS. BEST TEMPERATURE
REGIME FOR IDEAL SNOW CRYSTAL GROWTH IS AT THE VERY TOP OF THE MOIST
LAYER...SO MAY GET SOME SEEDER-FEEDER ACTION GOING IN TO ENHANCE
SNOW IN THE OROGRAPHIC FLOW FOR THE NRN MTNS AND STEAMBOAT VALLEY.
WILL LEAN TOWARD THE HIGHER SREF POPS...AND GO WITH 40-50 PCT CHANCE
WORDING FOR THE NRN MTNS THU NIGHT AND SEE HOW THINGS PAN OUT WITH
LATER MODEL RUNS.

CONCURRENTLY...MOISTURE DIMINISHES ACROSS SE UT/SW CO THU-THU NIGHT
FOR MOSTLY DRY CONDITIONS THERE TOMORROW.

.LONG TERM...FRIDAY THROUGH WEDNESDAY...

A WESTERN U.S. RIDGE WILL BRING A PERSISTENT NORTHWEST FLOW ALOFT
OVER EASTERN UT AND WESTERN CO FRI THROUGH WED. SPURTS OF WINTER
WEATHER WILL ACCOMPANY SHORTWAVE TROUGHS RIDING OVER THIS RIDGE AND
ACROSS THE FORECAST AREA. NE UT...NW AND CENTRAL CO WILL BE AFFECTED
THE MOST BY THESE TROUGHS AS THEY ENHANCE THE NORTHWEST OROGRAPHIC
FLOW...WITH SE UT AND SW CO HAVING LESS CHANCE OF PRECIPITATION.

GFS AND ECMWF ARE IN GOOD AGREEMENT THROUGH THE PERIOD. THE FIRST
SHORTWAVE WILL RIDE INTO THE AREA FROM THE NW FRI NIGHT AND SAT. HAVE
BOOSTED POPS AND CLOUD COVER A BIT. SAT NIGHT WILL SEE SOME
CLEARING...BUT NORTHWESTERLY OROGRAPHIC FLOW WILL CONTINUE TO CAUSE
SNOWFALL OVER THE CO NW AND CENTRAL MOUNTAINS...AND NORTH-FACING
SLOPES OF THE SOUTHERN CO MTS.

THE NEXT SHORTWAVE WILL MOVE THROUGH MONDAY AFTERNOON THROUGH MONDAY
NIGHT.  THIS CHANNELED VORT MAX WILL TAKE A SIMILAR TRACK AS THE FRI-
SAT SYSTEM AND PRODUCE SIMILAR AFFECTS IN THE NORTHERN AND CENTRAL
MTS. TUE AND WED SHOULD BE DRIER AS THE HIGH PRESSURE TO THE WEST
STRENGTHENS.

&&

.AVIATION...

AREAS OF -SN WILL PRODUCE MVFR AND LOCALLY IFR CONDITIONS IN SE UT
AND SW CO TODAY. GENERALLY VFR CONDITIONS ARE EXPECTED ACROSS THE
CENTRAL AND NORTH ALTHOUGH WITH BKN-OVC CLOUD DECK. LOCAL -SN OVER
THE NRN MTS NEAR THE CONTINENTAL DIVIDE.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...JAD
LONG TERM....CJC
AVIATION.....JAD