FXUS65 KGJT 291438 AAA
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
738 AM MST SUN NOV 29 2009
.UPDATE...MORNING OBSERVATIONS FROM THE SOUTHERN MOUNTAINS INDICATE
LITTLE IF ANY SNOW FALLING IN THE ADVISORY AREA. WEB CAMS CONFIRM
THESE REPORTS WITH ONLY A FEW SNOW SHOWERS OVER THE HIGHER TERRAIN
SURROUNDING PAGOSA SPRINGS. IR IMAGERY INDICATING BEST DIFLUENCE
WILL REMAIN SOUTH OF OUR AREA...AS THE UPPER LEVEL LOW TRACKS SLOWLY
EAST ACROSS THE NORTHERN BAJA. AS A RESULT...WILL BE DROPPING THE
HIGHLIGHTS THIS MORNING AND WILL ALSO TRIM POPS BACK SIGNIFICANTLY
FOR THE REST OF TODAY AND TONIGHT.
&&
.PREVIOUS DISCUSSION /331 AM MST/...
.SHORT TERM...TODAY THROUGH MONDAY NIGHT...
UPPER CLOSED LOW STARTS OUT OVER NRN BAJA THIS MORNING
THEN SINKS SLOWLY SOUTHWARD DURING THE DAY. THIS BRINGS A
SOUTHEASTERLY FLOW TO THE 4 CORNERS REGION WITH VORT CENTERS EMBEDDED
IN THE FLOW WHICH WILL CLIP SERN UT AND SWRN CO. THIS WILL KEEP
PERIODS OF PCPN GOING OVER THE SRN ZONES. CURRENT HILITES ON TRACK
AND WILL LEAVE ALONE. ELSEWHERE SCATTERED MTN SNOW SHOWERS WILL OCCUR
SOUTH OF I-70 WHILE ACTIVITY DECREASES FURTHER NORTH.
BY AROUND MIDNIGHT UPPER LOW WILL BE FAR ENOUGH SOUTH AS TO HAVE
LITTLE AFFECT ON OUR CWA WITH SIGNIFICANT WX COMING TO AN END. A
HIGH PRESSURE RIDGE ORIENTED FROM WEST TO EAST WILL BUILD OVER THE
NRN GREAT BASIN MONDAY AND MONDAY NIGHT BRINGING SUBSIDENCE AND
CLEARING SKIES.
.LONG TERM...TUESDAY THROUGH SATURDAY NIGHT...
CLOSED UPPER LOW TO OUR S CONTINUES TO MOVE EWRD AND SPREAD PRECIP
OVR TX AND LA AT BEGINNING OF LONG-TERM. AS THIS OCCURS...NEXT WAVE
OF LOW PRESSURE WILL DROP DOWN FROM CANADA. ALL MODELS IN FAIRLY
GOOD AGREEMENT THAT THIS LOW PRESSURE WILL TRACK ALONG CANADIAN/US
BORDER AND DRAG TROF BEHIND IT CAUSING PRECIP OVR MT AND WY.
DIFFERENCES ARISE IN AREAL COVERAGE OF SAID PRECIP. NAM AND GFS SHOW
SOME EXCEEDINGLY LGT PRECIP OVER SRN WY AND ERN CO BUT NOTHING OVR
OUR CWA WHILE ECMWF STILL PAINTS SOME OVR CONTINENTAL DIVIDE.
NORTHWEST AIRFLOW DURING THIS TIME...ALONG WITH OROGRAPHIC
LIFT...CERTAINLY SUGGESTS SOME SNOWFALL OVER THE DIVIDE SO FEEL
COMFORTABLE LEAVING LOW POPS AND SCHC PRECIP IN FORECAST. IF/WHEN
PRECIP FALLS WED NIGHT/THUR MORNING...IT WILL BE VERY LIGHT IN
NATURE WITH MINOR TO NO ACCUMULATION.
AS TROF FINALLY MOVES OFF...WEAK RIDGE APPROACHES FROM W AS ANOTHER
PAC STORM CRASHES ASHORE OVR BC/WA/OR COAST. MOISTURE WILL RAPIDLY
SPILL OVR RIDGE AXIS AND BRING SOME CLOUDS AND PRECIP AGAIN TO AREA
AS ENERGY DIGS DOWN AND CLOSED LOW FORMS DRAPING ASSOD COLD FRONT
OVER MT AND WY. GFS KEEPS LOW PRESSURE TO OUR N BUT DOES PUSH COLD
FRONT THRU UT/CO FRI NIGHT/SAT MORNING CAUSING SOME PRECIP TO FALL.
UNFORTUNATELY...EUROPEAN DOES NOT HAVE A GOOD HANDLE ON THIS SYSTEM
SO FOLLOWING GFS LINE OF THINKING AT THE MOMENT. ONLY MADE BROAD
BRUSH CHANGES TO FORECAST DUE TO SIGNIFICANTLY DIFF MODEL SOLNS.
&&
.AVIATION...
LOCAL MVFR TO IFR CONDITIONS WILL BE FOUND SOUTH AND EAST OF A
LINE FROM KEGE TO KASE TO KDRO TODAY WITH ISOLATED TO SCATTERED
SNOW SHOWERS. OTHERWISE...VFR CONDITIONS WILL PREVAIL OVER THE
REGION THROUGH MONDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE.......JDC
SHORT TERM...MC/JDC
LONG TERM....TGR
AVIATION.....JDC
