FXUS65 KGJT 291031
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
331 AM MST SUN NOV 29 2009

.SHORT TERM...
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 SRWRN 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 GRT 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...
VFR CONDITIONS CONTINUE FOR MOST SITES N OF I-70 EXCEPT FOR KEGE 
THAT HAS REPORTED IFR CONDITIONS FOR LAST FEW HOURS AS CIGS HAVE 
DROPPED CONSIDERABLY.  EXPECT THESE CONDITIONS TO CONTINUE THRU 18Z 
AT KEGE...AND POSSIBLY KASE...WITH CIGS VARYING BTWN VFR AND IFR 
DURING THIS TIMEFRAME.  ALL TAF SITES TO S CONTINUE TO REPORT VFR 
DESPITE SNOWFALL BEING REPORTED ACROSS SRN ZONES.  ONLY CONCERN WILL 
BE KMTR AS CIGS/VIS WILL FLUCTUATE UNDER HEAVIER SNOW SHOWERS TODAY 
THROUGH THIS AFTN.  CONDITIONS WILL RAPIDLY IMPROVE TOWARDS EVENING 
AS SYSTEM MOVES TO OUR E.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ023.
     WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ018-
     019.
UT...NONE.

&&

$$

SHORT TERM...MC
LONG TERM....TGR
AVIATION.....TGR