000 FXUS65 KGJT 222237 CCA AFDGJT AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE GRAND JUNCTION CO 337 PM MST SUN NOV 22 2009 CORRECTED FOR TYPOS .SHORT TERM...TONIGHT THROUGH MONDAY NIGHT... FINAL UPPER LEVEL DISTURBANCE MOVING OVER NRN UT THIS AFTN CAUSING SCTD SNOW-SHOWERS ACROSS SRN ID/NRN UT WITH ASSOCIATED COLD FRONT DRAPED ACROSS UT TRAILING INTO NV SLOWLY MOVING OUR WAY. ANTICIPATE CLOUDS TO BE ON THE INCREASE LATER THIS AFTN WITH SOME SNOWFALL OVER ERN UINTAS THOUGH VERY LIGHT ACCUMULATION EXPECTED. ALL MODELS... NAM12/GFS40/SREF/ECMWF...IN SURPRISING AGREEMENT AS STORM MOVES OVER CWA LATER TONIGHT. UPPER LEVEL SUPPORT LINES UP VERY WELL FOR PRECIP OVR CENTRAL/NRN MTNS AS LEFT EXIT REGION OF JET APPROACHES...THEN MOVES OVER AREA. NAM12 18Z RUN CONTINUES TO INDICATE TWO STRONG VORT MAXES ROTATING THRU MEAN FLOW OVR SAME AREA AS UPPER LEVEL DIVERGENCE...DECENT QG FORCING SHOWING UP OVR NRN/CENT MTNS AND FINALLY...H7 WIND FLOW FROM THE NW WILL AID OROGRAPHIC LIFT. ALL OF THESE INGREDIENTS ENSURE SOME SNOWFALL TONIGHT INTO TOMORROW FOR ELKHEAD PARK/GORE RANGE/ELK/FLATTOP RANGES ON THE ORDER OF 5 TO 7 INCHES...POSSIBLY 8 INCHES AT HIGHER ELEVATIONS. THUS...WINTER WEATHER ADVISORY WILL BE ISSUED THIS AFTN VALID MIDNIGHT TONIGHT THRU MIDNIGHT TOMORROW HIGHLIGHTING THIS SNOWFALL. REMAINING CWA WILL SEE SOME CLOUDS AND FLURRIES...MOSTLY TO THE N OF I-70 WITH SOME CLOUDS TO THE S. SYSTEM MOVES OUT OF AREA MONDAY NIGHT. .LONG TERM...TUESDAY THROUGH SATURDAY... ...A SUNNY AND MILD THANKSGIVING... TUESDAY-THURSDAY: HIGH PRESSURE AMPLIFIES ALONG THE WEST COAST AND PROGRESSES OVER THIS FORECAST AREA BY THANKSGIVING. MOSTLY CLEAR SKIES WILL BRING INCREASED DIURNAL SPREAD WITH AFTERNOON TEMPERATURES ABOVE NORMAL. WINDS WILL BE LIGHT AND GENERALLY TERRAIN DRIVEN. HIGH CLOUDS WILL LIKELY BEGIN TO INVADE THURSDAY AFTERNOON OR EVENING AS THE RIDGE AXIS SHIFTS EAST AND A PACIFIC TROUGH MAKES LANDFALL. FRIDAY: THE PACIFIC TROUGH DIGS INTO IDAHO BRINGING INCREASING CLOUDS AND SW GRADIENT WINDS OVER THIS FORECAST AREA. SATURDAY-SUNDAY: MODELS CONTINUE TO DIVERGE FOR THESE PERIODS FOR LOW FORECAST CONFIDENCE. THE GFS IS LESS AMPLIFIED AND THEREFORE MORE PROGRESSIVE SHOOTING THE LOW THROUGH THE NORTHERN ROCKIES AND ONTO THE PLAINS ON SATURDAY. THE EC/CANADIAN SLIDE THE LOW SWRD LEAVING A SIGNIFICANT AMOUNT OF CUTOFF ENERGY IN ARIZONA. THEN THE REMAINDER OF THE WEAKER TROUGH PASSES ON SUNDAY. THIS LATTER SOLUTION LOOKS MORE LIKELY WITH A POSITIVE PNA PATTERN FAVORED. FOR THIS FORECAST... HAVE A SLIGHT CHANCE OF SNOW MENTIONED IN THE MTNS OF NE UTAH FRIDAY NIGHT-SATURDAY...SPREADING TO ALL THE MTNS AND EVEN THE NW CO PLATEAUS SATURDAY NIGHT-SUNDAY. && .AVIATION... VFR CONDITIONS BEING REPORTED AT ALL TAF SITES THIS AFTN. AS FRONT APPROACHES FROM THE WEST...CIGS WILL DROP AT ALL TAF SITES THOUGH ONLY KASE AND KEGE WILL FALL BELOW VFR. BY MIDNIGHT...SNOW OVER THOSE TWO SITES WILL DROP CIGS TO BELOW 1K FT AND CIGS TO BETWEEN 1 TO 3 MILES...POSSIBLY LOWER IN HEAVIER SNOW. THESE CONDITIONS WILL PERSIST THROUGH MONDAY AS SUPPORT CONTINUES SNOWFALL OVER NRN/CENTRAL MTNS. REMAINING TAF SITES WILL SEE SOME CLOUDS BUT CLOUD BASES WELL ABOVE 5K FT. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ SHORT TERM.....TGR LONG TERM......JOE AVIATION.......TGR