FXUS63 KGLD 042340
AFDGLD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
440 PM MST FRI DEC 4 2009

.DISCUSSION...
150 PM MST FRI DEC 4 2009

MODERATING TEMPERATURES WERE OBSERVED TODAY ACROSS THE TRI-STATE 
AREA IN SOUTHWEST LOW LVL FLOW. A TROUGH OF LOW PRESSURE WAS DIGGING 
INTO THE NORTHERN INTERMOUNTAIN REGION THIS AFTERNOON AND IS PROGGED 
TO CONTINUE TO DIG SOUTH INTO THE CENTRAL GREAT BASIN AREA TOMORROW. 
MEANWHILE, A COLD FRONT WILL MOVE SOUTH ARRIVING OVER THE CENTRAL 
HIGH PLAINS LATE IN THE DAY ON SAT. A SLOWER ARRIVAL WOULD LEAD TO 
WARMER TEMPERATURES ACROSS THE WEST/NORTHWEST, HOWEVER GIVEN 
TIMING UNCERTAINTY LEANED COOLER WITH HIGHS STRUGGLING TO CLIMB OUT 
OF THE 30S. 

FROPA WILL REINTRODUCE A VERY COLD AIRMASS TO THE AREA ON SUN WHILE 
LARGE SCALE FORCING FOR ASCENT SPREADS OVER THE REGION. A PERIOD OF 
LIGHT SNOW IS ANTICIPATED AND WEIGHTED THE HIGHEST POPS EARLY IN THE 
PERIOD BEFORE FORCING FOR SUBSIDENCE KICKS IN. DUE TO THE 
PROGRESSIVE NATURE OF THE TROUGH ONLY LIGHT ACCUMULATIONS OF SNOW IN 
THE 1 TO PERHAPS 2 INCH RANGE ARE ANTICIPATED.

A PERIOD OF SUBSIDENCE IS EXPECTED SUN NIGHT/EARLY MON WITH ONLY A 
MENTION OF FLURRIES PLANNED. TRENDED HIGHS ON MON DOWN ACROSS THE 
NORTHEAST ZONES WHERE CONTINUED CAA IS ANTICIPATED. FURTHER WEST, 
TEMPERATURES MAY CLIMB INTO THE UPPER 20S/AROUND 30 WHERE SOUTHERLY 
FLOW WILL DEVELOP IN RESPONSE TO CYCLOGENESIS OVER CO LATE IN THE 
PERIOD. HELD MID POPS MON NIGHT ALTHOUGH BETTER CHANCES FOR SNOW 
SHOULD ARRIVE ON TUE WHEN MID/UPPER TROUGH TRANSLATES EAST ACROSS 
THE AREA. 

DAYS 4 THROUGH 7...AT THE START OF THE PERIOD (TUESDAY), A MID/UPPER 
TROUGH IS PROGGED TO BE OVER THE CENTRAL PLAINS STATES WITH ONLY 
MINOR DIFFERENCES IN AMPLITUDE NOTED BETWEEN THE VARIOUS MODELS. THE 
OPERATIONAL GFS IS THE DEEPEST WHILE THE ECMWF APPEARS RATHER 
SIMILAR TO THE NCEP ENS MEAN ALTHOUGH IT CONTINUES TO TREND DEEPER 
OR MORE SIMILAR TO THE GFS/NCEP ENS MEAN. THIS SCENARIO WOULD SLOW 
THE ARRIVAL OF PCPN BRINGING HIGHER POPS ON TUE AS OPPOSED TO MON 
NIGHT. A SLIGHTLY SLOWER/DEEPER SCENARIO WOULD ALLOW MORE MOIST 
ADVECTION WITH 4-5 G/KG MIXING RATIOS PROGGED ON THE 290K SFC, WHICH 
IS AN INCREASE COMPARED TO PREVIOUS MODEL RUNS. LARGE SCALE FORCING 
FOR SUBSIDENCE/DOWNGLIDE KICKS IN TUE NIGHT BRINGING A RAPID DEMISE 
TO SNOW PRODUCTION. 

WED-FRI...THE CHALLENGE DURING THIS PERIOD WILL BE LOCATING THE 
WESTERN PERIPHERY OF THE COLD AIRMASS AND LINGERING IMPACTS SNOW 
DEPTH HAS ON TEMPS. GENERALLY LEANED COOLER THROUGH THE PERIOD GIVEN 
THE UNCERTAINTIES WHILE INDICATING SUBTLE TEMPERATURE MODIFICATION 
THROUGH THURSDAY. BY FRIDAY THE COLD AIRMASS MAY BE REINFORCED AS A 
SHORTWAVE TROUGH LIFTS NORTHEAST ACROSS THE AREA. WILL MAINTAIN A 
DRY FORECAST WHILE TRENDING TEMPERATURES DOWN WITH POTENTIAL FROPA.

MCGUIRE
&&

.AVIATION...
439 PM MST FRI DEC 4 2009
FOR THE 00Z TAFS... VFR CONDITIONS WILL CONTINUE WITH LIGHT WINDS 
AND FEW/SCT CIRRUS DURING THE OVERNIGHT HOURS. TOWARDS THE END OF 
THE TAF PERIOD THE WINDS WILL SHIFT TO THE NORTH AS THE NEXT COLD 
FRONT NEARS THE REGION.

KJ
&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&

$$