FXUS65 KTFX 291745
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1045 AM MST SUN NOV 29 2009

.UPDATE...
SHOULD BE A MOSTLY QUIET MORNING ACROSS THE CWA. ONLY GRID EDITS
WERE TO UP CURRENT WINDS ALONG THE NORTHERN ROCKY MOUNTAIN FRONT
AREA AS BOTH SUSTAINED AND GUSTS ARE ALREADY A LITTLE HIGHER THAN
THE FORECAST. ALSO TOUCHED UP SKY COVER TO MATCH UP A BIT BETTER.
THE REST OF THE FORECAST LOOKS PRETTY GOOD. EXPECTING WINDS TO
PICK UP ACROSS THE NORTHWESTERN PORTION OF THE CWA LATER TODAY
INTO TOMORROW. THERE IS A WATCH IN EFFECT FOR THIS AREA AND THE
QUESTION OF WHETHER OR NOT TO UPGRADE IT AND FOR WHERE WILL BE
CLOSELY EXAMINED TODAY. CURRENTLY IT LOOKS AS IF IT MAY BE A
CLOSE CALL AT SOME LOCATIONS WHILE MORE LIKELY AT OTHERS.

&&

.AVIATION...
UPDATED 1645Z.
UPPER LEVEL HIGH PRESSURE RIDGE BUILDING OVER THE PACIFIC NORTHWEST. 
EXPECT MAINLY VFR CONDITIONS OVER THE REGION THROUGH THE PERIOD WITH 
GUSTY AFTERNOON WINDS...MAINLY ALONG THE EAST SLOPES OF THE ROCKIES 
AND ADJACENT PLAINS. WIND IN MOST AREAS EXPECTED TO CONTINUE THROUGH 
THE NIGHT...THEN INCREASING NEAR THE END OF THE PERIOD AS NEXT 
PACIFIC SYSTEM BREAKS THROUGH RIDGE USHERING IN GUSTY WINDS...COLDER 
CONDITIONS AND A CHANCE OF PRECIPITATION.

&&

.PREV DISCUSSION...
/ISSUED 430 AM MST SUN NOV 29 2009/

SUNDAY THROUGH TUESDAY...THE MAIN INTEREST THIS PERIOD IS THE 
SHORTWAVE TROF APPROACHING THE ZONES LATE MONDAY AFTERNOON AND THE 
RESULTING STRONG WINDS AND ASSOCIATED COLD FRONT PASSAGE. AN UPPER 
LEVEL HIGH PRESSURE RIDGE OVER THE ROCKIES WILL KEEP THE AIRMASS 
WARM AND DRY TODAY AND MONDAY. A SURFACE TROF IS IN PLACE ALONG THE 
LEE OF THE ROCKIES. STRONG WINDS ALOFT STAY WELL TO THE NORTH OF THE 
ZONES SO SURFACE WINDS WILL BE BRISK BUT NOT NEAR WARNING CRITERIA. 
BY MONDAY AFTERNOON...THE UPPER LEVEL JET WILL HAVE MOVED SOUTH OVER 
THE NORTHERN ROCKIES. MODELS INDICATE STRONG WINDS NEAR WARNING 
CRITERIA...WILL ISSUE A HIGH WIND WATCH...HOWEVER THE STRONGEST
WINDS SHOULD PASS THROUGH THE AREA QUICKLY. A LOW PRESSURE SHORT
WAVE WILL BE MOVING OVER THE WEST COAST MONDAY AND CROSSING THE
ROCKIES BY LATE AFTERNOON. THIS SYSTEM WILL HAVE STRONG DYNAMICS
BUT WILL BE FAST MOVING AND QPF WILL BE SKIMPY. AN ASSOCIATED COLD
FRONT WILL CROSS THE CANADIAN BORDER MONDAY NIGHT. PRECIP WILL
DEVELOP ACROSS THE NORTHERN ZONES BY MORNING AND INTO CENTRAL
MONTANA BY MID DAY. TEMPS WILL NOT RISE MUCH FROM OVERNIGHT LOWS.
ZELZER

TUESDAY NIGHT THROUGH FRIDAY NIGHT...A RATHER QUIET PERIOD OF 
WEATHER EXPECTED TO BEGIN THE PERIOD...AS THE MAIN COLD FRONT FROM 
TUESDAY MORNING SHOULD HAVE EXITED THE REGION BY TUESDAY EVENING. A 
FEW EVENING SNOW SHOWERS WILL BE POSSIBLE TUESDAY EVENING...MAINLY 
OVER SOUTHWEST MONTANA...OTHERWISE JUST EXPECT COLD AND DRY 
CONDITIONS. SEASONABLE CONDITIONS ARE EXPECTED WEDNESDAY AND 
THURSDAY...WITH ANY PRECIPITATION OCCURRING WILL BE VERY LIGHT AND 
MAINLY OVER THE MOUNTAINS. FOR FRIDAY...THE GFS/ECMWF HAVE VERY 
DRASTIC DIFFERENCES...AS THE GFS PROGS A FAIRLY GOOD SNOWSTORM OVER 
THE AREA ALONG WITH COLD CONDITIONS...WHILE THE ECMWF PROGS A FAIRLY 
STRONG RIDGE OF HIGH PRESSURE AND MOSTLY DRY CONDITIONS. SINCE THE 
EC HAS BEEN DOING FAIRLY WELL AS OF LATE...WENT WITH THAT 
SOLUTION...BUT THINGS COULD CHANGE SIGNIFICANTLY SHOULD THE GFS 
MODEL START TO PAN OUT. BRUSDA

SATURDAY THROUGH SUNDAY...MODEL DIFFERENCES AND RUN TO RUN 
INCONSISTENCY CONTINUE TO DETRACT FROM FORECAST CONFIDENCE DURING 
THIS PERIOD. THIS FORECAST WENT WITH A BLENDED COMPROMISE OF AN 
UPPER LEVEL TROUGH DROPPING SOUTHEAST FROM BRITISH COLUMBIA. A WEAK 
MODIFIED ARCTIC FRONT MOVES SOUTH OF THE BORDER SATURDAY MORNING... 
WITH WINDS SHIFTING NORTHERLY BEHIND THE FRONT AND TEMPERATURES 
FALLING. NOT MUCH MOISTURE WITH THE FRONT SO ONLY A CHANCE OF SNOW 
OVER THE MOUNTAINS IS EXPECTED. PRECIP LAGS THE FRONT SEVERAL HOURS 
WITH A SLIGHT CHANCE OF SNOW OVER THE PLAINS BY EARLY EVENING. 
TEMPERATURES WILL FALL TO A LITTLE BELOW SEASONAL AVERAGES BY 
SUNDAY. EK

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  50  35  54  30 /   0   0   0  50 
CTB  49  34  52  28 /  10   0   0  60 
HLN  45  28  48  29 /  10  10   0  30 
BZN  36  17  42  22 /  10   0   0  20 
WEY  31  11  34  15 /  10   0   0  10 
DLN  38  22  43  22 /  10   0   0  20 
HVR  50  29  53  26 /   0   0   0  40 
LWT  48  29  55  25 /   0   0   0  40 

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT 
FOR MTZ009-010-044-046-048-049.

&&

$$

SHORT TERM...GUSTAFSON
LONG TERM...BRUSDA/EK
AVIATION...BRUSDA

WEATHER.GOV/GREATFALLS