FXUS65 KTFX 271649
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
949 AM MST FRI NOV 27 2009
.UPDATE...
ONLY MINOR CHANGES THIS MORNING...LOWERED MAX TEMPS ACROSS THE
AREA DUE TO INCREASED CLOUD COVER AND LIGHT WINDS. REMAINDER OF
THE FORECAST SEEMS TO BE ON TRACK SO MADE NO FURTHER CHANGES. MLS
&&
.AVIATION...
UPDATED 1145Z.
A WEAK SURFACE COLD FRONT CONTINUES TO PUSH SOUTH THROUGH NORTH
CENTRAL MONTANA THIS MORNING. EXPECT A WIND SHIFT TO THE NORTH AT
GTF...HVR...AND LWT THIS MORNING...AS MID CLOUDS CONTINUE TO MOVE
INTO THE REGION. AN UPPER LEVEL TROF OF LOW PRESSURE WILL MOVE
THROUGH THE REGION TONIGHT. EXPECT SCATTERED SNOW SHOWERS TO DEVELOP
OVER THE ROCKY MOUNTAIN FRONT BY MID DAY...AND THEN THE SNOW SHOWERS
WILL SPREAD INTO PORTIONS OF NORTH CENTRAL AND SOUTHWEST MONTANA
THIS EVENING. MOUNTAINS WILL BECOME OBSCURED BY THIS AFTERNOON.
EXPECT VFR CONDITIONS THIS MORNING TO GENERALLY BECOME MVFR/IFR BY
THIS EVENING...ESPECIALLY IN/NEAR SNOW SHOWERS. BRUSDA
&&
.PREV DISCUSSION...
/ISSUED 445 AM MST FRI NOV 27 2009/
TODAY THROUGH SUNDAY...PROGRESSIVE PATTERN CONTINUES THROUGH THE
PERIOD. FAIRLY GOOD AGREEMENT WITH MODEL DATA FOR THE SHORT TERM.
AN UPPER LEVEL RIDGE CONTINUES TO PUSH EAST AS AN UPPER LEVEL
TROUGH MOVES INTO THE PACIFIC NORTHWEST...BRINGING PACIFIC
MOISTURE INTO THE AREA FRIDAY. ON FRIDAY EXPECT SCATTERED SHOWERS
ACROSS THE DIVIDE...ESPECIALLY ALONG THE ROCKY MOUNTAIN FRONT AND
ADJACENT PLAINS. TEMPERATURES ARE STILL RELATIVELY WARM SO
PRECIPITATION MAY START OUT AS RAIN IN SOME LOCATIONS CHANGING
OVER TO SNOW IN THE MOUNTAINS AS AS COOLER AIR BEHIND THE TROUGH
MOVES IN. NOT EXPECTING MUCH IN THE WAY OF SNOWFALL
ACCUMULATION...RANGING FROM 3 TO 5 INCHES IN THE HIGHEST
ELEVATIONS. WILL MONITOR THIS SYSTEM BUT NOT EXPECTING ANY WINTER
HIGHLIGHTS. PRECIPITATION WILL PROGRESS FROM WEST TO EAST FRIDAY.
EXPECT MOSTLY RAIN SHOWERS IN THE PLAINS...POSSIBLY MIXING WITH
SNOW SHOWERS BY LATE FRIDAY. HIGH TEMPERATURES ON FRIDAY WILL
REMAIN 10 TO 15 DEGREES ABOVE AVERAGE AHEAD OF THE FRONT. ON
SATURDAY EXPECT NORTHWEST WINDS AND THE RETURN OF SEASONAL
TEMPERATURES. THE CORE OF PRECIPITATION WILL HAVE PUSHED SOUTHEAST
OUT OF THE AREA...EXCEPT OVER SOUTHWEST MT WHERE A CHANCE OF
LINGERING SNOW SHOWERS EXIST. NORTHWEST FLOW WILL CONTINUE
SATURDAY NIGHT INTO SUNDAY...BRINGING ANOTHER SHOT OF PACIFIC
MOISTURE INTO THE NORTHWEST SECTION OF THE AREA...MAINLY OVER THE
ROCKY MOUNTAIN FRONT. EXPECT DRY CONDITIONS ELSEWHERE.
TEMPERATURES WILL CONTINUE TO BE NEAR AVERAGE TO SLIGHTLY ABOVE
ABOVE AVERAGE. BY SUNDAY AFTERNOON THE UPPER LEVEL TROUGH PUSHES
EASTWARD AS AN UPPER LEVEL RIDGE MOVES OVER THE PACIFIC NORTHWEST.
SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...A FAIRLY BIG CHANGE IN THE
WEATHER PATTERN WILL OCCUR EARLY NEXT WEEK...AS WINTER LIKE
CONDITIONS MOVE BACK INTO THE REGION FOR A FEW DAYS. OTHER THAN A
FEW ISOLATED SHOWERS SUNDAY NIGHT THROUGH MONDAY...EXPECT ONE MORE
MILD DAY. THEN A FAIRLY STRONG COLD FRONT WILL MOVE SOUTH THROUGH
THE REGION TUESDAY INTO TUESDAY EVENING. EXPECT A BAND OF SNOW TO
ACCOMPANY THE FRONTAL PASSAGE...ALONG WITH FALLING TEMPERATURES.
SNOW ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...AND THIS WILL NEED
TO BE MONITORED CLOSELY OVER THE NEXT FEW DAYS. AFTERNOON HIGHS BY
WEDNESDAY WILL BE CLOSE TO 10 DEGREES BELOW NORMAL OVER THE
REGION...WITH OVERNIGHT LOWS MORE WINTER LIKE...FALLING INTO THE
SINGLE DIGITS AND LOWER TEENS FOR MOST LOCATIONS BY THURSDAY
MORNING. BRUSDA
THURSDAY THROUGH FRIDAY...MODELS HAVE MADE SOME BIG CHANGES ON THIS
RUN BUT ARE IN ROUGH AGREEMENT DURING THIS PERIOD...WITH SOME
DIFFERENCES IN TIMING AND STRENGTH OF FEATURES. AN UPPER LEVEL RIDGE
MOVES OVER THE PACIFIC NORTHWEST...FURTHER EAST THAN ON PREVIOUS
RUNS...SHUNTING THE BRUNT OF AN ARCTIC CLIPPER MOSTLY EAST OF THE
REGION. WITH DRIER AIR MOVING OVER THE FORECAST AREA...OTHER THAN A
FEW STRAY LIGHT SNOW SHOWERS OR FLURRIES THURSDAY...THE ONLY CHANCE
OF SNOW WILL BE OVER THE MOUNTAINS. A MODIFIED ARCTIC AIR MASS OVER
THE FORECAST AREA WILL BE RESPONSIBLE FOR TEMPERATURES SOME 10 TO 15
DEGREES BELOW SEASONAL AVERAGES THURSDAY. ON FRIDAY AS THE RIDGE
BEGINS TO APPROACH MONTANA AND LIGHT DOWN SLOPE WINDS BEGIN TO
DEVELOP...TEMPERATURES WILL MODERATE A FEW DEGREES OVER THE PLAINS.
EK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 47 25 37 26 / 20 20 10 10
CTB 41 23 36 23 / 40 30 0 10
HLN 45 26 38 22 / 30 30 10 20
BZN 42 22 32 15 / 0 40 20 10
WEY 33 5 27 3 / 20 50 30 10
DLN 40 16 31 15 / 20 30 10 10
HVR 47 23 39 21 / 40 20 0 10
LWT 48 24 37 21 / 20 30 10 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...
LONG TERM...
AVIATION...
WEATHER.GOV/GREATFALLS
