FXUS65 KBYZ 081653
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT 
953 AM MST TUE DEC 8 2009

.SHORT TERM...VALID FOR TDY AND WED...

UPPER TROUGH OVER THE AREA THIS MORNING WITH A BIT OF MOISTURE
MOVING ACROSS THE SOUTHEAST ZONE AND NORTHERN WYOMING CAUSING
LIGHT SNOW. WEST OF BILLINGS DRIER AIR IS SHUTTING OFF THE SNOW
AND EXPECT THIS CLEARING TREND TO SPREAD ACROSS THE NEXT 24 HOURS.
HAVE UPDATED FORECAST TO INCLUDE A BIT MORE SNOW TODAY ACROSS THE
SOUTHEAST AS CLOUD TOPS CONTINUE TO COOL BUT DRIED OUT WESTERN
ZONES. CONTINUED BITTER COLD TODAY AND INTO TONIGHT WITH THE
SURFACE HIGH PRESSURE BEGINNING TO SHIFT EAST WHICH WILL CAUSE
INCREASED DRAINAGE WINDS. WILL LOOK AT BLOWING SNOW AND WIND CHILL
THREAT FOR TONIGHT AND WEDNESDAY IN RESPONSE TO THESE WINDS
PICKING UP. BORSUM 

.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...

MODELS CONTINUE TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE
EXTENDED AND CHANGES MADE WERE TO REFLECT THIS. UNSTABLE
NORTHWEST FLOW REMAINS OVER THE AREA ON THURSDAY AND FRIDAY WHICH
WILL BRING A SLIGHT CHANCE OF SNOW TO THE REGION. ANOTHER UPPER
LEVEL SYSTEM OVER CANADA WILL SLIDE A LITTLE BIT FATHER SOUTH AND
BRING ANOTHER SHOT OF ARCTIC AIR TO THE REGION ON SATURDAY. HAVE
LOWERED TEMPS A QUITE A BIT MORE FOR THIS PERIOD AS A RESULT.
HAVE ALSO CONTINUED POPS FOR THIS TIME PERIOD GIVEN THERE WILL BE
SOME WARM AIR ADVECTION ALOFT. THE GFS TRIES TO MOVE OUT THE
COLDEST AIR BY SUNDAY WHERE THE ECMWF KEEPS THE ARCTIC AIR IN A
BIT LONGER EVEN INTO MONDAY. HAVE LOWERED TEMPS A FEW DEGREES BUT
DID NOT GO TOO MUCH COLDER GIVEN THESE SLIGHT DIFFERENCES IN THE
MODELS. DID KEEP IN POPS THROUGH THESE PERIODS AS WELL AS MODELS
CONTINUE TO BRING WEAK SHORTWAVES THROUGH THE FLOW. SOLUM

&&

.AVIATION...

AREAS OF LIGHT SNOW AND FLURRIES WILL CONTINUE THIS MORNING FROM
BILLINGS SOUTH AND EAST. THE LIGHT SNOW WILL TAPER OFF THIS
AFTERNOON. SLIGHTLY HEAVIER SNOW IS LIKELY ALL DAY ACROSS FAR
SOUTHEAST MONTANA. IFR CONDITIONS WILL PERSIST THIS MORNING EAST
AND SOUTH OF KBIL WITH MVFR TO VFR CONDITIONS FOR THE AFTERNOON.
ELSEWHERE...VFR CONDITIONS WILL PREVAIL MAINLY WEST OF KBIL.
HOOLEY

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY WED     THU     FRI     SAT     SUN     MON     
-------------------------------------------------------
BIL 902 910/006 905/015 901/017 004/012 009/031 018/031
    3/J 02/S    22/S    22/S    22/S    22/S    21/B
LVM 906 911/006 901/016 002/024 008/022 010/029 019/035
    1/M 03/S    22/S    22/S    22/S    22/S    22/S
HDN 001 911/011 905/019 904/023 901/015 001/028 008/031
    +/J 02/S    22/S    21/B    22/S    22/S    21/B
MLS 001 913/007 909/013 909/014 906/006 906/017 002/021
    6/J 02/S    22/S    21/B    22/S    22/S    21/B
4BQ 006 913/009 908/017 903/021 001/015 000/027 010/031
    +/J 12/S    22/S    21/B    22/S    22/S    21/B
BHK 005 913/007 906/011 903/014 903/006 908/015 007/020
    6/J 12/S    22/S    21/B    22/S    22/S    21/B
SHR 001 914/009 909/018 906/025 000/021 002/033 010/034
    8/J 02/S    22/S    22/S    22/S    22/S    21/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

&&

$$
WEATHER.GOV/BILLINGS