Area Forecast Discussion
Issued by NWS Billings, MT

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000
FXUS65 KBYZ 260219
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
819 PM MDT SAT OCT 25 2014

.UPDATE...
THE CURRENT FORECAST TRENDS LOOK GOOD. DID SOME MINOR TWEAKS TO
INCREASE THE WINDS AROUND LIVINGSTON. REIMER

&&

.SHORT TERM...VALID FOR SUN AND MON...

RIDGE OF HIGH PRESSURE REMAINS OVER THE AREA THIS AFTERNOON AND
WILL SLOWLY SHIFT EAST TONIGHT. THIS WILL MAKE ROOM FOR DEEP TROF
OFF THE PACIFIC COAST TO SLIDE IN FROM THE WEST OVER THE NEXT 24
HOURS. FIRST IMPACTS FROM THIS SYSTEM WILL BE FELT LATE TONIGHT
OVER THE WESTERN MOUNTAINS. MOISTURE LADEN SOUTHWEST FLOW ALOFT
WILL BRING INCREASING CLOUD COVER AND PRECIPITATION CHANCES TO
THIS AREA LATE TONIGHT. IN THE LOWER ELEVATIONS A TIGHTENING
PRESSURE GRADIENT AND SOME STRONGER SOUTHWEST MID LEVEL WINDS WILL
HELP TO INCREASE WIND SPEEDS OVER WESTERN FOOTHILLS
LOCATIONS...THOUGH DO NOT EXPECT GUSTS TO EXCEED 45 MPH BASED ON
LATEST GUIDANCE AND PRESSURE GRADIENT STRENGTH. WINDS IN THE HIGH
COUNTRY HOWEVER COULD GUST OVER 60 MPH ON EXPOSED SLOPES BY
SUNRISE SUNDAY. FOR THE REST OF THE AREA A QUIET AND DRY NIGHT
EXPECTED WITH WINDS AND INCREASED CLOUD COVER HELPING TO HOLD
TEMPERATURES ABOVE SATURDAY MORNINGS COLD READINGS.

FIRST OF TWO COLD FRONTS WILL PUSH THROUGH THE AREA DURING THE DAY
ON SUNDAY. THIS FRONT IS PACIFIC IN NATURE AND THE WEST TO EAST
ORIENTATION OF THE LOW LEVEL PRESSURE GRADIENT WILL KEEP DOWNSLOPE
WINDS IN PLACE. THUS THERE ISN`T A LOT OF COLD AIR IN THE LOWER
ELEVATIONS...HOWEVER 700MB TEMPERATURES WILL DROP BELOW FREEZING
EARLY IN THE DAY AND DROP TO AROUND -8C BY LATE SUNDAY AFTERNOON.
THIS WILL ALLOW SNOW LEVELS TO DROP FROM 9000FT IN THE MORNING TO
AROUND 65O0FT BY SUNSET. DOWNSLOPE WILL KEEP PRECIPITATION CHANCES
LOW SUNDAY FOR THE LOWER ELEVATIONS WHILE MOUNTAINS SHOULD SEE A
GOOD CHANCE FOR A TENTH TO A QUARTER INCH OF PRECIPITATION ON
FAVORED SOUTHWEST TO WEST ASPECTS. THIS WILL TRANSLATE TO AN INCH
OR TWO OF SNOW AROUND 7000FT TO AROUND 4 INCHES ABOVE 8000FT
DURING THE DAY. IT WILL BE BREEZY ON SUNDAY ACROSS THE AREA WITH
MOSTLY CLOUDY SKIES HELPING TO HOLD TEMPERATURES IN THE 50S WEST
TO MID 60S EAST.

SUNDAY NIGHT INTO MONDAY A SECONDARY COLD FRONT WILL DROP INTO
THE AREA FROM THE NORTHWEST WITH COLDER LOW LEVEL AIR. 850
TEMPERATURES DROP TO AROUND FREEZING WEST...AND BELOW FREEZING
EAST. WHILE PRECIPITATION CHANCES ARE GENERALLY 30 PERCENT OR
BELOW...THESE SHOWERS WILL PROBABLY PRODUCE A MIX OF
RAIN/SNOW/GRAUPLE AS THEY CROSS THE AREA. AGAIN THE MOUNTAINS WILL
BE FAVORED WITH WEST TO NORTHWEST FACING SLOPES/FOOTHILLS SEEING
THE BEST CHANCE OF SIGNIFICANT PRECIPITATION...AND ANY SNOW
ACCUMULATION WILL BE CONFINED TO ELEVATIONS ABOVE 6000FT. TROF
SHIFTS TO THE EAST LATE MONDAY WITH A POTENTIALLY COLD NIGHT IN
STORE MONDAY NIGHT WITH TEMPERATURES DEPENDING ON HOW QUICKLY
WINDS AND CLOUD COVER DIMINISH. CHAMBERS

.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...

MODELS REMAIN IN GOOD AGREEMENT THROUGH THE EXTENDED WITH ONLY
SOME MINOR TIMING DIFFERENCES WITH SHORT WAVE ENERGY MOVING
ACROSS THE AREA.

AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BE BREAKING DOWN ON
TUESDAY AS ENERGY MOVES IN FROM THE WEST COAST. LOWERING HEIGHTS
ALOFT WILL SET UP A FAST ZONAL FLOW WHICH WILL BRING SEVERAL SHORT
WAVES ACROSS THE AREA TUESDAY NIGHT AND WEDNESDAY. 100KT JET
NOSING INTO THE AREA WITH THE LEFT EXIT REGION ACROSS OUR AREA FOR
BOTH OFT THESE PERIODS. MODELS ARE CONTINUING TO SHOW WEAK Q
VECTOR FORCING AND ISOLATED RAIN SHOWERS ARE EXPECTED OVER THE
PLAINS WITH SNOW FALLING OVER THE MOUNTAINS. GOOD FETCH OF
MOISTURE IN THE HIGHER TERRAIN AND 3 TO 5 INCHES OF SNOWFALL WILL
BE POSSIBLE IN THE MOUNTAINS NEAR COOKE CITY. FALLING HEIGHTS OVER
THE AREA WILL KEEP TEMPERATURES NEAR SEASONAL VALUES WITH MID TO
UPPER 50S. ANOTHER RIDGE OF HIGH PRESSURE IS PROGGED TO BUILD OVER
MONTANA THURSDAY THROUGH NEXT SATURDAY. THIS WILL RAISE
TEMPERATURES 10 TO 15 DEGREES ABOVE NORMAL BOTH DAYS. SUBSIDENCE
UNDER THE RIDGE WILL KEEP THE AREA DRY. RICHMOND


&&

.AVIATION...

EXPECT VFR CONDITIONS TO CONTINUE INTO TOMORROW. HOWEVER...A COLD
FRONT WILL MOVE THROUGH THE AREA DURING THE DAY SUNDAY. ALONG AND
AHEAD OF THE FRONT...RAIN CHANCES INCREASE. RIGHT NOW...GUIDANCE
IS PRODUCING SPOTTY SHOWERS AND GIVEN THE ENSEMBLE
PROBABILITIES...CURRENT TAFS REMAIN DRY. AS NEW GUIDANCE COMES IN
AND THE SYSTEM PROGRESSES...WILL REEVALUATE WITH THE NEXT TAF
PACKAGE. WINDS WILL REMAIN GUSTY AT LIVINGSTON OVERNIGHT...WITH
GUSTS GENERALLY 30 TO 40 KNOTS. REIMER
&&

.PRELIMINARY POINT TEMP/POPS...

    SUN     MON     TUE     WED     THU     FRI     SAT
-----------------------------------------------------------
BIL 046/063 040/052 029/054 037/059 035/059 034/063 041/065
    02/T    22/W    01/B    23/W    10/B    00/B    00/B
LVM 046/056 034/046 026/050 034/055 034/057 032/059 039/058
    13/T    32/W    01/N    34/W    10/B    00/B    00/B
HDN 044/066 038/053 029/055 033/060 033/060 032/064 039/066
    02/T    22/W    01/B    22/W    10/B    00/B    00/U
MLS 044/067 036/049 024/053 033/060 031/055 030/060 037/063
    02/T    23/W    10/U    11/B    00/U    00/B    00/U
4BQ 044/067 035/049 026/053 032/061 033/057 033/063 040/066
    02/T    33/W    00/U    11/B    00/U    00/B    00/U
BHK 042/067 035/044 024/047 029/056 029/050 029/058 036/063
    01/B    23/W    10/U    11/B    00/U    00/B    00/U
SHR 042/066 031/050 023/054 029/060 029/060 030/062 037/062
    02/T    42/W    11/U    22/W    10/B    00/U    00/U

&&

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

&&

$$
WEATHER.GOV/BILLINGS



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