Area Forecast Discussion
Issued by NWS Billings, MT

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000
FXUS65 KBYZ 220906
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
306 AM MDT WED OCT 22 2014

.SHORT TERM...VALID FOR TDY AND THU...

OVERALL SHORT TERM FORECAST APPEARS IN GOOD SHAPE...WITH MODELS IN
GOOD AGREEMENT ON DRY CONDITIONS ACROSS THE REGION.

TROF CROSSING THE REGION WILL COMPLETE PASSAGE THROUGH THE REGION
TODAY...BUT AIRMASS APPEARS TO BE DRYING OUT QUICKLY. BEST ENERGY
AND INSTABILITY IS ON THE LEADING EDGE OF THE TROF...WHICH IS
WELL INTO THE DAKOTAS...SO DO NOT EXPECT ANY PRECIP IN THE
EASTERN ZONES THIS MORNING. COOL AIRMASS WILL REMAIN IN THE AREA
TODAY...AS TROF PUSHES EAST AND RIDGING BEGINS TO REDEVELOP THIS
EVENING/NIGHT...SO TEMPS SHOULD REMAIN IN THE 60S TODAY.

UPPER LEVEL SHORTWAVE RIDGING PREVAILS ACROSS THE REGION FOR
THURSDAY...BRINGING DRY CONDITIONS AND A SLIGHT WARMUP TO THE
AREA. THIS RIDGING DOES SLIP OFF TO THE EAST FAIRLY
QUICKLY...ALLOWING A RETURN OF SHALLOW SOUTHWESTERLY FLOW TO THE
REGION BY THE EVENING. SOUTHWEST FLOW ALOFT OPENS THE DOOR FOR
SOME PACIFIC MOISTURE TO REACH WESTERLY AND SOUTHWESTERLY FACING
SLOPES OF THE BEARTOOTH / ABSAROKEE MOUNTAINS OVERNIGHT THURSDAY.
DID INCREASE MOUNTAIN POPS SLIGHTLY FOR THURSDAY NIGHT BUT KEPT
ISOLATED DUE SHORT WINDOW FOR PRECIP AS FLOW TURNS MORE ZONAL
THROUGH THE NIGHT. AAG

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

PACIFIC MOISTURE PLUME WILL LIFT NORTH W/ MID LEVEL WARM FRONT ON
FRIDAY...AND COULD SEE SOME LIGHT PCPN OVER OUR WESTERN MTNS AS
THIS OCCURS. OTHERWISE OUR LOWER ELEVATIONS SHOULD REMAIN DRY AS
UPPER LEVEL RIDGE STRENGTHENS INTO SATURDAY. TEMPS FRIDAY SHOULD
TURN A BIT COOLER THAN THURSDAY BEHIND WEAK FROPA...THEN SATURDAY
SHOULD TURN WARMER AGAIN AS OVERALL FLOW AMPLIFIES AHEAD OF PAC
COAST TROF. TEMPS WILL REMAIN SIGNIFICANTLY ABOVE NORMAL EACH OF
THESE DAYS...IE HIGHS IN THE 60S TO MID 70S.

A PATTERN SHIFT IS IN STORE BEGINNING SUNDAY AS AFOREMENTIONED PAC
TROF IS KICKED THROUGH THE NORTHERN ROCKIES. A COUPLE COOLER DAYS
WITH SOME SHOWER ACTIVITY APPEAR IN STORE FOR SUNDAY/MONDAY UNDER
CYCLONIC FLOW/COOLER AIR ALOFT...WITH A SECONDARY SHORTWAVE
POSSIBLE INTO SUNDAY. DO NOT EXPECT MUCH ORGANIZATION WITH THESE
SHOWERS WITH A LACK OF STRONG FORCING AND PERSISTENT LOW LEVEL
DOWNSLOPE WINDS...SO ISOLATED TO SCATTERED POPS SHOULD SUFFICE
FOR THESE PERIODS...WITH SOME SNOW SHOWERS OVER THE MOUNTAINS.
MODEL CONSENSUS IS FOR BRIEF SHORTWAVE RIDGING OVER OUR CWA NEXT
TUESDAY...SO AM COMFORTABLE KEEPING POPS A BIT BELOW CLIMATOLOGY
FOR DAY 7. TEMPS EARLY NEXT WEEK WILL COOL TO MUCH CLOSER TO
NORMAL...HIGHS SOMEWHERE NEAR 60F ON SUNDAY THEN IN THE 50S MONDAY
AND TUESDAY.

EVOLUTION OF FLOW IN THE PACIFIC IS VERY UNCERTAIN AS WE GET INTO
NEXT WEEK...AND THIS WILL NEED TO BE WATCHED AS WE EASE OUR WAY
INTO A PATTERN SHIFT. TROF NEAR 35N 170E WILL INTERACT W/ TROPICAL
STORM ANA BY THE END OF THE WEEK...THEN THIS AREA OF DISTURBED
FLOW WILL APPROACH THE PAC COAST AND EITHER PHASE OR NOT PHASE
WITH A SHORTWAVE EMERGING FROM THE NORTH PACIFIC NEAR THE MIDDLE
OF NEXT WEEK. MODELS SHOW WILDLY VARYING POSSIBILITIES WITH THE
EVOLUTION OF THESE FEATURES...SO MUST STRESS A GREAT DEAL OF
UNCERTAINTY REGARDING OUR WEATHER FOR THE MIDDLE TO LATE PART OF
NEXT WEEK. THIS INCLUDES HALLOWEEN.

JKL
&&

.AVIATION...

VFR FLIGHT CONDITIONS WILL PREVAIL ACROSS THE AREA TODAY AS DRIER
AIR PUSHES IN BEHIND TUESDAY EVENING FRONTAL PASSAGE. WEST WINDS
WILL REMAIN A BIT GUSTY...WITH 15 TO 25 KT GUSTS DURING THE LATE
MORNING AND AFTERNOON. JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY THU     FRI     SAT     SUN     MON     TUE
-------------------------------------------------------
BIL 065 042/070 047/066 042/073 044/058 036/055 034/058
    1/B 00/B    10/B    00/U    12/W    22/W    11/B
LVM 061 039/067 043/065 041/072 041/055 031/052 030/055
    1/B 00/N    11/B    10/U    23/W    22/W    11/B
HDN 067 038/073 043/070 038/074 040/060 034/056 031/059
    1/B 00/U    00/B    00/U    12/W    22/W    11/B
MLS 065 037/072 043/068 041/070 042/062 034/054 030/056
    1/B 00/U    00/B    00/U    02/W    22/W    11/B
4BQ 065 037/071 042/069 039/072 042/061 034/053 030/057
    1/U 00/U    00/B    00/U    02/W    22/W    11/B
BHK 062 035/070 040/067 037/066 041/060 033/050 028/054
    1/B 00/U    00/U    00/U    01/B    22/W    11/B
SHR 065 034/072 040/071 036/076 038/060 031/053 025/058
    1/B 00/B    00/B    00/U    02/W    22/W    11/B

&&

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

&&

$$
WEATHER.GOV/BILLINGS



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