Area Forecast Discussion
Issued by NWS Billings, MT

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KBYZ 260910
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
310 AM MDT THU MAR 26 2015

.SHORT TERM...VALID FOR TDY AND FRI...

STRONG UPPER LEVEL RIDGE EXISTS ALONG THE WEST COAST BUT IT IS
DIRTY...WITH AN ABUNDANCE OF PACIFIC MOISTURE SPILLING OVER THE
RIDGE IN THE NW FLOW OVER OUR REGION. WEAK ENERGY DROPPING INTO
THE NORTHERN PLAINS WITH A 140KT H3 JET OVER EASTERN MT IS
PRODUCING SOME LIGHT PCPN NEAR THE DAKOTAS BORDER...WHICH WILL
SHIFT EAST OF OUR CWA OVER THE COMING HOURS. NW FLOW IS ALSO
GENERATING SOME LIGHT SHOWERS OR SPRINKLES IN UPSLOPE AREAS S/SE
OF BILLINGS AND OVER THE MTNS. LOOKING UPSTREAM...AREAS OF LIGHT
PCPN IMPACT WESTERN MT AS WELL. OVERALL WE SHOULD SEE CLOUDY SKIES
PERSIST TODAY DESPITE THE SLOWLY BUILDING HEIGHTS WITH AREAS OF
LIGHT SHOWERS OR SPRINKLES...MAINLY OVER THE MTNS AND IN UPSLOPE
REGIONS BUT THERE MAY BE ENOUGH DIURNAL INSTABILITY WITH STEEP MID
LEVEL LAPSE RATES TO PRODUCE SOME SPRINKLES ELSEWHERE INCLUDING
BILLINGS...AS RECENT HRRR RUNS SUGGEST. ANOTHER PIECE OF ENERGY
WILL DROP INTO THE NORTHERN PLAINS TONIGHT AND THIS SHOULD ENHANCE
PCPN AGAIN NEAR THE DAKOTAS BORDER...IE NEAR AND EAST OF SFC TROF.
OTHERWISE WE WILL SEE DRYING FROM WEST TO EAST LATE TONIGHT INTO
FRIDAY AS THE RIDGE CONTINUES TO PUSH EAST INTO THE NORTHERN
ROCKIES. DOWNSLOPE GRADIENTS WILL PERSIST FOR GUSTY WINDS ALONG
OUR FOOTHILLS OVER THE NEXT TWO DAYS. DO NOT EXPECT ANY HIGHLIGHTS
BUT BIG TIMBER HAS BEEN GUSTING INTO THE 40S ALREADY. HAVE RAISED
WIND SPEEDS SOME FROM BIG TIMBER TO 3HT AS THESE AREAS ARE FAVORED
IN A NW FLOW CHINOOK. TEMPS WILL RISE INTO THE LOWER TO MID 60S
TODAY IN WEST AND CENTRAL PARTS...AND INTO THE LOWER 70S FRIDAY.
HIGHS WILL APPROACH RECORDS AT LIVINGSTON AND BILLINGS ON FRIDAY.

THINGS GET MORE INTERESTING SATURDAY AS THE UPPER RIDGE BREAKS
DOWN WITH THE PASSAGE OF A PACIFIC SHORTWAVE AND COLD FRONT.
MODELS CONTINUE TO DISAGREE IN THE AMOUNT OF SPLITTING THAT THIS
ENERGY WILL UNDERGO IN THE EASTERN PACIFIC BEFORE IT MOVES INLAND.
LATEST ECMWF AND CANADIAN HAVE TRENDED SLOWER AND STRONGER WITH
THE WAVE...WHEREAS THE GFS IS CONTINUING WITH A WEAKER NORTHERN
SPLIT AND IS THUS FASTER. GIVEN THIS FEATURE IS IN A DATA VOID
AREA OVER THE PACIFIC AM NOT SURE WHICH SCENARIO IS PREFERRED SO
WILL STAY WITH A COMPROMISE AT THIS TIME. OVERALL EXPECT A FRONTAL
PASSAGE BY AFTERNOON WITH INCREASED SHOWER ACTIVITY ALONG AND
BEHIND THE FRONT. A SLOWER TIMING OF THIS FRONT WOULD YIELD WARMER
PREFRONTAL CONDITIONS AND THE POSSIBILITY OF A FEW TSTMS...AS THE
NAM AND ECMWF SHOW LIFTED INDICES NEAR ZERO. MAIN ISSUES ON
SATURDAY WILL REVOLVE AROUND FIRE WEATHER AND WIND AND WILL
CONTINUE TO HIGHLIGHT POTENTIAL FOR HIGH TEMPS...LOW RHS...STRONG
WINDS AND A FRONTAL PASSAGE IN THE FIRE WEATHER FORECAST. ALL
MODELS SHOWING NEAR 50 KTS OF MID LEVEL WIND WITH THIS SYSTEM SO
AN AFTERNOON ONSET OF SUBSIDENCE COULD PRODUCE VERY STRONG WINDS
ESPECIALLY FOR OUR WESTERN PARTS. STRONG W-NW WINDS SHOULD PUSH
ACROSS OUR PLAINS BY SATURDAY NIGHT. AGAIN...STRESS THE TIMING
UNCERTAINTY HERE.

ANYONE PLANNING OUTDOOR ACTIVITIES ON SATURDAY SHOULD BE AWARE OF
THE POTENTIAL FOR STRONG WINDS AND MONITOR THE FORECAST.

JKL

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

MEDIUM RANGE GUIDANCE IN OVERALL GOOD AGREEMENT INTO THE EXTENDED.
UPPER HEIGHTS BUILD ACROSS THE NORTHERN ROCKIES FOR SUNDAY INTO
MONDAY BEHIND SATURDAYS SYSTEM FOR DRY CONDITIONS. NEXT VIGOROUS
SYSTEM TO BREAK DOWN THE RIDGE ON TUESDAY. THIS SYSTEM NOT LOOKING
LIKE A BIG PRECIP MAKER WITH DOWNSLOPE FLOW...BUT COULD BE
ANOTHER WIND PRODUCER. BEHIND THE TUESDAY SYSTEM...AN OVERALL
PRGRESSIVE FLOW PATTERN DEVELOPS WITH MUCH LESS AMPLIFICATION.
THIS WILL PUSH SEVERAL IMPULSES THROUGH THE FLOW AND KEEP A FEW
SHOWERS IN THE FORECAST INTO NEXT THURSDAY. HIGH TEMPERATURES WILL
COOL TO MORE SEASONAL LEVELS INTO THE 50S. FRIEDERS
&&

.AVIATION...

VFR CONDITIONS WILL PREVAIL INTO TONIGHT. THERE WILL BE A FEW
SHOWERS IN AND NEAR THE MOUNTAINS FOR LOCAL MOUNTAIN OBSCURATIONS.
OTHERWISE...MAINLY MID LEVEL CLOUDINESS EXPECTED. FRIEDERS

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY FRI     SAT     SUN     MON     TUE     WED
-------------------------------------------------------
BIL 064 045/073 048/073 040/065 041/070 045/065 038/058
    1/E 00/B    03/W    20/B    00/U    03/W    22/W
LVM 064 044/073 047/067 037/065 040/068 042/058 031/055
    1/N 00/N    03/W    21/B    00/U    14/W    22/W
HDN 064 038/075 042/076 035/066 035/072 039/068 036/059
    1/E 00/B    03/W    20/B    00/U    03/W    22/W
MLS 058 041/071 044/074 035/063 037/069 038/067 037/057
    1/E 10/B    03/W    20/B    00/U    02/W    22/W
4BQ 058 039/071 040/077 036/064 036/070 039/069 035/058
    2/W 20/B    03/W    30/B    00/U    01/B    21/N
BHK 050 035/065 039/073 035/061 033/066 037/066 035/054
    2/W 30/E    02/W    30/U    00/U    02/W    31/N
SHR 059 038/070 039/077 035/065 035/070 038/069 034/055
    2/W 10/B    03/W    31/B    00/B    02/W    32/W

&&

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

&&

$$
WEATHER.GOV/BILLINGS



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.