Area Forecast Discussion
Issued by NWS Billings, MT

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041
FXUS65 KBYZ 101025
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
325 AM MST WED FEB 10 2016

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

RIDGE AXIS RESPONSIBLE FOR OUR MILD WEATHER HAS SLID A TAD
FURTHER EAST AND NOW IS LINED UP OVER IDAHO. WE EXPECT ANOTHER
WARM DAY ACROSS OUR REGION. HOWEVER...WE DO HAVE A COUPLE OF
FORECAST ISSUES TO DEAL WITH FOR THIS SHORT TERM PACKAGE.

FIRST IS THE POTENTIAL FOR HITTING WIND ADVISORY CRITERIA IN THE
GAP LOCATIONS OF LIVINGSTON AND NYE. LIVINGSTON IS GUSTING TO JUST
UNDER 55 MPH EARLY THIS MORNING. SURFACE LOW IS SLIDING RATHER
QUICKLY FROM NE MONTANA INTO NW SOUTH DAKOTA THIS MORNING...AND
MAY BRIEFLY TIGHTEN THE PRESSURE GRADIENT A BIT MORE TOWARD
SUNRISE. COUNTER TO THIS ARGUMENT...ISOBARS ARE LINED UP A LITTLE
TO VERTICAL FOR GOOD GAP FLOW...AND GRADIENT WEAKENS AFTER 8 AM.
WE HAVE SOME WEB AND SOCIAL MEDIA CONTENT ALREADY COVERING THIS
MARGINAL GAP WIND EPISODE...SO WILL HOLD OFF ON ANY HIGHLIGHT AT
THIS TIME AS SIMPLY DO NOT FEEL THIS WILL BE A VERY SOLID OR
LENGTHY EPISODE.

THE OTHER ISSUE IS THE SLIGHT POSSIBILITY OF FREEZING
PRECIPITATION IN THE FALLON COUNTY VICINITY TONIGHT/THURSDAY
MORNING. THERE IS A WEAK SHORT WAVE /CURRENTLY NEAR THE BRITISH
COLUMBIA COASTLINE/ THAT WILL RACE AROUND THE RIDGE AND DROP DOWN
INTO EASTERN MONTANA AND THE WESTERN DAKOTAS LATE TONIGHT INTO
THURSDAY. THIS FEATURE IS PRECEDED BY SOME OTHER WEAK
PERTURBATIONS TODAY WHICH WILL ALLOW SOME COLDER AIR INTO FAR
EASTERN MONTANA LATE TODAY. THIS SETS THE STAGE FOR SOME
ISENTROPIC LIFT OVER LOW LEVEL COLD AIR...AND THUS THE POSSIBILITY
OF SOME FREEZING PRECIPITATION. WRF SOUNDINGS SUPPORT A SLIGHT
RISK OF THIS...BUT GFS SOUNDINGS KEEP THE COLUMN TO COLD. PROBABLY
TO MUCH THOUGHT INTO THIS CONSIDERING WE ONLY HAVE CHANCE POPS
ANYWAY...BUT WILL SIMPLY CARRY A CHANCE OF LIGHT SNOW OR FREEZING
DRIZZLE LATE TONIGHT INTO THURSDAY MORNING. BT


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

A FAST FLOW ALOFT WILL PREVAIL DURING THE EXTENDED PERIOD MAKING IT
DIFFICULT TO PINPOINT THE TIMING AND STRENGTH OF THE VARIOUS
SYSTEMS THAT WILL AFFECT THE AREA. OVERALL...CONDITIONS WILL BE
WETTER THAN THEY HAVE BEEN...BUT TEMPERATURES WILL REMAIN ABOVE
NORMAL.

THE UPPER RIDGE THAT HAS BEEN ANCHORED W OF THE FORECAST AREA WILL
SLIDE E OVER THE REGION ON FRI AND CONTINUE MOVING E FRI NIGHT AS
A PACIFIC SHORTWAVE APPROACHES THE AREA. THE ECMWF WAS WEAKER WITH
THE WAVE THAN THE GFS. WEAK ISENTROPIC LIFT WILL PRECEDE THE WAVE
ON FRI WITH SOME MOISTURE BRINGING A LOW CHANCE OF RAIN AND SNOW
SHOWERS TO PARTS OF THE AREA. THE WEAK LIFT/MOISTURE CONTINUES FRI
NIGHT WITH SLIGHT CHANCES FOR PRECIPITATION OVER MUCH OF THE
AREA. A COLD FRONT WILL WORK ITS WAY THROUGH THE REGION ON SAT
ASSOCIATED THE PACIFIC WAVE. MODEL DISAGREEMENT IN STRENGTH AND
TIMING OF THE WAVE CREATED DIFFERENCES IN QPF PLACEMENT BETWEEN
THE MODELS SO WENT WITH A MODEL BLEND FOR POPS WHICH RESULTED IN
AT LEAST A LOW CHANCE OF SHOWERS OVER THE ENTIRE AREA. THE QPF
DIFFERENCES CONTINUED SAT NIGHT SO CONTINUED WITH A CHANCE OF
PRECIPITATION FOR THE ENTIRE REGION.

UNSETTLED NW FLOW/ANTICYCLONIC FLOW WILL BE OVER THE AREA SUN
THROUGH MON AND THE GFS/GEFS SHOWED AN ATMOSPHERIC RIVER NUDGING
INTO THE REGION. CONTINUED WITH CHANCES OF PRECIPITATION FOR THE
ENTIRE AREA WITH POOR MODEL AGREEMENT WITH THE QPF. SYNOPTIC
RIDGING RETURNS TO THE AREA FOR LATE IN THE PERIOD WITH DRIER
WEATHER.

MON THROUGH TUE LOOKED LIKE POSSIBLE WINDY PERIODS OVER THE PLAINS
BUT WILL HAVE TO WATCH MODEL TRENDS REGARDING THE WINDS GIVEN THE
UNCERTAINTY IN THE FORECAST. ARTHUR
&&

.AVIATION...

VFR CONDITIONS WILL PREVAIL OVER THE AREA TODAY AND TONIGHT.
GUSTY WSW SURFACE WINDS WILL AFFECT BIG TIMBER AND KLVM WITH GUSTS
OF 45 TO 50 KT EXPECTED AT KLVM. IT WILL STILL BE BREEZY OVER BIG
TIMBER AND KLVM TONIGHT BUT GUSTS WILL BE ONLY IN THE 30S. ARTHUR
&&

.PRELIMINARY POINT TEMP/POPS...

    TDY THU     FRI     SAT     SUN     MON     TUE
-------------------------------------------------------
BIL 064 039/063 036/055 035/056 034/052 036/060 038/057
    0/N 01/N    12/W    22/W    32/W    22/W    21/N
LVM 058 039/055 038/055 038/052 033/047 038/054 039/053
    0/N 01/N    22/W    24/W    32/W    22/W    21/N
HDN 066 031/063 030/054 031/055 032/051 031/059 033/057
    0/U 01/B    12/W    22/W    33/W    22/W    21/N
MLS 055 029/052 028/044 029/051 031/049 032/056 037/054
    0/U 11/B    11/E    22/W    32/W    22/W    21/N
4BQ 060 028/058 027/047 028/052 030/049 030/056 033/056
    0/U 01/B    11/E    22/W    32/W    22/W    21/N
BHK 052 026/040 025/036 022/043 029/045 029/050 033/050
    0/U 13/O    11/E    33/J    32/W    12/W    21/N
SHR 063 030/059 030/052 031/054 029/046 028/054 032/054
    0/U 00/B    12/J    12/W    32/W    22/W    11/B

&&

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

&&

$$
WEATHER.GOV/BILLINGS



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