Area Forecast Discussion
Issued by NWS Billings, MT

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720
FXUS65 KBYZ 180932
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
232 AM MST Wed Jan 18 2017

.SHORT TERM...valid for Tdy and Thu...

Windy and mild conditions will continue for the next couple of
days. High pressure ridging will hold in place today. However,
some mid and high level clouds will move across the area ahead of
an upper low and trough approaching the Pacific Northwest coast.
In addition, lee-side troughing will remain in place allowing for
fairly tight pressure gradients across the Upper Yellowstone and
Upper Stillwater valleys. Gradient orientation is not perfectly
optimal for prolonged advisory winds for the Livingston and Nye
areas but it is close that we still believe advisory gusts will
hit on occasion today into this evening, and will therefore
continue with the wind advisory for the Livingston to Nye areas.
Temperatures today will be similar to Tuesday and possibly a few
degrees warmer.

The above mentioned low and trough move onshore tonight and
Thursday. This will flatten the ridge and lower heights just a
bit. In addition, some moisture will move into the western half of
our forecast area tonight and Thursday bringing a chance for
mountain snow showers and some rain or snow showers along and west
of a Roundup-Billings-Sheridan line. Precipitation amounts look
light so little if any impacts are expected. Hooley

.LONG TERM...valid for Fri...Sat...Sun...Mon...Tue...

Light precipitation in the form of rain/snow showers will linger
into Friday per weak shortwave and divergence in RRQ of southerly
100kt H3 jet. Best chances will be in our west and central parts
and will side with the EC here as its been a little more
consistent than the GFS. That being said, the GFS shows a bit more
energy affecting our east Friday night thru Saturday as southern
split of trof evolves into a weak closed low which lifts through
the Dakotas and MN. Flow aloft is rather weak during this time so
not a very high confidence forecast. Will keep broadbrushed slight
pops Friday night through Saturday night as we will be under some
kind of troffing and below normal heights, but the pattern is
certainly not very dynamic.

Consensus is for a period of drier wx Sunday into Sunday night
before next Pacific trof moves inland and moves through the
western CONUS. Jet energy will be well to our south through the
southern Rockies, but there is an opportunity for some snow in our
area Monday/Tuesday as trof moves across, and could even be some
upslope enhancement. GEFS plumes are quite scattered in terms of
QPF on the 23rd and 24th, and EC runs have also not been
consistent. Again, poor confidence per the weak flow pattern. Will
keep slight-to-chance pops in place for these days, greatest in
our south.

Temperatures will gradually cool through the extended period, with
Friday`s highs in the 30s to near 40F cooling to the mid 20s to
lower 30s early next week. Nothing extreme for sure, but there is
confidence in a cooling trend as we move into next week.

JKL

&&

.AVIATION...

VFR conditions will prevail over the next 24 hours. SW winds will
gusts from 40-50 kts at KLVM, with gusts to 30 kts extending as
far east as KBIL. A few snow showers are possible over the
Beartooth Absaroka Mountains late tonight. JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Thu     Fri     Sat     Sun     Mon     Tue
-------------------------------------------------------
BIL 043 028/044 029/036 021/033 020/034 018/032 016/026
    0/U 00/B    33/W    22/J    21/B    11/B    22/J
LVM 046 030/046 027/040 018/036 018/036 020/036 014/029
    0/N 02/W    43/W    22/J    21/B    23/J    22/J
HDN 041 020/041 020/035 016/031 011/031 009/030 009/025
    0/U 00/U    23/W    22/J    21/B    11/B    22/J
MLS 039 020/040 018/032 020/032 017/032 010/029 011/023
    0/U 00/U    12/J    22/J    21/B    11/B    22/J
4BQ 040 016/042 016/034 019/034 015/033 010/030 009/025
    0/U 00/U    12/W    22/J    21/B    11/B    22/J
BHK 038 018/039 014/033 020/032 018/031 011/029 011/023
    0/U 00/U    01/B    22/J    22/J    11/B    22/J
SHR 043 021/044 020/036 015/034 012/034 011/032 010/026
    0/U 00/U    23/W    22/J    21/B    01/B    22/J

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Wind Advisory in effect until 6 AM MST Thursday FOR ZONES
      65-66.
WY...None.

&&

$$
weather.gov/billings



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