Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 011629
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
929 AM MST Thu Dec 1 2016

.UPDATE...

No updates planned this morning for today`s forecast. A weak
disturbance aloft will move over the forecast area bringing a
slight chance for a snow shower this morning and rain or snow
shower this afternoon. Skies will be partly to mostly cloudy with
temperatures around normal for the 1st of December, the exception
will be out toward the Dakota borders where temperatures around
30 degrees will be common. The normal high today for Billings is
38 degrees. Hooley

&&

.SHORT TERM...valid for Tdy and Fri...

An upper trough was working its way into western Montana early
this morning and will shift across the forecast area today and
tonight. Cyclonic flow and weak upper divergence, especially this
morning, will generate a few light snow showers today. not
expecting much in the way of impacts with this activity. The
trough weakens and slides east Friday. Weak ascent progged to
continue into southeast Montana and have thus added low PoPs,
otherwise conditions will be dry. High temperatures the next two
days will be similar to those of Wednesday. Winds are expected to
increase through the Upper Yellowstone and Upper Stillwater
valleys Friday night. Gradient tightens enough to be concerned for
a possible advisory event overnight Friday into Saturday morning.
Increased winds a bit more for the overnight hours on Friday. TWH

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

Saturday, strong ridge in place over Idaho as a low slides
southeast out of Canada. This strong gradient will keep winds 40
to 50 mph through the gap areas as we head into Sunday morning.
The transition to winter begins on Sunday as a strong trough dives
southeastward out of British Columbia. Expect a round of snow
showers to accompany this trough some time between late Sunday and
Monday. Accumulation amounts become a bit tricky as the models
begin to diverge on Monday. ECMWF keeps QPF over most of the area
well into Monday night while the GFS has more isolated banding
developing in the wake of the trough ahead of an approaching
arctic air mass. Bottom line, expect snowy conditions and the
potential to see a few inches of accumulation at any point during
the Sunday night through Monday night time frame.

Coldest air in at least a year begins to move in early next week.
Both the MEX and ECE showing temperatures dropping into single
digits by Tuesday morning with near or below zero temperatures
possible across the area on Wednesday and Thursday morning. Our
forecast was on the warm side of the guidance spread and given the
consistency with temperatures in both the Euro and GFS, felt
confident enough to drop our forecast temperatures closer into
line with these models. Current thinking is the arctic air mass
should remain in place through Wednesday with Highs in the single
digits to low teens, and Lows in the single digits to around zero
Tuesday morning through Thursday morning. Walsh

&&

.AVIATION...

There will be isolated rain and snow showers over the area
today, and isolated snow showers tonight through Fri. morning.
Confidence was low in where the showers will form so have gone
with VCSH in TAF`s. Any showers could contain MVFR/IFR conditions.
Expect localized to areas of mountain obscuration through Fri.
morning. Arthur

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Fri     Sat     Sun     Mon     Tue     Wed
-------------------------------------------------------
BIL 040 022/038 026/043 029/043 022/028 007/011 002/015
    2/W 23/J    22/J    23/W    44/J    22/J    21/B
LVM 037 022/036 030/040 031/044 021/027 003/012 002/019
    2/W 42/J    33/W    45/W    53/J    22/J    21/B
HDN 039 022/035 022/043 027/044 024/028 006/012 000/013
    2/W 23/J    22/W    22/W    44/J    22/J    21/B
MLS 035 019/033 020/041 024/041 021/026 003/010 903/013
    1/E 22/J    13/W    12/W    34/J    22/J    22/J
4BQ 035 017/031 017/040 023/042 021/028 004/013 903/012
    1/E 22/J    03/W    11/B    22/J    22/J    22/J
BHK 030 014/031 014/039 021/038 019/024 001/010 906/010
    1/E 22/J    03/W    11/B    23/J    22/J    22/J
SHR 038 017/036 015/040 021/043 020/027 004/013 902/014
    2/W 22/J    12/J    11/B    22/J    22/J    21/B

&&

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

&&

$$
weather.gov/billings


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