Area Forecast Discussion
Issued by NWS Billings, MT

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000
FXUS65 KBYZ 281957
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
157 PM MDT Wed Oct 28 2020

.DISCUSSION...

Tonight through Thursday night...

Northwest flow aloft with scattered to broken mid/high clouds
exists over the region today. There is a weak shortwave that
passed into ND, and lee side pressure rises have resulted in
relatively light winds across much of our cwa today. The exception
being the western foothills where Livingston, Big Timber and
Harlowton are each gusting near a modest 30 mph. There is another
shortwave evident on satellite imagery moving into northern
British Columbia. As this wave approaches, mid level winds will
back a bit and induce lee side pressure falls late tonight. This
will get winds along the foothills to rise again, with the backed
flow favoring the gap locations more than our previous wind event.
Latest guidance suggests a good chance of 50+ mph gusts at
Livingston, and a shot at advisory level gusts by early Thursday.
Big Timber and Harlowton could see 50 mph gusts once pressure
falls axis shifts east (tomorrow morning). Will let the night
shift monitor the gap areas for a possible wind advisory. As the
wave passes we will see pressures rise again tomorrow afternoon.
We will then quickly transition back to lee side pressure falls
late Thursday night...so there will only be a brief decrease in
foothills wind in the late afternoon and evening.

Temperatures will continue to moderate with the loss of snow cover
and persistent downslope flow. Air mass tomorrow is plenty warm
enough to get temps widespread into the 50s, but that will depend
on mixing and timing of wind shift. If Billings is able to shift
to west or northwest winds tomorrow afternoon, we will see temps
in the 50s. Western foothills should push upper 50s.

JKL

Friday through Wednesday...

Seasonally warm day on Friday ahead of a frontal system moving in
from the northwest. Look for highs in the upper 50s and strong gusty
winds along the foothills. Mainly dry front moves through Friday
night leading to a cooler weekend under northwest flow aloft.
Ensemble clusters show high confidence in strong 500 mb ridging
across the region Monday slowly transitioning to zonal flow by
midweek. So temps should be above or around normal through this
period dry conditions. Expect windy conditions at times,
especially in the foothills. BT

&&

.AVIATION...

VFR will prevail tonight and Thursday under scattered to broken
mid and high clouds. Winds will remain gusty along the western
foothills with gusts 25-35 kts, increasing to 45 kts by early
tomorrow. There is a small risk of patchy valley fog east of KBIL
late tonight.  JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    Thu     Fri     Sat     Sun     Mon     Tue     Wed
-----------------------------------------------------------
BIL 032/050 029/053 035/046 028/051 036/058 038/058 038/055
    00/N    00/U    00/U    00/U    00/U    00/U    01/B
LVM 038/055 029/056 030/049 025/055 032/060 032/059 033/056
    00/N    00/N    10/U    00/U    00/U    00/U    01/B
HDN 025/051 025/055 032/047 023/052 029/059 032/060 032/057
    00/B    00/U    00/B    00/U    00/U    00/U    01/B
MLS 026/053 027/054 034/044 023/050 030/060 036/061 035/057
    00/B    00/U    00/U    00/U    00/U    00/U    01/B
4BQ 025/054 026/055 034/043 023/050 031/060 034/060 033/056
    00/B    00/U    00/U    00/U    00/U    00/U    00/B
BHK 025/050 025/051 032/040 020/046 029/056 036/058 034/055
    00/B    00/U    00/N    00/U    00/U    00/U    01/U
SHR 025/055 025/059 030/045 022/054 030/062 032/063 031/059
    00/B    00/U    00/U    00/U    00/U    00/U    01/B

&&

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

&&

$$
weather.gov/billings


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