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
FXUS65 KBYZ 152121

Area Forecast Discussion
National Weather Service Billings MT
321 PM MDT Sun Oct 15 2017

.SHORT TERM...valid for Mon and Tue...

Warm and dry conditions in store through Tuesday as we remain
under zonal flow aloft with above normal heights. Temperatures
should get to the lower 70s Monday and mid or perhaps upper 70s
Tuesday. This is well above mid October normals, but not quite to
record levels (which are mostly in the 80s).

Main issue is wind along the foothills, of course, as downslope
pressure gradients remain in place. Weak shortwave moving across
western Canada will help to tighten up gradients a bit tonight,
but mid level flow will remain weak at 30-35 kts. This should
yield 40-50 mph gusts at Livingston and Nye, with the orientation
of the gradient supportive of gustiness at Big Timber and
Harlowton as well. These winds will decrease with mixing during
the day tomorrow. Similar speeds expected Monday night, again with
mid level flow seeming to be weak enough to keep gusts under
advisory criteria.

Mid level winds will increase (40-50 kts at 700mb) on Tuesday as
stronger Pacific shortwave moves thru the Canadian Rockies. Looks
like increasing mixed winds on Tuesday with potential for some
enhanced pre-frontal gap winds Tuesday evening, depending on
frontal timing which is a bit uncertain. Advisory level gusts are
a possibility during this time period at Livingston and along the
Beartooth Foothills.

Have issued a weather story to message the period of gusty winds
along our western foothills the next couple days. Impacts will be
in the form of cross winds for travelers.


.LONG TERM...valid for Wed...Thu...Fri...Sat...Sun...

Overall, a mostly warm and dry week is expected over southern MT
and north central WY as weak upper ridging looks to dominate
Wednesday through Thursday and then again late Saturday into
Sunday. Winds will continue to be gusty in the Livingston area
throughout the next week as a surface high is generally maintained
over southeastern Idaho with lower pressures to the northeast.

On Friday, an upper trough slides eastward into the Pacific
Northwest with some weak lift east of the trough axis. This trough
can produce a few showers west of Billings during the day on
Friday. As the trough and an associated cold front propagate
eastward, scattered showers can occur across much of southern
MT/north central WY Friday night. Weak forcing and westerly winds
should limit rainfall to light amounts. Some cooler air will work
in behind the front, allowing any rain showers to change to snow
showers mainly in the mountains Friday night into Saturday

Upper ridge should build again behind the trough Saturday
afternoon into Sunday, bringing dry weather and warmer air back to
the region.

High temperatures should be in the lower to middle 70s Wednesday
and Thursday, then drop to the 60s and lower 70s under increased
cloud cover on Friday. Coolest day of the week looks to be
Saturday, behind the cold front, with highs in the 50s.
Temperatures will begin to rise again on Sunday with highs in the
upper 50s to middle 60s. RMS



Southwest winds will increase to around 40 kts overnight at LVM
as a low pressure system moves across Canada. By morning, winds
will increase to 20 to 30 kts at BIL and MLS. Aside from
increased wind speeds, no concerns through the TAF period as VFR
conditions are expected to prevail. Walsh



    Mon     Tue     Wed     Thu     Fri     Sat     Sun
BIL 043/072 047/075 045/070 045/073 048/067 041/058 039/062
    00/N    00/N    00/B    00/U    11/B    21/B    01/B
LVM 042/071 047/074 043/070 041/073 044/063 036/053 035/058
    00/N    00/N    00/N    00/N    13/W    42/W    11/N
HDN 036/074 039/076 042/072 042/076 044/071 039/060 035/064
    00/U    00/N    00/B    00/U    01/B    21/B    11/B
MLS 038/073 041/076 044/069 043/075 043/070 040/059 036/063
    00/U    00/U    00/B    00/U    01/B    21/B    11/B
4BQ 035/072 040/077 042/069 040/074 043/071 040/059 035/064
    00/U    00/U    00/U    00/U    01/B    21/B    11/U
BHK 036/071 040/076 041/067 041/075 042/071 039/058 035/061
    00/N    00/U    00/U    00/U    01/U    11/B    10/N
SHR 034/071 036/076 040/071 038/075 041/070 036/057 032/062
    00/U    00/U    00/U    00/U    01/B    21/B    11/U




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