Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 250926

Area Forecast Discussion
National Weather Service Billings MT
326 AM MDT Thu May 25 2017

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

Northwest flow and cold air aloft over the region this morning
with a strong upper level low pressure system over southern
Saskatchewan. Disturbance rotating around this low will track over
the area this morning supporting scattered shower activity but
moisture is not deep and showers will be transitory due to the
speed of the flow aloft. Precipitation amounts will be light but
it will be breezy as the momentum aloft mixes down. Combined with
cooler temperatures in the lower to mid 60s it will feel more like
late April than late May. Higher elevations will see snow showers.

Heights rise a little overnight as the upper low shifts east which
increases the stability in the atmosphere so will be drier
overnight with winds decreasing. Still a piece of energy lagging
back over Idaho so cannot rule out mountain showers but the plains
look dry. Friday sees the Idaho energy begin to get caught into
the northerly flow behind the upper low and this causes flow aloft
to be a bit more cyclonic over the area. Expect shower activity
to continue to favor terrain during with diurnal heating. Little
change in temperatures as weak mixing expected as pressure
gradients slacken and turn slightly northeasterly. Friday night
pressure gradients turn slightly downslopish as upper level
ridging west of the divide increases surface high pressures over
western Montana and southern Idaho. borsum

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

An upper low over southern Canada and the Great Lakes region will
provide a northwest flow aloft across our forecast area this
weekend into early next week. This will result in a brisk
northwest wind from mainly from Billings eastward. The low will
rotate some weak energy across Montana resulting in an unsettled
northwest flow aloft. As a result, there will be a chance for
showers and possibly an isolated thunderstorm Saturday and Sunday,
with the activity mainly confined to the mountains Monday and
Tuesday. High pressure ridging builds more with the axis shifting
east over central and eastern Montana Tuesday into Wednesday
keeping mainly dry conditions across the area except for chances
over the mountains. By next Thursday, an upper low approaching the
Pacific northwest coast will provide an unsettled southwest flow
aloft across the forecast area, a more typical pattern for this
time of year with scattered showers and thunderstorms.
Temperatures will start around normal on Saturday with a gradual
warming trend into next week when readings may be well above
normal by next Wednesday. Hooley



An upper low over southern Canada will bring a tight pressure
gradient across the forecast area today, especially for areas east
of KBIL where northwest winds will gust 35-40kts. There will also
be a chance for scattered showers, with some MVFR conditions
possible within the showers. Although some mountain obscuration
will be likely, VFR conditions will prevail throughout the day.



    Tdy Fri     Sat     Sun     Mon     Tue     Wed
BIL 062 042/065 046/071 048/074 048/074 047/076 049/082
    2/W 12/T    22/T    12/T    11/B    11/B    12/T
LVM 059 036/063 037/069 041/072 041/073 041/076 043/080
    3/W 14/T    33/T    12/T    12/T    12/T    12/T
HDN 063 040/067 043/071 045/075 045/074 045/077 047/082
    2/W 12/T    22/T    12/T    11/B    11/U    12/T
MLS 063 043/068 045/072 047/074 046/072 044/075 048/081
    1/N 11/B    12/T    12/T    00/U    00/U    01/U
4BQ 063 040/066 043/068 045/072 045/071 042/073 045/078
    1/N 11/B    12/T    12/T    10/U    01/U    02/T
BHK 061 039/065 042/067 043/070 041/067 039/070 042/075
    1/N 11/B    12/T    22/T    00/U    00/U    00/U
SHR 059 039/061 039/065 043/070 042/069 041/073 043/078
    2/W 23/T    23/T    12/T    12/T    11/B    12/T




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