Area Forecast Discussion
Issued by NWS Missoula, MT

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FXUS65 KMSO 292043

Area Forecast Discussion
National Weather Service Missoula MT
243 PM MDT FRI APR 29 2016

.DISCUSSION...As an upper level low pressure system circulates
directly over western Montana, it will continue to deliver streams
of precipitation across north central Idaho, as well as the
Bitterroot and Missoula valleys. Reports have come in that light
snow showers continue to persist across locations such as Lost
Trail Pass and east through Anaconda/Deer Lodge and into the
general Butte vicinity as well. Expect light snow to continue
tonight as well, though roads should only see very brief amounts
before snow melts.

As rain and/or snow continues through Saturday, this system will
be gradually exiting the region, eventually relieving much of the
region of any precipitation as we head into Sunday.

The wonky weather pattern continues into next week as high
pressure slowly builds over Canada and the Northwestern United
States (including Idaho & Montana) while the upper level low
(presently over the Northern Rockies) shifts into the Desert
Southwest. This will bring a quick warm up and some welcome
sunshine to the Northern Rockies starting Sunday and lasting
through Tuesday. This period of tranquil weather appears short
lived as yet another upper level trough approaches the west coast
by Tuesday, and slowly works its way inland through the middle of
next week. The resultant southwesterly flow will push
progressively increasing amounts of moisture into the Northern
Rockies Tuesday, and a growing threat for showers and
thunderstorms by Wednesday and Thursday.

But instead of the trough moving inland through the western
United States, forecast models are consistently wrapping energy
into a closed area of low pressure that will come ashore in
southern California late next week and shift to near the Grand
Canyon by next weekend. This would ultimately place the Northern
Rockies under yet another anomalous easterly flow pattern, with
seasonably cool temperatures and better chances for showers.


.AVIATION...Showers will continue to increase across the Northern
Rockies today with periodic light rain possible at all airfields.
While the showers may briefly be intense, minimal impacts to
ceilings and visibility are anticipated given their anticipated
short duration. Scattered showers are again in the forecast



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