Winter Storm in Montana, February 2, 2016

Area Forecast Discussion
National Weather Service Missoula MT
408 AM MST TUE FEB 2 2016

.DISCUSSION...Scattered snow showers across the area early this
morning will yet again grow in number and strength this afternoon
as an atmospheric wave moves across western Montana. This wave,
presently north of the border along the British Columbia/Alberta
providential line, will take a more of a north/south track than
disturbances which have occurred since Saturday. This will likely
change the orientation of where showers and snow bands organize
and could place several new locations (Ex. Highway 200 Corridor from
Thompson Falls to St. Ignatius/ Potomac/I-90 from Missoula to
Drummond) in a more favorable pattern for occasionally heavy but
persistent snow showers. Evaro Hill and areas butted up against
the Mission, Swan and Whitefish Mtn. ranges will also see
orographically enhanced snowfall today, likely measuring several
more inches by tonight. However those in the Bitterroot will see
their strongest showers this morning with less widespread or
organized convection this afternoon due to this change in
orientation.

Snow showers will linger mainly along the higher terrain of the
Missions and along the Continental Divide through tonight. But
advancing dry air with growing stability should bring many of
these to an end Wednesday morning. Patchy freezing fog is likely
to develop as well, though its impacts should remain minimal due
to steadily increasing cloud cover. The next weather system will
move into the Northern Rockies Wednesday afternoon/evening with
light, warm frontal type snow (lower initial snow to water ratio
snowfall) increasing throughout the night. Although there is
ample moisture moving ashore with this approaching weather system,
it remains loosely organized and could be prone to stretching with
time due to the main jet energy diving south into the Great Basin.
Regardless this weather system will produce widespread three to
six inch snowfall totals in central Idaho and along the
Montana/Idaho border. But many of the valleys in western Montana
will likely see less than an inch with only a few areas in NW
Montana measuring one to three total inches.

Another weather system is expected to move through on Saturday.
This weather system has some upper level jet support and is
expected to bring breezy winds to valleys, strong ridge top winds
and periods of moderate to heavy snow to mountain passes along the
MT/ID border and the Glacier Park region.

By early next, a strong high pressure ridge is expected to build
over the west coast. Latest model guidance has the ridge of high
pressure centered over western Oregon on Monday. As this ridge
gradually shifts east, drier weather and valley inversions will
become more common.

&&

.AVIATION...Scattered snow showers will continue to be a threat
across much of north-central Idaho and western Montana through at
least 03/0600z Tuesday night. The showers will be capable of
producing periods of intense snow, low visibility and ceilings at
times with KMSO and KGPI having the best chance for experiencing
showers today. KBTM has seen the development of fog/low stratus
this morning, but it is expected to clear off by mid morning with
periodic snow showers throughout the day.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory until 10 AM MST this morning
     Flathead/Mission Valleys...Lower Clark Fork Region...
     Missoula/Bitterroot Valleys...Potomac/Seeley Lake Region.

ID...None.
&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
816 AM MST TUE FEB 2 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0815 AM     SNOW             6 NE HERON              48.12N 115.85W
02/02/2016  M3.8 INCH        SANDERS            MT   TRAINED SPOTTER

            24 HOUR SNOWFALL

&&

NWS MISSOULA MT
IRIS SYSTEM