Area forecast discussion
National Weather Service Missoula Montana
323 am MDT Wed Jun 19 2013
..mountain snow to impact marias, Logan, lost trail passes
Thursday morning...
Discussion...the upper low pressure system will slowly enter the
region today, setting up for a very wet and cool day. Heavy rain
has already been falling in the Clearwater Mountains overnight and
this morning, and is expected to continue through most of the day.
This region and the Idaho Panhandle, including northwestern
Montana will likely to pick up the heaviest rain today, with 1" to
2" inches possible. Heavy rain will likely cause local streams and
rivers to rise, however flooding is not anticipated at this time.
Elsewhere in western Montana, showers and thunderstorms are
expected to develop ahead of the main shield of precipitation this
afternoon. These storms are not expected to be as strong as we saw
yesterday, though they could produce very heavy rain, gusty winds,
and small hail. Later this afternoon and evening, heavy rain is
expected to finally make in and around the Glacier National Park
area. An additional 1.00" to 1.50" inches of rain is possible, and
with already saturated ground, runoff from the rain could
potential cause small rock and mudslides. Keep apprised to any
changes to the forecast, and those spending anytime outdoors today
should keep an eye to the sky.
Wednesday night into Thursday morning snow levels will fall to
around 6000 feet as the coldest part the upper level low moves
east across the northern rockies. The heaviest precipitation will
be on the leading edge of the system, and should fall as rain.
However, snow is expected to affect Logan Pass and Glacier
National Park Thursday morning, and higher elevations in the park
throughout the day. Marias and lost trail passes will also be
affected by light snow accumulations Thursday morning around 1 to
2 inches. Accumulation on roadways is possible, so early morning
travelers should be prepared for winter driving conditions over
the passes.
Friday and Saturday will remain cool and showery as the system
slowly progresses east. Sunday afternoon into have the potential
to be nice with a weak ridge building ahead of the next system.
However, moist southwest flow from a digging trough off the
Washington coast may also cause thunderstorms. Generally, the
unsettled weather will continue well into next week.
&&
Aviation...an upper level low over Washington state continues to
meander east over the northern rockies today. Expect increasing
mountain obscurations and thunderstorms embedded in a broader
area of increasing clouds. Main threat from thunder storms is
heavy rain, but especially kmso and kgpi will be affected.
&&
Mso watches/warnings/advisories...
Montana...none.
Idaho...none.
&&
$$
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