Area Forecast Discussion
Issued by NWS Missoula, MT
FXUS65 KMSO 061212 CCA
Area Forecast Discussion...CORRECTED
National Weather Service Missoula MT
612 AM MDT FRI MAY 6 2016
...Breezy Easterly Winds Across the Region Today...
...Big Cool-Down Next Week...
.DISCUSSION...A plume of showers and embedded thunderstorms
continue to move across northwest Montana early this morning. The
shower activity will steadily diminish throughout the morning
hours. A secondary system will cause an increase in shower
activity this afternoon over Lemhi county (ID) into southwest
Montana. These storms are anticipated to decrease after sunset
In addition, easterly winds will be increasing throughout the day
over the Northern Rockies. Kalispell is already experiencing gusts
up to 30 mph. The tightening of the pressure gradient will cause
widespread gusts of 20 to 30 mph, particularly across western
Montana. The higher terrain, especially along the Divide, could
experience gusts in excess of 40 mph. The potential exists that
portions of Flathead Lake could experience downslope winds along
the Mission Mountains. Confidence is low to moderate on Flathead Lake
experiencing these winds with resulting impacts to boaters.
The main low pressure system will remain over the Great Basin of
Nevada and Utah on Saturday. The location of this low could keep
wrap-around precipitation going across Lemhi county into
southwest Montana. Easterly winds will persist over the region
through the weekend, but will not be as strong compared to today.
Saturday and Sunday temperatures should be around 5 to 10 degrees
A trough of low pressure will start to influence the Northern
Rockies on Sunday, increasing the chances of shower/thunderstorm
development Sunday afternoon and evening. Currently, models
suggest the focus of precipitation will be mainly over southwest
Montana, the Divide, and Lemhi County in Idaho.
As this low continues to approach Monday, a much cooler airmass
will settle over the region. This pattern may result in a ~20
degree temperature cool-down for Monday compared to weekend
temperatures. These temperatures will be cooler than normal, and
much cooler than what we have seen most recently. This low will
increase precipitation chances across the area, and drag snow
levels down to 4000-5000 ft. Those with outdoor plans, especially
in the mountains, should prepare for wet and raw conditions
through at least mid-week.
.AVIATION...A band of showers continue to move across northwest
Montana this morning, impacting KGPI. These showers will steadily
diminish as the morning progresses. A few very light showers
are moving over KBTM and KSMN this morning. This convection is
anticipated to increase in intensity and coverage this afternoon
as the atmosphere becomes unstable. Thunderstorms will be a
possibility near KBTM and KSMN this afternoon. Easterly winds have
already moved into KGPI this morning. These easterly winds will
become more widespread over the Northern Rockies today as the
pressure gradient tightens. Wind gusts up to 30 mph is a
possibility especially across northwest Montana.