Scientific Forecaster Discussion
fxus65 kmso 240908
Area forecast discussion
National Weather Service Missoula Montana
308 am MDT Mon Jul 24 2017
Discussion...a dry front moving south out of Alberta has caused
an increase in gusty winds early this morning east of The Divide.
The system associated with this frontal feature will also create
increased winds out of the north-northwest today for western
Montana and, to a lesser extent, north central Idaho. Drier air
will also be moving south out of Canada and will line up with
these blustery winds, creating critical fire weather conditions
for west central Montana. Given how much fire activity is present
across the region, red flag warnings have been issued to address
In addition, limited moisture could interact with instability
across extreme southwest Montana and Lemhi County, Idaho later today,
and may kick off some mostly-dry thunderstorms. Should this occur,
the main output from storms will be gusty winds, particularly in
the aforementioned areas through sunset.
Unfortunately, forecast models continue to only bring limited
moisture into the region Tuesday through Thursday. On Tuesday,
isolated thunderstorms look to be confined to Lemhi County and
southwest Montana with a gusty wind threat. Shower and
thunderstorm coverage will expand northward somewhat on Wednesday
and Thursday to around the I-90 corridor, but activity will
remain very hit and miss. There won't be much relief from the warm
temperatures either, with highs remaining in the 90s for valley
Looking further into the extended forecast through this weekend,
the general pattern supports very warm temperatures and mostly dry
conditions. Forecast models do show the potential for occasional
bouts of monsoonal moisture from the southwest, but significant
precipitation is not anticipated.
Aviation...a dry frontal passage will increase winds out of the
north-northwest today for all terminals roughly between 24/2000z
and 25/0300z. In addition, isolated dry thunderstorms will be
possible during this same window of time for kbtm and ksmn, with
lightning and gusty winds being the dominant aviation impact.
Confidence is low in this occurring, but the threat is certainly
there. Winds and all convective activity will diminish after
Montana... red flag warning from 2 PM this afternoon to 9 PM MDT this
evening east Lolo...west Lolo.