Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Missoula Montana
233 PM MST Friday Feb 27 2015
..more Arctic surges....
Discussion...an Arctic air mass is on its way across the northern
rockies setting up a cold and blustery weekend and beginning to
March. Tonight, light snow will impact southwest Montana,
including Butte, Anaconda, and areas south with around an inch of
snow. Expect difficult driving conditions over Homestake pass and
Divide pass south of Butte tonight with snow accumulating on the
roads, and blowing snow causing low visibility. These conditions
will extend south through Lemhi County in Idaho affecting Lost
Trail Pass and Gilmore Summit too.
Wind chills will also be big concern east of Kalispell and
Missoula and along the Continental Divide, where many locations
will see -10 to -20 degree wind chills. The rest of western
Montana will have low temperatures in the low teens and single
digits, and central Idaho will wake up to temperatures in the
teens and low 20s.
More cold arrives Sunday morning, where areas east of Kalispell
and Missoula have low temperatures in below zero, with the rest of
western Montana in the single digits and central Idaho waking up
to temperatures in the low teens.
Another surge of Arctic air is expected Monday into Tuesday. The
difference, compared to current cold air pushes, is that this one
looks to have the most cold intensity in terms of temperature and
wind chill. Also, there appears to be sufficient energy and
moisture with the Arctic weather system to produce a period of
light snow from Orofino to the Camas Prairie and eastward across
western Montana Monday and Monday night. This could translate into
very slick travel conditions, especially considering falling
temperatures will freeze slushy or wet Road conditions.
Temperatures should bottom out Monday night into Wednesday morning
20 to 30 degrees below normal. Below zero wind chills and strong
northeast winds should then be followed by subzero temperatures in
western Montana and zero to 10 above in north central Idaho.
A quick warm-up Thursday into next weekend is beginning to look
more likely. Although there is high confidence since all models
show some form of this warm-up, there is some disagreement as to
whether there could be another round of precipitation on Friday.
The take- away being that the cold will not hold on for more than
a few days.
Afternoon showers over the mountains will continue into this
evening causing mountain obscurations. An Arctic air mass is
currently surging over the Continental Divide and will cause some
light snow along The Divide tonight affecting kbtm with up to an
inch of snow by the morning. Other area terminals will mainly
experience strong east winds and very cold temperatures.
Montana...Winter Weather Advisory from 5 PM this afternoon to 11 am MST
Saturday Bitterroot/Sapphire Mountains...Butte/Blackfoot
Wind Chill Advisory from 8 PM this evening to 11 am MST Saturday
Potomac/Seeley Lake region...West Glacier region.
Idaho...Winter Weather Advisory from 5 PM this afternoon to 11 am MST
Saturday eastern Lemhi County...western Lemhi County.