Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Glasgow Montana
815 PM MST Thursday Nov 27 2014
Short term...for northeast Montana...tonight through Saturday...
some fog has moved into the region from southeastern Alberta and
do expect it to hold on through the overnight hours. Updated the
grids to reflect the addition of fog to the region. Going to keep
the High Wind Warning going for the Little Rockies even though the
winds have come down tonight they are expected to meet criteria
again tomorrow. Proton
near or sub freezing temperatures continue across much of northeast
Montana. With that said temperatures have warmed enough that we were
comfortable ending the winter weather advisories for southern and
central Phillips and Garfield counties. Additional warming is
expected through the afternoon...as precipitation tapers off. Thus
the expiration time of 5 PM for the remaining counties looks on
The warm front will begin to stall out this evening just north of
the Canadian border. As moisture becomes more limited this will
keep just chances for mixed precipitation in the forecast there. Temperatures
will be relatively mild for this time of year as we stay in the
warm sector overnight.
On Friday the warm front will continue to remain quasi stationary
over southern Saskatchewan...which will allow for another warm day
across most of northeast Montana. Some threat for mixed
precipitation will continue..mainly across the north near the
stalled front. With that said impacts are expected to be minimal
but it will need to be watched due to the hazardous nature of
Friday night into Saturday an Arctic front will begin to push
through northeast Montana...bringing falling temperatures...gusty
northwest winds and a change over to all snow. Accumulations look
to be significant but not too heavy and when the winds and wind
chills are factored in...a highlight may be needed. Gilchrist
Long term...Saturday night through Thursday...
The extended period begins Saturday evening with northeast Montana
in the grip of an Arctic air mass with the cold front located
already located well to the south in Wyoming. The polar air is
widespread across Canada and the trough extension into Montana will
maintain frigid temperatures through Sunday night. 850mb
temperatures at 00z Sunday will range from -25c to -20c resulting
in overnight lows from -15f to +2f. With wind expected to blow
from 10 to 15 knots...Saturday night and Sunday morning wind
chills are expected to become hazardous to 35 below.
Sunday night the trough retreats east and as a ridge axis moves
over The Divide. The resulting warm front will bring about a
gradual warming through the remainder of the extended periods...
but with highs still staying below normal.
Monday night...models show different interpretations of a clipper
that will knock temperatures lower again temporarily...and maybe
bring a quick shot of more mixed precipitation.
Models struggle late in the period with the next embedded
disturbance tripping across the central rockies. Timing is
Wednesday night...or Thursday night. Take your pick for now.
Location is also all over the place. But the GFS does suggest the
possibility of some light precipitation during that vague time
synoptic set up...a strong broad Arctic air-mass exists over the
majority of Canada...Montana...the Dakotas...and the upper
Mississippi Valley. A large weak trough sets behind this air-mass
over the Pacific northwest and off the coast of British Columbia.
Farther west behind the trough. A more powerful warm ridge lies
south of the Aleutians.
Saturday night through Sunday...super cold air will pass through
the region then modify warmer and exit to the east. 850 mb
temperatures will drop into the 20 below celsius range during this
time and the remnants of snow showers should exit the area by
Sunday night Onward...conditions look to be dry through most of
these periods. Flow will transition to northwest and keep Montana
on the warmer side of it. The weak trough off the coast of British
Columbia will move through the area on Monday night/Tuesday but
models are having a hard time placing its passage...dropping
confidence in any sort of impact weather maker. By Wednesday the
ridge begins to take hold and re-syncs the models fairly well with
progressively warmer conditions.
tonight and Friday a surface trough lingers over the region with
low cloud and fog to the north of the boundary. Reduced flight
conditions are expected mainly at kggw and kolf through Friday
Looking just beyond the taf period...an Arctic cold front will
begin to drop south through northeast Montana Friday night and
Saturday to bring about another round of mixed precipitation...
followed by snow. Expect strong northerly winds of 15kt to 25 kts
Friday night and Saturday.
High Wind Warning until 6 PM MST Friday for southwest Phillips.