Scientific Forecaster Discussion
fxus65 kggw 221643 aaa
Area forecast discussion...updated
National Weather Service Glasgow Montana
943 am MST Fri Nov 22 2019
Sent an update this morning to fine tune the expected coverage of
diminishing freezing fog this morning and the return of freezing
fog tonight. Warmer temperatures today will provide some melting
which will erode the edges of the Snow Field and provide some low
level moisture to support those chances of freezing fog.
Otherwise, the weather is expected to remain quiet over the next
few days. Stronger westerly winds may arrive by the end of the
weekend and could increase the need for a lake Wind Advisory.
Previous a generally weak upper ridge pattern over the region
will provide continued dry and relatively mild weather conditions
over the next couple of days. That said, look for patchy fog
formation in the valley locations this morning. Otherwise, skies
should remain mostly sunny with the presence of large scale
Heading into Saturday night and Sunday, a weak embedded shortwave
in northwest upper flow will drop southeast from Canada. This
system will bring with it an increase in cloud cover as well as a
chance for rain and snow Sunday morning, changing to all rain
Sunday afternoon. Ensemble guidance points to this being a low
precipitation event, with quantitative precipitation forecast within a few hundredths of an inch.
Thus, do not expect significant overall impacts.
A general trough pattern will set up for next week with a
decreasing trend in temperatures, with ensemble 500mb heights
showing a deepening trough and closed low pattern over the western
U.S. By the midweek. Guidance is also suggestive of a low pressure
system developing out a head of this trough and tracking
northeast. This will bring the next chance for snow for NE
Montana, though at day 7 and 8, confidence is reduced. Details are
often uncertain at larger time scales where a larger spread in
model solutions is evident. That said, this will be the next
period of interest, especially as it pertains to potential Holiday
travel impacts. Maliawco
Synopsis: high pressure is building into the region from the west
and allowing temperatures to increase through this weekend. This
will allow snow to melt. Freezing fog will be possible each night,
especially in the lower elevations and river valleys.
Flight categories: mainly VFR, with IFR or worse in freezing fog
again possible for kggw and kolf tonight through Saturday
Winds: today through tonight, from the west at 5 to 10 kts.
Saturday, from the west at 15 to 20 kts.