Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 201059
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
359 AM MST Mon Nov 20 2017

.SHORT TERM...for northeast Montana...today through Tue...

Synoptic Setup: Forecast begins with an exiting meso-ridge over
the High Plains of Montana and southern Alberta and the Dakotas.
On its heels is a large Arctic air plume is running down northern
Alberta and clashing against the exiting airmass. farther
upstream, another pacific ridge-trough couplet sets off the coast
of British Columbia. Meanwhile, off the coast of California a
surge of warm air is forming into a synoptic ridge.

Today through Tonight: Arctic air will move down the front range
and and arrive at the International Border around roughly Noon. as
the cold front moves through the CWA during the afternoon
temperatures will begin to fall and Winds will become gusty. This
should last through the evening hours. Therefore, a lake winds
Advisory is out.    GAH


.LONG TERM...Tue night through Mon...

Tuesday through Thursday: Pacific ridge off of the Pac Northwest
will move inland and the heat over California will quickly fill it
in making it larger over these periods. FLow will become
northwest aloft over northeast montana and temperatures should
rapidly warm with the peak hitting Thursday as the ridge axis
moves by. Conditions should remain dry through most of these
periods.

Thursday night into Friday: Ridge axis will exit as the pacific
trough part of the couplet moves through. Thankfully, models while
looking cooler do not appear to bring in arctic air into the
passing trough making things more seasonal.

Friday night into Saturday night: Models begin to break down
here. Best guess is for another Pacific Ridge to move through the
region warming things up briefly again.

Sunday onward: Rapid model breakdown post ridge leads to a below
confidence forecast. Expect the forecast to change from about here
onward. GAH


&&

.AVIATION...

FLIGHT CAT: VFR

LLWS: As an inversion sets in this morning chances for LLWS just
off the deck will become increasingly likely. LLWS should be over
by 18Z.

SYNOPSIS: Ridge across the area will exit around Noon as a cold
front moves in along the International Border. Winds should pick
up during the afternoon and last through the evening as well. Low
stratus may settle in just northeast of KSDY and KOLF during the
overnight hours along the ND/MT border.

WIND: West at 5 to 15 kts through the morning, veering to  the
northwest and increasing to 15 to 25 kts during the afternoon
hours and evening hours.

GAH


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory from 9 AM this morning to 10 PM MST this
evening For Fort Peck Lake for Central and Southeast Phillips...
Central and Southern Valley...Garfield...McCone...Petroleum.


&&

$$

weather.gov/glasgow



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