Red Flag Warning 24, NWS Glasgow, MT

Area Forecast Discussion
National Weather Service Glasgow MT
357 AM MDT Sun Oct 11 2020

.DISCUSSION...

In this post-frontal regime today, scattered rain showers or
otherwise virga showers or sprinkles will slowly drift and
diminish through the central and eastern portions of our CWA.
Overnight gusty winds from the northwest are slowly shifting more
out of the west today.

Apparently, the cold air advection is pulling down the stronger
winds from aloft to the surface. Our best forecast information
brings winds of about 30 to 35 mph to the area, but may be for
only a few hours at its peak around mid-day. The Lake Wind
Advisory remains well in place through today.

Of associated concern is the expected relative humidity drop to
around 20 to 25 percent, especially near and south of MT- Highway
200. See Fire weather discussion below for more details.

The cold air low pressure trough will continue to slide eastward
over the region today through tonight and a bit lingering on
Monday. Then, expect a a bit of a rebound high pressure ridge on
Tuesday. Another quick re-enforcing shot of colder air will sweep
through in another short-wave trough on Wednesday morning. This
may just be enough to realize a mix of rain and snow for our areas
near the border with Saskatchewan. Probably will not accumulate,
but stay tuned for updated forecast information.

Later in the week, another warm high pressure ridge tries to sneak
into the region from the west, but is quickly displaced by a cold
low pressure trough from the north for the weekend.

A friendly reminder that cold NW flow aloft weather patterns are
typically difficult for models to pick up accurately for
precipitation timing. We will try our best to anticipate and
fill in the gaps.

&&

.AVIATION...

FLIGHT CATEGORY: VFR

LLWS: Above 2000 feet. 40-50 kt winds aloft.

WINDS: From the west or slightly northwest at 20-30 kts with
gusts to 40 kts, and briefly higher around mid-day. Then more from
the west at 10 to 15 kts by tonight.

PATTERN DISCUSSION: Sudden and noticeable change in air mass and
flow regime places NE Montana in a post cold-frontal pattern with
a few scattered showers.

&&

.FIRE WEATHER...

No Fire Weather products were issued this morning, due to the
marginal or borderline nature of fire weather conditions expected
for today.

WINDS: From the west at 30 to 35 mph, with a few higher gusts.
Strongest winds are expected right around mid-day. Should diminish
to around 10 to 15 kts after sunset this evening.

RELATIVE HUMIDITY: Expected to drop to the 20 to 25 percent range
but not until the afternoon hours, likely after the strongest wind
gusts.

Area of concern is near and south of MT Highway 200.

Given the isolated area of impact and the off-set in timing of
elements, this looks like a marginal or borderline day for Fire
Weather concerns, but any slight change in this conditions could
increase the risk. Next shift will need to keep a close eye on
these conditions.

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 9 PM MDT this evening For Fort Peck
Lake for Central and Southeast Phillips...Central and Southern
Valley...Garfield...McCone...Petroleum.

&&

weather.gov/glasgow