240
FXUS65 KGGW 252010
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
210 PM MDT Sat May 25 2024

.DISCUSSION...

KEY MESSAGES:

1) Scattered showers and general thunderstorms in the west this
afternoon will move across northeast Montana slowly overnight.

2) On Sunday, NW winds at the surface will line up with NW winds
aloft to make for strong wind gusts by afternoon, thus a Lake Wind
Advisory is in effect from 9 AM-9 PM. Some of the late-day
showers and thunderstorms could bring additional strong gusty
winds.

3) Expect a slow warming trend into Wednesday with widespread 80s
Tuesday and Wednesday.

WEATHER PATTERN OVERVIEW:

A weak upper level disturbance over central Montana has helped
spawn showers and thunderstorms that are moving east into
northeast Montana this afternoon. These will gradually diminish
with the loss of daytime heating as they move east through the
CWA.

They are expected to regenerate mainly over the NE zones Sunday.
NW winds at the surface and aloft will bring strong wind gusts to
most areas with gusty winds accompanying any showers and
thunderstorms late in the day.

On Memorial Day, most of the area will experience the beginning of
a warming/drying trend, but the northeast zones could experience a
shower or thunderstorm before an upper ridge from the Pacific
Northwest moves in. Nothing severe is expected, but being that
it`s a NW flow, a storm could be briefly strong.

The upper ridge will bring warm sunshine to the area for Tuesday
before SW flow and an upper trough approaches Wednesday. This will
increase the chances for thunderstorms, some of which could be
severe as models are indicating CAPEs over 1000 J/kg in parts of
the area!

In the wake of a cold frontal passage late Wednesday, conditions
will be breezy and not as warm on Thursday.

Unsettled conditions are expected to last into Saturday with the
passage of the upper trough overhead. TFJ

CONFIDENCE & DEVIATIONS:
Used a local tool to calculate wind gusts for Sunday afternoon and
early evening as wind gusts look to be strong with good mixing.
That was the only change to the base forecast. TFJ


&&

.AVIATION...

LAST UPDATED: 2000Z

FLIGHT CAT: VFR.

DISCUSSION: Another round of rain showers and isolated
thunderstorms is expected to impact the terminals tonight. Look
for ceilings to remain VFR.

A few hours of clearing then takes place Sunday morning before
scattered showers and isolated thunderstorms develop in the
afternoon.

SFC WIND: Light and variable through tonight then increases from
the west Sunday with speeds of 15 to 25 kts with gusts of 30 to 40
kts. TFJ

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory from 9 AM to 9 PM MDT Sunday for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.

&&

$$

weather.gov/glasgow