873
FXUS65 KGGW 260848
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
248 AM MDT Sun May 26 2024

.DISCUSSION...

KEY MESSAGES:

1) Gusty west winds today keep a Lake Wind Advisory in effect
from 9 AM to 9 PM. Scattered afternoon and evening thunderstorms
could enhance wind gusts and carry small hail.

2) Expect a slow warming trend into Wednesday, when a cold front
brings increased chances for strong thunderstorms.

WEATHER PATTERN OVERVIEW:

Daytime instability thunderstorms are expected to regenerate
mainly near the Canadian border this afternoon. West winds at the
surface and aloft will combine to bring strong wind gusts to most
areas of up to 40 mph and higher with some storms. Limited
updraft potential and fast storm motion will limit hail and heavy
downpour concerns.

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. 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.

CONFIDENCE & DEVIATIONS:

No deviations were made to the base forecast besides slightly refining
the timing of thunderstorm chances and strength of winds today.
Confidence is high for temperatures remaining close to normal
overall for the next week, while currently medium for receiving
strong thunderstorms and widespread rainfall of a quarter inch or
more midweek.

-Zanker

&&

.AVIATION...

LAST UPDATED: 0830Z

FLIGHT CAT: VFR

DISCUSSION: After a few hours of clearing this morning, afternoon
instability will lead to scattered thunderstorms primarily near
KGGW and KOLF through early evening. Small hail and
enhanced/erratic gust potential are associated with the storms
before clouds mostly clear out tonight.

SFC WIND: West at 15-25 kts with gusts of 30-40 kts, becoming
northwest at 10-15 kts this evening.

&&

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

&&

$$

weather.gov/glasgow