329
FXUS65 KGGW 200854
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
254 AM MDT Sun Apr 20 2025

.DISCUSSION...

KEY MESSAGES:

*Look for scattered showers at times today, with more widespread
rain late tonight through Monday.

*Expect seasonable temperatures and mostly dry conditions for the
 rest of this week.

WEATHER PATTERN OVERVIEW:

A line of light showers is holding together this morning over
mainly the southwest zones and gradually progressing toward the
Yellowstone River over the next several hours, but the cold
frontal passage has mostly brought a gusty wind shift. Some midday
breaks in the clouds will be followed by a more pronounced and
developed, embedded short wave disturbance. This will
introduce instability into the western zones this afternoon with
showers redeveloping and eventually moving east tonight. Model
precip data suggests that this will result in at least a tenth of
an inch for most with mean totals around a quarter inch through
Monday night. The steadiest rain with a few embedded thunderstorms
will come during the day on Monday with the shortwave trough
forcing overhead.

For Tuesday and Wednesday, that low pressure trough will
generally give way to some weak ridging from the west and lessened
chances for rain. Later next week, a generally unsettled weather
pattern will prevail over our region, bringing periodic chances
for light rain showers and seasonable temperatures.

FORECAST CONFIDENCE & DEVIATIONS:

Minimal deviations were made from the base forecast at this time,
besides refining rain and thunder chance timing through Monday.

Confidence remains high overall on the temperature pattern for
the next several days, while now medium to high for a widespread
wetting rain on Monday.

&&

.AVIATION...

LAST UPDATED: 0830Z, Sunday morning, April 20th

FLIGHT CAT RANGE: VFR to MVFR

DISCUSSION: Behind a frontal passage this morning, a line of scattered
MVFR ceilings with light rain showers will gradually shift east
toward KSDY and KGDV by 15Z. After 21Z, scattered showers will
develop from the west and in the vicinity of KGGW from 23-03Z in
particular. Near the end of the 12Z TAF cycle, this activity
becomes more widespread and pushes east toward KOLF, brining MVFR
visibility under heavier showers.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...

None.

&&

$$

weather.gov/glasgow