739
FXUS65 KGGW 130839
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
239 AM MDT Thu Jun 13 2024

.DISCUSSION...

KEY MESSAGES:

1) Look for dry weather through Friday morning with near normal
temperatures today and highs 10 to 15 degrees above normal on
Friday.

2) There will be chances for showers and thunderstorms starting
Friday afternoon and continuing through Saturday night with a few
severe thunderstorms possible.

3) Models are pointing towards widespread rain on Monday and
Tuesday.

WEATHER PATTERN OVERVIEW:

Shortwave ridge builds over the area today and tonight with
surface high pressure. This will keep skies mostly clear today.
The ridge moves to the east on Friday with warmer and more moist
air moving into the area on Friday which will become unstable
during the afternoon. A surface low develops over SE Montana
during the day on Friday which will bring chances for showers and
thunderstorms Friday afternoon and night. Models and ensembles are
pointing towards enough CAPE especially along and east of the
Yellowstone River on Friday for the possibility of severe storms.

Flow aloft turns SW on Friday and an upper trough/low moves inland
from the Pacific over the weekend. This will push a cold front
through the forecast area either Saturday afternoon or night which
will bring more chances for showers and thunderstorms and enough
instability that there will be possibility of severe storms
especially in the east.

At this point, Sunday dry, cool and windy behind the cold front
with gusty west winds.

Ensembles are pointing toward widespread rain with an upper low
moving through the area Monday and Tuesday. The NBM has a 2 day
probability for at least a half inch of rainfall around 60
percent in most areas for Monday and Tuesday combined.


FORECAST CONFIDENCE and DEVIATIONS:

High confidence on the dry weather today and warmer temperatures
for Friday. Also, high confidence that there will be showers and
thunderstorms at some point between Friday afternoon and Saturday
night but low confidence on timing any specific storms and
location of any severe weather that could develop.

High confidence that there will be widespread rain Monday and
Tuesday but low to moderate confidence on specific amounts.

No deviations from the base forecast at this time.

&&

.AVIATION...

LAST UPDATE: 0845Z

FLIGHT CAT: VFR

DISCUSSION: Clear to partly cloudy skies through the cycle.

SFC WIND: NW 10 to 15 knots today becoming north 5 to 10 knots
this evening and east late tonight.

EQUIPMENT: Long term METARs are missing for KSDY, thus AMD NOT
SKED. COMMs outage since 14Z Wednesday across northeast Montana
has removed METARs for other terminals as well.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

weather.gov/glasgow