273
FXUS65 KGGW 131905
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
105 PM MDT Thu Aug 13 2026

.KEY MESSAGES...

- There is a threat of brief heavy rainfall over mainly the
  northeast zones late tonight but overall the showers and
  isolated thunderstorms through Friday morning should be
  beneficial.

- Precipitation chances don`t completely go away this weekend and
  into early next week, but overall conditions will trend towards
  drier and warmer.

&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:

An upper trough continued to dig over the western states which has
helped to bring rain showers to most of the area in the past 24
hours. This looks to continue into tonight with the possibility of
thunderstorms generating heavy rain, especially in the northeast
zones later tonight.

The latest NBM is suggesting close to an inch in Roosevelt
counties just this evening but the HREF mean was showing this
possibility also in other areas. There was the thought of issuing
a Flood Watch with the NBM output but the confidence is not high
enough (GTE 50%) for a Watch. Therefore, will pass this on to
later shifts. However, being that antecednt conditions have been
quite dry in the past month, flooding is highly unlikely. Impacts
affected could be covered with an advisory.

Showers are expected to end from west to east Friday with mainly
dry conditions expected through the weekend. The upper trough will
linger off the West Coast with weaker southwest to west flow
remaining over the area. This will allow for generally slight
chances of showers/thunderstorms returning Sunday that lingers
into next week.

Look for a slight warming trend to begin this weekend but will be
tempered next week by disturbances that move in.

FORECAST CONFIDENCE & DEVIATIONS:
Left the base (NBM) forecast alone. Confidence has increased with
rainfall amounts and temperatures for the next 2 to 3 days. TFJ

&&

.AVIATION...
LAST UPDATE: 1900Z.

FLIGHT CAT RANGE: Decreasing conditions into Friday morning with
VFR this afternoon decreasing to IFR by Friday morning.

DISCUSSION: Rainshowers will increase in intensity and coverage
into tonight from the W/SW. Brief IFR visibilty is possible but
IFR ceilings will be the predominant factor late tonight/Friday
morning.

Showers will end from west to east Friday allowing for improving
conditions.

WIND: Mainly E/NE at 10 to 20 kts this afternoon decreasing to
light and variable Friday morning. TFJ

&&

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

$$

weather.gov/glasgow