409
FXUS65 KGGW 181951
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
151 PM MDT Tue Jun 18 2024

.DISCUSSION...

KEY MESSAGES:
- Clouds will clear from the south tonight after the showers
  diminish later today.

- Warmer temperatures starting on Wednesday with frequent chances
  for showers and thunderstorm chances between Wednesday and
  Saturday, especially Friday afternoon and night.

WEATHER PATTERN OVERVIEW:
The upper flow will become southwest as the disturbance that
brought the rain to the area moves out. This will leave the area
somewhat unsettled the remainder of this week.

An upper trough to our west splits on Thursday and the northern
branch trough moves inland along the Canadian Border starting
Thursday night and reaching eastern Montana on Saturday. This will
gradually increase the chances for showers and thunderstorms
between Thursday night and Saturday. With warmer temperatures,
some of these thunderstorms could be severe.

An upper ridge on Sunday brings hot and dry weather with highs
near 90 then a slight cooldown occurs next week.

FORECAST CONFIDENCE and DEVIATIONS:
There is low confidence on patchy fog occurring tonight where
skies clear, mainly in valley locations.

From Wednesday onward, confidence is high on a gradual warming
trend. Confidence is low on precipitation chances Wednesday and
Thursday. Confidence increases to moderate of precipitation
chances between Thursday night and Saturday. TFJ


&&

.AVIATION...

LAST UPDATE: 2030Z

FLIGHT CAT RANGE: IFR (KGDV) till 00z/ MVFR (KSDY) - both improve
to VFR Wed morning (between 12z and 16z). Otherwise, VFR.

DISCUSSION: An area of rain NW of KSDY to KGDV will gradually
diminish. Isolated rainshowers west of this area is expected to
diminish by this evening. Low clouds may linger at KGDV and KSDY
into Wednesday morning. Widespread fog is not expected Wednesday
morning but it may be in isolated locations.

WIND: Light West then SW winds tonight (less than 10 kts) then
increase from the South Wednesday.

* We will continue at add "AMD NOT SKED" to the KSDY TAF till it
  is available online. TFJ

&&

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

$$

weather.gov/glasgow