Whitetail, Montana Weather Forecast Discussion

861
FXUS65 KGGW 140820
AFDGGW
Area Forecast Discussion
National Weather Service Glasgow MT
220 AM MDT Sun Sep 14 2025
.DISCUSSION...
KEY MESSAGES:
1) A few isolated and storms this morning for the area, and then
again in the afternoon and evening across the east.
2) There is good model agreement on showers in the southwest and
scattered thunderstorms across the northeast on Monday. Another
opportunity for storms exists on Tuesday.
3) Beyond Monday, temperatures are expected to be near seasonable.
WEATHER PATTERN OVERVIEW:
A trough pattern is allowing for moisture to remain in place
enough to keep a few showers and thunderstorms within the realm of
possibility through this morning, and again in the east this
afternoon. There is low to moderate of fog developing in the
northeast and lasting through about noon in the northeast.
There is high confidence that within the upper trough, a large
shortwave will move slowly south to north today through Monday.
Another large shortwave will impinge upon the southwest, so Monday
afternoon will have scattered rain showers and thunderstorms
across the entire area. In response to CAM model agreement, there
is high (80 percent) confidence of the stronger storms occurring
northeast of Glasgow, with heavy rain the main threat.
The broad trough and daytime heating on Tuesday will bring another
low wind shear, weak forcing possibility of storms. There expected
to be very little capping place in the afternoon, so there is at
least low to moderate confidence of scattered thunderstorms
occurring again.
By Wednesday, there is moderate to high confidence a shortwave
from the north will bring in some dry air and seasonable
temperatures.
FORECAST CONFIDENCE & DEVIATIONS:
Deviated from NBM to increase winds a bit in Day 1 and 2, and
increased PoPs in the short term. Confidence is described in the
above discussion.
&&
.AVIATION...
LAST UPDATE: 0900Z
FLIGHT CAT RANGE: VFR - IFR, with an isolated airport shutdown.
DISCUSSION: There will be isolated thunderstorms and scattered
showers through early this morning. There is low to moderate (20
to 40 percent) confidence of low clouds and fog occurring for
KSDY, KOLF, and KGGW between 10Z and 17Z. There is a ten percent
chance of an airport shutdown at KOLF and KSDY in this timeframe.
MVFR ceilings are expected to linger through about 20Z before a
few isolated thunderstorms pop up near KSDY. There is low
confidence of thunderstorms occurring for KGGW, KOLF, and KGDV.
WIND: Light and variable, becoming south southwest at 5 to 10
knots after 16Z, becoming light and variable after 01Z for KSDY,
KGDV, and KOLF. For KGGW, light and variable, becoming south at 5
to 10 knots after 15Z, becoming southeast at 6 to 12 knots after
00Z.
EQUIPMENT: NOTAM comms issues with the KSDY observation remain.
AMD NOT SKED will remain in place until METARs are available.
&&
.GGW WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
weather.gov/glasgow

NWS GGW Office Area Forecast Discussion