639
FXUS65 KGGW 181853
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
1253 PM MDT Fri Sep 18 2026

.KEY MESSAGES...
 - Temperatures remain warm through this afternoon before cooler
   than average temperatures move into the region Saturday and
   Sunday, trending cooler into the low to mid 60s. Beyond this
   weekend, warmer temperatures are expected to return early next
   week.

- Chances of widespread showers return this weekend with the
  heaviest totals in excess of 1.00" located south of Highway 200
  from Winnett to Glendive as well as south of I-94 through
  Wibaux. Embedded thunderstorms are possible and can cause local
  heavy rainfall.

- Confidence in rainfall totals remain below average in NE Montana
  due to southerly storm track trends and a sharp precipitation
  cutoff.



&&

.DISCUSSION...

SYNOPTIC SETUP:

A low pressure system over northern California will track east
into northern Wyoming into the weekend. This system is cutoff by a
northern stream shallow ridge in Canada which is leading to dry
air cutting off the northern extent of the precipitation for
Canadian border regions. Latest NBM forecast QPF shows a much
sharper gradient over NE Montana as a result with near little
precipitation near the Canadian border. The heaviest totals in
excess of 1.00" are likely south of Highway 200 from Winnett to
Glendive as well as south of I-94 through Wibaux. Across these
southern locations, heavier bands of showers and embedded
thunderstorms that remain persistent enough may produce minor
flooding of small streams, open fields, and poor drainage
locations such as low lying areas.

At this time, confidence in exact precipitation totals through
Sunday for NE Montana remains below average given the sharp
cutoff to the north, southward trend, and dynamic nature of this
system. Thus, will hold off on any flood watches for now.
Confidence is greater to the south of the CWA closer to the storm
track. The WPC maintains Marginal/Slight Risks for Excessive
Rainfall Outlook products over much of Montana for Day 1 and 2.
Those traveling across the state should monitor the latest
forecast as well as watch and warning products issued by
respective weather service offices.

The storm system looks to exit Sunday into Monday with ensembles
showing the northern stream ridge having a bit more influence over
conditions. As a result look for a warm up in temperatures and
drier weather into early next week.

FORECAST CONFIDENCE & DEVIATIONS:

Models continue to show poor run to run continuity in
precipitation amounts for NE Montana this weekend, with the
gradient tightening across the area and a southward shift. Thus,
confidence remains below average for rainfall totals, but
increases for southern tier zones closer to the storm track. Areas
south of Highway 200 from Wibaux to Glendive and south of I-94
through Wibaux may experience heavier rainfall totals and the
potential for minor flooding.



&&

.AVIATION...
LAST UPDATED: 1845Z

FLIGHT CAT RANGE: VFR trending toward MVFR/IFR.

DISCUSSION:

Showers and isolated thunder look to increase in coverage tonight
and Saturday, leading to associated reductions in ceilings and
visibility. The highest confidence in persistent heavy rain
showers will be across KGDV and KSDY and these terminals are
closer to the storm track over northern Wyoming.

SFC Wind: N to NE at 5 to 15 kts through this evening, becoming
east on Saturday after 18Z ranging from 10 to 20 kts.


&&

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

$$

weather.gov/glasgow