FXUS65 KGGW 210602

AFDGGW



Area Forecast Discussion

National Weather Service Glasgow MT

1202 AM MDT Sun Jun 21 2026



.KEY MESSAGES...



- An upper low will help bring several rounds of showers and

  thunderstorms across the area for Sunday. An isolated stronger

  storm near the MT/ND border remains possible.



- Expect lingering showers early next week with cooler

  temperatures, but a warm up begins by the middle of the week.



- Another system is expected at the end of the week to bring

  additional thunderstorms to the region.





&&



.DISCUSSION...



WEATHER PATTERN OVERVIEW:



An upper trough tracking over the region will lend support to a

couple of different rounds of showers and thunderstorms for

Sunday. The trough may produce enough of an unstable environment

for an isolated hail thread, with HREF max updraft helicity

showing support in the afternoon hours near the MT/ND border.

Given precipitable water in the forecast soundings, heavy rainfall

may also result with the steadier storms.



Look for lingering showers and isolated thunder early in the week

along with cooler temperatures as the upper trough swings 

through, with a ridge helping to bring about warmer temperatures 

and drier weather later in the week.



Ensembles are starting to show the next system approaching by the

weekend with additional thunderstorm chances expected at that

time.



FORECAST CONFIDENCE & DEVIATIONS:



NBM was used for the forecast cycle, which captured the trends

well for the expected thunderstorm chances on Sunday, followed by

later in the week. Confidence remains above average on

thunderstorm chances for today, though more moderate confidence on

exact precipitation amounts and placement of the heavier rainfall.





&&



.AVIATION...



LAST UPDATE: Sunday June 21, 2026 at 0600Z



FLIGHT CAT RANGE: VFR to MVFR.



DISCUSSION: An upper trough pattern will bring several rounds of 

showers and thunderstorms on Sunday. The storms will tend to push 

east into ND after 03Z. Some of the storms may be associated with 

brief reductions in visibility as well as lower ceilings.



WINDS: East winds early will switch to the west and northwest at 

5 to 15 kts at KGGW in the afternoon. Look for winds becoming 

south at 5 to 10 kts at KOLF, KSDY, KGDV in the afternoon. Winds

may be gusty and erratic with thunderstorms. 





&&



.GGW WATCHES/WARNINGS/ADVISORIES...

None.

&&



$$



weather.gov/glasgow