321
FXUS63 KFGF 240446
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1146 PM CDT Sun Aug 23 2026

.KEY MESSAGES...

- There is a level 1 out of 5 risk for severe thunderstorms
  Monday afternoon and evening. Hail to the size of golf balls
  and wind gusting to 70 mph will be the main threats.

&&

.UPDATE...
Issued at 1146 PM CDT Sun Aug 23 2026

Northern end of some convection has been tracking through the
Devils Lake basin for the last couple of hours, with the main
impacts being some rain up to 4 tenths of an inch so far and
some lightning. Heavier cells tracking southeastward through
Wells and Foster counties, but on a weakening trend as they move
into less unstable air. Most of the CAMs have the complex
weakening as it moves towards the Red River later tonight,
although a few models break out some stronger convection again
on the northwest side. Given cell currently tracking into
northwestern ND from MT, will keep a close eye on the activity.

&&

.DISCUSSION...
Issued at 258 PM CDT Sun Aug 23 2026

...Synopsis...

Northwest flow prevails this afternoon into the evening, gradually
becoming zonal overnight. Showers and isolated thunderstorms could
work into parts of eastern North Dakota overnight as warm air
advection increases ahead of an approaching shortwave. Upper flow
then becomes slightly southwest late overnight into Monday morning.
This will be in response to the shortwave and weak upper low moving
across southern Manitoba late Monday into Tuesday. Showers and
thunderstorms are expected as the associated cold front sweeps
across the Northern Plains into the Upper Midwest, with a chance for
isolated severe thunderstorms Monday afternoon and evening. Warm air
advection ahead of the front will allow afternoon temperatures to
climb well into the 80s across most of the area. Slightly cooler
temps return on Tuesday and Wednesday. Rain chances Late Tuesday
through Thursday will be minimal, with PoPs increasing once more
late Friday into the weekend.

...Isolated Severe Thunderstorms Late Monday...

Severe thunderstorm coverage on Monday afternoon and evening will
depend heavily on the timing of an approaching cold front. Warm air
advection will be strong through much of the day across eastern
North Dakota and west central Minnesota; however, with remnant
shower activity on Monday morning potentially lingering, this could
shorten the window of potential severe weather late Monday. Looking
at CAMs, there are several potential scenarios, ranging from
potential splitting supercells, to elevated clusters. Model
soundings are consistent with nearly straight hodographs as the
front approaches, which continue to support splitting supercells and
hybrid clusters. As such, a high end scenario supports supercells
developing west of the Red River during the late afternoon, with
hazards including wind gusts to 75 mph and large hail to the size of
golf balls. A more likely scenario would be that we have lingering
convective inhibition later into the afternoon, thus delaying
convection until later in the evening. This would still support wind
gusts up to 70 mph, but would transition into mainly an elevated
hail scenario that extends into the early overnight hours. With this
later scenario, we could see isolated severe thunderstorms lingering
into Tuesday morning across parts of northwest Minnesota.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1146 PM CDT Sun Aug 23 2026

The main challenge throughout the TAF period will be shower and
thunderstorm activity. Showers and thunderstorms have moved into the
Devils Lake Basin. This activity will continue pushing eastward
overnight, impacting KDVL, KGFK and KTVF. Instability is greatest
further west, therefore maintained a PROB30 for -TSRA at KDVL, while
at the other two terminals maintained -SHRA. Clouds will thin out as
showers/storms decrease in coverage on Monday morning. Southerly
winds of 10 to 14 knots accompanied by a few gusts to 20 knots
within the Red River Valley will prevail Monday afternoon.
Additional thunderstorm development may occur late Monday afternoon
and evening, persisting into the overnight. At this time, low
predictability in where storms form  precludes any mention of them
within the last few hours of the TAF. Once timing and location
information becomes more clear, future iterations of the TAF will
likely need PROB30s or TEMPOs for at least a handful of terminals.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.

&&

$$

UPDATE...JR
DISCUSSION...Lynch
AVIATION...Rafferty