811
FXUS63 KFGF 041734
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1234 PM CDT Fri Sep 4 2026

.KEY MESSAGES...

- Areas of dense fog this morning.

- Additional chances for strong to severe thunderstorms exist
  late Saturday and Sunday.

&&

.DISCUSSION...
Issued at 241 PM CDT Thu Sep 3 2026

...Synopsis...

Southwesterly flow aloft with a lead shortwave lifting from near
the MT border through the Northern Plains. Storms have been
ongoing in northeastern ND into far northwestern MN, and will
continue to push eastward along the warm front/theta-e gradient
that is between the Highway 2 and Highway 200 corridors. The
shortwave will move northeast overnight, and upper ridging will
begin to amplify over the Plains tomorrow. Upper ridging
continues to build over the region into the weekend, with
several weak embedded shortwaves possible. By early next week,
the upper ridge starts to flatten and move east, with continued
active weather under southwesterly flow aloft. A trough moving
through Manitoba and Ontario on Wednesday will push east
Thursday and leave the region in northwesterly flow.

...Convective trends and severe threat this evening...

Complex of thunderstorms in northeastern ND is currently
crossing into northwestern MN. Most of the instability seems to
be elevated, with SPC mesoanalysis still showing a good amount
of CIN on surface based and mixed layer CAPE, but there has been
enough mixing to get a few 60 and even 70 mph reports to the
surface. The shear at 0-3km is favorable for brief tornado spin
ups along some kinks in the line, but would need to get some
better low level CAPE developing before that could happen. Think
that this will be the case eventually with sunshine over the
southern forecast area. Even if we don`t get a fully mixed
boundary layer, with continued lift, good deep layer shear
around 50 kts, and dew points in the upper 60s to near 70
feeding into the complex, expect some re-intensification of
storms and a continued threat of large hail and winds up to 70
mph.

...Storm chances Saturday and Sunday...

After a break tomorrow, additional weak embedded shortwaves
under the building ridge will bring some rounds of showers and
thunderstorms. Temperatures will be well above average for early
September and there should be good instability to work with. The
deep layer shear is not as strong this weekend as today, but at
30 kts could still be adequate for strong to severe storms.
Machine learning has some low probabilities for severe impacts
for the weekend time period, mainly in the 5 to 15 percent
range. Still some uncertainty, but will have to watch for some
active convective days this holiday weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1234 PM CDT Fri Sep 4 2026

Ceilings at 800 ft continue to hang around the KBJI area, but
based on satellite should scatter out in the next few hours.
Light north to northeast winds under 10 kts will shift around to
a more southeasterly direction tonight, with some variability
as they come around. Some fog is not out of the question with
southeasterly winds and moisture pooling along an old boundary,
most likely in our far eastern forecast area and along the
escarpment in northeastern ND. Considering the good probability
of less than 3 miles visibility put KBJI down to 2SM for a time
tomorrow morning, and could get even lower. At this point fog
is not certain enough to include in the other TAF sites. All
airports should be VFR by the end of the period, with some
southeasterly winds gusting to 20 kts.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...Riddle