718
FXUS63 KFGF 201656
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1156 AM CDT Thu Aug 20 2026

.KEY MESSAGES...

- Next chance for strong thunderstorms are late Monday and
  Monday night.

&&

.DISCUSSION...
Issued at 235 PM CDT Wed Aug 19 2026

...Synopsis...

Northwesterly flow aloft continues with various weak shortwaves
moving into the Plains. One such shortwave comes through
tonight and Thursday, bringing a surface low with some weak cold
air advection behind it. The northwesterly flow amplifies a bit
into the weekend as ridging builds over the Rockies/Western
Plains. A shortwave coming over the top of the ridge will break
it down a bit on Monday, with some precipitation chances. The
northwesterly flow returns for mid-week, although ensemble
members show some differences in were exactly the ridge axis
sets up. NBM mean has been trending on the dry side with
temperatures just above seasonal averages.

...Showers and thunderstorms tonight and Thursday...

Many of the model solutions have scattered shower and a few
thunderstorms entering our northern counties late this afternoon
and into the evening as the shortwave currently over
southeastern Saskatchewan digs down. Some of the models such as
the NAM and the RAP have a narrow band of instability with the
system. The surface based CAPE is only in the 500-1000 J/kg
range, but some of the CAMs have MU CAPE a bit above 1000 J/kg.
Deep layer shear is around 25 to 30 kts, but HREF probabilities
of any strong updrafts are minimal, and model soundings this
evening are not very impressive. Could see some lightning as
HREF has 30 to 50 percent probabilities with this shortwave,
along with brief downpours.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 1156 AM CDT Thu Aug 20 2026

VFR for most this afternoon with some SCT MVFR cumulus hanging
around KBJI this morning. These may work off to the east but if
not, should remain SCT and not become a ceiling. Winds slowly
turning from W to NW today at 10-15kts and gusts occasionally
over 20kts. With light winds overnight we could see some fog
potential. Confidence in location is low but DVL, BJI and
potentially TVF look to be the favored areas. Would think more
of a patchy radiation fog that is locally 1/4-1sm if it does
develop. Tomorrow winds NW at around 10kts by 18z.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...TT