Casselton, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

235
FXUS63 KFGF 200426
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1126 PM CDT Wed Aug 19 2026

.KEY MESSAGES...

- Isolated thunderstorms in eastern North Dakota into Minnesota
  tonight into Thursday. No severe weather anticipated with the
  main impacts being lightning and brief rain.

&&

.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 /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1126 PM CDT Wed Aug 19 2026

Cloud bases will remain above 5,000ft AGL throughout the TAF
period. A few showers and weak thunderstorms are passing through
the region, and will impact KTVF and KBJI early in the TAF
period. Shower and thunderstorm activity will linger longest
into the morning at KBJI. Elsewhere, showers and storms will
end, with clouds slowly breaking up. As a cold front passes
from northwest to southeast overnight into Thursday morning,
winds will increase out of the northwest. A period of gusts
between 20 and 25 knots is forecasted during the afternoon
hours. In addition, afternoon cumulus will also develop, with
bases around 5,000ft AGL. There may be a several hour period
that a ceiling of low end VFR does develop in the afternoon,
especially at northern terminals.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...Rafferty