Casselton, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

441
FXUS63 KFGF 042320
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
620 PM CDT Sat Jul 4 2026

.KEY MESSAGES...

- Isolated to scattered t-storms today until sunset over the
  area. There is a 1 out of 5 risk of brief severe storms in
  southeastern North Dakota and west central Minnesota. But any
  storm is capable of heavy rain, lightning, and small hail.

- Level 1 out of 5 severe storm risk Monday as a frontal
  boundary moves through.

&&

.DISCUSSION...
Issued at 240 PM CDT Sat Jul 4 2026

...Synopsis...

Near zonal flow aloft over the Northern Plains, with a good
shortwave over the southern Red River currently providing some
lift for storms developing in west central Minnesota. The weak
frontal boundary/wind shift draped across that same area will
start to wash out tonight as lee troughing gets going to our
west. South to southeasterly winds will continue into Sunday as
upper ridging builds into the Plains and upper midwest. A
shortwave riding over the top of the ridge through southern
Canada will help push a front back south into ND by Monday. A
stronger shortwave comes through the Dakotas on Tuesday, pushing
the frontal boundary down into our southern counties.
Northwesterly flow aloft west up for mid to late week, with
several of the model solutions showing an embedded shortwave
coming through on Friday.

...Thunderstorm chances this afternoon and early evening...

Most of the development so far has been in west central MN ahead
of the shortwave, and with good heating boosting ML CAPE to over
2000 J/kg, several of the cells have gained enough height to
produce some 1 inch hail even with negligible shear. Any severe
threat from a individual cell will be short lived as they come
up and then right back down. Some localized street flooding is a
possibility with slow movement of storms and PWAT values over
1.5 inches. Further north and west, there is less instability
and deep moisture convergence is less impressive, and shear is
not any better. Could see some lightning and brief downpours,
maybe even some pea sized hail from any isolated cells that
develop this afternoon. A few of the CAMs show storms
redeveloping over the southern Red River Valley around 00Z, with
HREF showing around a 40 percent chance for some lightning. Not
a slam dunk but will have to keep an eye on general
thunderstorms for a while. By sunset, most of our instability will
be on a downward trend and the main shortwave will be pushing
east. HREF probabilities of thunder are on a rapid downward
trend after 03Z, but may have to watch a few spots at fireworks
time for any lingering convection.

...Severe chances Sunday night and again Monday...

The shortwave coming over the top of the upper ridge late Sunday
could bring some storms to north central ND that could clip our
far northwestern counties. HREF updraft helicity probabilities
are not too impressive with only a few members showing any
paintballs in Towner county, but can`t rule out a few isolated
cells. Better, but still marginal chances for severe storms will
be Monday as the frontal boundary sags south into our area.
Ensemble mean CAPE according to the NBM gets over 2000 J/kg by
Monday afternoon and deep layer shear increases to 35 to 40 kts.
Still a few days away, but if the trends that the NBM shows hold
Monday looks like a fairly busy convective day.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 616 PM CDT Sat Jul 4 2026

Scattered showers and thunderstorms may impact terminals this
evening but there is a low predictability on actual impacts.
Updates may be necessary through the early evening as these
storms continue. Isolated MVFR continues at BJI, but the
expectation is for this to diminish later on this evening.
These storms will diminish towards sunset, giving way to VFR
conditions and generally light winds, which will prevail through
the end of the TAF period.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...Perroux