874
FXUS63 KFGF 060246
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
946 PM CDT Sat Sep 5 2026

.KEY MESSAGES...

- Additional chances for thunderstorms exist over the holiday
  weekend, with a level 1 out of 5 chance each day. The main
  impacts for any storms that become severe will be ping pong
  ball sized hail and winds to 60 mph.

&&

.DISCUSSION...
Issued at 429 PM CDT Sat Sep 5 2026

...Synopsis...

Upper ridging continues to build over the Eastern Plains, with
several weak shortwaves evident on water vapor. A couple such
shortwaves have been producing showers and storms over northwestern
MN and along the north central ND/Manitoba border.
The next more significant shortwave is still down over WY and will
move into the Northern Plains tonight into tomorrow morning. The
upper ridge will begin to shift slightly east Sunday night, leaving
the region in southwesterly flow aloft into Labor Day. A broad
trough/upper low will move through south central Canada on Tuesday,
leaving the Northern Plains in slightly northwesterly to near zonal
flow aloft through the rest of the work week and into next Saturday.

...Marginal severe chances tonight, tomorrow and Monday...

Some MU CAPE still around, but SPC mesoanalysis page has a lot of
CIN with the mixed layer CAPE. Most of the CAMs don`t have much over
eastern ND until later tonight when the shortwave over WY comes
northeast, but given recent poor performance do not have much trust
in their solutions. There will be plenty of MU CAPE again overnight,
although bulk shear will be fairly modest around 30 kts. Some
convection could be ongoing tomorrow morning, with HREF showing a
low probability of strong updraft helicity tracks in west central
MN. Another shortwave coming through could bring more thunderstorm
activity Sunday afternoon and evening, although much will depend on
how the morning activity plays out and if the atmosphere recovers.
Better shear looks to be in store for Monday, although instability
is more uncertain. At this point, can`t rule out an isolated
instance of hail up to ping pong balls or 60 mph winds through the
rest of the holiday weekend, but confidence in exactly when and
where is low.

&&

.AVIATION /03Z TAFS THROUGH 06Z MONDAY/...
Issued at 946 PM CDT Sat Sep 5 2026

Several periods throughout the TAF period may bring aviation
impacts. The first period of concern is tonight into early
Sunday morning. MVFR to IFR pockets of stratus may develop,
along with a few areas of fog. However, where exactly this may
occur is highly uncertain, and timing of its development is also
uncertain. Therefore, kept any lower ceilings or visibilities
out of the TAFs for the overnight period. KDVL and KGFK seem to
hold at least a slightly higher chance of these impacts over
other terminals, but again, low predictability precludes any
addition into the TAFs.

The next period of concern is really all day Sunday into early
Sunday night, as thunderstorms are expected to develop.
Thunderstorm development in the morning is highly uncertain,
however it seems later in the day, coverage of activity should
increase. Therefore, introduced a PROB30 at all terminals after
0z Monday for -TSRA. Timing of this activity can be narrowed
down as we get closer in time.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...Rafferty