525
FXUS63 KFGF 171036
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
536 AM CDT Mon Aug 17 2026

.KEY MESSAGES...

- Isolated severe thunderstorms may develop over parts of
  southeast North Dakota and west central Minnesota this
  afternoon and early evening. Hail to 1 inch and wind gusts to
  70 mph would be the main threats.

&&

.UPDATE...
Issued at 532 AM CDT Mon Aug 17 2026

As been the case in recent weeks, short term CAM guidance hasnt
been doing too well. It earlier indicated some risk of showers
and t-storms developing in south central MN and moving east
along SD border and thus pops from NBM and in most models were
in the 30 pct range 12z-15z in SE ND. This doesnt appear to be
occurring so tried to trim them back. Cold front will work
southeast across the area. Limited moisture and instability this
morning but instability will increase later on this afternoon by
21z as front is near a Bemidji-Fargo line. Depending on dew pts,
MU CAPE values of 1000-1500 j/kg may be present near the
ND/SD/MN border area. Some hi-res models indicate dew pts 65-70
which would put instability considerably higher, while high res
model ensemble mean has dew pts lower 60s to give the 1000-1500
MU CAPE values. Soundings would support wind gusts 60-70 mph if
any supercell could develop due to dry sub cloud layer.


&&

.DISCUSSION...
Issued at 259 PM CDT Sun Aug 16 2026

...Synopsis...

Westerly flow is currently in place across the Northern Plains,
with the next mid/upper trough upstream over Alberta and
Saskatchewan. This feature tracks east tonight through Monday
night north of our region, and deepens into a larger upper low
over the Hudson Bay region Tuesday into Wednesday. This places
our region in northwest flow through the middle and later part
of the week before ridging begins to reamplify over the next
weekend. Outside of the Monday period when scattered
showers/thunderstorms may develop with the frontal passage, the
general pattern will not support organized precipitation
chances. Temperatures will tend to be below average once we
enter NW flow, with above average temperatures returning as the
ridge amplifies and builds back into the region during the later
periods.

...Severe Thunderstorm Risk Monday...

The severe risk Monday in our CWA will be dependent on the
timing of  the cold front and position of the the warm sector
ahead of this during the afternoon/peak heating period.
Initially elevated morning showers/storms may be progressing
through the region ahead of the front and this could result in
more cloud cover limiting initiation in our area as well. A lot
of guidance places the front near west central MN by time
afternoon destabilization occurs, narrowing the window and the
region where stronger/severe storm could initiate, while some
12Z guidance is just slow enough for the window to include
southeast ND. Shear profiles are top heavy, but there is enough
mid/upper level winds with the wave passing to the north to
support effective shear values 30kt+ as the front passes. Mid
level lapse rates are marginally steep (generally 7-7.4 C/km)
and the result in modest CAPE values in the warm sector. If
severe storms were to develop lower end severe impacts appear to
be favored (quarter size hail/60 mph winds).

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 1054 PM CDT Sun Aug 16 2026

VFR conditions with a few high clouds starting to move in from the
west. A bit of 5SM visibility in the northern Red River Valley but
at this point looks like will remain out of the TAF sites so will
leave BR and FG out for now. Light and variable winds overnight,
eventually shifting to the south and southwest at all TAF sites with
some lingering cumulus that will clear out in the next few hours.
Winds that are northwesterly around 10 kts will become light and
variable as the center of the surface high moves in overnight. Can`t
rule out some patchy ground fog developing towards morning with
mostly clear skies and light winds, but location uncertainty is high
and will not include in the TAFs at this point. Winds will shift
around to the south and southwest around 10 kts tomorrow morning. By
afternoon, a cold front coming through will shift winds to the
northwest then then, starting at KDVL and moving east. Gusts up to
20 kts will be possible.

&&

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

&&

$$

UPDATE...Riddle
DISCUSSION...DJR
AVIATION...JR