159
FXUS63 KFGF 242328
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
628 PM CDT Mon Aug 24 2026

.KEY MESSAGES...

- There is a level 2 out of 5 risk for severe thunderstorms this
  afternoon into the overnight. Hail to the size of golf balls
  and wind gusting to 70 mph will be the main threats.

&&

.UPDATE...
Issued at 628 PM CDT Mon Aug 24 2026

Severe thunderstorm watch #625 has been issued for much of
eastern North Dakota and northwestern MN. Deep convection has
initiated on a cold front across central ND. Further north,
satellite shows little cumulus development in our far western FA
and adjacent portions of Manitoba, so we likely still have an
hour or two until storms even initiate. Long, straight
hodographs with effective shear of up to 50 knots will promote
splitting supercells, with hail being the predominate threat.
Current thinking is that the cluster of supercells north of
Jamestown will continue to track east/southeastward towards
southeastern ND with time. Additional storms will develop in an
hour or two across southern Manitoba and northeastern ND. This
area of convection will also eventually track east/southeast
this evening into early tonight, impacting northern portions of
watch #625. The watch is in effect until 1 AM CDT.

&&

.DISCUSSION...
Issued at 242 PM CDT Mon Aug 24 2026

...Synopsis...

A shortwave and associated cold front will move across the area late
today into Tuesday. Showers and thunderstorms are expected to form
along and ahead of the front, with scattered severe thunderstorms
possible during the late afternoon, evening, and overnight. Heading
into Tuesday, the lingering frontal boundary could still be situated
in northwest Minnesota, where there is a chance for isolated severe
thunderstorms, primarily east of the Red River Valley. In the post
frontal environment, cooler highs in the 70s to low 80s are expected
Tuesday through Thursday, with warmer temperatures this weekend as
weak ridging builds across the western CONUS and High Plains.
Additional shortwaves bring showers and thunderstorms back into the
forecast for Saturday and Sunday.

...Scattered Severe Storms This Evening and Overnight...

Instability is slowly building this afternoon as warmer temps and
higher moisture levels work into the area. Dew points have increased
into the lower to middle 60s in most areas, with SBCAPE values
generally in the 1500 to 2000 J/Kg range early this afternoon. Model
soundings show the potential for 2500 to 3000 J/Kg by early evening.
Mid level shear is present, but unidirectional above 700 mb, leading
to straight hodographs and a continued support for splitting
supercells. It is worth noting, however, that given the tendency to
split, these supercells are also likely to interact and eventually
form clusters. The primary hazard during the afternoon and early
evening will be large hail to the size of golf balls, with a low
chance for an isolated tornado. Due to relatively weak low level
shear, tornado risk will be dependent on longer lived supercells
that avoid interaction with nearby cells. With DCAPE in the 1100 to
1400 J/Kg range, damaging wind gusts to 70 mph are supported
late this afternoon through mid evening.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 628 PM CDT Mon Aug 24 2026

Quite complicated set of TAFs, with thunderstorms rolling across
all terminals from west to east this evening into tonight.
Periods of MVFR visibility are likely under the strongest
thunderstorms. Behind these thunderstorms, winds will shift to
the west and eventually northwest. It will become gusty during
the late morning and afternoon hours of Tuesday. At KGFK, KDVL
and KFAR, gusts may flirt with 30 knots for a couple of hours in
the afternoon. However, the probability they prevail at this
magnitude is low at this time, therefore wind gusts in the 24 to
28 knot range. Clouds bases tomorrow morning and afternoon may
briefly fall below 5,000 ft AGL, but at this time any ceilings
that form look to remain VFR.

&&

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

&&

$$

UPDATE...Rafferty
DISCUSSION...Lynch
AVIATION...Rafferty