685
FXUS63 KFGF 300828
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
328 AM CDT Sat Aug 30 2025

.KEY MESSAGES...

- Patchy fog possible this morning.

&&

.DISCUSSION...
Issued at 328 AM CDT Sat Aug 30 2025

...Synopsis...

Showers and even some thunderstorms keep redeveloping over Otter
Tail county along the axis of a very weak surface trough. Storms
are nearly stationary due to weak flow aloft so will have to
monitor rainfall amounts but think they should finally dissipate
in the next few hours. The main weak upper circulations still
look at this point that they will remain south and west of our
CWA today into tomorrow, with blocking ridge to our northeast.
Some showers could drift towards our southwestern counties, but
at this point think the better chances for precipitation will be
on Monday. By that point, there is agreement in the ensembles
for another weak upper vort will be dropping down out of Canada
and coming into the Northern Plains. Probability of CAPE values
over 1000 J/kg are up to 50 percent by then, but deep layer
shear remains weak and think severe impacts will be very
limited. Lightning and locally heavy rain will be the main
threats.

Better upper flow starts to set up by Tuesday as a significant
trough starts to dig into the Northern Plains from Canada. That
transitions to north and then northwesterly flow aloft as the
strong upper low digs into the Great Lakes. Can`t completely
rule out some storms along the cold front as the GEFS machine
learning continues to show some very low probs for severe, but
most of the ensemble members have the instability to the south
of us by the time the upper trough arrives. Quiet conditions
with cool, stable air for the end of the week and beginning of
next weekend. Some of the NBM members go very cold and have a 20
percent chance for getting below 32 in the MN bog by Thursday
morning, but will have to watch cloud trends as the time gets
closer.

...Fog this morning...

Gwinner briefly went down to a quarter of a mile visibility but
is back up with some high clouds across the area. Light winds
and clear skies across the northern Red River Valley into the
Thief River Falls area could be the ideal set up for fog if it
forms pretty quickly in the areas with low dew point depression.
However, some cirrus is approaching from the north, so will see
if that has any impacts on fog development. HREF has some
probabilities around 70 percent for vis less than half a mile,
but mainly in our south where there is more cloud cover
currently. NBM probs are a lot lower for vis less than 1 mile,
around 20 percent. Will continue to watch obs and web cams to
see how things develop this morning.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1140 PM CDT Fri Aug 29 2025

VFR conditions prevail tonight along with light and variable
winds. Another round of fog is possible as sunrise approaches,
with the highest probability being at KFAR and KGFK. Will carry
BR for now and amend when confidence increases. Winds come up
slightly on Saturday and are expected to remain less than 10
knots.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...Lynch