052
FXUS63 KFGF 301457
AFDFGF

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

.KEY MESSAGES...

- Patchy fog possible this morning.

&&

.UPDATE...
Issued at 957 AM CDT Sat Aug 30 2025

Biggest issue this morning is stubborn fog in southeastern ND.
Gwinner remains socked in at a quarter mile or less. Area
webcams and METARs confirm fog along a wide swath from
Steele/Traill counties south to the state line, but visibilities
of a quarter mile or less seem to be very sporadic.Issued a new
SPS for this area through Noon. Otherwise the forecast remains
on track.

UPDATE
Issued at 706 AM CDT Sat Aug 30 2025

Showers in Otter Tail county starting to diminish, with many of
the cells on the northwestern end dissipating while lightning
continues around the Alexandria area. Adjusted POPs a bit more
for current trends. Fog has developed in several locations
across the forecast area, with many obs sites showing 1/4 mile
visibility. However, web cam coverage is still very patchy with
cameras a few miles away from the Bemidji and Valley City
airports showing fog free conditions. With the very patchy
nature included an SPS out through 10 AM CDT.

&&

.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 /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 706 AM CDT Sat Aug 30 2025

Fog and some stratus have brought all but KFAR down to IFR to
LIFR conditions. Should see some improvement in the next hour or
two, with KBJI starting to come back up as KGFK goes down. All
sites should be VFR by 15 or 16Z. Winds will remain light and
variable through much of the period. Can`t rule out fog
reforming tomorrow morning, but uncertainty too high to include
in the TAFs at this point.

&&

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

&&

$$

UPDATE...Rafferty/JR
DISCUSSION...JR
AVIATION...JR