273
FXUS63 KFGF 191942
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
242 PM CDT Thu Mar 19 2026

.KEY MESSAGES...

- There is a medium to high chance for dense fog during the
  evening into morning hours for the next several days. However,
  confidence in location and duration of fog is low.

- A quick moving system this weekend brings a 20% chance for
  advisory level impacts.

&&

.DISCUSSION...
Issued at 242 PM CDT Thu Mar 19 2026

...Synopsis...

Northwest flow aloft continues over the Northern Plains as
strong upper ridging builds over the Desert Southwest. A weak
shortwave will dig down out of Canada tonight into tomorrow
morning, and a few of the CAMs such as the HRRR and RAP bring a
few light showers down into the northern Red River Valley.
Can`t completely rule out some light rain or snow showers
reaching the ground in our north, but impacts look minimal at
this point. Another shortwave digs down from Manitoba and
Ontario into the Upper Midwest Friday night and Saturday, which
should push a cold front down into the Northern Plains. Some
mixed precipitation coming along with this frontal passage could
bring advisory level impacts for the weekend. Northwesterly flow
returns for the starts of the work week, with another weak
embedded shortwave possible. Some of the ensemble members make
flow more zonal ahead of another trough moving through late
Wednesday into Thursday, but predictability still low at this
point.

...Fog possible tonight...

Area of stratus and 1 to 2 miles of fog continues across the
Northern Red River Valley. Think this area should dissipate for
a time this afternoon and evening as surface low pressure over
southern Saskatchewan moves southeast and winds shift to the
northwest behind it. Another weak high pressure center follows
quickly behind it, so winds will again go light and variable and
with another warm day with plenty of melting, fog will again be
a concern. High resolution models don`t have any consensus on
where fog develops, and ensemble probabilities have a fairly
broad area of 50 to 70 percent. Previous shift had entire area
under patchy fog, and see little reason to change that at this
point. Will continue to monitor to watch for any dense fog
development.

...Mixed precipitation this weekend...

With colder air pushing down from the north this weekend, and
another weak shortwave moving through the northwesterly flow,
there is the chance for some rain showers, or even a bit of
freezing rain or snow Friday night into Saturday. Model
soundings have a mix at HCO, but amounts look very light at this
point. HREF probabilities of over a hundredth of freezing rain
are only 30 to 40 percent in a small area of northeastern ND,
and NBM probs are even lower. There isn`t a strong signal from
the ECMWF EHI for a lot of precipitation, and the probabilistic
WSSI has around 20 percent in our northern counties. At this
time, think that advisory level impacts are not terribly likely,
but not out of the question either. Will keep the 20 percent
going and mention in the forecast, but no stronger messaging.


&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1231 PM CDT Thu Mar 19 2026

Stratus and fog bank has spread northward along the west side of
the Red River Valley, with KFAR finally clearing out but some
200 ft ceilings and vis less than 1 mile at times near KGFK.
Should see the lower vis continue for the next hour or two
before the fog deck starts to dissipate a bit more. After some
period with all sites VFR through the late afternoon and
evening, fog will redevelop somewhere in the forecast area
tonight into Friday morning. The question will be where and how
dense. A few of the models bring vis down to 1/2 or 1/4 mile at
some of the airports, but model consistency and confidence is
low. Have KGFK and KTVF going down to 1SM as those spots seem to
have more agreement on the lower visibility. Kept the other TAF
sites in the 2-5SM range. Improvement by the end of the period,
but probably not all the way back to VFR. Winds that are
southerly around 10 kts will shift around this evening, with
some low level wind shear possible as the west and then
northwesterly winds at the surface lag behind the 1000-3000 ft
winds a bit. Several sites will become light and variable for a
time late tonight, then pick up out of the southwest for KDVL by
the end of the period.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...JR