153
FXUS63 KFGF 241922
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
222 PM CDT Thu Sep 24 2026

.KEY MESSAGES...

- Fog is expected to develop tonight behind the departing rain
  showers.

- Additional light rain is expected Friday night through
  Saturday night, and there is the potential for a widespread
  soaking rain early next week. These rain events may impact
  outdoor activities and harvest.

&&

.DISCUSSION...
Issued at 222 PM CDT Thu Sep 24 2026

...Synopsis...

Upper heights will rise briefly tonight behind today`s shortwave
departing through the Great Lakes and the next shortwave coming
in late Friday. The Friday night/Saturday shortwave will quickly
move off into northern MN and then Canada, leaving southwesterly
flow aloft again for Sunday and into the work week. A lead
shortwave coming in Monday will help push a decent surface low
and baroclinic zone into the Plains, although exact track is
still uncertain. The main upper trough pushing through late
Monday into early Tuesday, with high pressure building in behind
it. Near zonal flow sets up for mid-week with a few weak
shortwaves possible near the Canadian border.

...Fog tonight and Friday morning...

Satellite loop shows the edge of the stratus deck approaching
our far western counties, and could see some clearing in that
area this evening. However, fog will quickly fill in and several
of the CAMs show a fairly dense band from the Cooperstown area
into the northern Red River Valley. A few of the models have the
worst of the fog further west, and exactly where the line
between fog and low clouds will be is highly uncertain. HREF has
highest probabilities for less than a mile or even half a mile
in visibility along and west of the Red River Valley, so kept
the areas of fog mention there and patchy fog everywhere else.
How many areas will be under a quarter of a mile is still
uncertain, so will keep out any headlines for now. Will likely
need a dense fog advisory somewhere in the region overnight.

...Rain Friday night and again Monday/Tuesday...

Another quick moving shortwave coming through Friday night into
Saturday morning will bring another round of light rain to the
region. Probabilities of a tenth to a quarter of an inch of rain
is over 60 percent, but drops off quickly for over half an inch.
Some weak instability of less than 500 J/kg of MU CAPE could
bring a few claps of thunder, but nothing else impactful. A
stronger system moving in Monday into Tuesday could bring a more
interesting setup, with some ensemble members showing portions
of our forecast area in the warm sector with machine learning
having a low probability for severe. Others have the track of
the low a little further south and more stratiform precip
setting up. While chances of severe are not high, there is over
a 70 percent chance for an inch of rain or more over portions
of the forecast area, so another round of soaking rain seems
likely and will continue to message.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1224 PM CDT Thu Sep 24 2026

IFR conditions at most of the TAF sites with stratus below 1000
ft and some patchy BR and even drizzle lingering at the TAF
sites behind the departing rain. Some improvement to MVFR is
possible for a time this afternoon and evening, but conditions
will go back downhill tonight. Probabilities of less than 1000
ft ceilings are 70 to 100 percent in our forecast area according
to the HREF, and chances for less than 1 mile visibility are
similar along and west of the Red River. Still some uncertainty
where the lowest visibility will be and if there will be fog or
more low stratus, but low level moisture is a given and there
will be likely LIFR conditions across much of the area tomorrow
morning. Some improvement to IFR or even MVFR by the end of the
period at some airports, but stratus and even fog will hang
around for a few hours after sunrise.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...JR