204
FXUS63 KFGF 181735
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1235 PM CDT Fri Sep 18 2026

.KEY MESSAGES...

- Chance for 0.50 inch or more of rain is over 70 percent in the
  far southeast forecast area in Grant county MN, with chance
  for 1 inch or more 20 percent in that area. Much lighter
  rainfall farther north.

&&

.UPDATE...
Issued at 638 AM CDT Fri Sep 18 2026

06z data suggests similar thoughts from earlier this evening in
that north edge of rain will make it into Fargo-Detroit Lakes-
Park Rapids this morning and early afternoon before shifting
out. Light rain though with amounts under 0.10 inch. From
observations in South Dakota heaviest rainfall of 0.50 inch or
more is from Watertown to south of Aberdeen then to about I-90,
with pocket of 2+ inches Huron area. Lighter amounts under 0.25
inch along ND border. This goes along with thoughts of over 0.50
inch of rain a good bet (over 70 pct chance) in Elbow Lake/Grant
county MN area, but that percentage of 0.50 inch or more
dropping quickly northward. Also watching showers increase in
coverage from Estevan SK east along the border to Rolla and its
moving northeast. I do think these showers today will stay in
Manitoba, but graze the ND/MB border.

&&

.DISCUSSION...
Issued at 343 PM CDT Thu Sep 17 2026

...Synopsis...

Weak shortwave trough moving through zonal flow aloft will bring
medium chance for rain Friday, mainly near the SD border/tri-
state area into west-central MN. There is also a low chance for
showers in northeast ND into far northern Red River Valley
Friday. More details on amounts can be found below.

Thereafter into the weekend and next week, upper flow becomes
relatively week amid upper ridging into central Canada. Ensemble
guidance also suggests a weak, disorganized shortwave upper
trough gradually sliding west to east out of the Northern
Rockies through the Central Plains into mid-Mississippi Valley.
This present a weak Rex-block-type pattern late weekend into
early/mid next week. This trend in guidance has decreased rain
chances for our area this weekend, ultimately offering a now
mostly dry weekend forecast. This will also keep temperatures
near average through at least mid next week.

Into mid/late next week, guidance suggests either continued
weak upper ridging or zonal flow aloft. Both scenarios suggest
temperatures trending near average to slightly above average;
the former would favor mostly dry conditions, with the later
scenario bringing at least a slight uptick in rain chances with
the possibility of progressive shortwave troughs moving through
the region out of the Pacific Northwest.

...Rain chances Friday...

Guidance continues to keep the lion`s share of soaking rainfall
south of our area Friday. There is still a subset of guidance
that eeks the northern fringes of moderate to briefly heavy
rainfall into locations near the SD border/tri-state area into
west-central MN. Should this occur, rainfall totals may reach
into the 0.8-1.5 inch range. There is around a 30% chance for
this to occur. Otherwise, most likely amounts are expected to
remain less than 0.5 inches. The chance for 3 or more inches
remains very low/nill at this time.

Timing for rainfall in southeast ND into west-central MN begins
Friday morning around sunrise, lingering through early to mid
afternoon.

A separate area of showers are expected to develop in portions
of north-central ND into SK/MB Friday. This could spread into
northeast ND and the far northern Red River Valley. Rain amounts
will be light, only up to a few hundredths, if this occurs.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1235 PM CDT Fri Sep 18 2026

The main concern today into tonight will be the expansion of
MVFR to IFR ceilings. MVFR is already impacting KDVL and KFAR.
This will continue throughout the afternoon hours. By late
afternoon into the evening, MVFR will expand northward into all
remaining terminals, eventually turning into IFR. IFR will
persist into Saturday morning. A few gusts of up to 20 knots are
possible this afternoon. Once clouds set in and the sun sets,
winds will decrease substantially overnight, becoming variable
at under 5 knots. Fog and drizzle may also develop as ceilings
lower overnight, but predictability in these hazards remains
low at this time for any one terminal.

&&

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

&&

$$

UPDATE...Riddle
DISCUSSION...CJ
AVIATION...Rafferty