387 
FXUS63 KFGF 030449
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1149 PM CDT Wed Sep 2 2026

.KEY MESSAGES...

- Chance for thunderstorms returns mid to late this week. This
  includes potential for strong to severe storms. There is a
  level 2 out of 5 risk for severe storms Thursday.

- Late summer heat forecast to return this weekend.

&&

.UPDATE...
Issued at 1005 PM CDT Wed Sep 2 2026

Latest 00Z high resolution guidance still reveals multiple
potential scenarios regarding convection evolution tomorrow.
While confidence has grown in there being severe storms within
our area tomorrow, the evolution of which as well as location
remain in question.

Most impactful scenario includes severe storms in northeast ND
mid to late afternoon migrating east and southeast, including
discrete to semi-discrete supercells. This would allow all
hazards to be possible, with perhaps very large hail possible
(in excess of 2 inches) along with a tornado threat. Should
storms evolve into more of a line of storms, gusty winds to 70
mph and hail not exceeding 2 inches would be the main threats -
with some lowered chance for line-embedded tornadoes.

There is also a potential scenario that includes early morning 
isolated severe storms near the tri-state area into west-central
MN - of which could be elevated supercells capable of large 
hail. Despite forcing aloft being weak, there is some present 
(mainly via weak warm air advection near 700 mb). This is the 
main question - whether or not strong enough forcing will be 
present to sustain robust convection in amid very favorable
hail-producing environment comprised of moderate instability 
and moderate to strong shear.

&&

.DISCUSSION...
Issued at 155 PM CDT Wed Sep 2 2026

...Synopsis...

A few isolated sprinkles near the South Dakota border this
morning as a weak embedded shortwave moved though, but fairly
tranquil now with surface high pressure and the instability
pushed south of our area. Instability will return tonight into
tomorrow as surface winds shift to the east southeast, and a
lead shortwave coming out from the western Plains into Manitoba
will provide the focus for some convection tomorrow. Blocky 
upper ridging will build into the region for Friday and continue
into the weekend, with some ridge riding shortwaves coming 
through. The fairly active pattern will continue into Monday and
Tuesday as the upper ridge shifts slightly east and 
southwesterly flow aloft sets up over our area. Some of the 
deterministic solutions try to break down the ridge just to our 
east and shift flow to a more west to northwesterly direction, 
with cluster analysis showing about 30 percent of members 
agreeing while the majority of the ensemble keeps us in ridging 
or southwesterly flow.

...Severe chances Thursday...

Both the high resolution and synoptic models are all over the
place as to how far north the highest instability gets tomorrow
and where and when they break out convection. A few like the NAM
keep most of the surface based CAPE south of the SD border,
while the GFS brings a narrow band of instability all the way up
to Highway 200. Much will depend on what happens tonight, as
several of the CAMs bring out some storms into the southern Red
River Valley tomorrow morning with a weak lead shortwave. Some
of the CAMs intensify the early activity fairly quickly
tomorrow, with updraft helicity tracks starting to show up
before 18Z, while other models don't have anything until the
main shortwave comes out later in the afternoon and evening.
Even with the morning convection, several solutions show enough
recovery time to get over 2000 J/kg ML CAPE again in the
afternoon, and with 40 kts of deep layer shear, severe weather
is possible and the slight risk has been expanded northward.
Storm mode is also not well resolved, with several CAMs showing
linear storms along the surface boundary while others like the
HRRR have a much more curved hodograph and supercells. At this
point, all severe impacts are on the table, and will see how
things develop during the day tomorrow. 
 
...Heat Friday and into the weekend...

With rising heights as the upper ridge builds Friday and into
the weekend, temperatures will be well above average into the
weekend. The ECMWF EFI shows a strong signal for warm temps,
particularly in the southern Red River Valley. Apparent temps do
not get above advisory criteria unless looking at the max
percentile members, but the wet bulb globe gets into the 80s and
heat risk is up into the major category for portions of the
southern Red River Valley and west central MN both Friday and 
Saturday. May not need headlines especially this far in advance,
but will continue to message summer temps heading into the
weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1149 PM CDT Wed Sep 2 2026

VFR conditions are forecast throughout the TAF. Generally high
confidence in this as surface high pressure slides away from the
area with a persistent light easterly wind developing overnight.
Winds remain generally out of the east throughout the TAF
period.

There is a chance for scattered thunderstorms within the region
Thursday, including potentially severe thunderstorms capable of
gusty winds and large hail. While very unlikely to occur at a
TAF site, cannot rule out the possibility of a tornado.

Storms could develop as early as 11Z within southeast ND into
west-central MN before diminishing or moving away by 17Z. The
chance of this to occur is low, and was omitted from KFAR's TAF
at this time. Should this occur, however, storms may produce 
large hail and gusty winds. 

Then another round of thunderstorms may develop in the 
afternoon in northeast ND, moving generally east and/or 
southeast. Each TAF site has corresponding PROB30 groups to note
on general timeframe for potential storms.

&&

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

&&

$$

UPDATE...CJ
DISCUSSION...JR
AVIATION...CJ