656
FXUS63 KFGF 121210
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
710 AM CDT Wed Aug 12 2026

.KEY MESSAGES...

- Scattered thunderstorms mainly in southern North Dakota into
  parts of west central Minnesota today into tonight. Isolated
  severe with hail and wind hazards.

&&

.UPDATE...
Issued at 447 AM CDT Wed Aug 12 2026

The thunderstorm cluster than went thru various stages of
strength from small hail then from Valley City into Fargo wind.
Strongest winds around 50-55 mph in this stretch with pockets of
60 mph. These storms have weakened dramatically are not now into
MN lakes country. Balance of the upcoming day will see a chance
for additional t-storms just about anytime in the southern parts
of ND into west central MN as water vapor shows another area of
deeper moisture in southern Montana into SW ND spreading east
today. Then a break Thursday.


UPDATE Issued at 1154 PM CDT Tue Aug 11 2026

Strong to severe thunderstorms continue to slowly move east
across central North Dakota tonight. Storms will gradually
weaken as the night progresses, however, isolated severe storms
could bring impacts into portions of eastern North Dakota after
midnight. The primary hazard will be large hail.

UPDATE
Issued at 634 PM CDT Tue Aug 11 2026

Severe thunderstorm watch will be in effect for Barnes, Ransom,
and Sargent County through 1 AM CDT.

&&

.DISCUSSION...
Issued at 237 PM CDT Tue Aug 11 2026

...Synopsis...

Currently a very elongated ridge exists across the southern
CONUS with zonal to WNW mid level flow in the northern CONUS. As
we progress through the week, ridging over the four corners
into Texas panhandle will amplify. At the same time PNW
troughing begins to turn flow more zonal over us as the ridge
gets pushed east. By Thursday SW flow looks to dominate the
western CONUS bringing pacific moisture over the Rockies with
embedded shortwaves. Certainly still differences remaining among
clusters but the potential for a wet late week/weekend
continues to increase. Current guidance is now favoring western
areas (eastern North Dakota) over eastern areas (northwest
Minnesota) with a 60% chance for over half an inch in the next
seven days vs only 40% chance out east. As much of this rain
looks to be more convective and thunderstorm driven vs a slow
soaking rain totals will likley vary greatly over short
distances.

- Severe threat today

This morning MUCAPE of 1000-2000 j/kg atop a nearly stationary
surface boundary led to the formation of a lone supercell that
tracked from north of Jamestown towards Fort Ransom dropping up
to baseball sized hail along the way. Overall this was mostly a
surprise and not in the forecast given the skinny CAPE, however
the very favorable straight hodos and eff shear of around 50kts
at least helped explain it a little. Looking ahead to this
evening CAMS largely maintain the instability across the area
but fail to convect despite an overall capable environment
should a forcing mechanism exist. The chance for a storm this
evening is likely less than 10% but if one goes, something
similar to this morning is certainly possible. By the overnight
there is higher confidence in storms forming west of Bismarck
and moving east reaching the James/Sheyenne river valleys around
4-5am. Storms still look to be elevated and a primary hail
threat, but cant 100% rule out damaging winds. This threat
would persist into the mid morning hours mainly for southeast
North Dakota and perhaps west central Minnesota is storms made
it that far east.

- Severe threat Wednesday

A more pronounced shortwave will roll across the Dakotas
Wednesday evening bringing forcing for widespread convection.
thunderstorms may occasionally have large hail and gusty winds
but overall this looks to be more of a general
thunderstorm/widespread rain event for eastern North Dakota.
Amounts will generally will be a quarter to half inch but
isolated totals in excess of 1" are possible.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 708 AM CDT Wed Aug 12 2026

Scattered to broken mid level CU and cirrus once again today.
Light northeast winds. Isolated to scattered t-storms
anticipated today into tonight, but only place where I felt
chance was high enough to include a prob30 group was Fargo for
late aftn/eve.

&&

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

&&

$$

UPDATE...Lynch/Riddle
DISCUSSION...Riddle
AVIATION...Lynch