168
FXUS63 KFGF 181723
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1223 PM CDT Mon Aug 18 2025

.KEY MESSAGES...

- There is a medium chance for strong storms across the
region on Thursday.

&&

.UPDATE...
Issued at 1223 PM CDT Mon Aug 18 2025

Drizzle has ended across the region with the only noted
visibility impacts is under the low stratus in central Minnesota
from Wadena to Bemidji and points east. Monitoring some decaying
convection in south central ND for intensification later this
afternoon as it tracks east into a modestly unstable environment
with weak shear likely capable of some small hail and wind gusts
over 40 mph in any stronger storms.

UPDATE
Issued at 952 AM CDT Mon Aug 18 2025

Drizzle and patchy fog remains across the region with all areas
now above dense fog criteria (< 1/4sm) Continued improvement
through the next few hours will see visibility improve to 5sm
or greater for all but low clouds remaining into the afternoon.
Some light drizzle through the early afternoon but just enough
to keep things damp really. Still a chance for some
thunderstorms across portions of south central ND this
afternoon with clearing already present the southwest of
Jamestown but severe storms are unlikely east into the southern
Red River Valley.

UPDATE
Issued at 649 AM CDT Mon Aug 18 2025

In typical fashion after 11z fog visibilities became worse in
several hours, but will improve 13-14z. Vsbys in NE ND 1/4 to 1
1/2sm. Graphicast on fog and areas of fog in grids suffices, as
the larger dense fog area remains limited and lasting less than
3 hours.

&&

.DISCUSSION...
Issued at 349 AM CDT Mon Aug 18 2025

...Synopsis...

Area of rain showers gradually exiting far northwest MN and Lake
of the Woods area thru 12z as 500 mb short wave near Kenora
moves east. In its wake are clouds, with widespread low clouds
and areas of fog mainly in northeast North Dakota. Thru 0830z
vsbys in fog have remained manageable and above dense fog
levels, except at the Langdon AWOS. Did add areas of fog thru
13z for E ND and parts of NW MN. Will continue to monitor for
any psbl advisory. Coord with WFO BIS as they do have advisory
out.

Expectation is for the lowest levels to gradually mix out and
drier air at 850 mb moving into E ND to help break up the clouds
with sunshine increasing midday and aftn. Though clouds may hold
well into the afternoon in parts of NW MN and far NE ND. There
is an upper level wave with a few storms in SE Montana into SW
North Dakota and this wave will move east into south central ND
today with a few storms anticipated in south central ND and more
so southward thru western or central SD this aftn. With enough
sfc heating into the 80s in this area MUCAPES reach 2000 j/kg
DIK/BIS area southward. Does look like this chance holds just
west of our cwa. But something to monitor as a low pop may be
needed in Valley City-Lisbon area this aftn.

Mainly clear tonight, and with that and light winds there is a
signal for patchy fog Mon overnight.

Tuesday into Wednesday will see 500 mb heights build and warmer
air moving north with hottest temps in eastern Montana with near
100F possible there. Farther east into our area mid 80s to near
90F (warmest west) Wednesday. Expect mostly sunny conditions
both days. Wed afternoon and night will see some storms likely
north of the border and northwest ND as next surface front moves
eastward.

Much cooler this weekend. Highs 60s in most areas and lows in
the 40s.

...Strong Storm Potential Thursday...

Similar to the many upper air patterns we have seen this
summer....500 mb upper low and trough in northeast Alberta into
northern Saskatchewan Wed night-Thursday and southeast of that
is a 500 mb short wave moving along the border with associated
cold front into north central ND by 18z Thu and into NW MN 00z
Fri. Preference is for the solution given by 00z European based
on its forecast 500 mb forecast and its similarity to past
systems. MUCAPES 2500 to 3000 j/kg potential into E ND, RRV
Thursday aftn. 0-6 km bulk shear locally 40+ kts along with 40
kt 500 mb jet over E ND/RRV Thursday aftn. So ingredients
present for strong/severe storms. Machine learning tools
indicate similar with a chance in E ND Thursday.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1223 PM CDT Mon Aug 18 2025

LIFR/IFR stratus in BJI and DVL will lift (faster in DVL) by 00z
with fog expected to form overnight between 06 and 12z lasting
through ~15z for most. Cigs to MVFR and maybe IFR for BJI but
westward cloud coverage is uncertain with ceiling possibly
remaining sct but still around the 500 to 1500ft mark through
the night for any clouds that do form. Overall another night of
low clouds and potential fog for most.

&&

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

&&

$$

UPDATE...TT
DISCUSSION...Riddle
AVIATION...TT