353
FXUS63 KFGF 180915
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
412 AM CDT Mon Aug 18 2025

.KEY MESSAGES...

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


&&

.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 /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1012 PM CDT Sun Aug 17 2025

MVFR to IFR ceilings will expand across the region overnight
tonight and linger through the morning tomorrow. Fog may develop
in some spots as well but confidence is too low to add to any
TAF at this time. Winds will shift from easterly/southeasterly
to northwesterly from west to east over the course of the
morning hours with ceilings slowly rising. While this occurs,
sky cover will also lower from west to east with it, so expect
VFR conditions to start from west to east as well. By 00z,
expect most TAF sites to be mostly clear with the exception of
BJI where MVFR ceilings may linger through the early evening
hours.

&&

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

&&

$$

DISCUSSION...Riddle
AVIATION...Perroux