918
FXUS63 KFGF 200432
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1132 PM CDT Tue Aug 19 2025

.KEY MESSAGES...

- There is a 1 of 5 risk for severe thunderstorms Thursday
  across much of eastern North Dakota, northwest Minnesota, and
  west central Minnesota. Hazards could include golf ball sized
  hail and damaging wind gusts to 70 mph.

&&

.UPDATE...
Issued at 1001 PM CDT Tue Aug 19 2025

There are still a few lingering pockets of low clouds in our
east towards north central MN, with clear skies elsewhere.
Light fog has been reported at Gwinner with low Td depressions
and this aligns with areas where easterly BL flow is in place
along/west of the RRV escarpment. I added patchy fog mention to
those areas and adjusted sky cover. Otherwise, forecast is on
track.

UPDATE
Issued at 630 PM CDT Tue Aug 19 2025

Besides lingering low clouds in northwest MN which should clear
over the next few hours, forecast is on track for light winds
and clear skies overnight. Due to shallow moisture and northerly
BL flow confidence is lower in coverage of any
radiational/ground fog tonight. There is a signal for fog
development in central MN and there is a chance for patchy dense
fog in our far eastern CWA during peak pooling period around
sunrise Wednesday.

&&

.DISCUSSION...
Issued at 359 PM CDT Tue Aug 19 2025

...Synopsis...

Mid level ridging prevails today over the Four Corners Region, with
the H5 axis extending into eastern Montana and western North Dakota.
Heights increase heading into Wednesday as the ridge builds
eastward, allowing low level moisture return into the Northern
Plains and Upper Midwest. Scattered showers and thunderstorms enter
the forecast late Wednesday afternoon as an H5 upper low, and the
resultant trough, approaches the area. Chances increase further on
Thursday in response to the trough passage, with ridging retreating
southward. Strong to severe thunderstorms are possible Thursday
afternoon and evening. Much cooler temps follow heading into Friday
and the weekend, with highs on friday in the 70s and cooler highs in
the 60s both Saturday and Sunday.

...Severe Thunderstorms Thursday Afternoon and Evening...

Mid level ridging retreats south on Thursday, with a strong trough
and cold front passage expected during the late evening. Ahead of
the front, a relatively strong theta-e gradient boundary sets up as
moisture pools ahead of the cold front. Model soundings show the
potential for 3000 to 4000 J/Kg of MLCAPE Thursday afternoon, along
with 0-6 Km shear upwards of 45 knots. Low level flow looks somewhat
weak at the surface; however, the 0-3 Km shear remains supportive of
all modes of development, as well as upscale support heading into
Thursday evening. Good moisture loading, high instability, and
strong lapse rates all support the mention of 70 mph wind gusts, as
well as hail up to the size of golf balls. If supercells are able to
develop during the early to mid afternoon, a tornado cannot be ruled
out.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1132 PM CDT Tue Aug 19 2025

Radiational fog can`t be ruled out again tonight, however drier
BL conditions due to northerly flow does decrease the potential
at many location in eastern ND. The best chance is over
northwest and north central MN, with a period of IFR at KBJI
during the 10-14Z period Wednesday morning. Increasing
southerly gradient results in increasing south-soutehast winds
Wednesday. Strongest winds (gusts to 25kt) would be expected in
northeast ND in the afternoon period.

&&

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

&&

$$

UPDATE...DJR
DISCUSSION...Lynch
AVIATION...DJR