965
FXUS63 KFGF 090430
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1130 PM CDT Tue Jul 8 2025

.KEY MESSAGES...

- Severe storms are possible, risk level 1 out of 5, late
  Wednesday evening.

- Severe storms risk level 2 out of 5 will develop Thursday
  afternoon and night.

- Heat risk rises to the moderate category Thursday afternoon,
  but at this point it looks like heat index values will stay
  below 100 degrees.

&&

.UPDATE...
Issued at 1000 PM CDT Tue Jul 8 2025

There are a few locations reporting surface smoke in northeast
ND (4-6sm) otherwise smoke is mainly aloft and not in high
enough concentrations/causing low enough visibility reductions
for addition to weather grids at this time. Near term
adjustments were made, otherwise forecast is on track with a
weak/spotty radiational fog signal in the southern and northern
RRV.

UPDATE
Issued at 646 PM CDT Tue Jul 8 2025

CU is beginning to clear with low levels decoupling while high
live smoke is still lingering over parts of the region. As winds
go calm and cloud cover remains clear radiational conditions may
once again support fog development during the period of peak
radiational cooling Wednesday morning. The signal in guidance is
very spotty, and mainly confined to areas in the far north and
south. I added patchy fog mention for those areas during the
09-14Z period, but confidence in higher impacts/higher coverage
is low.

&&

.DISCUSSION...
Issued at 322 PM CDT Tue Jul 8 2025

...Synopsis...

Fairly quiet tonight as northwesterly flow gives way to very
weak ridging. A very weak shortwave riding over the top of the
ridge tomorrow night will bring a marginal threat for severe
weather Wednesday night. Stronger shortwave and a surface trough
axis arriving Thursday will bring another marginal chance for
severe impacts during the afternoon and evening hours. A trough
will be digging into the Dakotas for Friday and off into the
Great Lakes on Saturday, fairly open and fast moving although
exact impacts will depend on the way previous day`s convection
plays out. Another weak shortwave coming through Manitoba to the
Great Lakes on Sunday will help push a surface trough into the
region. West to southwest flow for the start of the work week
will bring more active pattern, but details unknown at this
time.

...Marginal severe risk Wednesday night...

A shortwave coming over the top of some weak ridging could be
the focus of some isolated severe impacts on Wednesday night.
Instability will be strong in central ND, as a narrow band of
moisture moving back up into the Dakotas. Shear in the central
Dakotas is decent, around 30 kts, but weaker further east in our
CWA. Forcing is pretty weak during that time period, but looks
like there will be some storms developing in central ND and then
moving east during the late evening and overnight Wednesday.

...Slight risk Thursday afternoon...

Thursday afternoon will see the upper ridge moving east and then
flow becoming southwesterly with a surface trough pushing into
the region. Shear is still not too impressive, but very strong
instability will be out ahead of the surface trough. CAPE is 70
to 90 percentiles higher than climatology for Thursday, and with
the stronger forcing there could be enough effective shear for
severe Thursday afternoon. Scattered large hail and damaging
winds will be possible with some of the stronger cells that
develop.

...Heat Thursday...

The instability on Thursday will be powered by very warm
temperatures ahead of the surface trough. EFI is not as high as
temperatures as it is for CAPE, but still a good signal for
heat. At this point heat index looks like it will stay below
advisory criteria and remain under 100 degrees, but heat risk is
up in the moderate category. Will have to monitor to see if
trends go higher in the upcoming shifts.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1130 PM CDT Tue Jul 8 2025

VFR conditions should prevail across eastern ND and northwest
MN through the TAF period for most locations, with a low chance
for radiational fog development 09-14Z Wednesday morning where
IFR (or less) visibility may occur. There has been a bit more
consistency on potential fog development over southeast ND to
the west and south of KFAR, but even then the guidance has
tended to be spotty in impacts. There are also still areas high
level smoke aloft over parts of the region. Winds increase
after sunrise Wednesday with southerly winds gusting 20kt+
mainly in eastern ND during the afternoon. CU should begin to
increase (6000-10000 ft agl) in coverage towards the end of the
TAF period with increasing chances (20-30%) for thunderstorms
Wednesday evening mainly in ND. Coverage/probability for
thunderstorms are too low at this range for TAF inclusion
Wednesday evening.

&&

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

&&

$$

UPDATE...DJR
DISCUSSION...JR
AVIATION...DJR