415
FXUS63 KFGF 100504
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1204 AM CDT Thu Jul 10 2025

.KEY MESSAGES...

- Severe storms are possible, risk level 1 out of 5, in eastern
  North Dakota tonight, with a small area of 2 out of 5 risk in
  the Sheyenne Basin.

- Severe storms risk level 1 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 948 PM CDT Wed Jul 9 2025

Severe weather has begun across the Devils Lake Basin. Shear is
weak, but instability continues to be impressive (about 5000
J/Kg), and DCAPE remains in excess of 1000 J/Kg. Therefore,
thinking brief supercellular characteristics that we have
witnessed so far could produce hail a little bigger then a
quarter, before the weaker shear causes storms to collapse with
more of a wind threat. This threat should continue for another
2 hours or so.

Further south, a line of storms is propagating in from Stutsman
county down to the SD state line. DCAPE is even higher here,
around 1500 J/Kg. 0-3 Km shear is not great, about 25 knots, but
sufficient for MCS maintenance as the line arrives in
southeastern ND. Wind gusts to 60 mph will be the main threat
with these storms. The line should continue to push east,
eventually shifting southeast with time following the
instability gradient.

UPDATE
Issued at 746 PM CDT Wed Jul 9 2025

Quick update here as severe thunderstorm watch 500 has been
issued from the Devils Lake Basin south to Sargent county.
Thinking of convective evolution remains similar to the
previous update. The only real change is that convective towers
west of the Devils Lake Basin and associated updrafts are
persisting, so some cluster of strong/severe storms should push
through the Devils Lake Basin over the next several hours.
Therefore, the watch encapsulates this area, along with the
region further south where the cluster of storms near Bismarck
should push into later this evening.

UPDATE
Issued at 705 PM CDT Wed Jul 9 2025

Thunderstorms have fired west of Bismarck along a dry line. A
warm front is situated approximately along our western FA
border with BIS. South of this warm front, dew points are in the
mid 70s, with an axis of MLCAPE of 4000 to 5000 J/Kg, with the
axis still residing to our west in central ND. A lack of forcing
and capping has kept things quiet in this FA for now. However,
as convection evolves further west, we will see how things hold
together as they push into Eastern ND. Shear, while currently 30
knots, will decrease with time as storms approach. In addition,
instability decreases as you approach the Red River Valley.

All told, while convection will hold together in some form into
eastern ND, severity of the storms remains more uncertain. The
greatest chance for severe weather seems to be in southeastern
ND, where at least marginal shear of 25 knots or so will
overlap with the best instability/CAPE along a gradient. As the
clusters/lines of storms approach from central ND, they will
likely ride this gradient, pushing south and east with time.
Another area to watch is between Minot and Devils Lake.
Orphaning anvils are evident on satellite. If more persistent
convective attempts can survive in this region, there is
plentiful instability with marginal shear, a cluster could hold
together into the Devils Lake Basin. Plenty to watch evolve over
the next several hours.

&&

.DISCUSSION...
Issued at 307 PM CDT Wed Jul 9 2025

...Synopsis...

Water vapor loop shows shortwave ridging over the Eastern Plains
with a few weak embedded vorts moving through. As expected, best
moisture and instability are just to our west so far, but no
convection so far except way south in western SD. A stronger
shortwave will be moving in for Thursday afternoon and evening
and pushing a cold front into the forecast area, but much will
depend on how tonight plays out. The cold front will push the
rest of the way through the forecast area on Friday as upper
troughing digs down into the Northern Plains. A bit of a break
with northwesterly flow on Saturday but then it switches back to
near zonal and then southwesterly late Sunday and into Monday.
Another quick moving trough through the Northern Plains on
Tuesday and moving east Wednesday with cooler temps and
additional thunderstorm chances.

...Severe chances tonight...

While plenty of instability available in central ND with temps
in the low 90s and dew points in the 70s, it has remained capped
so far. Several of the CAMs have the current convection in
western SD spreading northeastward into south central ND, which
fits current satellite and radar trends. Still not a lot of
upper support for development except some very weak vorts that
are moving through. However, instability is very strong at over
4000 J/kg and there is at least some deep layer bulk shear
around 30 kts in southeastern ND. Probabilities for strong
updraft helicities get above 50 percent in south central ND
later this evening, and are still around 30 to 40 percent as the
convection starts moving into our far southwestern counties.
Can`t rule out some isolated large hail and perhaps some
scattered damaging winds. Convection should linger after
midnight as the moisture plume moves east, but what little shear
there was goes downhill and probabilities of strong updraft
helicities drop to around 10 percent.

...Severe potential for Thursday...

Much will depend on how the convection tonight plays out and if
there are any MCVs or lingering outflow boundaries to help focus
redevelopment. There is more upper support with a surface
boundary moving through, however, much of the shear is behind
the cold front and not with the instability plume that will be
over the southern Red River Valley. SPC has lowered the risk
down to marginal due to the large uncertainty. Updraft helicity
probabilities are not very impressive, but some of the machine
learning are still highlighting our CWA for severe potential.

...Heat risk on Thursday...

The hot temperatures and moist dew points over central ND
currently are expected to shift east and be over our CWA
tomorrow. Wet bulb globe temps get into the low 80s, and heat
risk is up to moderate with a few spots of high. However, there
is still some question of if we will get to the heat index
values above 100, especially if there is lingering cloud cover
from morning convection. Will hold off on any heat headlines for
now, but continue to message hot and sticky conditions.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1204 AM CDT Thur Jul 10 2025

Forecast challenge in the short term is the timing and coverage
of thunderstorms. Overnight, thunderstorms will continue to push
to the east, impacting KTVF and KFAR. Storms may hold together
into KBJI, but there is uncertainty, therefore left any mention
out of the TAF. With recent moisture, patchy fog may be an issue
Thursday morning, but a lot of uncertainty in the coverage and
any impacts to visibility. Any fog would be favored at KGFK and
KTVF. The most favored period for fog has 6SM visibility
mentioned in the TAF. Finally, storms are possible again
Thursday afternoon, however there is a lot of uncertainty with
how they evolve. Made no mention of them in this set of TAFs,
hopefully the details will become more clear by the next set of
TAFs issuance.

&&

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

&&

$$

UPDATE...Rafferty
DISCUSSION...JR
AVIATION...Rafferty