115
FXUS63 KFGF 240243
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
943 PM CDT Thu Jul 23 2026

.KEY MESSAGES...

- There is a level 2 out of 5 risk for severe weather Friday
  afternoon and evening, with golf ball sized hail and 70 mph
  wind gusts the primary threats. Isolated tornadoes are
  possible.

- Increasing temperatures this weekend with potential for heat
  impacts, especially on Sunday.

&&

.DISCUSSION...
Issued at 234 PM CDT Thu Jul 23 2026

...Synopsis...

Northwesterly flow aloft continues through the end of the work
week, with a fairly vigorous shortwave moving over the top of
the ridge from Manitoba tonight to Ontario and northern MN
tomorrow. While the main upper forcing looks like it will remain
northwest, it will help push a frontal boundary down into
the Red River Valley tomorrow afternoon. Not much cooling behind
the front as ridging quickly builds back over the Plains this
weekend. The ridge will not move too much during the next few
days, remaining over the Rockies and western Plains. Our
forecast area could see a few weak shortwaves move through
Sunday and into next week on the front side of the upper ridge,
but no outstanding wet signal from the ensembles, only heat.

...Slight risk of severe tomorrow afternoon and evening...

The surface trough axis/frontal boundary will begin to push into
our northwestern counties by mid-day tomorrow, slowing to near
the Devils Lake Basin and Red River Valley by afternoon. Many of
the models have very unstable air pooling right ahead of the
front with over 3000 J/kg possible, and 45 to 50 kts of deep
layer shear. Machine learning is quite bullish on severe chances
tomorrow afternoon, with a few showing above 30 percent
probability of severe impacts across our north and central
counties. On the other hand, many model soundings show a fairly
stout cap that could inhibit convection. There is also a thick
layer of elevated smoke that could prevent temperatures rising a
few more degrees and getting convection going. If any convection
does develop, it will be severe, but the main question is if the
cap can be broken. HREF has a 30 percent chance for strong
updraft helicity values, and with the surface boundary nearby
can`t rule out any isolated tornadoes if we can get some surface
based convection going. Main threat though looks to be golf ball
hail and winds to 70 mph, so will continue messaging along those
lines. The front should push southeastward later in the
evening, moving south and east of our counties shortly after
sunset.

...Heat this weekend...

Ridging and ensembles all point to a return to heat impacts
Saturday and especially Sunday. Dew points will be in the 60s,
bringing heat index values into the 90s for Saturday and above
100 for Sunday. While heat index values will be meeting criteria
for advisory mainly Sunday, there are other indicators of high
heat impacts. Wet bulb globe temperatures on Saturday will be
well into the 80s, and mid 80s by Sunday. Heat risk should be
well into the major category over the weekend, and there is a 30
to 50 percent probability of extreme heat risk for the southern
Red River Valley on Sunday. Not quite ready for headlines, but
will have to watch this weekend closely.

&&

.AVIATION /03Z TAFS THROUGH 06Z SATURDAY/...
Issued at 943 PM CDT Thu Jul 23 2026

VFR throughout the TAF period. A few questions however do exist.
The first is if surface level smoke will impact visibilities.
There will be upper level smoke, but if it reaches the surface
is highly uncertain. Most model guidance keeps smoke aloft,
therefore I did not reduce surface visibilities. Second is
thunderstorm potential Friday evening. Right now, there is a
wide range of potential scenarios in how thunderstorms (if any)
evolve. Of the TAF sites, KTVF has a somewhat higher chance of
being impacted by a thunderstorm, but even here probabilities
are too low to add any mention into the TAF.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...Rafferty