069
FXUS63 KFGF 281145
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
645 AM CDT Sun Jun 28 2026

.KEY MESSAGES...

- Risk for multiple rounds of severe storms starting late
  Saturday through at least Monday. All hazards are possible.

- Potential for heat impacts next week, including the Fourth of
  July weekend.

&&

.UPDATE...
Issued at 645 AM CDT Sun Jun 28 2026

The line of showers and isolated thunderstorms continues to move
eastward this morning. Wind gusts ranging from 30-40 mph have
been seen through much of the night, but have slowly trended
downward over the past several hours. This activity will
continue moving out of the area this morning, with a break in
activity expected through late this morning. At that time,
thunderstorm chances will begin to increase heading into the
afternoon, which will continue into the evening. Recent guidance
is showing less coverage this afternoon, but it is worth noting
that run to run inconsistencies are still very large.

UPDATE
Issued at 1148 PM CDT Sat Jun 27 2026

Line of thunderstorms currently moving through central ND will
enter far western portions of the Devils Lake Basin in the next
hour or two. CAMs do show a slight weakening trend as the
complex enters our western counties, and DCAPE goes down except
in portions of southeastern ND. On the other hand, there is a
850mb jet of 40 kts to feed the storms. There should at least be
a decent chance for some continued severe potential as the line
enters the Devils Lake Basin, but think there should be
weakening as it moves into the Red River Valley around 3 to 5
am.

UPDATE
Issued at 655 PM CDT Sat Jun 27 2026

Warm air advection along with a weak shortwave embedded in the
southwesterly flow continues to bring showers and some
thunderstorms to the region. Instability is limited over our
area, and the strongest convection remains out close to the MT
border. However, with instability expected to increase over our
western counties and the storms moving in later tonight, there
remains some risk for damaging winds, mostly in the midnight and
after period. There is some question on how widespread winds
will be as the thunderstorm complex moves east, but risk for
isolated thunderstorms remains tonight.

&&

.DISCUSSION...
Issued at 229 PM CDT Sat Jun 27 2026

...Synopsis...

Troughing over the western CONUS with ridging downstream has lead to
southwest flow developing over much of the High and Northern Plains.
Located in the 500 mb jets left exit region, surface low pressure
is developing near Carter County, MT. While many miles away,
this region will be the seed for widespread thunderstorm
development on the High Plains of Eastern Montana and the
western Dakotas. Overnight, this activity will spread eastward
across North Dakota, bringing impacts to our FA tonight. Being
a linear complex, damaging winds will be the main threat.

Western troughing remains in place through the start of the work
week. As such, additional severe thunderstorm risks are in the
forecast for both Sunday and Monday. How thunderstorms evolve (or
just as importantly how they dont evolve) will determine the
coverage, magnitude and hazard type of severe weather each
subsequent day. Outside of thunderstorms, southerly flow will bring
a stretch of warm to hot weather across the FA. Monday in particular
looks warm, before a brief cool down on Tuesday, and then a building
ridge to our east allows for heat to build in slowly everyday
thereafter through the end of the work week.

...Severe Thunderstorms Today through Monday ...

Ample lift is present this afternoon over the High Plains as the
left exit region of the 500 mb jet overspreads the region. This area
will be where storms develop this afternoon, congeal into a linear
segment, then track eastward across North Dakota this evening. There
is generally good agreement between CAMs in an arrival time
after 11PM CDT in the Devils Lake Basin. By this point, the
environment will be characterized by 1,000 to 1,500 J/Kg of
MUCAPE, and effective shear around or just over 30 knots. Low
level flow also looks decent, with 0-3 km shear values of 25 to
30 knots. Combined, the linear complex that develops to our west
will hold together into this environment. The big question is
what its severity will be. DCAPE is not as impressive (due to a
saturated profile), on the order of 700 to 1000 J/Kg. Add in
the overnight inversion, it is hard to say how widespread severe
wind gusts will be, and their eastward extent. Right now, the
favored area for severe wind gusts with this activity is in
northeastern ND, especially in the Devils Lake Basin.

In addition, a nocturnal LLJ may kick off more widespread convection
ahead of the line. This activity may produce small hail, but with
effective shear approaching 35 knots at times, severe hail cannot
completely be ruled out if any thunderstorms are able to form in
this environment. The most likely area for this to occur is in
southeastern ND into west central MN.

Sunday brings another potential round of severe weather. Saturdays
convection will play a major role in how Sundays threat evolves.
Right now, model guidance depicts left over convection ongoing
Sunday morning, clearing midday or so. A stripe of higher
instabilty will set up somewhere over the eastern half of ND,
with ample shear as 500 mb winds increase overhead. However,
there remains uncertainty in if storms will be able to form
during the afternoon due to weaker forcing, and capping in
place. A potential scenario is that we see no severe weather at
all until after dark when the warm front surges north with
another LLJ. In this case, hail would be the primary hazard.
Plenty of uncertainty remains.

Finally, Monday. A fairly potent surface low looks to track
northward through eastern ND. Again, leftover convection Monday
morning will determine how well the atmosphere recovers by
afternoon. Based on shear profiles, all hazards are possible if
we can get storms to utilize this environment. This will be a
day to monitor closely, but at this range, with even some
synoptic details still uncertain, it is too early to try to pin
down any more details.

...Heat this Week...

In addition to thunderstorms, heat will be a concern heading into
the upcoming week. Monday will likely bring the highest heat
indicies as dew points in the 70s are advected into much of the FA.
We cool down a bit on Tuesday, but persistent southerly flow will
keep temperatures and dew points elevated all week, slowly rising
each day from Wednesday through Saturday. at this time, ares in
southeastern ND and west central MN have the highest chance of
seeing heat advisory level impacts (heat indicies of 100 degrees or
higher). It should be noted that even if afternoon temperatures
barely reach criteria, overnight lows in the upper 60s to low 70s
will likely provide very little relief from the heat.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 645 AM CDT Sun Jun 28 2026

VFR to MVFR conditions prevail this morning at all TAF sites
outside of shower activity. During periods of rain and
thunderstorms, brief IFR conditions have been reported,
primarily due to low visibility during heavy rain. This morning,
KBJI and KTVF still have showers in the vicinity, with perhaps
an isolated thunderstorm. There will be a break in activity late
this morning, with additional showers and thunderstorms possible
this afternoon and evening. The chance for severe thunderstorms
remains in the forecast from early afternoon through late this
evening. Winds remain out of the south to southeast at 15-20
knots, with gusts upwards of 30 knots through late this evening,
when gusts taper off and winds diminish slowly.

&&

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

&&

$$

UPDATE...Lynch
DISCUSSION...Rafferty
AVIATION...Lynch