Severe Thunderstorm Warning 142, NWS Grand Forks, ND

Area Forecast Discussion
National Weather Service Grand Forks ND
1250 AM CDT Fri Aug 8 2025

.KEY MESSAGES...

- Significant severe weather overnight, with high winds being
  the primary threat, especially in eastern North Dakota into
  the Red River Valley.

- With already primed soils in some areas of southeastern ND
  and west central MN, localized flooding may occur tonight due
  to additional rain from thunderstorms.

- Severe weather is again forecasted for Friday afternoon and
  evening, with all hazards of severe weather possible.

&&

.UPDATE...
Issued at 954 PM CDT Thu Aug 7 2025

Storms along the Canadian border have moved north and
dissipated, but another complex is already moving through north
central ND. Should be approaching the Devils Lake Basin around
midnight or so. Adjusted POPs a bit more for current radar
trends. Pretty high MU CAPE over 3000 J/kg and decent shear at
30 kts, so think storms will continue to hold together as they
move into our northwestern counties.

UPDATE
Issued at 642 PM CDT Thu Aug 7 2025

Supercell thunderstorms firing along the warm front near the
Canadian border have impacted our far northwest, and will
continue to monitor for any additional development or rotation
as we go through the next few hours. CAMs have that activity
lifting north into Canada by late evening, with our next round
coming out of eastern MT and not moving in until late
tonight/early Friday morning. Still quite a lot of uncertainty
with how storms evolve, so will keep a close eye as the night
goes on.

&&

.DISCUSSION...
Issued at 320 PM CDT Thu Aug 7 2025

...Synopsis...

Synoptically, a transient ridge is propagating across the Northern
Plains this afternoon, with troughing over the northern US Rockies.
To our west, the main 500 mb wave responsible for tonights severe
weather is still over MT, but a weaker one is near the
MT/ND/Canadian border. At the surface, southeast winds have
overspread the Northern Plains, with a warm front set up from
near Beach northeastwards towards Minot into Pembina, slowly
pushing northward. Recent mesoanalysis in the warm sector shows
dew points rising in to the mid 70s, with MLCAPE of 3000 - 4000
J/Kg, which showcases just how buoyant of an airmass is in
place this afternoon across much of ND.

...Severe Tonight...

The main area of initial storm initiation looks to be west of this
FA, closer to the surface low and warm front in western/central ND.
This would be somewhere near Williston to Minot and points to the
south. Even further west back into MT, more storms are expected to
develop on the high plains closer to the stronger 500 mb wave
upstream. These two areas of storm development will push east
through the evening. How this evolves is still uncertain. The initial
area of concern this evening in western/central ND would foster
supercell development. Could one of these hold together into
the Devils Lake Basin? Theoretically, but the chances of that
seem to be low. Of more interest is that as long as this initial
activity does not grow upscale, it will leave a fairly intact
environment for the approaching storms from MT. With a buoyant
airmass in place and strong shear, this would foster the
incoming convection from MT to propagate through ND in a linear
mode. Based on the environment of 4000 J/Kg of MUCAPE, along
with sufficient 0-3 Km shear of 30 knots and DCAPE of 1200 -
1400 J/Kg, this could be a potentially intense linear segment
when it arrives in this FA, with gusts to 80 mph on the table,
along with QLCS tornado potential along the leading edge of the
line.

One thing that should be reiterated is that there remains
significant uncertainty in how tonight plays out. However, if storms
are able to fully utilize the environmental ingredients that are in
place, especially on the North Dakota side of the FA, high end
severe weather could occur. Uncertainty revolves around two main
points. 1) How do storms ahead of the MCS, if any impact the
environment? This mornings guidance had storms in ND this afternoon
growing upscale and pushing east earlier, wiping out the
environment. Most guidance has backed off this idea, leaving a much
more favorable environment in place for the approaching MCS to
utilize. The degree of storm coverage ahead of the approaching MCS
will determine its severity. 2) While the MCS will be traversing
through a prime environment upstream, especially if only a few
supercells develop, the environment does become less favorable in
this FA, especially on the MN side of the river. In MN, 0-3 km shear
in particular drops down in the 20 knot range or even a little
lower. However, the degree of instability (still near 3000 J/Kg of
CAPE) along with the potential for a well established, mature MCS to
push into the region counter the thought that it will weaken
quickly. This means predictability is quite low with how far east
the severe threat holds together, or in the case of a high end
event, how far east significant severe wind gusts hold together.

...Flooding Potential Overnight...

Some areas of our FA have recently seen significant rainfall (2-5
inches), particularly in the southeastern portions of ND. While this
is a secondary threat to the anticipated severity of the linear
segment,it is worth a mention. Storm motions appear quick
enough to limit this threat, especially for rural areas. This is
something that will need to be monitored though, as area
webcams do show sitting water in ditches in spots, and recent
heavy rainfall has produced a flurry of flooding reports in
places such as Fargo and along I94 the past several days.

...Severe Friday...

Another round of severe weather is expected on Friday. How this
evolves is questionable, as what happens tonight will play a
major role in how things play out. Convective debris leftover in
the morning may limit destabilization, while at the same time
the front may push through quick enough keeping storms on the MN
side of the FA. Shear profiles still support an all hazards
day, but shear vectors would indicate a messier mode with time,
which should limit maximum hail sizes and the tornado threat. As
storms grow upscale, we could again see a wind threat develop
with 0-3 Km shear in excess of 30 knots and DCAPE near 1000
J/Kg. However, by the time this occurs this may be in our far
northeast, or entirely east of our FA, limiting potential
impacts from any higher end wind gusts. Much like today, many
questions surround tomorrows convective evolution. Once we see
what happens tonight, predictability for tomorrows severe threat
will increase substantially.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1248 AM CDT Fri Aug 8 2025

The mature MCS bearing west to east along/near the terminal
corridor is the aviation weather focus for the late night and
morning. The system brings brief IFR with strong to severe NW
wind gusts shifting back SE in the wake. Approximate timing gets
storms the the MN border around 08Z and east of BJI around 12Z.
Predictability is lower on storm clusters farther south and
west later in the morning.

MVFR stratus is set to fill in behind the storms and within the
front/inverted trough tied to low pressure moving south of the
region. Ceiling attempts to grind up into VFR during the afternoon
with some renewed shower activity possible. NW wind follows the low
pressure system Friday night.

&&

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

&&

UPDATE...JR
DISCUSSION...Rafferty
AVIATION...JR/BT

Hazardous Weather Outlook
National Weather Service Grand Forks ND
336 PM CDT Thu Aug 7 2025

MNZ001>005-007-008-013>016-022-023-027>031-040-NDZ006>008-014>016-
024-026>030-038-039-049-052>054-082045-
West Polk-Norman-Clay-Kittson-Roseau-West Marshall-East Marshall-
Pennington-Red Lake-East Polk-North Clearwater-Mahnomen-
South Clearwater-West Becker-East Becker-Wilkin-West Otter Tail-
East Otter Tail-Grant-Towner-Cavalier-Pembina-Benson-Ramsey-
Eastern Walsh-Eddy-Nelson-Grand Forks-Griggs-Steele-Traill-Barnes-
Cass-Ransom-Sargent-Richland-Western Walsh-
336 PM CDT Thu Aug 7 2025

This hazardous weather outlook is for portions of eastern North
Dakota, west central and northwest Minnesota.

.DAY ONE...This Afternoon and Tonight

The potential exists for significant severe weather overnight,
with high winds being the primary threat, especially in eastern
North Dakota into the Red River Valley.

With already primed soils in some areas of southeastern ND
and west central MN, localized flooding may occur tonight due
to additional rain from thunderstorms.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Severe weather is again forecasted for Friday afternoon and
evening, with all hazards of severe weather possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be required today.

MNZ006-009-017-024-032-082045-
Lake Of The Woods-North Beltrami-South Beltrami-Hubbard-Wadena-
336 PM CDT Thu Aug 7 2025

This hazardous weather outlook is for portions of west central
and northwest Minnesota.

.DAY ONE...This Afternoon and Tonight

The potential exists for severe weather overnight, with high
winds being the primary threat.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Severe weather is again forecasted for Friday afternoon and
evening, with all hazards of severe weather possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be required today.

Special Weather Statement
National Weather Service Grand Forks ND
140 AM CDT Fri Aug 8 2025

NDZ006-007-014-015-054-080745-
Benson ND-Towner ND-Western Walsh County ND-Ramsey ND-Cavalier ND-
140 AM CDT Fri Aug 8 2025

...STRONG THUNDERSTORMS WILL IMPACT SOUTHEASTERN BENSON...
SOUTHEASTERN TOWNER...WESTERN CAVALIER AND RAMSEY COUNTIES THROUGH
245 AM CDT...

At 140 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles southwest of Clyde to 6 miles northeast
of Penn to near Minnewaukan. Movement was east at 30 mph.

HAZARD...Wind gusts of 50 to 55 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Devils Lake, Langdon, Cando, Camp Grafton, Lakewood Park, Fort
Totten, and Minnewaukan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 300 AM CDT for
northeastern North Dakota. A Severe Thunderstorm Watch also remains
in effect until 700 AM CDT for northeastern North Dakota.

&&

LAT...LON 4824 9920 4873 9919 4895 9826 4839 9824
      4793 9865 4788 9956
TIME...MOT...LOC 0640Z 252DEG 26KT 4872 9901 4830 9902 4800 9932

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...55 MPH

Thomas