Severe Thunderstorm Warning 100, NWS Grand Forks, ND

Area Forecast Discussion
National Weather Service Grand Forks ND
635 PM CDT Mon Jul 7 2025

.KEY MESSAGES...

- Severe risk, level 2 out of 5 continues into this evening.
Damaging wing gusts, hail to golf ball size and an isolated
tornado are the main severe threats...

- A severe risk, level 1 out of 5 is possible Wednesday
  afternoon into Wednesday night...

- There is an 80 percent chance for thunderstorms across the
  area Thursday into Thursday night. Storms may be strong to
  severe...

&&

.UPDATE...
Issued at 635 PM CDT Mon Jul 7 2025

We continue to have strong to severe thunderstorms impacting
portions of eastern North Dakota and northwestern Minnesota this
evening. Some of these have been supercellular producing large
hail. Latest report was from the Severe Thunderstorm over
northeastern Grand Forks county moving into northwestern Polk
county of quarter size hail in the city of Manvel. Overall the
environment still remains conducive for strong to severe
thunderstorms through this evening, but we are starting to see a
downward trend in intensity of the current storms. Low and Mid
level lapse rates are slowly diminishing and CAPE is trending
downward in parts of the area. Ramsey, Cavalier, and Towner
counties have been removed from the Severe Thunderstorm Watch
and the rest of the counties in the watch remain through 10pm.

&&

.DISCUSSION...
Issued at 433 PM CDT Mon Jul 7 2025

...Synopsis...

Storms developing along and ahead of a frontal boundary moving
through the area this afternoon and evening with severe activity
already occuring and expected through the evening hours. Frontal
boundary moves east into Tuesday with high pressure building
into the region. Another weak shortwave will move through the
area mid-week bringing another round of storm chances and
potential isolated severe storms before a larger storm system
impacts the area Thursday into Friday. This system will bring
more widespread chances for storms and severe weather.

...Severe risk, level 2 out of 5 continues into this evening.
Damaging wing gusts, hail to golf ball size and an isolated
tornado are the main severe threats...

Storms continue to form along and ahead of the cold front
stretching from north to south across northeast ND. Instability
is decent, with deep layer shear in the 35-45kt range. Initially
have the chance for an isolated tornado near the boundary and
closer to the low across the northern forecast area where low
level shear is stronger and greater low level
instability/stretching, etc. A transition to more hail/wind is
expected through the evening and as the front pushes east.

Previous Discussion...
...Wednesday Severe Risk...

Wednesday late aftn/eve will see a short wave move ESE across
the area. The airmass advecting north into the area, esp central
ND, is more unstable with MUCAPES over 3500 j/kg and high temps
in central ND fcst to be low 90s. 0-6 km shear is 30kts or less
though. SPC did insert a marginal risk for eastern and central
ND due to instability being quite high and weak wave moving ESE
thru the area.

...Thursday into Thursday night....

Thursday afternoon and night has for the last several days been
highlighted as the most unstable day in the 7 days. MUCAPE
values from ensembles (EC/GEM,GFS) from 00z runs all over 3500
j/kg with likely over 4000 j/kg. But issue is placement of 500
mb system with this and placement of 500 mb jet. Model
continuity has been poor. Thus question is with all the
instability will there be enough forcing and shear aloft to
generate a higher end severe threat. That remains to be seen.
Given the conditions fcst all hazards would be possible, though
wind/hail favored vs tornado as unsure of any surface boundary
location. We also have some sfc CIN to overcome. But highs are
forecast to be low 90s and dew pts low 70s. If either one can
over achieve that will add to instability.

For Friday and Saturday forecast hangs on development of 500 mb
low and placement and track. GFS been all over the place in the
last 24 hours with ECMWF the most consistent in having upper low
in the area Saturday with persistent area of showers and
t-storms near and just east of the wave over much of the area
Friday. Slower ECMWF would keep rain chance longer into Saturday
vs NBM.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 635 PM CDT Mon Jul 7 2025

Thunderstorms continue to move toward GFK this evening, with
lightning and erratic winds possible through 2z. DVL, TVF, FAR,
and BJI will be an isolated chance for thunderstorms through
the 4z timeframe as our environment slowly improves. Around 6z
conditions clear out, with winds shifting toward the north and
SCT clouds remain. There is a potential for overnight fog, but
chances remain low at this time. VFR conditions post 6z for all
TAF locations. Skies clear out around 18z through the end of the
TAF period.

&&

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

&&

UPDATE...Spender
DISCUSSION...MJB
AVIATION...Spender

Hazardous Weather Outlook
National Weather Service Grand Forks ND
434 AM CDT Mon Jul 7 2025

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-080945-
West Polk-Norman-Clay-Kittson-Roseau-Lake Of The Woods-
West Marshall-East Marshall-North Beltrami-Pennington-Red Lake-
East Polk-North Clearwater-South Beltrami-Mahnomen-
South Clearwater-Hubbard-West Becker-East Becker-Wilkin-
West Otter Tail-East Otter Tail-Wadena-Grant-Towner-Cavalier-
Pembina-Benson-Ramsey-Eastern Walsh-Eddy-Nelson-Grand Forks-
Griggs-Steele-Traill-Barnes-Cass-Ransom-Sargent-Richland-
Western Walsh-
434 AM CDT Mon Jul 7 2025

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

.DAY ONE...Today and Tonight

There is a level 2 out of 5 risk for severe thunderstorms this
afternoon and early evening for eastern North Dakota and northwest
and west central Minnesota. The main hazards will be hail to 1.50
inch, wind gust 60 mph and frequent lightning.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

There is a level 1 out of 5 risk for severe thunderstorms
Wednesday afternoon and evening, but this is conditional risk as
storms may not form. If they do then large hail and damaging wind
risk.

Thursday afternoon and evening will see a potentially higher risk
of severe storms.  All hazards are possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be required today.

Preliminary Local Storm Report
National Weather Service Grand Forks ND
649 PM CDT Mon Jul 7 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0514 PM     Tstm Wnd Dmg     2 ENE Grand Forks       47.93N 97.03W
07/07/2025                   Grand Forks        ND   Public

            pictures of multiple 1-3 inch tree limbs,
            and one 4-5 inch limb down near Greenway
            portal.

0351 PM     Tornado          1 SSW Calio             48.61N 98.95W
07/07/2025                   Cavalier           ND   Public

            Corrects previous tornado report from 1 SW
            Calio. Report relayed via media.

0636 PM     Hail             6 N East Grand Forks    48.02N 97.02W
07/07/2025  M0.75 Inch       Polk               MN   Public

&&

Preliminary Local Storm Report
National Weather Service Grand Forks ND
650 PM CDT Mon Jul 7 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0353 PM     Tornado          1 SSW Calio             48.61N 98.95W
07/07/2025                   Cavalier           ND   Public

            Corrects previous tornado report from 1 SW
            Calio. Report relayed via media.

&&

TT

Special Weather Statement
National Weather Service Grand Forks ND
713 PM CDT Mon Jul 7 2025

MNZ014-015-080045-
Red Lake MN-East Polk MN-
713 PM CDT Mon Jul 7 2025

...A STRONG THUNDERSTORM WILL IMPACT SOUTH CENTRAL RED LAKE AND
SOUTHEASTERN POLK COUNTIES THROUGH 745 PM CDT...

At 712 PM CDT, trained weather spotters reported a strong
thunderstorm over Marcoux, or 25 miles south of Thief River Falls,
moving southeast at 15 mph.

HAZARD...Wind gusts up to 40 mph and nickel size hail.

SOURCE...Trained weather spotters.

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

Locations impacted include...
Erskine, Mentor, Dugdale, and Marcoux.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
northwestern Minnesota.

&&

LAT...LON 4771 9632 4782 9624 4779 9588 4758 9607
TIME...MOT...LOC 0012Z 300DEG 12KT 4775 9624

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

Thomas

Special Weather Statement
National Weather Service Grand Forks ND
715 PM CDT Mon Jul 7 2025

MNZ001-080045-
West Polk MN-
715 PM CDT Mon Jul 7 2025

...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL POLK COUNTY THROUGH
745 PM CDT...

At 715 PM CDT, Doppler radar was tracking a strong thunderstorm over
Key West, or 13 miles east of Grand Forks, moving southeast at 20
mph.

HAZARD...Wind gusts up to 40 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...
Crookston, Euclid, and Key West.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
northwestern Minnesota.

&&

LAT...LON 4796 9648 4792 9648 4778 9660 4791 9686
      4801 9678
TIME...MOT...LOC 0015Z 301DEG 16KT 4792 9676

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

Thomas

Preliminary Local Storm Report
National Weather Service Grand Forks ND
717 PM CDT Mon Jul 7 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0710 PM     Hail             5 NW Mentor             47.75N 96.22W
07/07/2025  M0.88 Inch       Polk               MN   Trained Spotter

&&

Special Weather Statement
National Weather Service Grand Forks ND
733 PM CDT Mon Jul 7 2025

MNZ001-NDZ027-030-080100-
West Polk MN-Traill ND-Grand Forks ND-
733 PM CDT Mon Jul 7 2025

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN POLK...SOUTHEASTERN
GRAND FORKS AND NORTHEASTERN TRAILL COUNTIES THROUGH 800 PM CDT...

At 733 PM CDT, Doppler radar was tracking a strong thunderstorm over
Thompson, or 7 miles south of Grand Forks, moving southeast at 35
mph.

HAZARD...Wind gusts up to 50 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...
Thompson, Climax, Merrifield, Eldred, and Bygland.

This includes Interstate 29 between mile markers 123 and 136.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
northwestern Minnesota...and southeastern and northeastern North
Dakota.

&&

LAT...LON 4778 9725 4787 9714 4776 9666 4752 9686
TIME...MOT...LOC 0033Z 301DEG 31KT 4780 9707

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Thomas