Tornado Watch 408

Issued

Jul 11, 2017, 4:48 PM CDT (21:48 UTC)

Expired

Jul 11, 2017, 11:00 PM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

The Fargo/Grand Forks radar (KMVX), 36 km from the middle of the area, began a volume at 21:52 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Two or more tornadoes

40%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

10%

Ten or more severe hail reports

60%

One or more hailstones of 2 inches or more

50%

Six or more combined severe hail and wind reports

90%

• Mesoscale Discussion 1287Jul 11, 3:48 PM CDT
• Mesoscale Discussion 1289Jul 11, 7:09 PM CDT

834 
WWUS20 KWNS 112140
SEL8  
SPC WW 112140
MNZ000-NDZ000-120400-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 408
NWS Storm Prediction Center Norman OK
440 PM CDT Tue Jul 11 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northwestern Minnesota
  Eastern North Dakota

* Effective this Tuesday afternoon and evening from 440 PM until
  1100 PM CDT.

* Primary threats include...
  A couple tornadoes possible
  Scattered large hail likely with isolated very large hail events
    to 2.5 inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Thunderstorm development is expected from 5-7 pm CDT
across eastern North Dakota, and storms will subsequently spread to
the east-southeast into Minnesota.  Initial supercells will be
capable of producing a couple of tornadoes and isolated very large
hail, while storms could grow upscale into a small cluster or two
late this evening with an increase in the damaging wind threat.

The tornado watch area is approximately along and 65 statute miles
east and west of a line from 20 miles northwest of Hallock MN to 50
miles south southwest of Detroit Lakes MN. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 29025.

...Thompson

Tornado Watches in Minnesota, 2017Tornado Watches in North Dakota, 2017Every tornado watch in 2017

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.