Alert archive / North Dakota / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 239
The Storm Prediction Center issued this severe thunderstorm watch at Jun 6, 2021, 1:39 AM CDT for 6 counties in Minnesota; 12 counties in North Dakota. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 6, 2021, 1:39 AM CDT (06:39 UTC)
- Expired
- Jun 6, 2021, 4:37 AM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 65 kt
Counties Kittson County, MN, Marshall County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Roseau County, MN, Benson County, ND, Cavalier County, ND, Eddy County, ND, Grand Forks County, ND, Griggs County, ND, Nelson County, ND, Pembina County, ND, Ramsey County, ND, Steele County, ND, Towner County, ND, Traill County, ND, Walsh County, ND
The radar
The Fargo/Grand Forks radar (KMVX), 91 km from the middle of the area, began a volume at 06:38 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 5%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 6, 1:55 AM CDT | Severe Thunderstorm Warning | FGF | Benson, Cavalier, Eddy, Ramsey, Towner | 65 min |
| Jun 6, 2:17 AM CDT | Severe Thunderstorm Warning | FGF | Cavalier, Towner | 43 min |
| Jun 6, 2:39 AM CDT | Severe Thunderstorm Warning | FGF | Benson, Cavalier, Eddy, Grand Forks, Griggs, Nelson and 4 more | 51 min |
| Jun 6, 3:24 AM CDT | Severe Thunderstorm Warning | FGF | Kittson, Marshall | 66 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
International Fa, MN (KINL), launched 00:00Z, 6.7 hours before the alert went out and 281 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 383 J/kg
- Mixed-layer CIN
- -63 J/kg
- Mixed-layer LCL
- 2694 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 164 m²/s²
- 0-3 km storm-relative helicity
- 334 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.2
The text
As transmitted.
187
WWUS20 KWNS 060631
SEL9
SPC WW 060631
MNZ000-NDZ000-061200-
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 239
NWS Storm Prediction Center Norman OK
135 AM CDT Sun Jun 6 2021
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northwestern Minnesota
Northeastern North Dakota
* Effective this Sunday morning from 135 AM until 700 AM CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph possible
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...A loosely organized, yet still severe complex of
thunderstorms -- with several measured-severe gusts along and behind
the leading gust front over the past few hours -- will move across
the watch area mainly before dawn. A continued threat exists for
damaging wind, and isolated hail also is possible from trailing,
elevated convection atop the cold pool.
The severe thunderstorm watch area is approximately along and 45
statute miles either side of a line from Roseau MN to 25 miles
southwest of Devils Lake ND. For a complete depiction of the watch
see the associated watch outline update (WOUS64 KWNS WOU9).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for 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. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 238...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
24045.
...EdwardsSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 6, 5:57 PM CDT | Mesoscale Discussion | SPC | Aitkin, Benton, Carlton, Chippewa, Crow Wing, Itasca and 18 more | 93 min |
| Jun 5, 9:15 PM CDT | Mesoscale Discussion | SPC | Adams, Benson, Billings, Bowman, Burleigh, Dunn and 16 more | 2 hr |
| Jun 5, 10:21 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Billings, Bowman, Burleigh, Dunn, Foster and 16 more | 5 hr |
| Jun 5, 11:47 PM CDT | Mesoscale Discussion | SPC | Adams, Bowman, Dunn, Grant, Hettinger, McHenry and 8 more | 88 min |
| Jun 6, 1:22 AM CDT | Mesoscale Discussion | SPC | Benson, Burleigh, Cavalier, Eddy, Emmons, Foster and 14 more | 113 min |
| Jun 6, 2:52 AM CDT | Mesoscale Discussion | SPC | McLean, Oliver, Sheridan, Wells | 53 min |
Nearby
Severe Thunderstorm Watches in North Dakota, 2021Severe Thunderstorm Watches in Minnesota, 2021Every severe thunderstorm watch in 2021
Sources
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.