Alert archive / Minnesota / Tornado Watches in 2018
Tornado Watch 271
The Storm Prediction Center issued this tornado watch at Jul 11, 2018, 6:42 PM CDT for 20 counties in Minnesota; Richland County, North Dakota. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 11, 2018, 6:42 PM CDT (23:42 UTC)
- Expired
- Jul 12, 2018, 1:00 AM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 21 counties
Aitkin County, MN, Becker County, MN, Beltrami County, MN, Cass County, MN, Clay County, MN, Clearwater County, MN, Crow Wing County, MN, Grant County, MN, Hubbard County, MN, Itasca County, MN, Koochiching County, MN, Lake of the Woods County, MN, Mahnomen County, MN, Norman County, MN, Otter Tail County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Wadena County, MN, Wilkin County, MN, Richland County, ND
The radar
The Fargo/Grand Forks radar (KMVX), 206 km from the middle of the area, began a volume at 23:42 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
- 40%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 50%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
17 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 8:16 PM CDT | Severe Thunderstorm Warning | FGF | Beltrami, Lake of the Woods | 59 min |
| Jul 11, 8:48 PM CDT | Severe Thunderstorm Warning | FGF | Beltrami, Lake of the Woods | 57 min |
| Jul 11, 9:08 PM CDT | Severe Thunderstorm Warning | FGF | Clearwater, Mahnomen, Polk | 67 min |
| Jul 11, 9:23 PM CDT | Tornado Warning | FGF | Beltrami | 52 min |
| Jul 11, 9:30 PM CDT | Tornado Warning | FGF | Beltrami, Lake of the Woods | 30 min |
| Jul 11, 9:37 PM CDT | Severe Thunderstorm Warning | DLH | Koochiching | 38 min |
| Jul 11, 9:42 PM CDT | Severe Thunderstorm Warning | FGF | Beltrami | 48 min |
| Jul 11, 10:20 PM CDT | Severe Thunderstorm Warning | DLH | Koochiching | 40 min |
| Jul 11, 10:42 PM CDT | Tornado Warning | DLH | Koochiching | 33 min |
| Jul 11, 11:10 PM CDT | Severe Thunderstorm Warning | DLH | Itasca, Koochiching | 50 min |
| Jul 11, 11:26 PM CDT | Severe Thunderstorm Warning | FGF | Becker, Clearwater, Hubbard | 64 min |
| Jul 11, 11:42 PM CDT | Severe Thunderstorm Warning | DLH | Cass | 48 min |
| Jul 11, 11:59 PM CDT | Severe Thunderstorm Warning | DLH | Aitkin, Cass, Itasca | 46 min |
| Jul 12, 12:18 AM CDT | Severe Thunderstorm Warning | DLH | Cass, Crow Wing | 42 min |
| Jul 12, 12:34 AM CDT | Flash Flood Warning | DLH | Itasca, Koochiching | 3 hr |
| Jul 12, 12:42 AM CDT | Severe Thunderstorm Warning | DLH | Aitkin, Cass, Itasca, Saint Louis | 48 min |
| Jul 12, 12:53 AM CDT | Severe Thunderstorm Warning | DLH | Aitkin, Cass, Crow Wing | 37 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 12:00Z, 11.7 hours before the alert went out and 132 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1634 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 153 m²/s²
- 0-3 km storm-relative helicity
- 239 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
396
WWUS20 KWNS 112339
SEL1
SPC WW 112339
MNZ000-NDZ000-120600-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 271
NWS Storm Prediction Center Norman OK
640 PM CDT Wed Jul 11 2018
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Northern Minnesota
Southeast North Dakota
* Effective this Wednesday night and Thursday morning from 640 PM
until 100 AM CDT.
* Primary threats include...
A couple tornadoes possible
Scattered damaging wind gusts to 70 mph likely
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
SUMMARY...Thunderstorms are expected to develop along a cold front
over northwest MN and spread eastward across the watch through the
evening. Damaging winds and hail are the main threats, but some
tornado potential also exists for a few hours this evening.
The tornado watch area is approximately along and 80 statute miles
east and west of a line from 60 miles west northwest of
International Falls MN to 55 miles south southeast of Detroit Lakes
MN. For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU1).
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 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 27035.
...HartSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 3:56 PM CDT | Mesoscale Discussion | SPC | Becker, Beltrami, Cass, Clay, Clearwater, Hubbard and 10 more | 3 hr |
| Jul 10, 7:32 PM CDT | Mesoscale Discussion | SPC | Billings, Burke, Divide, Dunn, Golden Valley, McKenzie and 5 more | 118 min |
| Jul 10, 8:50 PM CDT | Severe Thunderstorm Watch | SPC | Bottineau, Burke, Divide, McHenry, McKenzie, Mountrail and 5 more | 5 hr |
| Jul 10, 11:20 PM CDT | Mesoscale Discussion | SPC | Bottineau, Burke, McHenry, Mountrail, Pierce, Renville and 3 more | 115 min |
Nearby
Tornado Watches in Minnesota, 2018Tornado Watches in North Dakota, 2018Every tornado watch in 2018
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.