Alert archive / Minnesota / Tornado Watches in 2019
Tornado Watch 522
The Storm Prediction Center issued this tornado watch at Jul 18, 2019, 5:30 PM CDT for 10 counties in Iowa; 13 counties in Minnesota; Minnehaha County, Moody County, South Dakota. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 18, 2019, 5:30 PM CDT (22:30 UTC)
- Expired
- Jul 18, 2019, 9:33 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 25 counties
Cerro Gordo County, IA, Dickinson County, IA, Emmet County, IA, Hancock County, IA, Kossuth County, IA, Lyon County, IA, Osceola County, IA, Palo Alto County, IA, Winnebago County, IA, Worth County, IA, Blue Earth County, MN, Cottonwood County, MN, Faribault County, MN, Freeborn County, MN, Jackson County, MN, Martin County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Steele County, MN, Waseca County, MN, Watonwan County, MN, Minnehaha County, SD, Moody County, SD
The radar
The Sioux Falls radar (KFSD), 120 km from the middle of the area, began a volume at 22:31 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
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 18, 5:43 PM CDT | Tornado Warning | FSD | Jackson | 32 min |
| Jul 18, 5:59 PM CDT | Severe Thunderstorm Warning | MPX | Blue Earth, Faribault, Waseca | 31 min |
| Jul 18, 6:35 PM CDT | Tornado Warning | MPX | Martin | 25 min |
| Jul 18, 6:37 PM CDT | Tornado Warning | MPX | Waseca | 23 min |
| Jul 18, 6:58 PM CDT | Tornado Warning | MPX | Faribault, Martin | 32 min |
| Jul 18, 7:21 PM CDT | Tornado Warning | FSD | Murray | 24 min |
| Jul 18, 7:32 PM CDT | Severe Thunderstorm Warning | MPX | Brown, Watonwan | 43 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
Minneapolis, MN (KMPX), launched 12:00Z, 10.5 hours before the alert went out and 178 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
- 686 J/kg
- Mixed-layer CIN
- -120 J/kg
- Mixed-layer LCL
- 845 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 53 m²/s²
- 0-3 km storm-relative helicity
- 54 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.5
The text
As transmitted.
602
WWUS20 KWNS 182227
SEL2
SPC WW 182227
IAZ000-MNZ000-SDZ000-190500-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 522
NWS Storm Prediction Center Norman OK
530 PM CDT Thu Jul 18 2019
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Extreme northern Iowa
Southern Minnesota
Extreme southeastern South Dakota
* Effective this Thursday afternoon from 530 PM until Midnight
CDT.
* Primary threats include...
A couple tornadoes possible
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
Scattered damaging wind gusts to 70 mph possible
SUMMARY...Thunderstorm development is underway along a weak wind
shift from southeastern South Dakota eastward near the
Minnesota/Iowa border. The storm environment will favor supercells
capable of producing large hail, damaging winds, and a couple of
tornadoes through late evening as storms spread generally eastward.
The tornado watch area is approximately along and 35 statute miles
north and south of a line from 10 miles north of Sioux Falls SD to
35 miles north northeast of Mason City IA. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU2).
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 650. Mean
storm motion vector 28025.
...ThompsonSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 10:43 PM CDT | Mesoscale Discussion | SPC | Allamakee, Black Hawk, Bremer, Buchanan, Butler, Cerro Gordo and 10 more | 2 hr |
| Jul 18, 4:54 PM CDT | Mesoscale Discussion | SPC | Lyon | 66 min |
| Jul 17, 7:46 PM CDT | Mesoscale Discussion | SPC | Butte, Corson, Custer, Fall River, Haakon, Lawrence and 5 more | 119 min |
| Jul 17, 11:06 PM CDT | Mesoscale Discussion | SPC | Edmunds, Faulk, Hand, Hughes, Hyde, Potter and 1 more | 54 min |
Nearby
Tornado Watches in Minnesota, 2019Tornado Watches in Iowa, 2019Tornado Watches in South Dakota, 2019Every tornado watch in 2019
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.