Alert archive / Wisconsin / Tornado Watches in 2017

Tornado Watch 376

June 28, 20177 counties in Minnesota; 21 counties in Wisconsin

The Storm Prediction Center issued this tornado watch at Jun 28, 2017, 4:09 PM CDT for 7 counties in Minnesota; 21 counties in Wisconsin. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 28, 2017, 4:09 PM CDT (21:09 UTC)
Expired
Jun 28, 2017, 10:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 28 counties

Chisago County, MN, Fillmore County, MN, Goodhue County, MN, Houston County, MN, Wabasha County, MN, Washington County, MN, Winona County, MN, Barron County, WI, Buffalo County, WI, Burnett County, WI, Chippewa County, WI, Clark County, WI, Dunn County, WI, Eau Claire County, WI, Jackson County, WI, La Crosse County, WI, Monroe County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Price County, WI, Rusk County, WI, Saint Croix County, WI, Sawyer County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI, Washburn County, WI

The radar

The Minneapolis radar (KMPX), 135 km from the middle of the area, began a volume at 21:10 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
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jun 28, 4:23 PM CDTSevere Thunderstorm WarningMPXPierce, Saint Croix40 min
Jun 28, 4:30 PM CDTTornado WarningMPXPierce, Saint Croix32 min
Jun 28, 4:59 PM CDTSevere Thunderstorm WarningMPXDunn, Pepin, Pierce46 min
Jun 28, 5:09 PM CDTSevere Thunderstorm WarningARXBuffalo51 min
Jun 28, 5:10 PM CDTTornado WarningDLHBurnett20 min
Jun 28, 5:29 PM CDTTornado WarningDLHBurnett18 min
Jun 28, 5:57 PM CDTSevere Thunderstorm WarningARXBuffalo, Trempealeau78 min
Jun 28, 6:46 PM CDTTornado Warning Tornado observedARXWinona23 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, 9.2 hours before the alert went out and 138 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.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2017-06-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 2017-06-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 511 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
6 J/kg
Mixed-layer CIN
-111 J/kg
Mixed-layer LCL
537 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
511 m²/s²
0-3 km storm-relative helicity
568 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

495 
WWUS20 KWNS 282105
SEL6  
SPC WW 282105
MNZ000-WIZ000-290300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 376
NWS Storm Prediction Center Norman OK
410 PM CDT Wed Jun 28 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Eastern Minnesota
  Western Wisconsin

* Effective this Wednesday afternoon and evening from 410 PM
  until 1000 PM CDT.

* Primary threats include...
  A couple tornadoes possible
  Isolated very large hail events to 2 inches in diameter possible
  Isolated damaging wind gusts to 70 mph possible

SUMMARY...Thunderstorms are likely to gradually intensify through
late afternoon and early evening as some additional air mass
destabilization occurs. While the air mass will not be overly
unstable, sufficient low-level/deep-layer shear, particularly near a
warm front, will support some tornado risk aside from severe hail
and damaging winds.

The tornado watch area is approximately along and 55 statute miles
east and west of a line from 70 miles north northwest of Eau Claire
WI to 10 miles east of La Crosse WI. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU6).

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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 375...

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 27025.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 27, 7:35 PM CDTSevere Thunderstorm WatchSPCCottonwood, Jackson, Lyon, Murray, Nobles, Pipestone and 1 more5 hr
Jun 28, 2:49 PM CDTMesoscale DiscussionSPCCarver, Dakota, Dodge, Goodhue, Hennepin, Houston and 7 more116 min
Jun 28, 2:53 PM CDTTornado WatchSPCGrant9 hr
Jun 28, 5:00 PM CDTMesoscale DiscussionSPCColumbia, Dane, Dodge, Green, Iowa, Jefferson and 3 more30 min
Jun 28, 5:14 PM CDTTornado WatchSPCColumbia, Dane, Dodge, Green, Iowa, Jefferson and 10 more4 hr
Jun 28, 5:29 PM CDTMesoscale DiscussionSPCGrant, Lafayette91 min

Nearby

Tornado Watches in Wisconsin, 2017Tornado Watches in Minnesota, 2017Every tornado watch in 2017

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.