Alert archive / Wisconsin / Tornado Watches in 2017

Tornado Watch 377

June 28, 201716 counties in Wisconsin

The Storm Prediction Center issued this tornado watch at Jun 28, 2017, 5:14 PM CDT for 16 counties in Wisconsin. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jun 28, 2017, 5:14 PM CDT (22:14 UTC)
Expired
Jun 28, 2017, 9:09 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Columbia County, WI, Dane County, WI, Dodge County, WI, Green County, WI, Iowa County, WI, Jefferson County, WI, Kenosha County, WI, Lafayette County, WI, Milwaukee County, WI, Ozaukee County, WI, Racine County, WI, Rock County, WI, Sauk County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 80 km from the middle of the area, began a volume at 22:16 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
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

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

IssuedProductOfficeCountiesLasted
Jun 28, 5:43 PM CDTSevere Thunderstorm WarningMKXIowa, Lafayette62 min
Jun 28, 6:14 PM CDTSevere Thunderstorm WarningMKXDane, Green46 min
Jun 28, 6:33 PM CDTTornado WarningMKXDane, Green, Iowa, Lafayette42 min
Jun 28, 6:45 PM CDTSevere Thunderstorm WarningMKXMilwaukee, Ozaukee, Washington, Waukesha30 min
Jun 28, 6:57 PM CDTSevere Thunderstorm WarningMKXGreen, Rock33 min
Jun 28, 7:08 PM CDTSevere Thunderstorm WarningMKXDane, Jefferson67 min
Jun 28, 7:11 PM CDTSevere Thunderstorm WarningMKXColumbia, Dodge34 min
Jun 28, 7:18 PM CDTFlash Flood WarningMKXLafayette3 hr
Jun 28, 7:22 PM CDTSevere Thunderstorm WarningMKXRock38 min
Jun 28, 7:38 PM CDTTornado WarningMKXRock22 min
Jun 28, 7:45 PM CDTSevere Thunderstorm WarningMKXWaukesha45 min
Jun 28, 7:47 PM CDTSevere Thunderstorm WarningMKXWalworth43 min
Jun 28, 8:26 PM CDTSevere Thunderstorm WarningMKXKenosha, Racine34 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

Davenport, (KDVN), launched 12:00Z, 10.2 hours before the alert went out and 171 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, Davenport, at 12:00Z on 2017-06-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 134 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2017-06-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 square meters per square second.193958Sfc1 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
134 J/kg
Mixed-layer CIN
-204 J/kg
Mixed-layer LCL
1152 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
217 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted.

551 
WWUS20 KWNS 282211
SEL7  
SPC WW 282211
WIZ000-290300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 377
NWS Storm Prediction Center Norman OK
515 PM CDT Wed Jun 28 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southern Wisconsin

* Effective this Wednesday afternoon and evening from 515 PM
  until 1000 PM CDT.

* Primary threats include...
  A couple tornadoes possible
  Isolated damaging wind gusts to 70 mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...A band of intense storms from northeast Iowa into far
southwest Wisconsin will spread eastward into the evening with a
threat to produce several tornadoes, strong wind gusts and possible
hail.

The tornado watch area is approximately along and 55 statute miles
east and west of a line from 15 miles west southwest of Janesville
WI to 35 miles north of Madison WI. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU7).

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...WW 376...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 26030.

...Weiss

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 28, 2:49 PM CDTMesoscale DiscussionSPCBarron, Buffalo, Chippewa, Clark, Dunn, Eau Claire and 13 more116 min
Jun 28, 2:53 PM CDTTornado WatchSPCGrant9 hr
Jun 28, 4:09 PM CDTTornado WatchSPCBarron, Buffalo, Burnett, Chippewa, Clark, Dunn and 15 more6 hr
Jun 28, 5:00 PM CDTMesoscale DiscussionSPCColumbia, Dane, Dodge, Green, Iowa, Jefferson and 3 more30 min
Jun 28, 5:29 PM CDTMesoscale DiscussionSPCGrant, Lafayette91 min

Nearby

Tornado Watches in Wisconsin, 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.