Alert archive / Wisconsin / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 483

September 19, 201619 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Sep 19, 2016, 2:31 PM CDT for 19 counties in Wisconsin. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Sep 19, 2016, 2:31 PM CDT (19:31 UTC)
Expired
Sep 19, 2016, 5:54 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Grant 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, Richland County, WI, Rock County, WI, Sauk County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 96 km from the middle of the area, began a volume at 19:34 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 19, 2:42 PM CDTSevere Thunderstorm WarningARXRichland, Vernon32 min
Sep 19, 2:52 PM CDTSevere Thunderstorm WarningMKXColumbia, Sauk38 min
Sep 19, 3:13 PM CDTSevere Thunderstorm WarningARXGrant62 min
Sep 19, 3:25 PM CDTSevere Thunderstorm WarningMKXDane, Iowa, Sauk50 min
Sep 19, 4:01 PM CDTSevere Thunderstorm WarningMKXDane44 min
Sep 19, 4:38 PM CDTSevere Thunderstorm WarningMKXDane, Jefferson, Rock32 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, 7.5 hours before the alert went out and 180 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 2016-09-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2016-09-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 117 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1974 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
117 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 19, 2:02 PM CDTMesoscale DiscussionSPCGrant, Green, Iowa, Lafayette58 min
Sep 19, 2:19 PM CDTMesoscale DiscussionSPCColumbia, Dane, Dodge, Fond du Lac, Green Lake, Iowa and 7 more26 min
Sep 19, 5:07 PM CDTMesoscale DiscussionSPCColumbia, Crawford, Dane, Dodge, Grant, Green and 14 more113 min

Nearby

Severe Thunderstorm Watches in Wisconsin, 2016Every severe thunderstorm watch in 2016

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.