Alert archive / Indiana / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 158

April 19, 201124 counties in Indiana; 8 counties in Ohio

The Storm Prediction Center issued this severe thunderstorm watch at Apr 19, 2011, 9:37 PM EDT for 24 counties in Indiana; 8 counties in Ohio. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Apr 19, 2011, 9:37 PM EDT (01:37 UTC)
Expired
Apr 20, 2011, 12:20 AM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
70 kt
All 32 counties

Adams County, IN, Allen County, IN, Blackford County, IN, Cass County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Grant County, IN, Huntington County, IN, Jay County, IN, Kosciusko County, IN, LaGrange County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Noble County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Wabash County, IN, Wells County, IN, White County, IN, Whitley County, IN, Allen County, OH, Defiance County, OH, Fulton County, OH, Henry County, OH, Paulding County, OH, Putnam County, OH, Van Wert County, OH, Williams County, OH

The radar

The Northern Indiana radar (KIWX), 20 km from the middle of the area, began a volume at 01:39 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
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
50%
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
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 19, 10:46 PM EDTSevere Thunderstorm WarningIWXAdams, Allen, Blackford, DeKalb, Grant, Huntington and 6 more59 min
Apr 19, 11:31 PM EDTSevere Thunderstorm WarningIWXAllen, Defiance, Fulton, Henry, Paulding, Putnam and 2 more49 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

Cncnati-Daytn, OH (KILN), launched 00:00Z, 1.6 hours before the alert went out and 257 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, Cncnati-Daytn, OH at 00:00Z on 2011-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1686 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, Cncnati-Daytn, OH at 00:00Z on 2011-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 387 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
1686 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
1003 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
387 m²/s²
0-3 km storm-relative helicity
474 m²/s²
Significant tornado parameter
4.3
Supercell composite
18.7

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 19, 9:07 PM EDTMesoscale DiscussionSPCBlackford, Boone, Carroll, Cass, Clay, Clinton and 39 more83 min
Apr 19, 9:47 PM EDTMesoscale DiscussionSPCClark, Dearborn, Floyd, Jefferson, Ohio, Switzerland88 min
Apr 19, 10:13 PM EDTTornado WatchSPCClark, Crawford, Dearborn, Dubois, Fayette, Floyd and 12 more6 hr
Apr 20, 12:56 AM EDTMesoscale DiscussionSPCClark, Dearborn, Franklin, Jefferson, Ohio, Ripley and 1 more94 min
Apr 19, 11:47 PM EDTMesoscale DiscussionSPCAshland, Carroll, Crawford, Fulton, Hancock, Henry and 14 more58 min
Apr 20, 12:18 AM EDTSevere Thunderstorm WatchSPCAshland, Ashtabula, Crawford, Erie, Geauga, Hancock and 21 more4 hr
Apr 20, 1:59 AM EDTTornado WatchSPCAthens, Gallia, Jackson, Lawrence, Meigs, Morgan and 3 more5 hr
Apr 20, 2:22 AM EDTSevere Thunderstorm WatchSPCBelmont, Carroll, Columbiana, Coshocton, Guernsey, Harrison and 5 more3 hr
Apr 20, 3:20 AM EDTMesoscale DiscussionSPCAthens, Belmont, Carroll, Columbiana, Gallia, Guernsey and 10 more85 min

Nearby

Severe Thunderstorm Watches in Indiana, 2011Severe Thunderstorm Watches in Ohio, 2011Every severe thunderstorm watch in 2011

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.