Alert archive / Indiana / Tornado Watches in 2011

Tornado Watch 242

April 27, 201155 counties in Indiana; 12 counties in Kentucky; 42 counties in Ohio

The Storm Prediction Center issued this tornado watch at Apr 27, 2011, 7:22 PM EDT for 55 counties in Indiana; 12 counties in Kentucky; 42 counties in Ohio. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Apr 27, 2011, 7:22 PM EDT (23:22 UTC)
Expired
Apr 28, 2011, 3:00 AM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 109 counties

Adams County, IN, Bartholomew County, IN, Blackford County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Cass County, IN, Clay County, IN, Clinton County, IN, Daviess County, IN, Dearborn County, IN, Decatur County, IN, Delaware County, IN, Fayette County, IN, Fountain County, IN, Franklin County, IN, Grant County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jackson County, IN, Jay County, IN, Jennings County, IN, Johnson County, IN, Knox County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Martin County, IN, Miami County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Ohio County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Randolph County, IN, Ripley County, IN, Rush County, IN, Shelby County, IN, Sullivan County, IN, Switzerland County, IN, Tippecanoe County, IN, Tipton County, IN, Union County, IN, Vermillion County, IN, Vigo County, IN, Wabash County, IN, Wayne County, IN, Wells County, IN, Boone County, KY, Bracken County, KY, Campbell County, KY, Carroll County, KY, Gallatin County, KY, Grant County, KY, Kenton County, KY, Lewis County, KY, Mason County, KY, Owen County, KY, Pendleton County, KY, Robertson County, KY, Adams County, OH, Allen County, OH, Auglaize County, OH, Brown County, OH, Butler County, OH, Champaign County, OH, Clark County, OH, Clermont County, OH, Clinton County, OH, Crawford County, OH, Darke County, OH, Delaware County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Greene County, OH, Hamilton County, OH, Hancock County, OH, Hardin County, OH, Highland County, OH, Hocking County, OH, Knox County, OH, Licking County, OH, Logan County, OH, Madison County, OH, Marion County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Morrow County, OH, Pickaway County, OH, Pike County, OH, Preble County, OH, Putnam County, OH, Richland County, OH, Ross County, OH, Scioto County, OH, Shelby County, OH, Union County, OH, Van Wert County, OH, Warren County, OH, Wyandot County, OH

The radar

The Indianapolis radar (KIND), 72 km from the middle of the area, began a volume at 23:23 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
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 27, 10:36 PM EDTFlash Flood WarningILNLewis3 hr
Apr 27, 10:54 PM EDTTornado WarningIWXJay51 min
Apr 27, 10:58 PM EDTTornado WarningINDDelaware, Randolph27 min
Apr 27, 11:15 PM EDTSevere Thunderstorm WarningILNDarke, Mercer60 min
Apr 27, 11:19 PM EDTTornado WarningINDRandolph15 min
Apr 27, 11:31 PM EDTTornado WarningILNMercer29 min
Apr 27, 11:55 PM EDTTornado WarningIWXAllen, Van Wert36 min
Apr 27, 11:58 PM EDTTornado WarningILNAuglaize, Mercer29 min
Apr 28, 2:10 AM EDTSevere Thunderstorm WarningILNChampaign, Clark, Clinton, Fayette, Greene, Madison and 3 more50 min
Apr 28, 2:51 AM EDTSevere Thunderstorm WarningILNDelaware, Fairfield, Fayette, Franklin, Hardin, Hocking and 6 more54 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 12:00Z, 11.4 hours before the alert went out and 155 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 12:00Z on 2011-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 279 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 12:00Z on 2011-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 470 square meters per square second.1939587897Sfc1 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
279 J/kg
Mixed-layer CIN
-56 J/kg
Mixed-layer LCL
846 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
470 m²/s²
0-3 km storm-relative helicity
503 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

093 
WWUS20 KWNS 272322
SEL2
SPC WW 272322
INZ000-KYZ000-OHZ000-280700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 242
NWS STORM PREDICTION CENTER NORMAN OK
725 PM EDT WED APR 27 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       INDIANA
       NORTHERN KENTUCKY
       WESTERN AND CENTRAL OHIO

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 725 PM
UNTIL 300 AM EDT.

TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 15 MILES NORTHWEST OF TERRE
HAUTE INDIANA TO 25 MILES EAST SOUTHEAST OF COLUMBUS OHIO.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU2).

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 232...WW 235...WW
236...WW 237...WW 238...WW 239...WW 240...WW 241...

DISCUSSION...SURFACE LOW OVER FAR SWRN IND IS FORECAST TO DEVELOP
NEWD TO NEAR CLE BY 28/06Z IN ADVANCE OF STRONG VORTICITY MAXIMUM
CURRENTLY NEAR THE CONFLUENCE OF THE MS/OH RIVERS.  INTENSE DYNAMIC
FORCING FOR ASCENT ASSOCIATED WITH THIS UPPER-LEVEL SYSTEM WILL BE
SUPPORTIVE OF SUFFICIENT DESTABILIZATION FOR LOW-TOPPED
SUPERCELLS/BOWS CAPABLE OF TORNADOES AND DAMAGING WINDS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
300. MEAN STORM MOTION VECTOR 21050.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 26, 8:33 PM EDTMesoscale DiscussionSPCAdams, Allen, Blackford, Boone, Carroll, Cass and 35 more57 min
Apr 26, 9:35 PM EDTMesoscale DiscussionSPCBartholomew, Boone, Brown, Clark, Clay, Crawford and 44 more55 min
Apr 26, 10:13 PM EDTMesoscale DiscussionSPCPosey, Vanderburgh, Warrick62 min
Apr 26, 10:58 PM EDTTornado WatchSPCClark, Crawford, Dubois, Floyd, Harrison, Jefferson and 4 more7 hr
Apr 27, 4:06 PM EDTMesoscale DiscussionSPCCrawford, Daviess, Dubois, Gibson, Knox, Lawrence and 8 more54 min
Apr 27, 4:29 PM EDTTornado WatchSPCGibson, Pike, Posey, Spencer, Vanderburgh, Warrick5 hr
Apr 27, 5:38 PM EDTMesoscale DiscussionSPCClark, Crawford, Floyd, Harrison, Jefferson, Ohio and 4 more37 min
Apr 27, 5:44 PM EDTTornado WatchSPCClark, Crawford, Dubois, Floyd, Harrison, Jefferson and 5 more7 hr
Apr 27, 6:27 PM EDTMesoscale DiscussionSPCBartholomew, Blackford, Boone, Brown, Clark, Clay and 53 more63 min
Apr 27, 5:33 AM EDTMesoscale DiscussionSPCAdair, Barren, Boyle, Casey, Clinton, Cumberland and 12 more57 min
Apr 27, 6:07 AM EDTTornado WatchSPCAdair, Allen, Anderson, Barren, Bourbon, Boyle and 28 more5 hr
Apr 27, 8:34 AM EDTTornado WatchSPCBath, Bell, Breathitt, Clay, Elliott, Estill and 21 more4 hr
Apr 27, 9:39 AM EDTMesoscale DiscussionSPCBoyd, Carter, Greenup, Lewis66 min
Apr 27, 1:42 PM EDTSevere Thunderstorm WatchSPCBallard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 16 more5 hr
Apr 27, 3:22 PM EDTMesoscale DiscussionSPCBell, Breathitt, Clay, Floyd, Harlan, Jackson and 11 more83 min
Apr 27, 1:24 PM EDTMesoscale DiscussionSPCAshtabula, Belmont, Carroll, Columbiana, Guernsey, Harrison and 9 more96 min

Nearby

Tornado Watches in Indiana, 2011Tornado Watches in Ohio, 2011Tornado Watches in Kentucky, 2011Every tornado 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.