Alert archive / Indiana / Tornado Watches in 2013

Tornado Watch 197

May 20, 20134 states

The Storm Prediction Center issued this tornado watch at May 20, 2013, 10:56 PM CDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 20, 2013, 10:56 PM CDT (03:56 UTC)
Expired: May 21, 2013, 5:00 AM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 105 counties

Alexander County, IL, Champaign County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Douglas County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Massac County, IL, Moultrie County, IL, Perry County, IL, Piatt County, IL, Pope County, IL, Pulaski County, IL, Richland County, IL, Saline County, IL, Shelby County, IL, Union County, IL, Vermilion County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Bartholomew County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Clay County, IN, Clinton County, IN, Daviess County, IN, Decatur County, IN, Delaware County, IN, Fountain County, IN, Gibson County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Jackson County, IN, Jennings County, IN, Johnson County, IN, Knox County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Pike County, IN, Posey County, IN, Putnam County, IN, Randolph County, IN, Rush County, IN, Shelby County, IN, Sullivan County, IN, Tippecanoe County, IN, Tipton County, IN, Vanderburgh County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN, Warrick County, IN, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Henderson County, KY, Hickman County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Mississippi County, MO, New Madrid County, MO, Perry County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO

The radar

The Evansville,IN radar (KVWX), 108 km from the middle of the area, began a volume at 03:55 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: 80%
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: 5%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 21, 12:14 AM CDT	Severe Thunderstorm Warning	PAH	Edwards, Franklin, Hamilton, Jefferson, Perry, Wayne and 1 more	46 min
May 21, 1:02 AM CDT	Severe Thunderstorm Warning	PAH	Butler, Ripley	28 min
May 21, 1:39 AM CDT	Severe Thunderstorm Warning	IND	Boone, Carroll, Clinton, Hendricks, Montgomery, Morgan and 3 more	51 min
May 21, 1:45 AM CDT	Severe Thunderstorm Warning	IND	Daviess, Greene, Lawrence, Martin, Monroe, Morgan and 1 more	45 min
May 21, 1:55 AM CDT	Tornado Warning	IND	Hendricks	35 min
May 21, 2:00 AM CDT	Severe Thunderstorm Warning	IND	Boone, Carroll, Clinton, Hamilton, Hendricks, Howard and 4 more	45 min
May 21, 2:49 AM CDT	Severe Thunderstorm Warning	IND	Delaware, Henry, Madison	41 min
May 21, 2:57 AM CDT	Severe Thunderstorm Warning	IND	Decatur, Henry, Jennings, Rush	48 min
May 21, 3:17 AM CDT	Severe Thunderstorm Warning	IND	Randolph	43 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

Lincoln, IL (KILX), launched 00:00Z, 3.9 hours before the alert went out and 229 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1540 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 1320 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 173 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 6.7

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 20, 7:17 PM CDT	Mesoscale Discussion	SPC	Boone, Bureau, Carroll, DeKalb, DeWitt, DuPage and 25 more	58 min
May 20, 7:39 PM CDT	Tornado Watch	SPC	Randolph	6 hr
May 20, 7:48 PM CDT	Severe Thunderstorm Watch	SPC	Boone, Bureau, Carroll, Cook, DeKalb, DuPage and 20 more	6 hr
May 20, 8:07 PM CDT	Mesoscale Discussion	SPC	Calhoun, Pike	23 min
May 20, 8:53 PM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Calhoun, Cass, Christian and 27 more	67 min
May 20, 10:25 PM CDT	Mesoscale Discussion	SPC	Alexander, Champaign, Clark, Clay, Coles, Crawford and 33 more	65 min
May 21, 2:59 AM CDT	Mesoscale Discussion	SPC	Alexander, Franklin, Gallatin, Hamilton, Hardin, Johnson and 7 more	91 min
May 20, 11:15 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Cass, Elkhart, Fulton, Grant, Huntington and 16 more	5 hr
May 21, 7:47 AM CDT	Mesoscale Discussion	SPC	Fulton	58 min
May 21, 11:27 AM CDT	Mesoscale Discussion	SPC	Adair, Allen, Barren, Clinton, Cumberland, Logan and 7 more	63 min
May 21, 2:12 PM CDT	Mesoscale Discussion	SPC	Adair, Anderson, Bell, Boyle, Breathitt, Casey and 36 more	63 min
May 21, 2:26 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Anderson, Bath, Bell, Bourbon, Boyd and 55 more	7 hr
May 21, 6:00 PM CDT	Mesoscale Discussion	SPC	Bath, Bell, Boyd, Breathitt, Carter, Clay and 22 more	60 min
May 21, 12:50 AM CDT	Severe Thunderstorm Watch	SPC	Dunklin, Pemiscot	3 hr
May 21, 2:42 PM CDT	Mesoscale Discussion	SPC	Dunklin, Pemiscot	63 min
May 21, 3:00 PM CDT	Tornado Watch	SPC	Dunklin, Pemiscot	7 hr

Nearby

Tornado Watches in Indiana, 2013 Tornado Watches in Illinois, 2013 Tornado Watches in Kentucky, 2013 Every tornado watch in 2013

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.