Alert archive / Tennessee / Tornado Watches in 2011

Tornado Watch 206

April 25, 20116 states

The Storm Prediction Center issued this tornado watch at Apr 25, 2011, 4:50 PM CDT for 6 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Apr 25, 2011, 4:50 PM CDT (21:50 UTC)
Expired: Apr 26, 2011, 12:00 AM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Particularly dangerous situation: Yes
Largest hail expected: 2.5 in
Strongest gust expected: 70 kt

All 89 counties

Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, Poinsett County, AR, St. Francis County, AR, Alexander County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Johnson County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saline County, IL, Union County, IL, White County, IL, Williamson County, IL, 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, Dunklin County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Perry County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Benton County, MS, Calhoun County, MS, Coahoma County, MS, DeSoto County, MS, Lafayette County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Carroll County, TN, Chester County, TN, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 36 km from the middle of the area, began a volume at 21:49 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: 90%
One or more EF2 to EF5 tornadoes: 70%
Ten or more severe wind reports: 70%
One or more gusts of 65 knots or more: 60%
Ten or more severe hail reports: 60%
One or more hailstones of 2 inches or more: 40%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Apr 25, 4:54 PM CDT	Severe Thunderstorm Warning	PAH	Ripley	66 min
Apr 25, 4:58 PM CDT	Flash Flood Warning	PAH	Daviess, Henderson, Hopkins, McLean, Webster	118 min
Apr 25, 4:59 PM CDT	Flash Flood Warning	MEG	Clay, Greene, Lawrence, Randolph	7 hr
Apr 25, 5:12 PM CDT	Tornado Warning	PAH	Ripley	33 min
Apr 25, 5:24 PM CDT	Severe Thunderstorm Warning	PAH	Butler, Carter, Ripley, Wayne	51 min
Apr 25, 5:25 PM CDT	Tornado Warning	MEG	Clay, Lawrence, Randolph	50 min
Apr 25, 5:32 PM CDT	Severe Thunderstorm Warning	PAH	Bollinger, Butler, Stoddard, Wayne	73 min
Apr 25, 5:38 PM CDT	Tornado Warning	PAH	Butler, Ripley, Wayne	37 min
Apr 25, 5:50 PM CDT	Severe Thunderstorm Warning	LSX	Madison	40 min
Apr 25, 5:52 PM CDT	Tornado Warning	PAH	Butler, Stoddard, Wayne	23 min
Apr 25, 6:01 PM CDT	Severe Thunderstorm Warning	PAH	Bollinger, Cape Girardeau, Perry	59 min
Apr 25, 6:11 PM CDT	Tornado Warning	PAH	Bollinger, Cape Girardeau, Wayne	34 min
Apr 25, 6:14 PM CDT	Severe Thunderstorm Warning	MEG	Clay, Lawrence, Randolph	46 min
Apr 25, 6:15 PM CDT	Tornado Warning	LSX	Madison	15 min
Apr 25, 6:41 PM CDT	Tornado Warning	PAH	Jackson	34 min
Apr 25, 6:46 PM CDT	Flash Flood Warning	PAH	Alexander, Franklin, Hamilton, Jackson, Jefferson, Johnson and 8 more	6 hr
Apr 25, 6:57 PM CDT	Severe Thunderstorm Warning	PAH	Jackson, Perry, Union	48 min
Apr 25, 7:23 PM CDT	Flash Flood Warning	LSX	Clinton, Marion, Monroe, Randolph, Saint Clair, Washington	9 hr
Apr 25, 7:23 PM CDT	Severe Thunderstorm Warning	PAH	Alexander	37 min
Apr 25, 7:29 PM CDT	Flash Flood Warning	PAH	Butler	24 hr
Apr 25, 7:44 PM CDT	Flash Flood Warning	MEG	Clay, Greene	3 hr
Apr 25, 7:45 PM CDT	Severe Thunderstorm Warning	PAH	Franklin, Jackson, Jefferson, Perry, Saline, Williamson	45 min
Apr 25, 8:09 PM CDT	Severe Thunderstorm Warning	PAH	Cape Girardeau, Scott	35 min
Apr 25, 8:28 PM CDT	Tornado Warning	MEG	Clay	35 min
Apr 25, 8:39 PM CDT	Severe Thunderstorm Warning	MEG	Cross, Lee, Phillips, St. Francis	66 min
Apr 25, 9:00 PM CDT	Tornado Warning	MEG	Cross, Poinsett	45 min
Apr 25, 9:15 PM CDT	Flash Flood Warning	MEG	Clay	3 hr
Apr 25, 9:18 PM CDT	Severe Thunderstorm Warning	MEG	Craighead, Crittenden, Cross, Poinsett	42 min
Apr 25, 9:33 PM CDT	Flash Flood Warning	MEG	Craighead, Crittenden, Cross, Greene, Lee, Poinsett and 1 more	3 hr
Apr 25, 9:35 PM CDT	Severe Thunderstorm Warning	MEG	Crittenden, Cross, Lee, St. Francis	55 min
Apr 25, 9:44 PM CDT	Severe Thunderstorm Warning	MEG	Phillips	61 min
Apr 25, 9:45 PM CDT	Severe Thunderstorm Warning	MEG	Craighead, Crittenden, Mississippi, Poinsett	45 min
Apr 25, 10:00 PM CDT	Flash Flood Warning	PAH	Edwards, Gallatin, Wabash, White	6 hr
Apr 25, 10:16 PM CDT	Severe Thunderstorm Warning	MEG	DeSoto, Marshall, Tate, Tunica	59 min
Apr 25, 10:18 PM CDT	Severe Thunderstorm Warning	MEG	Coahoma, Panola, Quitman, Tallahatchie, Tate, Tunica	57 min
Apr 25, 10:21 PM CDT	Severe Thunderstorm Warning	MEG	Fayette, Hardeman, Haywood, Madison, Shelby, Tipton	39 min
Apr 25, 10:28 PM CDT	Severe Thunderstorm Warning	MEG	Mississippi	47 min
Apr 25, 10:38 PM CDT	Flash Flood Warning	MEG	Mississippi	3 hr
Apr 25, 10:45 PM CDT	Flash Flood Warning	MEG	Clay, Greene	3 hr
Apr 25, 10:47 PM CDT	Severe Thunderstorm Warning	MEG	Mississippi	43 min
Apr 25, 10:55 PM CDT	Severe Thunderstorm Warning	MEG	Chester, Fayette, Hardeman, Haywood, McNairy, Madison and 2 more	50 min
Apr 25, 10:58 PM CDT	Severe Thunderstorm Warning	MEG	Benton, Marshall, Tate, Tippah, Union	62 min
Apr 25, 11:01 PM CDT	Severe Thunderstorm Warning	MEG	Coahoma, Lafayette, Panola, Quitman, Tallahatchie, Union and 1 more	59 min
Apr 25, 11:03 PM CDT	Flash Flood Warning	PAH	Hardin	5 hr
Apr 25, 11:11 PM CDT	Severe Thunderstorm Warning	MEG	Carroll, Crockett, Dyer, Gibson, Haywood, Henderson and 2 more	49 min
Apr 25, 11:22 PM CDT	Severe Thunderstorm Warning	MEG	Gibson, Henry, Obion, Weakley	38 min
Apr 25, 11:33 PM CDT	Severe Thunderstorm Warning	PAH	Fulton, Graves, Hickman	42 min
Apr 25, 11:35 PM CDT	Severe Thunderstorm Warning	MEG	Carroll, Chester, Decatur, Gibson, Hardin, Henderson and 1 more	40 min
Apr 25, 11:45 PM CDT	Severe Thunderstorm Warning	MEG	Chester, Decatur, Fayette, Hardeman, Hardin, McNairy and 1 more	45 min
Apr 25, 11:49 PM CDT	Severe Thunderstorm Warning	PAH	Massac, Pope	26 min
Apr 25, 11:55 PM CDT	Severe Thunderstorm Warning	MEG	Carroll, Henry, Weakley	35 min
Apr 25, 11:59 PM CDT	Severe Thunderstorm Warning	MEG	Alcorn, Benton, Itawamba, Lafayette, Lee, Prentiss and 3 more	76 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

Little Rock, AR (KLZK), launched 12:00Z, 9.8 hours before the alert went out and 85 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: 11 J/kg
Mixed-layer CIN: -189 J/kg
Mixed-layer LCL: 729 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 210 m²/s²
0-3 km storm-relative helicity: 321 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.8

Open this sounding in Storm Lab

The text

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

615 
WWUS20 KWNS 252151
SEL6
SPC WW 252151
ARZ000-ILZ000-INZ000-KYZ000-MOZ000-MSZ000-TNZ000-260500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 206
NWS STORM PREDICTION CENTER NORMAN OK
450 PM CDT MON APR 25 2011

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

       PARTS OF NORTHEAST ARKANSAS
       PARTS OF ILLINOIS
       SMALL PART OF SOUTHWEST INDIANA
       PARTS OF WESTERN KENTUCKY
       PARTS OF SOUTHEAST MISSOURI
       LARGE PART OF NORTHERN MISSISSIPPI
       WESTERN TENNESSEE

EFFECTIVE THIS MONDAY AFTERNOON FROM 450 PM UNTIL MIDNIGHT CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 2.5 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE
POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 80 STATUTE
MILES EAST AND WEST OF A LINE FROM 70 MILES WEST SOUTHWEST OF
OXFORD MISSISSIPPI TO 35 MILES EAST NORTHEAST OF CARBONDALE
ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

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 201...WW 202...WW
203...WW 204...WW 205...

DISCUSSION...AS SURFACE LOW DEEPENS THIS EVENING NEWD TOWARD LOWER
OH VALLEY...STRONG SHEAR PROFILES AND RAPID NWD DESTABILIZATION WILL
TAKE PLACE NWD THRU THE WATCH.  THIS SUPPORTS CURRENT SUPERCELLS NOW
IN AR TO DEVELOP RAPIDLY NEWD ACROSS THE WATCH WITH POTENTIAL FOR
STRONG TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 23035.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 24, 10:13 PM CDT	Mesoscale Discussion	SPC	Clark, Cleburne, Conway, Faulkner, Garland, Grant and 15 more	2 hr
Apr 24, 11:43 PM CDT	Severe Thunderstorm Watch	SPC	Hempstead, Howard, Little River, Miller, Nevada, Sevier	5 hr
Apr 25, 1:57 AM CDT	Mesoscale Discussion	SPC	Cleveland, Dallas, Jefferson, Lincoln	63 min
Apr 25, 4:41 AM CDT	Severe Thunderstorm Watch	SPC	Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 25 more	7 hr
Apr 25, 7:23 AM CDT	Mesoscale Discussion	SPC	Calhoun, Clark, Cleveland, Columbia, Dallas, Garland and 11 more	97 min
Apr 25, 8:37 AM CDT	Mesoscale Discussion	SPC	Arkansas, Cleveland, Crittenden, Desha, Drew, Jefferson and 7 more	53 min
Apr 25, 9:17 AM CDT	Severe Thunderstorm Watch	SPC	Crittenden, Lee, Phillips, St. Francis	6 hr
Apr 25, 10:46 AM CDT	Mesoscale Discussion	SPC	Hempstead, Howard, Lafayette, Little River, Miller, Sevier	59 min
Apr 25, 11:00 AM CDT	Tornado Watch	SPC	Carroll, Clark, Crawford, Franklin, Hempstead, Howard and 13 more	7 hr
Apr 25, 1:15 PM CDT	Mesoscale Discussion	SPC	Crittenden, Cross, Lee, Phillips, St. Francis	60 min
Apr 25, 1:28 PM CDT	Mesoscale Discussion	SPC	Crawford, Franklin, Howard, Johnson, Little River, Logan and 5 more	92 min
Apr 25, 3:08 PM CDT	Mesoscale Discussion	SPC	Arkansas, Ashley, Baxter, Boone, Bradley, Calhoun and 29 more	37 min
Apr 25, 3:22 PM CDT	Tornado Watch PDS	SPC	Arkansas, Baxter, Boone, Bradley, Calhoun, Clark and 50 more	8 hr
Apr 25, 4:34 PM CDT	Mesoscale Discussion	SPC	Arkansas, Clay, Craighead, Crittenden, Cross, Greene and 11 more	56 min
Apr 25, 2:29 PM CDT	Severe Thunderstorm Watch	SPC	Allen, Barren, Butler, Christian, Edmonson, Grayson and 7 more	4 hr
Apr 25, 1:48 PM CDT	Mesoscale Discussion	SPC	Bedford, Benton, Carroll, Cheatham, Davidson, Decatur and 20 more	87 min

Nearby

Tornado Watches in Tennessee, 2011 Tornado Watches in Illinois, 2011 Tornado Watches in Missouri, 2011 Every 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.