Alert archive / Mississippi / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 145
The Storm Prediction Center issued this severe thunderstorm watch at Apr 5, 2012, 12:18 PM CDT for 4 states. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 5, 2012, 12:18 PM CDT (17:18 UTC)
- Expired
- Apr 5, 2012, 5:06 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 45 counties
Crittenden County, AR, Mississippi County, AR, Pemiscot County, MO, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin 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), 56 km from the middle of the area, began a volume at 17:17 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
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 20%
- 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.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 5, 12:25 PM CDT | Severe Thunderstorm Warning | MEG | Dunklin, Pemiscot | 20 min |
| Apr 5, 12:33 PM CDT | Severe Thunderstorm Warning | MEG | Carroll | 27 min |
| Apr 5, 12:42 PM CDT | Severe Thunderstorm Warning | MEG | Carroll, Chester, Gibson, Henderson, Madison | 33 min |
| Apr 5, 1:23 PM CDT | Severe Thunderstorm Warning | MEG | Carroll, Henry, Weakley | 36 min |
| Apr 5, 2:45 PM CDT | Severe Thunderstorm Warning | MEG | Lee, Pontotoc, Union | 30 min |
| Apr 5, 4:02 PM CDT | Severe Thunderstorm Warning | MEG | Itawamba, Monroe | 28 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, 5.3 hours before the alert went out and 95 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.
- Mixed-layer CAPE
- 42 J/kg
- Mixed-layer CIN
- -132 J/kg
- Mixed-layer LCL
- 1448 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- -41 m²/s²
- 0-3 km storm-relative helicity
- 51 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.2
The text
As transmitted, in the capitals the NWS used until 2016.
632
WWUS20 KWNS 051720
SEL5
SPC WW 051720
ARZ000-MOZ000-MSZ000-TNZ000-060100-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 145
NWS STORM PREDICTION CENTER NORMAN OK
1220 PM CDT THU APR 5 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
FAR NORTHEAST ARKANSAS
MISSOURI BOOTHEEL
NORTHERN MISSISSIPPI
WESTERN TENNESSEE
EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 1220 PM UNTIL
800 PM CDT.
HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTHEAST OF
DYERSBURG TENNESSEE TO 30 MILES SOUTH OF OXFORD MISSISSIPPI. FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU5).
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.
OTHER WATCH INFORMATION...CONTINUE...WW 143...WW 144...
DISCUSSION...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND
INTENSITY THIS AFTERNOON WITHIN MIDLEVEL COLD CORE OF UPPER LOW.
DESPITE MARGINAL VERTICAL SHEAR...STEEP LAPSE RATES AND COOL
THERMODYNAMIC PROFILES WILL SUPPORT HAIL PRODUCTION WITH THE
STRONGEST STORMS. A BRIEF TORNADO IS POSSIBLE OWING TO AMBIENT
VERTICAL VORTICITY...THOUGH ANY OCCURRENCE SHOULD BE SHORT-LIVED.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM
MOTION VECTOR 24015.
...MEADSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 4, 8:31 PM CDT | Mesoscale Discussion | SPC | Calhoun, Clark, Columbia, Conway, Crawford, Dallas and 24 more | 119 min |
| Apr 5, 1:35 AM CDT | Mesoscale Discussion | SPC | Ashley, Chicot | 85 min |
| Apr 5, 1:53 AM CDT | Tornado Watch | SPC | Ashley, Chicot | 9 hr |
| Apr 5, 3:30 AM CDT | Mesoscale Discussion | SPC | Ashley, Chicot, Union | 2 hr |
| Apr 5, 7:36 AM CDT | Mesoscale Discussion | SPC | Chicot | 54 min |
| Apr 5, 12:09 PM CDT | Mesoscale Discussion | SPC | Clay, Craighead, Crittenden, Greene, Mississippi, Randolph | 96 min |
| Apr 5, 3:56 AM CDT | Tornado Watch | SPC | Amite, Hancock, Harrison, Jackson, Pearl River, Pike and 2 more | 6 hr |
| Apr 5, 9:14 AM CDT | Severe Thunderstorm Watch | SPC | Greene, Perry, Wayne | 8 hr |
| Apr 5, 10:41 AM CDT | Mesoscale Discussion | SPC | Greene, Wayne | 94 min |
| Apr 5, 10:43 AM CDT | Severe Thunderstorm Watch | SPC | Clarke, Covington, Forrest, Franklin, Jasper, Jefferson Davis and 7 more | 4 hr |
| Apr 5, 2:22 PM CDT | Mesoscale Discussion | SPC | Alcorn, Benton, Calhoun, Chickasaw, DeSoto, Itawamba and 14 more | 53 min |
| Apr 5, 12:54 PM CDT | Mesoscale Discussion | SPC | Anderson, Bledsoe, Blount, Bradley, Campbell, Claiborne and 23 more | 96 min |
| Apr 5, 1:21 PM CDT | Severe Thunderstorm Watch | SPC | Anderson, Bedford, Benton, Bledsoe, Blount, Bradley and 61 more | 8 hr |
| Apr 5, 3:06 PM CDT | Mesoscale Discussion | SPC | Anderson, Bedford, Bledsoe, Blount, Bradley, Campbell and 60 more | 54 min |
Nearby
Severe Thunderstorm Watches in Mississippi, 2012Severe Thunderstorm Watches in Tennessee, 2012Severe Thunderstorm Watches in Arkansas, 2012Every severe thunderstorm watch in 2012
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.