Alert archive / Mississippi / Tornado Watches in 2016

Tornado Watch 505

November 29, 201618 counties in Mississippi; 6 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Nov 29, 2016, 3:48 PM CST for 18 counties in Mississippi; 6 counties in Tennessee. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Nov 29, 2016, 3:48 PM CST (21:48 UTC)
Expired
Nov 29, 2016, 11:00 PM CST
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 24 counties

Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw 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, Tippah County, MS, Tishomingo County, MS, Union County, MS, Yalobusha County, MS, Chester County, TN, Hardeman County, TN, Hardin County, TN, Lawrence County, TN, McNairy County, TN, Wayne County, TN

The radar

The Memphis radar (KNQA), 107 km from the middle of the area, began a volume at 21:48 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
70%
One or more EF2 to EF5 tornadoes
40%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Nov 29, 4:14 PM CSTSevere Thunderstorm WarningMEGCalhoun, Tallahatchie, Yalobusha46 min
Nov 29, 4:56 PM CSTSevere Thunderstorm WarningMEGCalhoun, Chickasaw, Pontotoc49 min
Nov 29, 5:08 PM CSTTornado WarningMEGCalhoun, Chickasaw, Pontotoc37 min
Nov 29, 5:40 PM CSTSevere Thunderstorm WarningMEGChickasaw, Itawamba, Lee, Pontotoc50 min
Nov 29, 5:47 PM CSTSevere Thunderstorm WarningMEGCalhoun, Yalobusha43 min
Nov 29, 5:53 PM CSTFlash Flood WarningMEGCalhoun, Chickasaw, Lafayette, Pontotoc, Yalobusha3 hr
Nov 29, 6:01 PM CSTSevere Thunderstorm WarningMEGChickasaw, Monroe44 min
Nov 29, 6:16 PM CSTTornado Warning Tornado observedMEGMonroe44 min
Nov 29, 6:23 PM CSTSevere Thunderstorm WarningMEGCalhoun, Chickasaw, Pontotoc52 min
Nov 29, 6:29 PM CSTSevere Thunderstorm WarningMEGItawamba, Tishomingo31 min
Nov 29, 6:49 PM CSTFlash Flood WarningMEGAlcorn, Benton, Chickasaw, Itawamba, Lee, Monroe and 5 more6 hr
Nov 29, 7:01 PM CSTSevere Thunderstorm WarningMEGMonroe12 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 (KBYH), launched 12:00Z, 9.8 hours before the alert went out and 68 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, Little Rock, AR at 12:00Z on 2016-11-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Little Rock, AR at 12:00Z on 2016-11-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 180 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1496 m above ground
0-6 km bulk shear
92 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
338 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

757 
WWUS20 KWNS 292146
SEL5  
SPC WW 292146
ALZ000-MSZ000-TNZ000-300500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 505
NWS STORM PREDICTION CENTER NORMAN OK
350 PM CST TUE NOV 29 2016

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  EXTREME NORTHWEST ALABAMA
  NORTHEAST MISSISSIPPI
  A SMALL PART OF WESTERN AND SOUTHERN MIDDLE TENNESSEE

* EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 350 PM UNTIL
  1100 PM CST.

* PRIMARY THREATS INCLUDE...
  A FEW TORNADOES LIKELY WITH A COUPLE INTENSE TORNADOES POSSIBLE
  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
  ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE

SUMMARY...SCATTERED SUPERCELLS IN MISSISSIPPI WILL SPREAD
NORTHEASTWARD THROUGH THE EVENING AND LIKELY BEGIN TO AFFECT AREAS
AS FAR NORTHEAST AS ALABAMA AND TENNESSEE BY ABOUT 6-7 PM CST.  AS
THE STORM ENVIRONMENT BECOMES MORE FAVORABLE FOR ROTATING STORMS...
THERE WILL BE THE POTENTIAL FOR A COUPLE OF STRONG TORNADOES
(ESPECIALLY ACROSS NORTHEAST MISSISSIPPI)...AS WELL AS LARGE HAIL AND
DAMAGING WINDS THROUGH EARLY TONIGHT.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE MILES
EAST AND WEST OF A LINE FROM 40 MILES SOUTH SOUTHWEST OF OXFORD MS
TO 90 MILES NORTH NORTHEAST OF TUPELO MS. FOR A COMPLETE DEPICTION
OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS
WOU5).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 504...

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN
STORM MOTION VECTOR 24045.

...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 28, 6:36 PM CSTMesoscale DiscussionSPCClarke, Covington, Forrest, George, Greene, Jasper and 11 more2 hr
Nov 28, 8:39 PM CSTMesoscale DiscussionSPCAmite, Clarke, Covington, Forrest, George, Greene and 12 more96 min
Nov 28, 11:38 PM CSTMesoscale DiscussionSPCForrest, George, Greene, Lamar, Marion, Pearl River and 4 more3 hr
Nov 29, 12:38 PM CSTMesoscale DiscussionSPCAdams, Amite, Claiborne, Copiah, Covington, Franklin and 18 more2 hr
Nov 29, 1:48 PM CSTTornado WatchSPCAdams, Attala, Bolivar, Carroll, Choctaw, Claiborne and 27 more7 hr
Nov 29, 3:08 PM CSTMesoscale DiscussionSPCAlcorn, Benton, Bolivar, Calhoun, Chickasaw, Clay and 17 more2 hr
Nov 29, 4:20 PM CSTMesoscale DiscussionSPCAttala, Carroll, Choctaw, Claiborne, Copiah, Hinds and 17 more55 min
Nov 29, 5:24 PM CSTMesoscale DiscussionSPCItawamba, Tishomingo96 min

Nearby

Tornado Watches in Mississippi, 2016Tornado Watches in Tennessee, 2016Every tornado watch in 2016

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.