Alert archive / Mississippi / Tornado Watches in 2015

Tornado Watch 574

December 28, 201513 parishes in Louisiana; 66 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Dec 28, 2015, 2:23 AM CST for 13 parishes in Louisiana; 66 counties in Mississippi. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: Dec 28, 2015, 2:23 AM CST (08:23 UTC)
Expired: Dec 28, 2015, 10:00 AM CST
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1 in
Strongest gust expected: 60 kt

All 79 counties

Assumption Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, Alcorn County, MS, Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Coahoma County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, George County, MS, Greene County, MS, Grenada County, MS, Hancock County, MS, Harrison County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Itawamba County, MS, Jackson County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lee County, MS, Leflore County, MS, Lincoln County, MS, Lowndes County, MS, Madison County, MS, Marion County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Panola County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Sunflower County, MS, Tallahatchie County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Walthall County, MS, Wayne County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 16 km from the middle of the area, began a volume at 08:23 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: 50%
One or more EF2 to EF5 tornadoes: 30%
Ten or more severe wind reports: 40%
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: 70%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Dec 28, 2:35 AM CST	Severe Thunderstorm Warning	LIX	Ascension, Assumption, Livingston, Saint James, Saint John the Baptist	40 min
Dec 28, 2:48 AM CST	Severe Thunderstorm Warning	JAN	Lincoln	57 min
Dec 28, 2:53 AM CST	Tornado Warning	LIX	Livingston, Saint Helena, Tangipahoa	67 min
Dec 28, 3:03 AM CST	Severe Thunderstorm Warning	LIX	Livingston, Saint Helena, Tangipahoa	57 min
Dec 28, 3:05 AM CST	Severe Thunderstorm Warning	LIX	Lafourche, Terrebonne	40 min
Dec 28, 3:11 AM CST	Severe Thunderstorm Warning	JAN	Claiborne, Copiah, Jefferson	64 min
Dec 28, 3:18 AM CST	Tornado Warning	JAN	Franklin, Lincoln	57 min
Dec 28, 3:28 AM CST	Tornado Warning	LIX	Saint John the Baptist, Tangipahoa	32 min
Dec 28, 3:30 AM CST	Severe Thunderstorm Warning	JAN	Hinds, Issaquena, Warren	60 min
Dec 28, 3:33 AM CST	Tornado Warning	LIX	Saint Tammany, Tangipahoa, Washington	27 min
Dec 28, 3:47 AM CST	Severe Thunderstorm Warning	LIX	Saint Tammany, Tangipahoa, Washington	58 min
Dec 28, 3:58 AM CST	Severe Thunderstorm Warning	JAN	Copiah	37 min
Dec 28, 4:00 AM CST	Tornado Warning	LIX	Saint Tammany, Washington	30 min
Dec 28, 4:09 AM CST	Severe Thunderstorm Warning	MEG	Coahoma	51 min
Dec 28, 4:10 AM CST	Severe Thunderstorm Warning	JAN	Holmes, Humphreys, Yazoo	65 min
Dec 28, 4:13 AM CST	Severe Thunderstorm Warning	JAN	Hinds, Madison, Rankin, Simpson	62 min
Dec 28, 4:22 AM CST	Severe Thunderstorm Warning	JAN	Lawrence	38 min
Dec 28, 4:28 AM CST	Tornado Warning	LIX	Saint Tammany	32 min
Dec 28, 4:29 AM CST	Severe Thunderstorm Warning	LIX	Washington	31 min
Dec 28, 4:32 AM CST	Severe Thunderstorm Warning	JAN	Jefferson Davis, Lawrence, Marion	58 min
Dec 28, 4:35 AM CST	Tornado Warning	LIX	Washington	25 min
Dec 28, 4:47 AM CST	Severe Thunderstorm Warning	LIX	Orleans, Plaquemines, Saint Bernard, Saint Tammany	28 min
Dec 28, 4:50 AM CST	Tornado Warning	JAN	Lamar, Marion	43 min
Dec 28, 4:51 AM CST	Severe Thunderstorm Warning	JAN	Carroll, Holmes, Leflore, Sunflower	54 min
Dec 28, 4:59 AM CST	Severe Thunderstorm Warning	MEG	Coahoma, Tunica	46 min
Dec 28, 5:01 AM CST	Severe Thunderstorm Warning	JAN	Rankin, Simpson	59 min
Dec 28, 5:10 AM CST	Severe Thunderstorm Warning	JAN	Attala, Holmes, Leake, Madison, Yazoo	65 min
Dec 28, 5:25 AM CST	Severe Thunderstorm Warning	JAN	Covington, Forrest, Jefferson Davis, Jones, Lamar	65 min
Dec 28, 5:28 AM CST	Tornado Warning	JAN	Covington, Jefferson Davis	47 min
Dec 28, 5:33 AM CST	Severe Thunderstorm Warning	JAN	Leake, Scott, Smith	72 min
Dec 28, 5:41 AM CST	Severe Thunderstorm Warning	MEG	Tunica	49 min
Dec 28, 5:45 AM CST	Severe Thunderstorm Warning	JAN	Carroll, Grenada, Montgomery	75 min
Dec 28, 5:51 AM CST	Severe Thunderstorm Warning	MEG	DeSoto, Panola, Quitman, Tallahatchie, Tate, Tunica and 1 more	39 min
Dec 28, 5:55 AM CST	Severe Thunderstorm Warning	JAN	Attala	69 min
Dec 28, 6:06 AM CST	Tornado Warning	JAN	Jasper, Jones, Smith	40 min
Dec 28, 6:19 AM CST	Severe Thunderstorm Warning	JAN	Forrest, Jones	56 min
Dec 28, 6:23 AM CST	Severe Thunderstorm Warning	MEG	DeSoto, Panola, Tate, Tunica	67 min
Dec 28, 6:31 AM CST	Tornado Warning	LIX	Harrison	29 min
Dec 28, 6:38 AM CST	Severe Thunderstorm Warning	JAN	Choctaw, Webster	82 min
Dec 28, 6:41 AM CST	Severe Thunderstorm Warning	MOB	George, Greene, Perry, Wayne	49 min
Dec 28, 6:48 AM CST	Severe Thunderstorm Warning	JAN	Choctaw, Winston	72 min
Dec 28, 6:53 AM CST	Severe Thunderstorm Warning	MOB	Perry, Stone	52 min
Dec 28, 6:59 AM CST	Tornado Warning	MOB	Greene, Wayne	46 min
Dec 28, 7:28 AM CST	Tornado Warning	MOB	Wayne	47 min
Dec 28, 7:33 AM CST	Severe Thunderstorm Warning	JAN	Clarke, Lauderdale	45 min
Dec 28, 7:50 AM CST	Severe Thunderstorm Warning	JAN	Oktibbeha	55 min
Dec 28, 7:56 AM CST	Severe Thunderstorm Warning	MEG	Calhoun, Chickasaw, Lafayette, Lee, Pontotoc, Union	49 min
Dec 28, 8:05 AM CST	Severe Thunderstorm Warning	JAN	Clay	55 min
Dec 28, 8:13 AM CST	Severe Thunderstorm Warning	MOB	George, Greene, Wayne	62 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

Jackson, MS (KJAN), launched 00:00Z, 8.4 hours before the alert went out and 26 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: 1137 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 767 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 204 m²/s²
0-3 km storm-relative helicity: 306 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 8.4

Open this sounding in Storm Lab

The text

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

934 
WWUS20 KWNS 280821
SEL4  
SPC WW 280821
LAZ000-MSZ000-CWZ000-281400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 574
NWS STORM PREDICTION CENTER NORMAN OK
225 AM CST MON DEC 28 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  SOUTHEAST LOUISIANA
  MISSISSIPPI
  COASTAL WATERS

* EFFECTIVE THIS MONDAY MORNING FROM 225 AM UNTIL 800 AM CST.

* PRIMARY THREATS INCLUDE...
  A FEW TORNADOES AND A COUPLE INTENSE TORNADOES POSSIBLE
  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
  ISOLATED LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE

SUMMARY...A LINE OF STRONG THUNDERSTORMS EXTENDING FROM SOUTHERN AR
SOUTHWARD ACROSS EASTERN LA WILL TRACK EASTWARD ACROSS THE WATCH
AREA THROUGH DAYBREAK.  SOME INTENSIFICATION OF THE LINE IS EXPECTED
EARLY THIS MORNING...WITH DAMAGING WINDS AND A FEW TORNADOES
POSSIBLE.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 5 MILES NORTHWEST OF OXFORD
MISSISSIPPI TO 40 MILES SOUTH SOUTHWEST OF BOOTHVILLE LOUISIANA. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU4).

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 573...

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 22040.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 27, 7:11 PM CST	Mesoscale Discussion	SPC	Allen, Beauregard, Bienville, Bossier, Caddo, Claiborne and 10 more	94 min
Dec 27, 8:59 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 30 more	91 min
Dec 27, 9:57 PM CST	Tornado Watch	SPC	Acadia, Allen, Ascension, Avoyelles, Beauregard, Bienville and 38 more	7 hr
Dec 27, 11:49 PM CST	Mesoscale Discussion	SPC	Acadia, Avoyelles, Bienville, Caldwell, Catahoula, Concordia and 26 more	86 min
Dec 28, 2:03 AM CST	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Carroll, East Feliciana, Franklin and 19 more	117 min
Dec 28, 5:14 AM CST	Mesoscale Discussion	SPC	Jefferson, Orleans, Plaquemines, Saint Bernard, Saint Tammany, Washington	2 hr

Nearby

Tornado Watches in Mississippi, 2015 Tornado Watches in Louisiana, 2015 Every tornado watch in 2015

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.