Alert archive / Mississippi / Tornado Watches in 2015

Tornado Watch 1

January 3, 201528 parishes in Louisiana; 41 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Jan 3, 2015, 11:04 AM CST for 28 parishes in Louisiana; 41 counties in Mississippi. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jan 3, 2015, 11:04 AM CST (17:04 UTC)
Expired
Jan 3, 2015, 6:00 PM CST
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 69 counties

Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Choctaw County, MS, Claiborne County, MS, Clarke County, MS, Clay County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Hancock County, MS, Hinds County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Lowndes County, MS, Madison County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS, Wilkinson County, MS, Winston County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 89 km from the middle of the area, began a volume at 17:04 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
20%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jan 3, 12:31 PM CSTSevere Thunderstorm WarningLIXSaint Helena, Tangipahoa59 min
Jan 3, 1:18 PM CSTSevere Thunderstorm WarningLIXPike, Walthall27 min
Jan 3, 1:23 PM CSTSevere Thunderstorm WarningJANJefferson Davis, Lawrence, Lincoln, Marion67 min
Jan 3, 1:29 PM CSTTornado WarningLIXPike, Walthall31 min
Jan 3, 1:56 PM CSTTornado WarningJANJefferson Davis, Lawrence, Marion37 min
Jan 3, 2:11 PM CSTTornado WarningJANCovington, Jasper, Smith64 min
Jan 3, 2:21 PM CSTFlash Flood WarningJANJefferson Davis, Lawrence114 min
Jan 3, 2:25 PM CSTTornado WarningJANCovington, Simpson35 min
Jan 3, 2:50 PM CSTTornado WarningJANSmith26 min
Jan 3, 2:54 PM CSTTornado WarningJANRankin20 min
Jan 3, 3:05 PM CSTSevere Thunderstorm WarningJANAttala, Choctaw, Montgomery, Winston40 min
Jan 3, 3:08 PM CSTTornado Warning Tornado observedJANJasper, Lauderdale, Newton67 min
Jan 3, 3:15 PM CSTSevere Thunderstorm WarningJANJasper45 min
Jan 3, 3:34 PM CSTSevere Thunderstorm WarningJANChoctaw, Clay, Oktibbeha, Webster41 min
Jan 3, 3:37 PM CSTTornado WarningJANJasper17 min
Jan 3, 3:43 PM CSTFlash Flood WarningJANCovington, Jasper, Newton, Scott, Smith6 hr
Jan 3, 3:51 PM CSTTornado WarningJANLauderdale13 min
Jan 3, 4:01 PM CSTSevere Thunderstorm WarningJANKemper, Lauderdale59 min
Jan 3, 4:02 PM CSTTornado WarningJANClay, Lowndes, Oktibbeha43 min
Jan 3, 4:13 PM CSTFlash Flood WarningJANKemper, Lauderdale6 hr
Jan 3, 4:20 PM CSTFlash Flood WarningJANJefferson Davis, Lawrence, Marion3 hr
Jan 3, 4:23 PM CSTTornado WarningJANKemper, Lauderdale24 min
Jan 3, 4:32 PM CSTTornado WarningJANLowndes43 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 12:00Z, 5.1 hours before the alert went out and 92 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, Jackson, MS at 12:00Z on 2015-01-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 92 joules per kilogram.LCLLFCEL10008507005003002001001 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, Jackson, MS at 12:00Z on 2015-01-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 353 square meters per square second.1939587897Sfc1 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
92 J/kg
Mixed-layer CIN
-86 J/kg
Mixed-layer LCL
505 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
353 m²/s²
0-3 km storm-relative helicity
556 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.3

Open this sounding in Storm Lab

The text

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

972 
WWUS20 KWNS 031703
SEL1  
SPC WW 031703
LAZ000-MSZ000-CWZ000-040000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 1
NWS STORM PREDICTION CENTER NORMAN OK
1105 AM CST SAT JAN 3 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  SOUTHEAST LOUISIANA
  CENTRAL AND SOUTHERN MISSISSIPPI
  COASTAL WATERS

* EFFECTIVE THIS SATURDAY MORNING AND EVENING FROM 1105 AM UNTIL
  600 PM CST.

* PRIMARY THREATS INCLUDE...
  A FEW TORNADOES POSSIBLE
  SCATTERED DAMAGING WIND GUSTS TO 70 MPH LIKELY

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH NORTHWEST OF
MERIDIAN MISSISSIPPI TO 50 MILES SOUTHWEST OF HOUMA LOUISIANA. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU1).

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.

&&

DISCUSSION...THUNDERSTORMS ARE INCREASING OVER SOUTHEAST LA.  THIS
ACTIVITY WILL TRACK NORTHEASTWARD ACROSS THE WATCH AREA THIS
AFTERNOON.  STRONG WINDS ALOFT AND SUFFICIENT INSTABILITY WILL POSE
A RISK OF A FEW SEVERE STORMS CAPABLE OF DAMAGING WINDS AND ISOLATED
TORNADOES.

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 22035.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 3, 10:24 AM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Lafourche and 14 more2 hr
Jan 3, 12:00 PM CSTMesoscale DiscussionSPCSaint Bernard90 min
Jan 3, 1:43 PM CSTMesoscale DiscussionSPCEast Baton Rouge, East Feliciana, Livingston, Saint Helena, Tangipahoa, Washington92 min
Jan 3, 5:31 PM CSTMesoscale DiscussionSPCLivingston, Saint John the Baptist, Saint Tammany, Tangipahoa, Washington44 min
Jan 3, 2:54 PM CSTMesoscale DiscussionSPCChoctaw, Clarke, Clay, Covington, Jasper, Jefferson Davis and 16 more96 min

Nearby

Tornado Watches in Mississippi, 2015Tornado Watches in Louisiana, 2015Every 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.