Alert archive / Mississippi / Tornado Watches in 2011
Tornado Watch 377
The Storm Prediction Center issued this tornado watch at May 25, 2011, 9:43 PM CDT for 20 parishes in Louisiana; 39 counties in Mississippi. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- May 25, 2011, 9:43 PM CDT (02:43 UTC)
- Expired
- May 26, 2011, 3:07 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
All 59 counties
Avoyelles Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Vernon Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Attala County, MS, Carroll County, MS, Choctaw County, MS, Claiborne County, MS, Clay County, MS, Copiah County, MS, Franklin County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jasper County, MS, Jefferson County, MS, Kemper County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Leflore County, MS, Lincoln County, MS, Lowndes County, MS, Madison County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS
The radar
The Jackson/Brandon,MS radar (KDGX), 49 km from the middle of the area, began a volume at 02:46 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 70%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
15 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 25, 9:45 PM CDT | Tornado Warning | SHV | Natchitoches, Sabine | 30 min |
| May 25, 9:45 PM CDT | Severe Thunderstorm Warning | JAN | Bolivar, Washington | 21 min |
| May 25, 9:52 PM CDT | Tornado Warning | JAN | Holmes, Humphreys, Leflore, Sunflower | 23 min |
| May 25, 9:53 PM CDT | Severe Thunderstorm Warning | JAN | Sharkey, Washington | 22 min |
| May 25, 9:57 PM CDT | Severe Thunderstorm Warning | SHV | Caldwell, LaSalle, Winn | 39 min |
| May 25, 10:02 PM CDT | Flash Flood Warning | JAN | Grenada | 79 min |
| May 25, 10:09 PM CDT | Severe Thunderstorm Warning | JAN | Carroll, Choctaw, Clay, Montgomery, Oktibbeha, Webster | 66 min |
| May 25, 10:16 PM CDT | Tornado Warning | SHV | Grant, Natchitoches, Winn | 44 min |
| May 25, 10:18 PM CDT | Severe Thunderstorm Warning | JAN | Holmes, Humphreys, Leflore, Sunflower | 42 min |
| May 25, 10:21 PM CDT | Tornado Warning | JAN | Carroll | 24 min |
| May 25, 11:06 PM CDT | Severe Thunderstorm Warning | SHV | Grant, LaSalle, Natchitoches | 39 min |
| May 25, 11:15 PM CDT | Severe Thunderstorm Warning | LCH | Avoyelles, Rapides | 60 min |
| May 26, 12:12 AM CDT | Severe Thunderstorm Warning | LCH | Avoyelles, Rapides | 63 min |
| May 26, 12:28 AM CDT | Severe Thunderstorm Warning | JAN | Catahoula, Concordia | 57 min |
| May 26, 12:32 AM CDT | Severe Thunderstorm Warning | JAN | Attala, Choctaw, Montgomery | 43 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, 2.7 hours before the alert went out and 39 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
- 1200 J/kg
- Mixed-layer CIN
- -105 J/kg
- Mixed-layer LCL
- 2164 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 104 m²/s²
- 0-3 km storm-relative helicity
- 160 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.0
The text
As transmitted, in the capitals the NWS used until 2016.
646
WWUS20 KWNS 260241
SEL7
SPC WW 260241
LAZ000-MSZ000-260900-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 377
NWS STORM PREDICTION CENTER NORMAN OK
945 PM CDT WED MAY 25 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
PARTS OF CENTRAL AND NORTHEAST LOUISIANA
LARGE PART OF CENTRAL MISSISSIPPI
EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 945 PM
UNTIL 400 AM CDT.
TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTHEAST OF
COLUMBUS MISSISSIPPI TO 25 MILES WEST SOUTHWEST OF FORT POLK
LOUISIANA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).
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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 374. WATCH NUMBER 374 WILL NOT BE IN EFFECT AFTER
945 PM CDT. CONTINUE...WW 373...WW 375...WW 376...
DISCUSSION...SEVERE THUNDERSTORMS EXPECTED TO CONTINUE DEVELOPING
E/SE ACROSS THE WATCH AREA WHERE A MDTLY UNSTABLE AND FAVORABLE
SHEARED AIR MASS IS IN PLACE. IN ADDITION TO LARGE HAIL/DAMAGING
WINDS...TORNADOES WILL BE POSSIBLE...PARTICULARLY ASSOCIATED WITH
ANY SUPERCELL.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 25030.
...HALESSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 25, 7:22 PM CDT | Mesoscale Discussion | SPC | Union | 53 min |
| May 25, 7:45 PM CDT | Mesoscale Discussion | SPC | Bienville, Caldwell, De Soto, Grant, Jackson, Lincoln and 9 more | 60 min |
| May 26, 2:05 AM CDT | Mesoscale Discussion | SPC | Ascension, East Baton Rouge, East Feliciana, Iberville, Livingston, Orleans and 10 more | 85 min |
| May 26, 5:18 PM CDT | Mesoscale Discussion | SPC | Orleans, Saint Bernard, Saint Tammany | 57 min |
| May 25, 8:33 PM CDT | Tornado Watch | SPC | Alcorn, Benton, Calhoun, Chickasaw, DeSoto, Itawamba and 14 more | 7 hr |
| May 25, 10:27 PM CDT | Mesoscale Discussion | SPC | Attala, Calhoun, Carroll, Chickasaw, Choctaw, Clay and 14 more | 2 hr |
| May 26, 7:56 AM CDT | Mesoscale Discussion | SPC | Lowndes | 94 min |
| May 26, 12:22 PM CDT | Mesoscale Discussion | SPC | Clarke, Covington, Forrest, George, Greene, Jasper and 6 more | 83 min |
Nearby
Tornado Watches in Mississippi, 2011Tornado Watches in Louisiana, 2011Every 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.