Alert archive / Louisiana / Mesoscale Discussions in 2011
Mesoscale Discussion 209
The Storm Prediction Center issued this mesoscale discussion at Mar 8, 2011, 9:40 PM CST for Columbia County, Lafayette County, Union County, Arkansas; 38 parishes in Louisiana; 35 counties in Mississippi. It was in force for 65 min.
The area
The outline as issued.
The facts
- Issued
- Mar 8, 2011, 9:40 PM CST (03:40 UTC)
- Expired
- Mar 8, 2011, 10:45 PM CST
- In force
- 65 min
- Issued by
- the Storm Prediction Center
All 76 counties
Columbia County, AR, Lafayette County, AR, Union County, AR, Avoyelles Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Livingston Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Saint Helena Parish, LA, Saint Landry Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, Washington Parish, LA, Webster Parish, LA, West Baton Rouge Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Hinds County, MS, Issaquena County, MS, Jackson County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion 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, Warren County, MS, Wayne County, MS, Wilkinson County, MS
The radar
The Jackson/Brandon,MS radar (KDGX), 151 km from the middle of the area, began a volume at 03:40 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.
The nearest sounding before it
Jackson, MS (KJAN), launched 00:00Z, 3.7 hours before the alert went out and 143 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 600 m above ground
- 0-6 km bulk shear
- 65 kt
- 0-1 km storm-relative helicity
- 542 m²/s²
- 0-3 km storm-relative helicity
- 664 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
933 ACUS11 KWNS 090340 SWOMCD SPC MCD 090340 ALZ000-MSZ000-LAZ000-ARZ000-TXZ000-090445- MESOSCALE DISCUSSION 0209 NWS STORM PREDICTION CENTER NORMAN OK 0940 PM CST TUE MAR 08 2011 AREAS AFFECTED...SRN AR...LA...SRN MS...SWRN AL CONCERNING...TORNADO WATCH 44... VALID 090340Z - 090445Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 44 CONTINUES. WARM ADVECTION CONTINUES TO DRIVE A SUBSTANTIAL AMOUNT OF CONVECTION ACROSS TORNADO WATCH #44 THIS EVENING. AS LLJ BEGINS TO INCREASE ACROSS MS INTO TN IT APPEARS A GRADUAL NWD SHIFT TO ONGOING ELEVATED CONVECTION WILL ENSURE RAIN-COOLED AIRMASS OVER NRN GULF STATES WILL STUBBORNLY HOLD. AS A RESULT...SLOWLY RETREATING NW-SE ORIENTED WARM FRONT WILL REMAIN THE PRIMARY FOCUS FOR NEAR-SFC BASED SUPERCELL DEVELOPMENT. DURING THE LAST HOUR OR SO A POTENTIALLY TORNADIC CYCLICAL SUPERCELL HAS TRACKED ACROSS CNTRL LA AND AT 0330Z IS JUST SE OF ESF. THIS STORM SHOULD ENCOUNTER THE WARM FRONT OVER NERN LA BEFORE LIFTING ATOP AFOREMENTIONED COOLER AIRMASS. OTHER STORMS HAVE STRUGGLED TO ATTAIN ANY MEANINGFUL INTENSITY ALONG SURGING COLD FRONT AS IT SWEEPS ACROSS NWRN PORTIONS OF WW. ..DARROW.. 03/09/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...JAN...LIX...LCH...SHV... LAT...LON 33429362 32208841 29748841 30969363 33429362
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 8, 6:27 PM CST | Mesoscale Discussion | SPC | Bradley, Calhoun, Columbia, Hempstead, Howard, Lafayette and 6 more | 63 min |
| Mar 8, 7:37 PM CST | Tornado Watch | SPC | Ashley, Bradley, Calhoun, Columbia, Hempstead, Lafayette and 4 more | 7 hr |
| Mar 9, 1:28 AM CST | Mesoscale Discussion | SPC | Ashley, Union | 92 min |
| Mar 9, 6:28 AM CST | Mesoscale Discussion | SPC | Ashley, Union | 92 min |
| Mar 9, 2:39 AM CST | Tornado Watch | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more | 5 hr |
| Mar 9, 4:39 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, Iberville, Livingston, Orleans and 9 more | 66 min |
| Mar 9, 7:26 AM CST | Tornado Watch | SPC | Plaquemines, Saint Bernard | 6 hr |
| Mar 9, 9:31 AM CST | Mesoscale Discussion | SPC | Plaquemines, Saint Bernard | 59 min |
Nearby
Mesoscale Discussions in Louisiana, 2011Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Arkansas, 2011Every mesoscale discussion 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.