Alert archive / Mississippi / Mesoscale Discussions in 2011
Mesoscale Discussion 2116
The Storm Prediction Center issued this mesoscale discussion at Sep 4, 2011, 4:30 AM CDT for 4 states. It was in force for 60 min.
The area
The outline as issued.
The facts
- Issued
- Sep 4, 2011, 4:30 AM CDT (09:30 UTC)
- Expired
- Sep 4, 2011, 5:30 AM CDT
- In force
- 60 min
- Issued by
- the Storm Prediction Center
All 45 counties
Baldwin County, AL, Clarke County, AL, Conecuh County, AL, Escambia County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Escambia County, FL, Santa Rosa County, FL, Ascension Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines 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 Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, Amite County, MS, Covington County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson 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, Stone County, MS, Walthall County, MS, Wayne County, MS
The radar
The Mobile radar (KMOB), 66 km from the middle of the area, began a volume at 09:29 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Slidell Radar S, LA (KSIL), launched 00:00Z, 9.5 hours before the alert went out and 89 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
- 1081 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 495 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 150 m²/s²
- 0-3 km storm-relative helicity
- 154 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
255
ACUS11 KWNS 040931
SWOMCD
SPC MCD 040930
FLZ000-ALZ000-MSZ000-LAZ000-041030-
MESOSCALE DISCUSSION 2116
NWS STORM PREDICTION CENTER NORMAN OK
0430 AM CDT SUN SEP 04 2011
AREAS AFFECTED...SERN LA...SRN MS...SWRN AL AND THE WRN FL PANHANDLE
CONCERNING...TORNADO WATCH 830...
VALID 040930Z - 041030Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 830 CONTINUES.
TORNADO WATCH 830 WILL BE REPLACED BY ANOTHER TORNADO WATCH SOON
THAT WILL REMAIN VALID INTO THE AFTERNOON. TORNADO THREAT IS
EXPECTED TO EXPAND A LITTLE FARTHER NWD INTO SRN MS AND SWRN AL.
CENTER OF TROPICAL STORM LEE IS LOCATED NEAR THE CNTRL LA COAST AND
IS EXPECTED TO MOVE VERY SLOWLY NWD OR NNEWD TODAY. SEE THE LATEST
DISCUSSIONS FROM NHC FOR MORE INFORMATION. CORRIDOR OF HIGHEST
THETA-E AIR IS ENTRAINING NWD FROM SERN LA THROUGH SERN MS AND SWRN
AL WHICH IS ALSO CO-LOCATED WITH THE LARGEST LOW LEVEL HODOGRAPHS.
WITH MID-UPPER DRY AIR CONTINUING TO WRAP AROUND THE SRN PERIPHERY
OF LEE...POTENTIAL WILL EXIST FOR SOME HEATING BETWEEN THE BANDS
LATER THIS MORNING INTO THE AFTERNOON AS LOW CLOUDS MIX OUT...WHICH
WOULD BOOST UPDRAFT STRENGTH AND SUBSEQUENT TORNADO THREAT.
..DIAL.. 09/04/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MOB...JAN...LIX...
LAT...LON 29538715 29258955 29389090 30699121 31689049 31838717
30588660 29538715SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 3, 9:43 PM CDT | Tornado Watch | SPC | Baldwin, Butler, Choctaw, Clarke, Conecuh, Covington and 6 more | 9 hr |
| Sep 3, 11:35 PM CDT | Mesoscale Discussion | SPC | Baldwin, Escambia, Mobile, Washington | 115 min |
| Sep 4, 5:05 AM CDT | Tornado Watch | SPC | Baldwin, Butler, Choctaw, Clarke, Coffee, Conecuh and 8 more | 11 hr |
| Sep 4, 9:50 AM CDT | Mesoscale Discussion | SPC | Baldwin, Butler, Choctaw, Clarke, Coffee, Conecuh and 12 more | 85 min |
| Sep 4, 11:41 AM CDT | Tornado Watch | SPC | Coffee, Dale, Geneva, Henry, Houston | 10 hr |
| Sep 4, 2:47 PM CDT | Mesoscale Discussion | SPC | Autauga, Baldwin, Bibb, Butler, Chilton, Choctaw and 26 more | 88 min |
| Sep 4, 3:47 PM CDT | Tornado Watch | SPC | Autauga, Baldwin, Butler, Choctaw, Clarke, Conecuh and 13 more | 6 hr |
| Sep 4, 6:29 PM CDT | Mesoscale Discussion | SPC | Autauga, Baldwin, Barbour, Bullock, Butler, Choctaw and 22 more | 2 hr |
| Sep 4, 11:27 AM CDT | Mesoscale Discussion | SPC | Calhoun, Gadsden, Jackson, Jefferson, Leon, Liberty and 2 more | 33 min |
Nearby
Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Louisiana, 2011Mesoscale Discussions in Alabama, 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.