Alert archive / Mississippi / Mesoscale Discussions in 2012
Mesoscale Discussion 323
The Storm Prediction Center issued this mesoscale discussion at Mar 21, 2012, 11:49 PM CDT for Saint Bernard Parish, Louisiana; 8 counties in Mississippi. It was in force for 56 min.
The area
The outline as issued.
The facts
- Issued
- Mar 21, 2012, 11:49 PM CDT (04:49 UTC)
- Expired
- Mar 22, 2012, 12:45 AM CDT
- In force
- 56 min
- Issued by
- the Storm Prediction Center
Counties Saint Bernard Parish, LA, Clarke County, MS, George County, MS, Greene County, MS, Harrison County, MS, Jackson County, MS, Lauderdale County, MS, Stone County, MS, Wayne County, MS
The radar
The Mobile radar (KMOB), 66 km from the middle of the area, began a volume at 04:51 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
Slidell Radar S, LA (KSIL), launched 00:00Z, 4.8 hours before the alert went out and 83 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
- 131 J/kg
- Mixed-layer CIN
- -28 J/kg
- Mixed-layer LCL
- 505 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- -10 m²/s²
- 0-3 km storm-relative helicity
- 17 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
189
ACUS11 KWNS 220449
SWOMCD
SPC MCD 220449
ALZ000-MSZ000-LAZ000-220545-
MESOSCALE DISCUSSION 0323
NWS STORM PREDICTION CENTER NORMAN OK
1149 PM CDT WED MAR 21 2012
AREAS AFFECTED...SERN MS
CONCERNING...TORNADO WATCH 98...
VALID 220449Z - 220545Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 98 CONTINUES.
AN AREA OF LOW LEVEL CONVERGENCE EXTENDED FROM SERN MS SSWWD THROUGH
FAR SERN LA AND THEN OFFSHORE INTO THE GULF OF MEXICO TO AT LEAST
200 SSW BVE. OBJECTIVE ANALYSES INDICATED DEEP LAYER MOISTURE FLUX
CONVERGENCE EXISTED OVER SERN MS AND THUS SHOULD SUPPORT ADDITIONAL
CONVECTION/TSTM DEVELOPMENT FOR THE NEXT SEVERAL HOURS. TRENDS IN
LATE EVENING REGIONAL RADAR IMAGERY INDICATED THE REDEVELOPMENT OF
TSTMS OFFSHORE SERN MS /HARRISON COUNTY/ DURING THE LAST 3 HOURS...
WITH MORE RECENT TSTM DEVELOPMENT SWD ACROSS FAR SERN LA. CAPE/
SHEAR PARAMETER SPACE /MUCAPE OF 500-1000 J/KG...EFFECTIVE BULK
SHEAR 40-50 KT AND EFFECTIVE SRH OF 200 M2 PER S2/ REMAIN SUFFICIENT
FOR ROTATING UPDRAFTS PRIMARILY OFFSHORE AND COASTAL AREAS.
FARTHER N ACROSS EAST CENTRAL MS...GREATER INHIBITION IS LIKELY
DETERRING PARCELS FROM REMAINING SURFACE BASED AND THUS LIMITING THE
TORNADO THREAT WITH NWD EXTENT.
..PETERS.. 03/22/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BMX...MOB...JAN...LIX...
LAT...LON 29138897 29508958 30228940 31518883 32578887 32568843
29788825 29278840 29138897SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 21, 9:27 PM CDT | Mesoscale Discussion | SPC | Plaquemines, Saint Bernard | 93 min |
| Mar 22, 2:28 AM CDT | Mesoscale Discussion | SPC | George, Greene, Jackson | 2 hr |
| Mar 22, 6:49 AM CDT | Mesoscale Discussion | SPC | George, Jackson | 116 min |
| Mar 22, 7:15 AM CDT | Tornado Watch | SPC | George, Harrison, Jackson, Stone | 5 hr |
| Mar 22, 9:53 AM CDT | Mesoscale Discussion | SPC | Jackson | 67 min |
Nearby
Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Louisiana, 2012Every mesoscale discussion in 2012
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.