Alert archive / Mississippi / Mesoscale Discussions in 2012

Mesoscale Discussion 216

March 2, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Mar 2, 2012, 2:42 PM CST for 4 states. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Mar 2, 2012, 2:42 PM CST (20:42 UTC)
Expired
Mar 2, 2012, 3:45 PM CST
In force
63 min
Issued by
the Storm Prediction Center
All 68 counties

Autauga County, AL, Baldwin County, AL, Bullock County, AL, Butler County, AL, Choctaw County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Hale County, AL, Lowndes County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Sumter County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Ascension Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Livingston Parish, LA, Saint Helena Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, Amite 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, Jackson County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Newton 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

The radar

The Mobile radar (KMOB), 76 km from the middle of the area, began a volume at 20:44 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 12:00Z, 8.7 hours before the alert went out and 190 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, Slidell Radar S, LA at 12:00Z on 2012-03-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 720 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, Slidell Radar S, LA at 12:00Z on 2012-03-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 165 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
720 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
473 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
165 m²/s²
0-3 km storm-relative helicity
257 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.9

Open this sounding in Storm Lab

The text

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

111 
ACUS11 KWNS 022042
SWOMCD
SPC MCD 022042 
ALZ000-FLZ000-MSZ000-LAZ000-022145-

MESOSCALE DISCUSSION 0216
NWS STORM PREDICTION CENTER NORMAN OK
0242 PM CST FRI MAR 02 2012

AREAS AFFECTED...SRN AL/MS...SERN LA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 022042Z - 022145Z

A THREAT FOR ISOLATED DMGG WIND/HAIL REPORTS AND PERHAPS A TORNADO
WILL BE POSSIBLE THIS AFTERNOON/EVENING ACROSS SRN AL/MS AND SERN
LA. COVERAGE IS ANTICIPATED TO REMAIN TOO SPARSE TO WARRANT WW
ISSUANCE ATTM...BUT CONVECTIVE TRENDS WILL BE MONITORED. 

ISOLATED SHOWERS/TSTMS HAVE DEVELOPED WITHIN A BROAD/WEAK LOW-LEVEL
WAA REGIME ACROSS SRN AL/MS TOWARDS THE CNTRL GULF COAST. THE AIR
MASS REMAINS RELATIVELY HOMOGENEOUS /WITHOUT ANY APPARENT MESOSCALE
BOUNDARIES AND WEAK LARGE-SCALE FORCING/...BUT STRONG SFC HEATING
AND LITTLE TO NO CINH HAS RESULTED IN INCREASING COVERAGE OF WEAK
SHOWERS/TSTMS. RADAR REFLECTIVITY TRENDS INDICATE THESE ECHOES ARE
RATHER WEAK/UNORGANIZED...BUT WITH STRONG BACKGROUND FLOW FIELDS AND
VEERING LOW-LEVEL WINDS WITH HEIGHT /20-25 KTS 0-1 KM
SHEAR/...ISOLATED DMGG WIND GUSTS...HAIL...AND PERHAPS A TORNADO
CANNOT BE RULED OUT SHOULD STRONGER/BETTER ORGANIZED TSTMS DEVELOP.
CURRENT COVERAGE PRECLUDES WW ISSUANCE ATTM...BUT CONVECTIVE TRENDS
WILL BE MONITORED SHOULD A MORE WIDESPREAD THREAT BECOME APPARENT.

..ROGERS.. 03/02/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...TAE...BMX...MOB...JAN...LIX...

LAT...LON   30468601 30348770 30168996 30209099 30689151 32319058
            32798869 32868719 32648586 32088554 30468601

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 2, 9:07 AM CSTMesoscale DiscussionSPCDeKalb, Jackson, Lawrence, Limestone, Madison, Marshall and 1 more53 min
Mar 2, 9:25 AM CSTTornado WatchSPCDeKalb, Jackson, Lawrence, Limestone, Madison, Marshall and 1 more5 hr
Mar 2, 11:46 AM CSTMesoscale DiscussionSPCDeKalb, Jackson, Madison, Marshall, Morgan29 min
Mar 2, 12:57 PM CSTMesoscale DiscussionSPCColbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 2 more63 min
Mar 2, 1:20 PM CSTTornado WatchSPCBlount, Colbert, Cullman, DeKalb, Fayette, Franklin and 14 more9 hr
Mar 2, 3:25 PM CSTMesoscale DiscussionSPCColbert, Cullman, Fayette, Franklin, Lamar, Lauderdale and 9 more65 min
Mar 2, 4:37 PM CSTTornado WatchSPCAutauga, Baldwin, Barbour, Bibb, Blount, Bullock and 50 more7 hr
Mar 2, 5:41 PM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Blount, Bullock, Butler and 36 more2 hr
Mar 2, 1:26 PM CSTMesoscale DiscussionSPCBienville, Caldwell, Claiborne, De Soto, East Carroll, Franklin and 15 more64 min
Mar 2, 1:47 PM CSTSevere Thunderstorm WatchSPCAllen, Avoyelles, Beauregard, Bienville, Caldwell, Catahoula and 22 more9 hr
Mar 2, 3:47 PM CSTMesoscale DiscussionSPCAllen, Avoyelles, Beauregard, Bienville, Caldwell, Catahoula and 21 more58 min
Mar 2, 10:28 AM CSTMesoscale DiscussionSPCDeSoto, Tate62 min
Mar 2, 4:47 PM CSTTornado WatchSPCAttala, Choctaw, Clarke, Clay, Copiah, Covington and 23 more6 hr

Nearby

Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Alabama, 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.