Alert archive / Mississippi / Mesoscale Discussions in 2012

Mesoscale Discussion 212

March 2, 20128 counties in Alabama; 38 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 2, 2012, 12:57 PM CST for 8 counties in Alabama; 38 counties in Mississippi. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Mar 2, 2012, 12:57 PM CST (18:57 UTC)
Expired
Mar 2, 2012, 2:00 PM CST
In force
63 min
Issued by
the Storm Prediction Center
All 46 counties

Colbert County, AL, Fayette County, AL, Franklin County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Marion County, AL, Winston County, AL, Alcorn County, MS, Attala County, MS, Benton County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Itawamba County, MS, Lafayette County, MS, Leake County, MS, Lee County, MS, Leflore County, MS, Lowndes County, MS, Madison County, MS, Marshall County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Noxubee County, MS, Oktibbeha County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS, Yazoo County, MS

The radar

The Columbus AFB radar (KGWX), 29 km from the middle of the area, began a volume at 18:57 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

Little Rock, AR (KLZK), launched 12:00Z, 7.0 hours before the alert went out and 156 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, Little Rock, AR at 12:00Z on 2012-03-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1625 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, Little Rock, AR at 12:00Z on 2012-03-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 291 square meters per square second.1939587897117136Sfc1 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
1625 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
645 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
291 m²/s²
0-3 km storm-relative helicity
304 m²/s²
Significant tornado parameter
3.2
Supercell composite
11.9

Open this sounding in Storm Lab

The text

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

606 
ACUS11 KWNS 021857
SWOMCD
SPC MCD 021857 
ALZ000-MSZ000-022000-

MESOSCALE DISCUSSION 0212
NWS STORM PREDICTION CENTER NORMAN OK
1257 PM CST FRI MAR 02 2012

AREAS AFFECTED...NRN/CNTRL MS...NWRN AL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 021857Z - 022000Z

THE POTENTIAL FOR TSTMS CAPABLE OF PRODUCING LARGE HAIL...DMGG
WINDS...AND ISOLATED TORNADOES APPEARS TO BE INCREASING. CONVECTIVE
TRENDS ARE BEING MONITORED FOR A POSSIBLE WW.

STRONG DIABATIC HEATING IS OCCURRING ACROSS MUCH OF MS/AL WITH
TEMPERATURES REACHING THE LOWER 80S...SUPPORTING MLCAPE VALUES NEAR
1000-1500 J/KG /PER 18Z JAN AND BMX SOUNDINGS/. RECENT RADAR TRENDS
SHOW WEAK ECHOES DEVELOPING APPROXIMATELY 35 SSE GWO ALONG A
PERSISTENT CLOUD BAND /PERHAPS COINCIDENT WITH A BROAD LOW-LEVEL
CONFLUENCE ZONE/...WHILE A WEAK WAA ADVECTION REGIME IS PRESENT
AHEAD OF AN APPROACHING CNTRL CONUS UPPER TROUGH...BUT VISIBLE
SATELLITE IMAGES SUGGEST WEAK CINH MAY STILL BE PRESENT ACROSS MOST
OF THE AREA. A SYNOPTIC-SCALE COLD FRONT STILL REMAINS POSITIONED
WELL TO THE W...BUT A GRADUAL INCREASE IN TSTM COVERAGE/INTENSITY IS
ANTICIPATED THROUGH THIS AFTERNOON IN THE PRE-FRONTAL AIR MASS.
DGX/GWX VWP DATA SHOW STRONG LOW-LEVEL WINDS VEERING WITH
HEIGHT...WITH THE ENVIRONMENT SUPPORTIVE OF ROTATING STORMS CAPABLE
OF PRODUCING LARGE HAIL...DMGG WINDS...AND ISOLATED TORNADOES.

..ROGERS.. 03/02/2012

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

ATTN...WFO...BMX...HUN...MEG...JAN...

LAT...LON   34368692 33388809 32418968 32509069 33659082 34888975
            34958785 34888706 34368692

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, 1:20 PM CSTTornado WatchSPCBlount, Colbert, Cullman, DeKalb, Fayette, Franklin and 14 more9 hr
Mar 2, 2:42 PM CSTMesoscale DiscussionSPCAutauga, Baldwin, Bullock, Butler, Choctaw, Clarke and 18 more63 min
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, 10:28 AM CSTMesoscale DiscussionSPCDeSoto, Tate62 min
Mar 2, 1:26 PM CSTMesoscale DiscussionSPCHumphreys, Issaquena, Sharkey, Warren, Washington, Yazoo64 min
Mar 2, 1:47 PM CSTSevere Thunderstorm WatchSPCAdams, Bolivar, Claiborne, Franklin, Issaquena, Jefferson and 4 more9 hr
Mar 2, 3:47 PM CSTMesoscale DiscussionSPCHolmes, Humphreys, Issaquena, Sharkey, Warren, Washington and 1 more58 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, 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.