Alert archive / Mississippi / Mesoscale Discussions in 2012

Mesoscale Discussion 431

April 3, 2012Chicot County, Arkansas; East Carroll Parish, Madison Parish, West Carroll Parish, Louisiana; 40 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2012, 1:42 PM CDT for Chicot County, Arkansas; East Carroll Parish, Madison Parish, West Carroll Parish, Louisiana; 40 counties in Mississippi. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Apr 3, 2012, 1:42 PM CDT (18:42 UTC)
Expired
Apr 3, 2012, 3:15 PM CDT
In force
93 min
Issued by
the Storm Prediction Center
All 44 counties

Chicot County, AR, East Carroll Parish, LA, Madison Parish, LA, West Carroll Parish, LA, Attala County, MS, Carroll County, MS, Choctaw County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Leflore County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Wayne County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 61 km from the middle of the area, began a volume at 18:41 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

Jackson, MS (KJAN), launched 12:00Z, 6.7 hours before the alert went out and 56 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, Jackson, MS at 12:00Z on 2012-04-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 159 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, Jackson, MS at 12:00Z on 2012-04-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.1939Sfc1 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
159 J/kg
Mixed-layer CIN
-252 J/kg
Mixed-layer LCL
1092 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
-33 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

360 
ACUS11 KWNS 031843
SWOMCD
SPC MCD 031842
ALZ000-MSZ000-ARZ000-LAZ000-032015-

MESOSCALE DISCUSSION 0431
NWS STORM PREDICTION CENTER NORMAN OK
0142 PM CDT TUE APR 03 2012

AREAS AFFECTED...FAR SERN AR...FAR NERN LA...CNTRL/SRN MS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 031842Z - 032015Z

DAMAGING WIND THREAT MAY INCREASE DURING THE AFTERNOON FOR PORTIONS
OF FAR SERN AR...FAR NERN LA AND SRN/CNTRL MS. AREA IS BEING
MONITORED FOR A WW.

REGIONAL RADAR IMAGERY AT 1830Z SHOWS A BOWING MCS LOCATED OVER FAR
W-CNTRL MS INTO FAR SERN AR. MEANWHILE...SURFACE OBSERVATIONS AND
OBJECTIVE ANALYSIS INDICATE A BAROCLINIC ZONE EXTENDING SEWD FROM
THE MCS INTO SERN MS. TEMPERATURES ALONG AND W OF THE BAROCLINIC
ZONE ARE WARMING TO AROUND 80F WITH DEWPOINTS IN THE MID 60S. WITH
CONTINUED HEATING THROUGH MID-AFTERNOON...MLCAPE VALUES WILL RESIDE
BETWEEN 1500-2500 J/KG. THOUGH DEEP-LAYER SHEAR IS MARGINALLY
SUPPORTIVE FOR A LONG-LIVED BOWING MCS...SEWD FORWARD PROPAGATION
ALONG THE BAROCLINIC ZONE IS POSSIBLE...WHICH WOULD INCREASE THE
THREAT FOR DAMAGING WIND GUSTS ACROSS MUCH OF CNTRL AND SRN MS.
CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

..GARNER.. 04/03/2012

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

ATTN...WFO...BMX...MOB...MEG...JAN...LIX...LZK...

LAT...LON   33919071 33898893 32768823 31308863 31179004 32429151
            33229165 33919071

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 3, 2:22 PM CDTSevere Thunderstorm WatchSPCColumbia, Hempstead, Lafayette, Nevada, Union8 hr
Apr 3, 2:36 PM CDTTornado WatchSPCHoward, Little River, Miller, Sevier7 hr
Apr 3, 3:05 PM CDTMesoscale DiscussionSPCHempstead, Howard, Little River, Montgomery, Nevada, Pike and 2 more85 min
Apr 3, 3:43 PM CDTSevere Thunderstorm WatchSPCBoone, Bradley, Calhoun, Clark, Crawford, Dallas and 16 more6 hr
Apr 3, 5:00 PM CDTMesoscale DiscussionSPCLittle River, Miller60 min
Apr 3, 5:24 PM CDTMesoscale DiscussionSPCAshley, Chicot, Union66 min
Apr 3, 6:53 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Lafayette, Little River, Miller, Nevada and 1 more67 min
Apr 2, 10:10 PM CDTMesoscale DiscussionSPCIberia, St. Mary3 hr
Apr 3, 1:46 PM CDTMesoscale DiscussionSPCCaddo, De Soto89 min

Nearby

Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Louisiana, 2012Mesoscale Discussions in Arkansas, 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.