Alert archive / Mississippi / Mesoscale Discussions in 2003

Mesoscale Discussion 1349

June 12, 2003Washington County, Alabama; 11 parishes in Louisiana; 23 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jun 12, 2003, 8:51 AM CDT for Washington County, Alabama; 11 parishes in Louisiana; 23 counties in Mississippi. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jun 12, 2003, 8:51 AM CDT (13:51 UTC)
Expired
Jun 12, 2003, 10:15 AM CDT
In force
84 min
Issued by
the Storm Prediction Center
All 35 counties

Washington County, AL, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Livingston Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jefferson 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, Wilkinson County, MS

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, 1.9 hours before the alert went out and 102 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 2003-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1553 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 2003-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 square meters per square second.193958Sfc1 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
1553 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
852 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

356 
ACUS11 KWNS 121351
SWOMCD
SPC MCD 121351 
ALZ000-MSZ000-LAZ000-121515-

MESOSCALE DISCUSSION 1349
NWS STORM PREDICTION CENTER NORMAN OK
0851 AM CDT THU JUN 12 2003

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

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 121351Z - 121515Z

...WW MAY BE REQUIRED ACROSS PORTIONS OF THE CENTRAL GULF COAST IF
ONGOING ACTIVITY INTENSIFIES...

REMNANTS OF OVERNIGHT COMPLEX OF STORMS IS PROGRESSING STEADILY EWD
ACROSS ERN PORTIONS OF LA...ROUGHLY 30KT...WITH SOMEWHAT FASTER
MOVEMENT...35KT...OBSERVED WITH MORE ARCED SHAPED SEGMENTS ALONG THE
LINE.  OF PARTICULAR INTEREST IS THE LARGE-SCALE OUTFLOW THAT HAS
SAGGED SWD ACROSS CENTRAL MS INTO AL AHEAD OF THIS ACTIVITY.  THIS
MAY PROVIDE ADDITIONAL FOCUS FOR FUTURE DEVELOPMENT AHEAD OF
ORGANIZED LINE.  IN ADDITION...12Z SOUNDINGS INDICATE WEAK WARM
ADVECTION AS A BACKGROUND ENVIRONMENT WHICH SUPPORTS DEVELOPMENT
WELL AHEAD OF THE WIND SHIFT GIVEN MARGINAL INHIBITION.

..DARROW.. 06/12/2003

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

ATTN...WFO...MOB...JAN...LIX...LCH...

31769159 31878867 31338779 30508843 30269006 30459190

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 11, 7:50 PM CDTSevere Thunderstorm WatchSPCBibb, Chilton, Coosa, Fayette, Greene, Hale and 10 more5 hr
Jun 11, 9:18 PM CDTMesoscale DiscussionSPCBibb, Chilton, Fayette, Greene, Hale, Jefferson and 6 more87 min
Jun 12, 9:10 AM CDTSevere Thunderstorm WatchSPCBaldwin, Choctaw, Clarke, Mobile, Washington5 hr
Jun 12, 11:10 AM CDTMesoscale DiscussionSPCChoctaw, Clarke, Mobile, Washington95 min
Jun 12, 1:15 PM CDTMesoscale DiscussionSPCClarke, Mobile, Washington60 min
Jun 12, 1:34 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Chambers, Chilton, Clay and 19 more86 min
Jun 12, 12:30 AM CDTMesoscale DiscussionSPCBossier, Caddo, De Soto2 hr
Jun 12, 1:10 AM CDTSevere Thunderstorm WatchSPCBossier, Caddo, De Soto4 hr
Jun 12, 4:20 AM CDTMesoscale DiscussionSPCBossier, Caddo, De Soto55 min
Jun 12, 4:40 PM CDTSevere Thunderstorm WatchSPCEast Baton Rouge, East Feliciana, Livingston, Saint Helena, Saint Tammany, Tangipahoa and 2 more4 hr
Jun 11, 7:14 PM CDTMesoscale DiscussionSPCBolivar, Calhoun, Chickasaw, Clay, Coahoma, Grenada and 8 more2 hr

Nearby

Mesoscale Discussions in Mississippi, 2003Mesoscale Discussions in Louisiana, 2003Mesoscale Discussions in Alabama, 2003Every mesoscale discussion in 2003

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.