Alert archive / Mississippi / Mesoscale Discussions in 2003

Mesoscale Discussion 121

February 22, 2003Chicot County, Arkansas; 12 parishes in Louisiana; 40 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Feb 22, 2003, 2:02 AM CST for Chicot County, Arkansas; 12 parishes in Louisiana; 40 counties in Mississippi. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Feb 22, 2003, 2:02 AM CST (08:02 UTC)
Expired
Feb 22, 2003, 5:00 AM CST
In force
3 hr
Issued by
the Storm Prediction Center
All 53 counties

Chicot County, AR, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Richland Parish, LA, Tensas Parish, LA, West Carroll Parish, LA, Adams County, MS, Attala County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Claiborne County, MS, Clay County, MS, Copiah County, MS, Franklin County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Lafayette County, MS, Leake County, MS, Lee County, MS, Leflore County, MS, Madison County, MS, Montgomery County, MS, Neshoba County, MS, Oktibbeha County, MS, Panola County, MS, Pontotoc County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Union County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Wilkinson County, MS, Winston County, MS, Yalobusha County, MS, Yazoo County, MS

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 8.0 hours before the alert went out and 86 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 00:00Z on 2003-02-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2003-02-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 164 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
589 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
164 m²/s²
0-3 km storm-relative helicity
289 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.

874 
ACUS11 KWNS 220802
SWOMCD
SPC MCD 220802 
LAZ000-MSZ000-221100-

MESOSCALE DISCUSSION 0121
NWS STORM PREDICTION CENTER NORMAN OK
0202 AM CST SAT FEB 22 2003

AREAS AFFECTED...NERN LA / W CENTRAL AND NRN MS

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 220802Z - 221100Z

SEVERE THREAT IS EXPECTED TO INCREASE LATER THIS MORNING FROM
NERN LA INTO ADJACENT W CENTRAL MS...AND EVENTUALLY NWD INTO NRN
MS AHEAD OF STRONG / DEEPENING SURFACE LOW.  WW MAY BE REQUIRED
IF STORMS DO INDEED DEVELOP ACROSS THIS REGION.



LATEST SURFACE ANALYSIS SHOWS DEEPENING LOW OVER NRN LA...WHICH
IS EXPECTED TO MOVE INTO W CENTRAL MS OVER THE NEXT SEVERAL HOURS
AHEAD OF STRONG VORT MAX OVER NWRN LA.	MARGINAL / MAINLY
ELEVATED INSTABILITY EXISTS ACROSS THIS REGION...BUT VERY STRONG
FORCING SUGGESTS THAT THUNDERSTORMS WILL DEVELOP OVER THE NEXT
COUPLE OF HOURS.  VERY STRONG WIND FIELD /65 KT 0-6 KM SHEAR PER
LATEST OKOLONA MS PROFILER/ WOULD SUPPORT ROTATION WITH ANY
SUSTAINED UPDRAFT.  



MAIN SEVERE THREAT APPEARS TO BE LARGE HAIL ACROSS THIS REGION. 
HOWEVER...AS LOW-LEVEL THETA-E ADVECTION CONTINUES AHEAD OF
APPROACHING LOW...STABLE LAYER NEAR THE SURFACE SHOULD BECOME
INCREASINGLY WEAKER / SHALLOWER -- PARTICULARLY ACROSS SRN
PORTIONS OF THE THREAT AREA.  THUS...THREAT FOR DAMAGING WINDS
AND PERHAPS A TORNADO OR TWO MAY ALSO INCREASE ROUGHLY ALONG AND
SOUTH OF A LINE FROM MLU TO GWO.

..GOSS.. 02/22/2003

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

32999190 33729110 34588979 34458850 33278859 32258943
31019148 31339208 32219229

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 21, 7:26 PM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Livingston, Orleans and 9 more2 hr
Feb 21, 8:15 PM CSTTornado WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 17 more6 hr
Feb 21, 10:22 PM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 17 more113 min
Feb 21, 10:54 PM CSTMesoscale DiscussionSPCBeauregard, Bienville, Bossier, Caddo, De Soto, Natchitoches and 4 more3 hr
Feb 21, 11:14 PM CSTMesoscale DiscussionSPCBienville, Bossier, Caddo, Catahoula, De Soto, Grant and 6 more4 hr
Feb 22, 12:35 AM CSTTornado WatchSPCJefferson, Orleans, Saint Bernard, Saint Tammany5 hr
Feb 22, 3:51 AM CSTMesoscale DiscussionSPCJefferson, Orleans, Saint Bernard, Saint Tammany114 min
Feb 21, 9:03 PM CSTMesoscale DiscussionSPCAttala, Chickasaw, Choctaw, Clarke, Clay, Jasper and 16 more3 hr
Feb 21, 9:30 PM CSTSevere Thunderstorm WatchSPCAttala, Choctaw, Clarke, Clay, Jasper, Kemper and 15 more7 hr
Feb 21, 10:40 PM CSTMesoscale DiscussionSPCAttala, Choctaw, Clarke, Clay, Jasper, Kemper and 15 more2 hr

Nearby

Mesoscale Discussions in Mississippi, 2003Mesoscale Discussions in Louisiana, 2003Mesoscale Discussions in Arkansas, 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.