Alert archive / Mississippi / Mesoscale Discussions in 2021

Mesoscale Discussion 246

March 24, 20214 states

The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2021, 9:25 PM CDT for 4 states. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Mar 24, 2021, 9:25 PM CDT (02:25 UTC)
Expired
Mar 24, 2021, 10:30 PM CDT
In force
65 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%
All 67 counties

Baldwin County, AL, Mobile County, AL, Washington County, AL, Escambia County, FL, Ascension Parish, LA, Avoyelles Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Iberville Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Livingston Parish, LA, Madison Parish, LA, Orleans Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Saint Bernard Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne 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 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, Rankin County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Warren County, MS, Wayne County, MS, Wilkinson County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 2.4 hours before the alert went out and 127 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 00:00Z on 2021-03-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 109 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 00:00Z on 2021-03-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 281 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
109 J/kg
Mixed-layer CIN
-186 J/kg
Mixed-layer LCL
681 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
281 m²/s²
0-3 km storm-relative helicity
382 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.0

Open this sounding in Storm Lab

The text

As transmitted.

032 
ACUS11 KWNS 250226
SWOMCD
SPC MCD 250225 
ALZ000-FLZ000-MSZ000-LAZ000-250330-

Mesoscale Discussion 0246
NWS Storm Prediction Center Norman OK
0925 PM CDT Wed Mar 24 2021

Areas affected...southern/central Louisiana into southern
Mississippi and southwestern Alabama

Concerning...Severe potential...Watch unlikely 

Valid 250225Z - 250330Z

Probability of Watch Issuance...5 percent

SUMMARY...An isolated severe storm may develop within a warm
advection regime across the region tonight.  A WW issuance is not
anticipated.

DISCUSSION...Showers and isolated thunderstorms have maintained
themselves over the past several hours within a broad warm-advection
regime just north of a front near the coast.  The frontal zone
itself separates an unstable and weakly capped regime with 400-600
m2/s2 0-3km SRH noted via the wind profiler at KLIX recently.  Most
of the convection is slightly elevated atop the warm frontal zone,
though recent indications are that a couple of cells have acquired
right-moving characteristics.  Storms that can move right of the
mean storm motion vector may pose a risk for hail and damaging wind
gusts, though their slightly elevated nature may limit a more robust
tornado threat.  As low-level wind fields increase to around 60
knots, the warm frontal regime and isolated severe risk should
gradually shift northward toward the I-20 and U.S. 82 corridors over
the next few hours.

..Cook/Grams.. 03/25/2021

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   31779261 32239214 32459161 32419011 32158844 31138731
            30368718 29968771 29918952 29949088 30169206 30539256
            31249254 31779261

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 25, 9:02 AM CDTMesoscale DiscussionSPCBlount, Calhoun, Cherokee, Cleburne, Colbert, Cullman and 21 more118 min
Mar 25, 10:12 AM CDTMesoscale DiscussionSPCBibb, Blount, Colbert, Cullman, DeKalb, Etowah and 22 more3 hr
Mar 25, 10:58 AM CDTMesoscale DiscussionSPCColbert, Fayette, Franklin, Lamar, Lawrence, Marion and 2 more3 hr
Mar 25, 11:26 AM CDTTornado Watch PDSSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 39 more9 hr
Mar 25, 12:28 PM CDTMesoscale DiscussionSPCBibb, Calhoun, Clay, Cleburne, Shelby, Talladega2 hr
Mar 25, 1:24 PM CDTMesoscale DiscussionSPCColbert, Fayette, Franklin, Greene, Lamar, Lawrence and 4 more2 hr
Mar 25, 3:45 PM CDTMesoscale DiscussionSPCBibb, Chilton, Choctaw, Dallas, Greene, Hale and 8 more2 hr
Mar 25, 4:45 PM CDTMesoscale DiscussionSPCBibb, Chilton, Coosa, Perry, Shelby, Talladega60 min
Mar 25, 5:45 PM CDTMesoscale DiscussionSPCClay, Randolph60 min
Mar 25, 11:00 AM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, Livingston, Orleans, Saint Charles and 6 more2 hr
Mar 25, 2:29 PM CDTMesoscale DiscussionSPCAlcorn2 hr
Mar 25, 3:48 PM CDTTornado WatchSPCAlcorn7 hr

Nearby

Mesoscale Discussions in Mississippi, 2021Mesoscale Discussions in Louisiana, 2021Mesoscale Discussions in Alabama, 2021Every mesoscale discussion in 2021

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.