Alert archive / Mississippi / Mesoscale Discussions in 2021

Mesoscale Discussion 185

March 16, 202110 parishes in Louisiana; 19 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 16, 2021, 3:48 PM CDT for 10 parishes in Louisiana; 19 counties in Mississippi. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: Mar 16, 2021, 3:48 PM CDT (20:48 UTC)
Expired: Mar 16, 2021, 5:45 PM CDT
In force: 117 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

All 29 counties

Caldwell Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Jackson Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Richland Parish, LA, Tensas Parish, LA, West Carroll Parish, LA, Attala County, MS, Choctaw County, MS, Claiborne County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Kemper County, MS, Leake County, MS, Madison County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Warren County, MS, Winston County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 72 km from the middle of the area, began a volume at 20:51 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 nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 8.8 hours before the alert went out and 62 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 812 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 660 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 99 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

762 
ACUS11 KWNS 162049
SWOMCD
SPC MCD 162048 
ALZ000-MSZ000-LAZ000-ARZ000-162245-

Mesoscale Discussion 0185
NWS Storm Prediction Center Norman OK
0348 PM CDT Tue Mar 16 2021

Areas affected...North-Central LA...Central MS

Concerning...Severe potential...Watch unlikely 

Valid 162048Z - 162245Z

Probability of Watch Issuance...20 percent

SUMMARY...A few stronger storms capable of hail and/or damaging wind
gusts are possible from north-central LA into central MS over the
next few hours.

DISCUSSION...Thunderstorm currently moving through Franklin Parish
has recently strengthening after struggling to maintain updraft
consistency over the past hour. This better organization may be a
result of stronger deep-layer vertical shear and more buoyancy
within the environment it now resides. A few cells to the east of
this storm are also showing signs of strengthening as they too move
into an area with slightly stronger deep-layer vertical shear.
Buoyancy decreases with northern extent and the overall storm
longevity will be mitigated by this decreasing buoyancy as well as
the lack of stronger large scale support. Even so, instances of
isolated severe hail are possible as well as the potential for a
damaging wind gust or two.

..Mosier/Grams.. 03/16/2021

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

ATTN...WFO...BMX...JAN...SHV...

LAT...LON   32549260 33129114 33488831 32698808 32198916 31689260
            32549260

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 15, 11:44 PM CDT	Mesoscale Discussion	SPC	Attala, Carroll, Chickasaw, Choctaw, Clay, Itawamba and 7 more	91 min
Mar 16, 1:07 PM CDT	Mesoscale Discussion	SPC	Forrest, Greene, Jones, Perry, Wayne	2 hr

Nearby

Mesoscale Discussions in Mississippi, 2021 Mesoscale Discussions in Louisiana, 2021 Every 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; radar from the NEXRAD Level II archive.