Alert archive / Mississippi / Mesoscale Discussions in 2021

Mesoscale Discussion 955

June 13, 20217 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jun 13, 2021, 3:43 PM CDT for 7 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 13, 2021, 3:43 PM CDT (20:43 UTC)
Expired
Jun 13, 2021, 5:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 265

Counties Covington County, MS, Jasper County, MS, Jones County, MS, Leake County, MS, Newton County, MS, Scott County, MS, Smith County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 70 km from the middle of the area, began a volume at 20:47 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, 8.7 hours before the alert went out and 80 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 2021-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2570 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, Jackson, MS at 12:00Z on 2021-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 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
2570 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
869 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

267 
ACUS11 KWNS 132043
SWOMCD
SPC MCD 132043 
MSZ000-132245-

Mesoscale Discussion 0955
NWS Storm Prediction Center Norman OK
0343 PM CDT Sun Jun 13 2021

Areas affected...central MS

Concerning...Severe Thunderstorm Watch 265...

Valid 132043Z - 132245Z

The severe weather threat for Severe Thunderstorm Watch 265
continues.

SUMMARY...The greatest risk for damaging gusts will focus over
east-central MS as a thunderstorm cluster moves to the
south-southwest through 530pm.

DISCUSSION...Radar mosaic shows an organizing thunderstorm cluster
over east-central MS as of 330pm.  Surface temperatures to the
south-southwest of the activity have warmed int the mid 90s deg F
and dewpoints are generally in the mid 70s.  Wet microbursts will
likely accompany the stronger cores with damaging gusts the end
result.  IR cloud tops have cooled over the past 2 hours with this
cluster of storms and the deeper cores (per 10-km CAPPI information)
have developed on the southern and western portion of the cluster. 
This re-orientation and organization of the deeper updrafts on the
southwest portion of the cluster is the initial signal for a greater
surge of thunderstorm outflow to begin.  The Meridian, MS ASOS
observed a 51-kt gust at 328pm.  The expectation is for the severe
risk/wind damage threat to be its peak intensity phase for the next
several hours before a gradual weakening as this activity moves into
southern MS.

..Smith.. 06/13/2021

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

ATTN...WFO...MOB...JAN...

LAT...LON   32318908 31818865 31288896 31578955 32038984 32898963
            32888926 32318908

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 13, 10:45 AM CDTMesoscale DiscussionSPCAttala, Calhoun, Carroll, Chickasaw, Choctaw, Claiborne and 40 more60 min
Jun 13, 12:22 PM CDTSevere Thunderstorm WatchSPCAdams, Amite, Attala, Calhoun, Carroll, Chickasaw and 59 more9 hr
Jun 13, 12:51 PM CDTMesoscale DiscussionSPCAdams, Amite, Claiborne, Copiah, Covington, Forrest and 18 more114 min
Jun 13, 1:25 PM CDTMesoscale DiscussionSPCClarke, Kemper, Lauderdale, Neshoba, Newton, Noxubee and 2 more2 hr

Nearby

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