Alert archive / Mississippi / Mesoscale Discussions in 2021

Mesoscale Discussion 480

May 2, 202120 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 2, 2021, 6:51 PM CDT for 20 counties in Mississippi. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
May 2, 2021, 6:51 PM CDT (23:51 UTC)
Expired
May 2, 2021, 7:45 PM CDT
In force
54 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 125

Counties Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Leake County, MS, Leflore County, MS, Madison County, MS, Montgomery County, MS, Neshoba County, MS, Oktibbeha County, MS, Pontotoc County, MS, Tallahatchie County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 107 km from the middle of the area, began a volume at 23:55 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, 11.9 hours before the alert went out and 105 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 2021-05-02Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jackson, MS at 12:00Z on 2021-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1640 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

262 
ACUS11 KWNS 022351
SWOMCD
SPC MCD 022351 
MSZ000-030045-

Mesoscale Discussion 0480
NWS Storm Prediction Center Norman OK
0651 PM CDT Sun May 02 2021

Areas affected...Central Mississippi

Concerning...Tornado Watch 125...

Valid 022351Z - 030045Z

The severe weather threat for Tornado Watch 125 continues.

SUMMARY...Supercells with a history of tornadoes will likely persist
through early evening where a corridor of greater tornado risk
appears likely this evening.

DISCUSSION...Several small supercells along and west of I-55 have
produced confirmed tornadoes over the last 90 minutes. KDGX analysis
shows several low-level mesocyclones with VROTs of 40-50 kts and a
considerable TDS near Yazoo City, MS. SPC mesoanalysis and regional
VWPS show strong veering wind profiles with 200-300 m2/s2 ESRH ahead
of the ongoing storms to near the warm front across north-central
Mississippi. A corridor of greater tornado potential is likely
evolving. The potential exists for several additional tornadoes,
(possibly significant) to develop and track northeastward to the
warm front over the next 1 to 3 hours.

..Lyons.. 05/02/2021

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

ATTN...WFO...MEG...JAN...

LAT...LON   32909053 33579039 34239013 34388969 34298927 34198886
            33558871 33178875 32808902 32658931 32468980 32419002
            32349060 32569071 32909053

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 3:33 PM CDTMesoscale DiscussionSPCAdams, Amite, Claiborne, Copiah, Franklin, Hinds and 16 more117 min
May 2, 4:46 PM CDTTornado WatchSPCAttala, Bolivar, Calhoun, Carroll, Chickasaw, Choctaw and 34 more5 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.