Alert archive / Mississippi / Mesoscale Discussions in 2021

Mesoscale Discussion 838

June 2, 202113 counties in Alabama; 43 counties in Mississippi; Hardin County, McNairy County, Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jun 2, 2021, 2:34 PM CDT for 13 counties in Alabama; 43 counties in Mississippi; Hardin County, McNairy County, Tennessee. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
Jun 2, 2021, 2:34 PM CDT (19:34 UTC)
Expired
Jun 2, 2021, 4:30 PM CDT
In force
116 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 58 counties

Choctaw County, AL, Colbert County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Marion County, AL, Pickens County, AL, Sumter County, AL, Winston County, AL, Alcorn County, MS, Attala County, MS, Benton County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Claiborne County, MS, Clarke County, MS, Clay County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Itawamba County, MS, Jasper County, MS, Kemper County, MS, Lafayette County, MS, Lauderdale County, MS, Leake County, MS, Lee County, MS, Lowndes County, MS, Madison County, MS, Marshall County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pontotoc County, MS, Prentiss County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Warren County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS, Yazoo County, MS, Hardin County, TN, McNairy County, TN

The radar

The Columbus AFB radar (KGWX), 68 km from the middle of the area, began a volume at 19:33 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

Little Rock, AR (KLZK), launched 12:00Z, 7.6 hours before the alert went out and 125 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, Little Rock, AR at 12:00Z on 2021-06-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 205 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, Little Rock, AR at 12:00Z on 2021-06-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
205 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
551 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
66 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

800 
ACUS11 KWNS 021935
SWOMCD
SPC MCD 021934 
ALZ000-TNZ000-MSZ000-022130-

Mesoscale Discussion 0838
NWS Storm Prediction Center Norman OK
0234 PM CDT Wed Jun 02 2021

Areas affected...Much of MS...Western AL...Southwest TN

Concerning...Severe potential...Watch unlikely 

Valid 021934Z - 022130Z

Probability of Watch Issuance...20 percent

SUMMARY...Thunderstorms are expected to continue throughout the
afternoon across portions of MS, AL, and southwest TN. A few of
these storms may become strong enough to produce damaging wind gusts
and/or isolated hail.

DISCUSSION...Broad low-level confluence is contributing to banded
multicellular storm development across much of MS and into southwest
TN. Thus far, updrafts have been rather transient with relatively
short duration. However, the air mass continues to further
destabilize amid strong heating and only partly cloudy skies. Recent
mesoanalysis estimates MLCAPE around 2000 J/kg from most of MS, with
around 1500 J/kg reaching across much of western TN.  Instability
drops off quickly with eastern extent, with only around 500 J/kg of
MLCAPE across central AL. Even so, persistent low-level confluence
is expected to result in increasing thunderstorm coverage, and
vertical shear is strong enough to support a few more organized
updrafts. Additionally, greater storm coverage increases the
likelihood of storm mergers and resulting brief updraft
intensification. Primary threat with any stronger storms is damaging
wind gusts, although isolated hail is also possible.

..Mosier/Hart.. 06/02/2021

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

ATTN...WFO...OHX...BMX...HUN...MOB...MEG...JAN...

LAT...LON   34938940 35348839 34798691 31728832 31989104 34188999
            34938940

Nearby

Mesoscale Discussions in Mississippi, 2021Mesoscale Discussions in Alabama, 2021Mesoscale Discussions in Tennessee, 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.