Alert archive / Mississippi / Mesoscale Discussions in 2023

Mesoscale Discussion 1069

June 15, 202312 parishes in Louisiana; 29 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jun 15, 2023, 9:26 AM CDT for 12 parishes in Louisiana; 29 counties in Mississippi. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Jun 15, 2023, 9:26 AM CDT (14:26 UTC)
Expired
Jun 15, 2023, 11:00 AM CDT
In force
94 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch likely
Chance of a watch
95%
All 41 counties

Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Saint Helena 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, 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, 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, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS, Wilkinson County, MS

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 2.4 hours before the alert went out and 110 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 2023-06-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2276 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jackson, MS at 12:00Z on 2023-06-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 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
2276 J/kg
Mixed-layer CIN
-36 J/kg
Mixed-layer LCL
589 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.8

Open this sounding in Storm Lab

The text

As transmitted.

826 
ACUS11 KWNS 151427
SWOMCD
SPC MCD 151426 
MSZ000-LAZ000-151600-

Mesoscale Discussion 1069
NWS Storm Prediction Center Norman OK
0926 AM CDT Thu Jun 15 2023

Areas affected...Portions of southern/central MS and southeastern LA

Concerning...Severe potential...Watch likely 

Valid 151426Z - 151600Z

Probability of Watch Issuance...95 percent

SUMMARY...Increasing severe hail and damaging wind threat will
likely warrant watch issuance this morning. A tornado or two also
appears possible.

DISCUSSION...Two supercells are ongoing this morning across central
MS. The 12Z sounding from JAN shows ample MUCAPE (nearly 3000 J/kg),
with a residual cap around 700 mb. Strong flow at mid/upper levels
is still promoting 50+ kt of deep-layer shear, and supercells posing
a threat for large to very large hail (2+ inches in diameter) appear
possible given the steep mid-level lapse rates present.
Severe/damaging winds may also occur with any clusters that can form
and spread east-southeastward. The airmass downstream of this
ongoing activity is already strongly unstable, and the threat for
severe thunderstorms will likely increase this morning. Watch
issuance will be needed soon. The tornado threat is a bit more
uncertain given somewhat veered low-level flow. But, there may still
be enough low-level shear for a tornado or two.

..Gleason/Thompson.. 06/15/2023

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

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

LAT...LON   32339129 32198892 31528855 30538855 30218967 30269143
            31109162 31789184 32339129

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 14, 7:10 PM CDTMesoscale DiscussionSPCEast Carroll, Franklin, Madison, Morehouse, Richland, Tensas and 1 more65 min
Jun 14, 7:33 PM CDTSevere Thunderstorm WatchSPCEast Carroll, Franklin, Madison, Morehouse, Richland, Tensas and 1 more8 hr
Jun 15, 1:35 AM CDTMesoscale DiscussionSPCEast Carroll, Madison, Morehouse, Union, West Carroll115 min
Jun 15, 6:46 AM CDTMesoscale DiscussionSPCEast Carroll, Madison, Morehouse, West Carroll119 min
Jun 15, 9:41 AM CDTSevere Thunderstorm WatchSPCCatahoula, Concordia, East Feliciana, Franklin, Jefferson, Orleans and 10 more7 hr
Jun 15, 12:52 PM CDTMesoscale DiscussionSPCSaint Helena, Saint Tammany, Tangipahoa, Washington83 min
Jun 15, 3:50 PM CDTMesoscale DiscussionSPCOrleans, Saint Charles, Saint John the Baptist, Saint Tammany, Tangipahoa, Washington85 min
Jun 14, 9:37 PM CDTMesoscale DiscussionSPCAttala, Bolivar, Carroll, Choctaw, Holmes, Humphreys and 15 more113 min
Jun 15, 3:52 AM CDTMesoscale DiscussionSPCJackson83 min
Jun 15, 1:40 PM CDTMesoscale DiscussionSPCAlcorn, Benton, Chickasaw, Itawamba, Lafayette, Lee and 7 more3 hr

Nearby

Mesoscale Discussions in Mississippi, 2023Mesoscale Discussions in Louisiana, 2023Every mesoscale discussion in 2023

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.