Alert archive / Mississippi / Mesoscale Discussions in 2019

Mesoscale Discussion 252

March 30, 20194 states

The Storm Prediction Center issued this mesoscale discussion at Mar 30, 2019, 7:33 PM CDT for 4 states. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: Mar 30, 2019, 7:33 PM CDT (00:33 UTC)
Expired: Mar 30, 2019, 9:00 PM CDT
In force: 87 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 61 counties

Colbert County, AL, Cullman County, AL, Fayette County, AL, Franklin County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Morgan County, AL, Pickens County, AL, Walker County, AL, Winston County, AL, Cumberland County, KY, Monroe County, KY, Attala County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Hinds County, MS, Itawamba County, MS, Kemper County, MS, Lauderdale County, MS, Leake County, MS, Lee County, MS, Lowndes County, MS, Madison County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Tishomingo County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS, Bedford County, TN, Cannon County, TN, Clay County, TN, Coffee County, TN, DeKalb County, TN, Franklin County, TN, Giles County, TN, Jackson County, TN, Lawrence County, TN, Lincoln County, TN, Macon County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Overton County, TN, Putnam County, TN, Rutherford County, TN, Smith County, TN, Trousdale County, TN, Warren County, TN, Wilson County, TN

The radar

The Columbus AFB radar (KGWX), 63 km from the middle of the area, began a volume at 00:32 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

Birmingham, AL (KBMX), launched 00:00Z, 0.6 hours before the alert went out and 145 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1536 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 104 m²/s²
0-3 km storm-relative helicity: 236 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

356 
ACUS11 KWNS 310034
SWOMCD
SPC MCD 310033 
TNZ000-KYZ000-ALZ000-MSZ000-310200-

Mesoscale Discussion 0252
NWS Storm Prediction Center Norman OK
0733 PM CDT Sat Mar 30 2019

Areas affected...central MS...northwest AL...middle TN and extreme
south-central KY

Concerning...Severe potential...Watch unlikely 

Valid 310033Z - 310200Z

Probability of Watch Issuance...20 percent

SUMMARY...Thunderstorms are expected to continue weakening trend
from south-central KY into middle TN this evening. A marginal severe
threat may persist further south into central/northeast MS and
northwest AL for a couple more hours, but a watch is not expected.

DISCUSSION...After a brief uptick in convection across south-central
KY into middle TN over the last hour or two, convection has trended
toward weakening and a more disorganized state recently. Based on
the 00z RAOB from BNA, steep midlevel lapse rates are still present,
however, instability is meager with less than 200 J/kg MUCAPE
indicated. Effective shear around 54 kt and a fairly large, curved
low level hodograph gives some clues into the brief organization in
convection earlier. But, with loss of daytime heating and
increasingly poorer quality airmass with eastward extent, severe
threat is expected to quickly diminish across KY/TN.

Further south, convection has shown some upward trends in intensity
as cells track east/northeast into central and northeast MS.
Boundary layer moisture in better further south, with dewpoints in
the low to mid 60s F resulting in MUCAPE around 500-750 J/kg per JAN
00z RAOB. A weak capping inversion near 700mb was still evident in
this observation and is likely precluding more robust
intensification. Convection therefore will likely continue to
struggle in weaker forcing with southward extent. A marginal threat
of a strong wind gust or hail may persist for a couple of hours
across central/northeast MS into northwest AL as the cold front
continues to push eastward this evening.

..Leitman/Guyer.. 03/31/2019

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

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

LAT...LON   32158914 32139016 32329063 32649053 33368980 34368876
            35798702 36308640 36968566 36948537 36798522 36338526
            35548579 34398659 33778712 33108770 32598828 32288882
            32158914

Nearby

Mesoscale Discussions in Mississippi, 2019 Mesoscale Discussions in Tennessee, 2019 Mesoscale Discussions in Alabama, 2019 Every mesoscale discussion in 2019

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.