Alert archive / Mississippi / Mesoscale Discussions in 2019

Mesoscale Discussion 331

April 13, 201925 counties in Alabama; 31 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 13, 2019, 9:13 PM CDT for 25 counties in Alabama; 31 counties in Mississippi. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Apr 13, 2019, 9:13 PM CDT (02:13 UTC)
Expired
Apr 13, 2019, 10:45 PM CDT
In force
92 min
Issued by
the Storm Prediction Center
All 56 counties

Bibb County, AL, Blount County, AL, Chilton County, AL, Choctaw County, AL, Colbert County, AL, Cullman County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lawrence County, AL, Marengo County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Itawamba County, MS, Jasper 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, Pontotoc County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS

The radar

The Columbus AFB radar (KGWX), 42 km from the middle of the area, began a volume at 02:12 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 watches that followed

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

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 2.2 hours before the alert went out and 140 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, Birmingham, AL at 00:00Z on 2019-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 506 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, Birmingham, AL at 00:00Z on 2019-04-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 240 square meters per square second.1939587897Sfc1 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
506 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
1458 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
240 m²/s²
0-3 km storm-relative helicity
428 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.3

Open this sounding in Storm Lab

The text

As transmitted.

065 
ACUS11 KWNS 140213
SWOMCD
SPC MCD 140213 
ALZ000-MSZ000-140345-

Mesoscale Discussion 0331
NWS Storm Prediction Center Norman OK
0913 PM CDT Sat Apr 13 2019

Areas affected...Eastern Mississippi and northwest Alabama

Concerning...Tornado Watch 55...

Valid 140213Z - 140345Z

The severe weather threat for Tornado Watch 55 continues.

SUMMARY...The severe weather threat continues across tornado watch
55. The primary threat will likely be damaging winds into the
overnight hours.

DISCUSSION...The cold front is currently surging across Mississippi
and has started to catch the pre frontal convection in north central
Mississippi. As this front continues to move eastward, bowing line
segments may become increasingly likely with the threat for damaging
winds. Given the strong low-level helicity across the area (greater
than 500 m2/s2 per HTX VWP), embedded QLCS tornadoes are possible.
The warm front may lift a few counties north in the next few hours
to the northern most row of counties in Alabama. The greatest
damaging wind threat will be anywhere south of this warm front with
the tornado threat maximized in close proximity to this warm front
where low-level flow will be more backed.

..Bentley.. 04/14/2019

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

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

LAT...LON   34058980 34498873 34718793 34848735 34778679 34678626
            34028622 33188629 32428703 31738888 31778940 31959044
            32749033 34058980

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 13, 7:11 PM CDTTornado WatchSPCBibb, Blount, Colbert, Cullman, Fayette, Franklin and 19 more11 hr
Apr 13, 8:25 PM CDTMesoscale DiscussionSPCChoctaw, Washington95 min
Apr 13, 9:33 PM CDTTornado WatchSPCBaldwin, Choctaw, Clarke, Mobile, Monroe, Washington and 1 more8 hr
Apr 13, 11:01 PM CDTMesoscale DiscussionSPCBibb, Choctaw, Clarke, Dallas, Fayette, Franklin and 15 more119 min
Apr 14, 12:39 AM CDTMesoscale DiscussionSPCCalhoun, Cherokee, Clay, Cleburne, DeKalb, Etowah and 2 more66 min
Apr 14, 1:04 AM CDTTornado WatchSPCAutauga, Barbour, Bullock, Calhoun, Chambers, Cherokee and 19 more9 hr
Apr 14, 2:15 AM CDTMesoscale DiscussionSPCBaldwin, Butler, Choctaw, Clarke, Coffee, Conecuh and 10 more60 min
Apr 14, 2:45 AM CDTTornado WatchSPCButler, Coffee, Conecuh, Covington, Crenshaw, Dale and 4 more7 hr
Apr 14, 4:20 AM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 18 more115 min
Apr 14, 5:36 AM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 18 more54 min
Apr 14, 7:28 AM CDTMesoscale DiscussionSPCHenry, Houston3 hr
Apr 14, 9:40 AM CDTTornado WatchSPCHenry, Houston6 hr
Apr 14, 10:07 AM CDTMesoscale DiscussionSPCBarbour, Henry, Houston, Russell83 min
Apr 13, 8:31 PM CDTMesoscale DiscussionSPCAdams, Amite, Attala, Carroll, Choctaw, Claiborne and 17 more119 min

Nearby

Mesoscale Discussions in Mississippi, 2019Mesoscale Discussions in Alabama, 2019Every 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.