Alert archive / Mississippi / Mesoscale Discussions in 2016

Mesoscale Discussion 370

April 11, 2016Choctaw County, Washington County, Alabama; 8 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2016, 6:40 PM CDT for Choctaw County, Washington County, Alabama; 8 counties in Mississippi. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued: Apr 11, 2016, 6:40 PM CDT (23:40 UTC)
Expired: Apr 11, 2016, 7:45 PM CDT
In force: 65 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

Counties Choctaw County, AL, Washington County, AL, Clarke County, MS, Covington County, MS, Forrest County, MS, Greene County, MS, Jones County, MS, Lamar County, MS, Perry County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 121 km from the middle of the area, began a volume at 23:42 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.

Severe Thunderstorm Watch 86Apr 11, 6:50 PM CDT

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 11.7 hours before the alert went out and 137 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: 807 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 303 m²/s²
0-3 km storm-relative helicity: 445 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

316 
ACUS11 KWNS 112341
SWOMCD
SPC MCD 112340 
ALZ000-MSZ000-120045-

MESOSCALE DISCUSSION 0370
NWS STORM PREDICTION CENTER NORMAN OK
0640 PM CDT MON APR 11 2016

AREAS AFFECTED...FAR SE MS...FAR SW AL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 112340Z - 120045Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...LINE OF TSTMS MOVING THROUGH CNTRL MS IS EXPECTED TO
CONTINUE SEWD INTO PORTIONS OF FAR SE MS AND FAR SW AL. SOME
DAMAGING WIND GUSTS ARE POSSIBLE AND A WW MAY BE NEEDED.

DISCUSSION...RECENT RADAR IMAGERY DEPICTS A LINE A TSTMS EXTENDING
FROM W-CNTRL AL SWWD INTO CNTRL MS. WITHIN THIS LINE OF STORMS...A
FEW STRONGER UPDRAFTS EXISTS...PARTICULARLY ACROSS
SMITH...JASPER...AND LAUDERDALE COUNTIES IN E-CNTRL MS. A MESOVORTEX
WAS ALSO OBSERVED IN JASPER COUNTY. THIS PORTION OF THE LINE HAS
BECOME ORIENTED A LITTLE LESS PARALLEL TO THE SHEAR VECTORS THAN
PORTIONS OF THE LINE FARTHER W...SUGGESTING SOME FORWARD-PROPAGATION
IS POSSIBLE. AS A RESULT...THE DAMAGING WIND THREAT HERE IS EXPECTED
TO PERSIST FOR THE NEXT HOUR OR TWO AND A WW MAY BE NEEDED ACROSS
FAR SE MS AND FAR SW AL.

..MOSIER/BROYLES.. 04/11/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

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

LAT...LON   31318991 31678972 31978896 32138867 32168845 32218807
            31638786 31068821 30788907 31318991

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 11, 6:58 PM CDT	Severe Thunderstorm Watch	SPC	Choctaw, Clarke, Washington	5 hr
Apr 11, 11:48 AM CDT	Mesoscale Discussion	SPC	Bolivar, Coahoma, Humphreys, Issaquena, Leflore, Sharkey and 3 more	2 hr
Apr 11, 12:15 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Claiborne, Copiah, Covington, Franklin and 11 more	3 hr
Apr 11, 1:05 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Amite, Attala, Bolivar, Carroll, Choctaw and 37 more	6 hr
Apr 11, 3:42 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Attala, Carroll, Choctaw, Claiborne and 26 more	93 min
Apr 11, 6:09 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Carroll, Claiborne, Copiah, Franklin and 14 more	66 min

Nearby

Mesoscale Discussions in Mississippi, 2016 Mesoscale Discussions in Alabama, 2016 Every mesoscale discussion in 2016

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.