Alert archive / Mississippi / Mesoscale Discussions in 2016

Mesoscale Discussion 366

April 11, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2016, 3:42 PM CDT for 4 states. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Apr 11, 2016, 3:42 PM CDT (20:42 UTC)
Expired
Apr 11, 2016, 5:15 PM CDT
In force
93 min
Issued by
the Storm Prediction Center
All 71 counties

Ashley County, AR, Bradley County, AR, Chicot County, AR, Columbia County, AR, Drew County, AR, Union County, AR, Allen Parish, LA, Avoyelles Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Attala County, MS, Carroll County, MS, Choctaw County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Lawrence County, MS, Leake County, MS, Leflore County, MS, Lincoln County, MS, Madison County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Winston County, MS, Yazoo County, MS, Newton County, TX, Sabine County, TX

The radar

The Jackson/Brandon,MS radar (KDGX), 162 km from the middle of the area, began a volume at 20:46 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

Jackson, MS (KJAN), launched 12:00Z, 8.7 hours before the alert went out and 153 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 2016-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2016-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 303 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
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.

146 
ACUS11 KWNS 112042
SWOMCD
SPC MCD 112042 
MSZ000-LAZ000-ARZ000-TXZ000-112215-

MESOSCALE DISCUSSION 0366
NWS STORM PREDICTION CENTER NORMAN OK
0342 PM CDT MON APR 11 2016

AREAS AFFECTED...PORTIONS OF CNTRL/NRN LA...SRN AR...CNTRL/SRN MS

CONCERNING...SEVERE THUNDERSTORM WATCH 84...

VALID 112042Z - 112215Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 84
CONTINUES.

SUMMARY...THE SVR RISK CONTINUES ACROSS WW 84. EWD EXTENSION OF THE
WW ACROSS PARTS OF CNTRL/E-CNTRL MS MAY BECOME NECESSARY.

DISCUSSION...A SEMI-ORGANIZED CONVECTIVE CLUSTER/LINE EXTENDS FROM
NEAR GREENWOOD MS TO NEAR RUSTON LA AND IS SPREADING EWD/ESEWD. AS
THE EVOLVING CONVECTIVE LINE BECOMES INCREASINGLY ORIENTED PARALLEL
TO THE MID-LEVEL FLOW...THE OVERALL SVR-HAIL RISK WILL BECOME
RELATIVELY SUPPRESSED WHILE EMBEDDED SMALL BOWING SEGMENTS
POTENTIALLY SUPPORT LOCALLY DMGG WIND GUSTS. THIS ACTIVITY WILL
CONTINUE TO GRADUALLY SPREAD EWD/ESEWD...POTENTIALLY YIELDING SOME
SVR RISK INTO OTHER PARTS OF CNTRL/E-CNTRL MS. THIS IS WHERE
DESTABILIZATION IS ONGOING IN THE WAKE OF EARLIER ELEVATED
CONVECTION AMIDST 45-55 KT OF EFFECTIVE BULK SHEAR. ALSO...IN THE
WAKE OF THIS CONVECTION...ONGOING MODIFICATION/DESTABILIZATION OF
THE PREVIOUSLY OVERTURNED AIR MAY EVENTUALLY SUPPORT A SVR RISK
SPREADING INTO PARTS OF SRN AR AND NRN LA LATER THIS AFTERNOON.
FARTHER S...WEAK WARM ADVECTION CONTINUES SUPPORTING ISOLATED TO
WIDELY SCATTERED CONVECTION FROM ERN TX TO WRN LA. A FEW CONVECTIVE
ELEMENTS EVOLVING IN THIS REGIME COULD DEEPEN SUFFICIENTLY TO
PRODUCE AN ISOLATED SVR RISK...THOUGH WEAK ASCENT AND CAPPING ALOFT
WILL TEND TO MITIGATE THE OVERALL SVR RISK.

..COHEN.. 04/11/2016

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

ATTN...WFO...JAN...LIX...LZK...LCH...SHV...

LAT...LON   32159388 33229338 33709209 33759152 33699054 33588959
            33178875 32358882 31798972 30819094 30579297 30769386
            31349399 32159388

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 11, 12:57 AM CDTSevere Thunderstorm WatchSPCCrawford, Sebastian, Washington4 hr
Apr 11, 11:48 AM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 15 more2 hr
Apr 11, 1:05 PM CDTSevere Thunderstorm WatchSPCAshley, Bradley, Calhoun, Chicot, Columbia, Desha and 5 more6 hr
Apr 11, 1:38 PM CDTSevere Thunderstorm WatchSPCHempstead, Howard, Little River, Miller, Polk, Sevier9 hr
Apr 11, 6:09 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Columbia, Drew and 2 more66 min
Apr 11, 12:15 PM CDTMesoscale DiscussionSPCAllen, Avoyelles, Catahoula, Concordia, East Feliciana, Evangeline and 12 more3 hr
Apr 11, 6:58 PM CDTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 20 more5 hr
Apr 11, 6:40 PM CDTMesoscale DiscussionSPCClarke, Covington, Forrest, Greene, Jones, Lamar and 2 more65 min
Apr 10, 7:36 PM CDTMesoscale DiscussionSPCMontague114 min
Apr 10, 8:54 PM CDTMesoscale DiscussionSPCDimmit, Edwards, Kinney, Maverick, Real, Uvalde and 2 more66 min
Apr 10, 9:31 PM CDTMesoscale DiscussionSPCArcher, Baylor, Childress, Clay, Cooke, Cottle and 19 more59 min
Apr 10, 9:52 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Clay, Cooke, Foard, Hardeman and 4 more6 hr
Apr 10, 11:06 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Comal, Dimmit, Frio and 9 more54 min
Apr 11, 6:15 AM CDTMesoscale DiscussionSPCClay, Collin, Cooke, Delta, Denton, Fannin and 7 more3 hr
Apr 11, 12:39 PM CDTMesoscale DiscussionSPCArcher, Baylor, Camp, Clay, Collin, Cooke and 33 more2 hr
Apr 11, 1:43 PM CDTMesoscale DiscussionSPCAustin, Brazos, Grimes, Hardin, Harris, Liberty and 8 more3 hr
Apr 11, 3:26 PM CDTMesoscale DiscussionSPCClay, Collin, Cooke, Dallas, Delta, Denton and 18 more94 min
Apr 11, 4:49 PM CDTMesoscale DiscussionSPCCollin, Dallas, Denton, Hunt, Rains, Rockwall and 1 more86 min
Apr 11, 5:27 PM CDTMesoscale DiscussionSPCArcher, Baylor, Fisher, Haskell, Jones, King and 7 more93 min

Nearby

Mesoscale Discussions in Mississippi, 2016Mesoscale Discussions in Louisiana, 2016Mesoscale Discussions in Arkansas, 2016Every 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.