Alert archive / Mississippi / Mesoscale Discussions in 2016

Mesoscale Discussion 306

March 31, 2016Chicot County, Arkansas; 18 parishes in Louisiana; 36 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2016, 1:30 PM CDT for Chicot County, Arkansas; 18 parishes in Louisiana; 36 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 31, 2016, 1:30 PM CDT (18:30 UTC)
Expired
Mar 31, 2016, 3:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 55 counties

Chicot County, AR, Avoyelles Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Richland Parish, LA, Tensas Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Attala County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Claiborne County, MS, Clay County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Lafayette County, MS, Leake County, MS, Lee County, MS, Leflore County, MS, Madison County, MS, Marshall County, MS, Monroe County, MS, Montgomery County, MS, Oktibbeha County, MS, Panola County, MS, Pontotoc County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Union County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Yalobusha County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 84 km from the middle of the area, began a volume at 18:34 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, 6.5 hours before the alert went out and 74 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 2016-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 481 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 2016-03-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 501 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
481 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
647 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
501 m²/s²
0-3 km storm-relative helicity
572 m²/s²
Significant tornado parameter
1.4
Supercell composite
9.2

Open this sounding in Storm Lab

The text

As transmitted.

184 
ACUS11 KWNS 311830
SWOMCD
SPC MCD 311830 
MSZ000-ARZ000-LAZ000-312030-

MESOSCALE DISCUSSION 0306
NWS STORM PREDICTION CENTER NORMAN OK
0130 PM CDT THU MAR 31 2016

AREAS AFFECTED...CNTRL/NERN LA...CNTRL AND NRN MS

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 311830Z - 312030Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...A SEVERE THREAT WILL LIKELY DEVELOP FROM CNTRL AND NERN LA
NEWD INTO CNTRL AND NRN MS. TORNADOES...WIND DAMAGE AND HAIL WILL BE
POSSIBLE ACROSS PARTS OF CNTRL AND NRN MS. ISOLATED LARGE HAIL AND
WIND DAMAGE WILL BE POSSIBLE SWWD ACROSS WRN MS INTO NERN AND CNTRL
LA. WW ISSUANCE WILL LIKELY BE NEEDED ACROSS THE REGION THIS
AFTERNOON.

DISCUSSION...LATEST SFC ANALYSIS SHOWS A DISTINCT CORRIDOR OF
LOW-LEVEL MOISTURE LOCATED FROM ERN LA NNEWD ALONG THE MS RIVER INTO
WRN TN. SFC DEWPOINTS ALONG THIS CORRIDOR RANGE FROM THE MID 60S TO
THE LOWER 70S F AND MLCAPE IS ESTIMATED FROM NEAR 1500 J/KG IN NERN
LA TO AROUND 750 J/KG IN NERN MS. OVER THE LAST HOUR...RADAR TRENDS
SHOW CONVECTION TRYING TO INITIATE IN WRN MS BUT THIS PROCESS MAY
TAKE AN HOUR OR SO.  THE HRRR IS IN AGREEMENT WITH THIS
THINKING...SUGGESTING THAT THUNDERSTORMS WILL DEVELOP IN NW MS AND
NERN LA IN THE 19Z TO 20Z TIMEFRAME WITH A GRADUAL INCREASE IN
CONVECTIVE COVERAGE LATE THIS AFTERNOON. REGIONAL WSR-88D VWPS IN
CNTRL AND NERN MS SHOW 0-6 KM SHEAR OF 60 KT WITH 0-3 KM STORM
RELATIVE HELICITIES NEAR 350 M2/S2. THIS COMBINED WITH SFC SSELY
FLOW ACROSS NERN MS WILL BE FAVORABLE FOR SUPERCELLS WITH TORNADOES
AND WIND DAMAGE LATER THIS AFTERNOON. FURTHER TO THE SOUTHWEST
ACROSS NERN LA AND WRN MS...SFC WINDS ARE GENERALLY FROM THE
SOUTHWEST SUGGESTING THAT THE TORNADO THREAT WILL BE LESS.
STILL...STEEP MID-LEVEL LAPSE RATES AND STRONG DEEP LAYER SHEAR OVER
NE LA AND WRN MS WILL FAVOR SUPERCELLS WITH ISOLATED LARGE HAIL AND
WIND DAMAGE.

..BROYLES/THOMPSON.. 03/31/2016

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

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

LAT...LON   33448867 32658963 31779077 30939195 31019285 31279308
            31869320 32769219 34009071 34818962 34548855 33908834
            33448867

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 30, 7:44 PM CDTSevere Thunderstorm WatchSPCBenton4 hr
Mar 30, 8:37 PM CDTMesoscale DiscussionSPCBenton53 min
Mar 30, 8:39 PM CDTMesoscale DiscussionSPCAshley, Bradley, Chicot, Desha, Drew, Lincoln and 1 more96 min
Mar 30, 10:00 PM CDTTornado WatchSPCAshley, Bradley, Chicot, Desha, Drew, Union6 hr
Mar 30, 11:30 PM CDTMesoscale DiscussionSPCChicot, Desha60 min
Mar 31, 10:26 AM CDTMesoscale DiscussionSPCArkansas, Cleveland, Craighead, Crittenden, Cross, Dallas and 14 more3 hr
Mar 31, 10:58 AM CDTSevere Thunderstorm WatchSPCClay, Craighead, Crittenden, Cross, Greene, Jackson and 9 more5 hr
Mar 31, 2:05 PM CDTSevere Thunderstorm WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 7 more8 hr
Mar 31, 2:14 PM CDTMesoscale DiscussionSPCCrittenden, Cross91 min
Mar 31, 2:35 PM CDTTornado WatchSPCLee, Phillips7 hr
Mar 31, 3:04 AM CDTMesoscale DiscussionSPCEast Feliciana, Pointe Coupee, Saint Helena, Tangipahoa, Washington, West Feliciana86 min
Mar 31, 3:20 AM CDTTornado WatchSPCEast Baton Rouge, East Feliciana, Livingston, Pointe Coupee, Saint Helena, Saint Tammany and 4 more6 hr
Mar 31, 3:30 PM CDTMesoscale DiscussionSPCAscension, East Baton Rouge, East Feliciana, Iberville, Livingston, Pointe Coupee and 6 more2 hr
Mar 31, 5:22 PM CDTMesoscale DiscussionSPCCaldwell, Catahoula, East Carroll, Franklin, Grant, Jackson and 9 more53 min
Mar 31, 7:47 AM CDTMesoscale DiscussionSPCCovington, Forrest, Greene, Jefferson Davis, Jones, Lamar and 3 more58 min
Mar 31, 8:43 AM CDTTornado WatchSPCGeorge, Greene, Perry, Stone5 hr
Mar 31, 4:47 PM CDTMesoscale DiscussionSPCAlcorn, Attala, Benton, Bolivar, Calhoun, Carroll and 55 more58 min
Mar 31, 5:58 PM CDTTornado WatchSPCWayne7 hr
Mar 31, 6:52 PM CDTMesoscale DiscussionSPCAlcorn, Calhoun, Chickasaw, Choctaw, Clarke, Clay and 29 more53 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.