Alert archive / Tennessee / Mesoscale Discussions in 2016

Mesoscale Discussion 620

May 12, 20166 states

The Storm Prediction Center issued this mesoscale discussion at May 12, 2016, 9:10 AM CDT for 6 states. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
May 12, 2016, 9:10 AM CDT (14:10 UTC)
Expired
May 12, 2016, 10:45 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 52 counties

Colbert County, AL, Lauderdale County, AL, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Mississippi County, AR, Poinsett County, AR, Calloway County, KY, Fulton County, KY, Dunklin County, MO, Pemiscot County, MO, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Marshall County, MS, Prentiss County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Giles County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Perry County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Wayne County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 84 km from the middle of the area, began a volume at 14:10 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

Little Rock, AR (KBYH), launched 12:00Z, 2.2 hours before the alert went out and 114 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, Little Rock, AR at 12:00Z on 2016-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 932 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, Little Rock, AR at 12:00Z on 2016-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 square meters per square second.19395878Sfc1 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
932 J/kg
Mixed-layer CIN
-67 J/kg
Mixed-layer LCL
860 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
26 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted.

542 
ACUS11 KWNS 121411
SWOMCD
SPC MCD 121410 
ALZ000-TNZ000-KYZ000-MSZ000-MOZ000-ARZ000-121545-

MESOSCALE DISCUSSION 0620
NWS STORM PREDICTION CENTER NORMAN OK
0910 AM CDT THU MAY 12 2016

AREAS AFFECTED...NE AR...WRN TN...NRN MS...NW AL...FAR SW KY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 121410Z - 121545Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ISOLATED STRONG WIND GUSTS WILL BE POSSIBLE INTO WESTERN
TN THROUGH EARLY AFTERNOON. CONVECTIVE TRENDS WILL BE MONITORED FOR
POSSIBLE WATCH ISSUANCE SHOULD STORM INTENSITY INCREASE.

DISCUSSION...AN MCV ASSOCIATED WITH REMNANT MCS WILL CONTINUE
TRACKING EASTWARD TOWARD THE MS RIVER/WRN TN INTO THE EARLY
AFTERNOON. WHILE BOUNDARY LAYER INHIBITION IS STILL EVIDENT PER
OBJECTIVE ANALYSIS...DEWPOINTS IN THE UPPER 60S TO LOW 70S WERE
EVIDENT SOUTH OF A W-E SURFACE BOUNDARY FROM FAR NE AR INTO NW
TN...AND WILL CONTRIBUTE TO MODEST DESTABILIZATION WITH CONTINUED
HEATING AHEAD OF CONVECTION. INCREASED EFFECTIVE SHEAR NEAR 40 KT
DUE IN PART TO THE MCV WILL ALLOW FOR CONTINUED STORM ORGANIZATION
AND STRONGER DOWNDRAFTS WILL BE POSSIBLE INTO THE AFTERNOON AS LOW
LEVEL LAPSE RATES INCREASE. GROUND TRUTH HAS BEEN LIMITED THIS
MORNING...WHICH SUPPORTS INHIBITION PREVENTING STRONGER GUSTS FROM
CURRENTLY REACHING THE SURFACE. HOWEVER...TRENDS WILL BE MONITORED
FOR POSSIBLE WATCH ISSUANCE SHOULD INCREASE IN STORM INTENSITY
OCCUR.

..LEITMAN/HART.. 05/12/2016

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

ATTN...WFO...OHX...HUN...PAH...MEG...

LAT...LON   35549081 36099087 36448993 36718847 36738819 36598780
            36098737 35608711 35118701 34938706 34798721 34608775
            34408921 34418966 34569044 34829067 35159080 35549081

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 8:11 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 5 more3 hr
May 11, 10:13 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more7 hr
May 11, 11:46 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Logan, Scott, Sebastian119 min
May 12, 2:48 AM CDTMesoscale DiscussionSPCCleburne, Conway, Craighead, Faulkner, Garland, Greene and 17 more87 min
May 12, 2:33 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Desha, Drew and 1 more87 min
May 11, 8:24 PM CDTMesoscale DiscussionSPCAdair, Anderson, Barren, Bourbon, Boyle, Bullitt and 40 more96 min
May 11, 11:28 PM CDTMesoscale DiscussionSPCBallard, Butler, Caldwell, Carlisle, Christian, Crittenden and 21 more92 min

Nearby

Mesoscale Discussions in Tennessee, 2016Mesoscale Discussions in Mississippi, 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.