Alert archive / Tennessee / Mesoscale Discussions in 2016

Mesoscale Discussion 521

May 1, 20167 counties in Kentucky; 10 counties in Mississippi; 24 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at May 1, 2016, 1:11 PM CDT for 7 counties in Kentucky; 10 counties in Mississippi; 24 counties in Tennessee. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
May 1, 2016, 1:11 PM CDT (18:11 UTC)
Expired
May 1, 2016, 2:15 PM CDT
In force
64 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 41 counties

Butler County, KY, Calloway County, KY, Christian County, KY, Logan County, KY, Muhlenberg County, KY, Todd County, KY, Trigg County, KY, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Lafayette County, MS, Marshall County, MS, Panola County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dickson County, TN, Fayette County, TN, Gibson 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, Madison County, TN, McNairy County, TN, Montgomery County, TN, Perry County, TN, Robertson County, TN, Stewart County, TN, Weakley County, TN

The radar

The Ft Campbell radar (KHPX), 144 km from the middle of the area, began a volume at 18:10 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 watches that followed

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

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 6.2 hours before the alert went out and 164 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, Nashville Metro, TN at 12:00Z on 2016-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 259 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 2016-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 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
259 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
732 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

290 
ACUS11 KWNS 011812
SWOMCD
SPC MCD 011811 
KYZ000-TNZ000-ALZ000-MSZ000-011915-

MESOSCALE DISCUSSION 0521
NWS STORM PREDICTION CENTER NORMAN OK
0111 PM CDT SUN MAY 01 2016

AREAS AFFECTED...SW KY...WRN TN...NRN MS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 011811Z - 011915Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...SCATTERED TSTMS ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF
A COLD FRONT MOVING INTO THE WRN OH/TN VALLEYS. SOME OF THESE STORMS
MAY PRODUCE LARGE HAIL AND/OR DAMAGING WIND GUSTS. TRENDS WILL BE
MONITORED FOR A POSSIBLE WW.

DISCUSSION...RECENT VISIBLE SATELLITE TRENDS HAVE SHOWN INCREASINGLY
AGITATED CU ALONG THE COLD FRONT MOVING EWD INTO FAR SW KY...WRN
TN...AND NW MS. AIRMASS AHEAD OF THE FRONT CONTINUES TO DESTABILIZE
WITH RECENT MESOANALYSIS SUGGEST LITTLE...IF ANY...CINH REMAINS
AMIDST MLCAPE NEAR 15OO J PER KG. LOW-LEVEL FLOW THROUGHOUT THE
REGION IS WEAK BUT 12Z BNA SOUNDING SAMPLED 500-MB FLOW AROUND 50 KT
WITH SOME INCREASE IN MID-LEVEL FLOW POSSIBLE AHEAD OF THE SHORTWAVE
TROUGH MOVING INTO THE MID-MS VALLEY. MESOANALYSIS CURRENTLY
ESTIMATES EFFECTIVE SHEAR OF 50-55 KT. THIS ENVIRONMENT APPEARS
SUPPORTIVE OF ORGANIZED CONVECTION CAPABLE OF SEVERE HAIL AND
DAMAGING WIND GUSTS AND TRENDS ACROSS THE REGION WILL BE MONITORED
FOR A POSSIBLE WW.

..MOSIER/THOMPSON.. 05/01/2016

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

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

LAT...LON   34948818 34398906 34289030 34609044 35368957 36338879
            36868818 37258761 37228666 36798655 36338686 34948818

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 1, 12:39 PM CDTMesoscale DiscussionSPCBoone, Bracken, Breckinridge, Bullitt, Campbell, Carroll and 18 more2 hr
May 1, 1:36 PM CDTSevere Thunderstorm WatchSPCAdair, Allen, Anderson, Barren, Boone, Bourbon and 67 more6 hr
May 1, 2:59 PM CDTMesoscale DiscussionSPCBoyd, Breathitt, Carter, Clay, Elliott, Floyd and 13 more61 min
May 1, 3:12 PM CDTSevere Thunderstorm WatchSPCBath, Boyd, Breathitt, Carter, Elliott, Estill and 20 more6 hr
May 1, 5:48 PM CDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Boone and 72 more87 min
May 1, 6:30 PM CDTMesoscale DiscussionSPCFloyd, Knott, Martin, Pike60 min
May 1, 3:22 AM CDTMesoscale DiscussionSPCAmite, Wilkinson113 min

Nearby

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