Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 595

April 26, 201219 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2012, 4:52 PM CDT for 19 counties in Tennessee. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Apr 26, 2012, 4:52 PM CDT (21:52 UTC)
Expired
Apr 26, 2012, 6:15 PM CDT
In force
83 min
Issued by
the Storm Prediction Center

Counties Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dickson County, TN, Gibson County, TN, Hardeman County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Humphreys County, TN, Lauderdale County, TN, Lewis County, TN, Madison County, TN, Maury County, TN, McNairy County, TN, Perry County, TN

The radar

The Memphis radar (KNQA), 125 km from the middle of the area, began a volume at 21:51 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 (KLZK), launched 12:00Z, 9.9 hours before the alert went out and 160 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 2012-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1264 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 2012-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 216 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
1264 J/kg
Mixed-layer CIN
-306 J/kg
Mixed-layer LCL
757 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
216 m²/s²
0-3 km storm-relative helicity
322 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

998 
ACUS11 KWNS 262153
SWOMCD
SPC MCD 262152
TNZ000-262315-

MESOSCALE DISCUSSION 0595
NWS STORM PREDICTION CENTER NORMAN OK
0452 PM CDT THU APR 26 2012

AREAS AFFECTED...WRN TN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 262152Z - 262315Z

ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE OVER
WRN TN DURING THE REMAINDER OF THE AFTERNOON. CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

SURFACE OBSERVATIONS AND VISIBLE SATELLITE IMAGERY AT 2130Z SHOW
THAT A NARROW WEDGE OF STRONGER HEATING/BOUNDARY LAYER
DESTABILIZATION HAS DEVELOPED BETWEEN A COLD FRONT ENTERING WRN TN
AND A ZONE OF STRATUS OVER NRN MS/AL AND SRN PORTIONS OF TN. WITH
SURFACE TEMPERATURES IN THE LOW TO MID 80S...DEWPOINTS IN THE MID
60S...AND STEEP MIDLEVEL LAPSE RATES PRESENT ACROSS THE
REGION...MLCAPE VALUES ARE NEAR 2500 J/KG. THIS ENVIRONMENT IS
SUPPORTING ISOLATED THUNDERSTORM DEVELOPMENT ALONG THE FRONT. THESE
STORMS WILL HAVE THE POTENTIAL TO EVOLVE INTO ORGANIZED MULTICELLS
OR SUPERCELLS GIVEN THE PRESENCE OF LOW-LEVEL WLYS VEERING TO NWLY
ALOFT...WHICH IS AIDING IN EFFECTIVE BULK WIND DIFFERENCE VALUES
FROM 30-40 KT. THUS...A THREAT FOR LARGE HAIL AND DAMAGING WIND
GUSTS WILL EXIST THROUGH THE REMAINDER OF THE AFTERNOON.
HOWEVER...GIVEN THE PRESENCE OF STRATUS AND A MORE STABLE BOUNDARY
LAYER S OF STORM INITIATION...STORM PERSISTENCE MAY BE
COMPROMISED...WHICH COULD LIMIT THE NEED FOR A WW. TRENDS WILL
CONTINUE TO BE MONITORED.

..GARNER.. 04/26/2012

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

ATTN...WFO...OHX...MEG...

LAT...LON   35868968 36398818 36148724 35578693 35108858 35258976
            35868968

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 26, 4:07 AM CDTMesoscale DiscussionSPCAnderson, Campbell, Claiborne, Clay, Cumberland, Davidson and 15 more83 min
Apr 26, 5:22 AM CDTSevere Thunderstorm WatchSPCAnderson, Bedford, Bledsoe, Blount, Campbell, Cannon and 44 more3 hr
Apr 26, 6:24 AM CDTMesoscale DiscussionSPCAnderson, Bledsoe, Blount, Bradley, Campbell, Carter and 35 more96 min
Apr 26, 7:10 AM CDTSevere Thunderstorm WatchSPCBradley, Hamilton, Polk3 hr
Apr 26, 7:47 AM CDTMesoscale DiscussionSPCBlount, Bradley, Carter, Johnson, Loudon, McMinn and 6 more88 min
Apr 26, 1:23 PM CDTMesoscale DiscussionSPCCheatham, Clay, Davidson, DeKalb, Dickson, Fentress and 17 more2 hr
Apr 26, 2:11 PM CDTSevere Thunderstorm WatchSPCBedford, Campbell, Cannon, Cheatham, Claiborne, Clay and 30 more6 hr
Apr 26, 3:22 PM CDTMesoscale DiscussionSPCAnderson, Benton, Blount, Campbell, Cheatham, Claiborne and 33 more83 min
Apr 26, 5:40 PM CDTMesoscale DiscussionSPCAnderson, Bedford, Bledsoe, Blount, Campbell, Cannon and 58 more95 min
Apr 26, 6:09 PM CDTMesoscale DiscussionSPCBradley, Polk96 min

Nearby

Mesoscale Discussions in Tennessee, 2012Every mesoscale discussion in 2012

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.