Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 588

April 26, 20127 counties in Kentucky; 21 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2012, 5:07 AM EDT for 7 counties in Kentucky; 21 counties in Tennessee. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Apr 26, 2012, 5:07 AM EDT (09:07 UTC)
Expired
Apr 26, 2012, 6:30 AM EDT
In force
83 min
Issued by
the Storm Prediction Center
All 28 counties

Bell County, KY, Clay County, KY, Knox County, KY, Laurel County, KY, Leslie County, KY, McCreary County, KY, Whitley County, KY, Anderson County, TN, Campbell County, TN, Claiborne County, TN, Clay County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Fentress County, TN, Jackson County, TN, Macon County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Scott County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Union County, TN, White County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 123 km from the middle of the area, began a volume at 09:09 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 00:00Z, 9.1 hours before the alert went out and 130 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 00:00Z on 2012-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1411 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, Nashville Metro, TN at 00:00Z on 2012-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 250 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
1411 J/kg
Mixed-layer CIN
-108 J/kg
Mixed-layer LCL
1242 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
250 m²/s²
0-3 km storm-relative helicity
383 m²/s²
Significant tornado parameter
1.3
Supercell composite
4.7

Open this sounding in Storm Lab

The text

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

671 
ACUS11 KWNS 260908
SWOMCD
SPC MCD 260907
VAZ000-KYZ000-TNZ000-261030-

MESOSCALE DISCUSSION 0588
NWS STORM PREDICTION CENTER NORMAN OK
0407 AM CDT THU APR 26 2012

AREAS AFFECTED...PORTIONS OF MIDDLE/EASTERN TN AND SOUTHEAST KY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 260907Z - 261030Z

IT SEEMS LIKELY THAT AN ONGOING MCS IN CENTRAL KY WILL MOVE
SOUTHEASTWARD INTO NORTHERN PORTIONS OF MIDDLE/EASTERN TN AND
SOUTHEAST KY BY AROUND 10Z. AT LEAST AN ISOLATED SEVERE HAIL/WIND
THREAT WILL EXIST THROUGH THE EARLY MORNING HOURS. WILL CONTINUE TO
MONITOR SHORT-TERM TRENDS FOR A POSSIBLE SEVERE TSTM WATCH.

A RELATIVELY COMPACT/WELL-ORGANIZED QUASI-LINEAR MCS CONTINUES TO
STEADILY MOVE SOUTHEASTWARD AT AROUND 45 KT ACROSS WEST-CENTRAL KY
AS OF 09Z. THE REGION IS BEING INFLUENCED BY A SOUTHEASTWARD MOVING
SHORTWAVE TROUGH/SPEED MAX AS READILY APPARENT PER WATER VAPOR
IMAGERY...WITH A PERSISTENT WESTERLY MOISTURE/INSTABILITY FEED
OCCURRING NEAR/ABOVE THE SURFACE. SOME POTENTIALLY SEVERE HAIL WILL
LIKELY REMAIN POSSIBLE AS THE MCS MOVES INTO TN/SOUTHEAST KY.
ISOLATED BOUTS OF DAMAGING WINDS WILL ALSO BE POSSIBLE GIVEN THE
FAST FORWARD MOTION/POSSIBLY SOME ADDITIONAL ACCELERATION OF THE
MCS...BUT CONSIDERABLE NEAR-SURFACE CINH WILL LIKELY CONTINUE TO
TEMPER DOWNDRAFT INTENSITY TO THE GROUND AND PRECLUDE A MORE
SUBSTANTIAL SEVERE WIND THREAT.

..GUYER.. 04/26/2012

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

ATTN...WFO...MRX...JKL...LMK...OHX...

LAT...LON   36608658 36618497 37328437 37108329 36618346 36098385
            35788548 36008672 36388693 36608658

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 25, 11:11 PM EDTMesoscale DiscussionSPCAnderson, Bath, Boone, Bourbon, Boyd, Boyle and 72 more2 hr
Apr 26, 1:40 AM EDTSevere Thunderstorm WatchSPCAdair, Allen, Anderson, Barren, Bourbon, Boyle and 53 more6 hr
Apr 26, 3:23 AM EDTMesoscale DiscussionSPCAnderson, Barren, Boyle, Breckinridge, Bullitt, Butler and 30 more97 min
Apr 26, 6:22 AM EDTSevere Thunderstorm WatchSPCMcCreary, Wayne, Whitley3 hr
Apr 26, 7:24 AM EDTMesoscale DiscussionSPCBell, Harlan, Leslie, Letcher, Perry96 min
Apr 26, 2:23 PM EDTMesoscale DiscussionSPCAdair, Allen, Barren, Bath, Bell, Boyd and 61 more2 hr
Apr 26, 3:11 PM EDTSevere Thunderstorm WatchSPCAdair, Allen, Barren, Bell, Breathitt, Calloway and 42 more6 hr
Apr 26, 4:22 PM EDTMesoscale DiscussionSPCAdair, Allen, Barren, Bell, Breathitt, Clay and 26 more83 min
Apr 26, 6:40 PM EDTMesoscale DiscussionSPCAdair, Allen, Barren, Bell, Breathitt, Clay and 23 more95 min
Apr 26, 8:10 AM EDTSevere Thunderstorm WatchSPCBradley, Hamilton, Polk3 hr
Apr 26, 8:47 AM EDTMesoscale DiscussionSPCBlount, Bradley, Carter, Johnson, Loudon, McMinn and 6 more88 min
Apr 26, 5:52 PM EDTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Decatur, Dickson and 13 more83 min
Apr 26, 7:09 PM EDTMesoscale DiscussionSPCBradley, Polk96 min

Nearby

Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in Kentucky, 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.