Alert archive / Kentucky / Mesoscale Discussions in 2011

Mesoscale Discussion 384

April 9, 201131 counties in Kentucky; 11 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2011, 12:07 PM EDT for 31 counties in Kentucky; 11 counties in Tennessee. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Apr 9, 2011, 12:07 PM EDT (16:07 UTC)
Expired
Apr 9, 2011, 1:30 PM EDT
In force
83 min
Issued by
the Storm Prediction Center
All 42 counties

Bath County, KY, Bell County, KY, Breathitt County, KY, Clark County, KY, Clay County, KY, Clinton County, KY, Estill County, KY, Garrard County, KY, Harlan County, KY, Jackson County, KY, Knott County, KY, Knox County, KY, Laurel County, KY, Lee County, KY, Leslie County, KY, Lincoln County, KY, Madison County, KY, Magoffin County, KY, McCreary County, KY, Menifee County, KY, Montgomery County, KY, Morgan County, KY, Owsley County, KY, Perry County, KY, Powell County, KY, Pulaski County, KY, Rockcastle County, KY, Russell County, KY, Wayne County, KY, Whitley County, KY, Wolfe County, KY, Campbell County, TN, Clay County, TN, Cumberland County, TN, Fentress County, TN, Jackson County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Scott County, TN, Smith County, TN

The radar

The Knoxville radar (KMRX), 134 km from the middle of the area, began a volume at 16:08 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, 4.1 hours before the alert went out and 201 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 2011-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2430 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 12:00Z on 2011-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 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
2430 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
760 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.5

Open this sounding in Storm Lab

The text

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

575 
ACUS11 KWNS 091607
SWOMCD
SPC MCD 091607 
KYZ000-VAZ000-TNZ000-091730-

MESOSCALE DISCUSSION 0384
NWS STORM PREDICTION CENTER NORMAN OK
1107 AM CDT SAT APR 09 2011

AREAS AFFECTED...CNTRL AND ERN KY THROUGH NRN AND NERN TN

CONCERNING...SEVERE THUNDERSTORM WATCH 111...

VALID 091607Z - 091730Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 111
CONTINUES.

THREAT FOR ISOLATED DAMAGING WIND AND HAIL CONTINUES ACROSS CNTRL
KY...BUT NRN PORTION OF LINE HAS BECOME LESS ORGANIZED.
HOWEVER...SEVERE THREAT MAY SPREAD INTO PARTS OF E-CNTRL THROUGH
SERN KY AND NRN TN WHERE TRENDS ARE BEING MONITORED FOR A WW LATER
THIS MORNING OR AFTERNOON.

LATE THIS MORNING AN MCS CONTINUES THROUGH CNTRL KY AT 45-50
KT....BUT OVERALL TREND HAS BEEN FOR THIS ACTIVITY TO WEAKEN. WELL
DEFINED MCV OVER SRN IND WILL ADVANCE ESEWD TODAY. CURRENT THINKING
IS THAT STORMS MAY REDEVELOP/REORGANIZE ALONG SRN FRINGES OF THE MCS
THIS AFTERNOON WHERE INFLUX OF HIGHER THETA-E AIR IS MAXIMIZED. THE
STRONGER FORCING ATTENDING THE MCV WILL REMAIN JUST NORTH OF THE
WARM SECTOR...AND STRONGER CAP WITH SWD EXTENT TOWARD SRN KY AND TN
MIGHT DELAY NEW DEVELOPMENT UNTIL THE AFTERNOON. VISIBLE IMAGERY
SHOWS EVIDENCE OF A POSSIBLE GRAVITY WAVE MOVING THROUGH S-CNTRL KY
AND N-CNTRL TN WHICH MIGHT BECOME A SOURCE OF INITIATION. VERTICAL
SHEAR OF 45-50 KT...STEEP LAPSE RATES AND MODERATE INSTABILITY WILL
SUPPORT A THREAT OF SUPERCELLS AND BOWING SEGMENTS ONCE STORMS
REDEVELOP.

..DIAL.. 04/09/2011

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

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

LAT...LON   36218613 36958517 38298396 37958286 36948287 35858492
            36218613

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 8, 11:07 PM EDTSevere Thunderstorm WatchSPCBreathitt, Estill, Floyd, Knott, Lee, Letcher and 6 more6 hr
Apr 9, 12:42 AM EDTMesoscale DiscussionSPCKnott, Letcher, Perry93 min
Apr 9, 7:41 AM EDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bourbon, Boyle and 72 more2 hr
Apr 9, 8:25 AM EDTSevere Thunderstorm WatchSPCAdair, Allen, Anderson, Ballard, Barren, Bourbon and 72 more6 hr
Apr 9, 12:34 PM EDTSevere Thunderstorm WatchSPCBath, Bell, Boyd, Breathitt, Carter, Clay and 30 more4 hr
Apr 9, 2:00 PM EDTTornado WatchSPCBell, Boyd, Breathitt, Carter, Clay, Elliott and 27 more7 hr
Apr 9, 3:23 AM EDTMesoscale DiscussionSPCCarter, Johnson, Sullivan67 min
Apr 9, 4:21 PM EDTMesoscale DiscussionSPCAnderson, Blount, Bradley, Campbell, Carter, Claiborne and 21 more84 min

Nearby

Mesoscale Discussions in Kentucky, 2011Mesoscale Discussions in Tennessee, 2011Every mesoscale discussion in 2011

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.