Alert archive / Kentucky / Mesoscale Discussions in 2011

Mesoscale Discussion 852

May 22, 20116 states

The Storm Prediction Center issued this mesoscale discussion at May 22, 2011, 12:55 PM CDT for 6 states. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
May 22, 2011, 12:55 PM CDT (17:55 UTC)
Expired
May 22, 2011, 2:00 PM CDT
In force
65 min
Issued by
the Storm Prediction Center
All 149 counties

Cullman County, AL, DeKalb County, AL, Jackson County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Fannin County, GA, Murray County, GA, Walker County, GA, Whitfield County, GA, Adair County, KY, Allen County, KY, Anderson County, KY, Barren County, KY, Bath County, KY, Bell County, KY, Bourbon County, KY, Boyle County, KY, Breathitt County, KY, Bullitt County, KY, Butler County, KY, Casey County, KY, Clark County, KY, Clay County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Elliott County, KY, Estill County, KY, Fayette County, KY, Fleming County, KY, Floyd County, KY, Franklin County, KY, Garrard County, KY, Grayson County, KY, Green County, KY, Hardin County, KY, Harlan County, KY, Hart County, KY, Jackson County, KY, Jessamine County, KY, Johnson County, KY, Knott County, KY, Knox County, KY, Larue County, KY, Laurel County, KY, Lee County, KY, Leslie County, KY, Letcher County, KY, Lincoln County, KY, Logan County, KY, Madison County, KY, Magoffin County, KY, Marion County, KY, McCreary County, KY, Menifee County, KY, Mercer County, KY, Metcalfe County, KY, Monroe County, KY, Montgomery County, KY, Morgan County, KY, Nelson County, KY, Nicholas County, KY, Owsley County, KY, Perry County, KY, Powell County, KY, Pulaski County, KY, Rockcastle County, KY, Rowan County, KY, Russell County, KY, Scott County, KY, Simpson County, KY, Spencer County, KY, Taylor County, KY, Warren County, KY, Washington County, KY, Wayne County, KY, Whitley County, KY, Wolfe County, KY, Woodford County, KY, Cherokee County, NC, Graham County, NC, Swain County, NC, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Cannon County, TN, Claiborne County, TN, Clay County, TN, Cocke County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grainger County, TN, Greene County, TN, Grundy County, TN, Hamblen County, TN, Hamilton County, TN, Hancock County, TN, Hawkins County, TN, Jackson County, TN, Jefferson County, TN, Knox County, TN, Lincoln County, TN, Loudon County, TN, Macon County, TN, Marion County, TN, Marshall County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Robertson County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Union County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Williamson County, TN, Wilson County, TN, City of Norton, VA, Lee County, VA, Scott County, VA, Wise County, VA

The radar

The Nashville radar (KOHX), 112 km from the middle of the area, began a volume at 17:55 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, 5.9 hours before the alert went out and 116 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 2011-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1543 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 2011-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 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
1543 J/kg
Mixed-layer CIN
-103 J/kg
Mixed-layer LCL
1025 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
215 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

101 
ACUS11 KWNS 221755
SWOMCD
SPC MCD 221755 
TNZ000-KYZ000-VAZ000-NCZ000-GAZ000-ALZ000-221900-

MESOSCALE DISCUSSION 0852
NWS STORM PREDICTION CENTER NORMAN OK
1255 PM CDT SUN MAY 22 2011

AREAS AFFECTED...NRN AL...NWRN GA...MIDDLE/ERN TN...CNTRL/ERN KY

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 221755Z - 221900Z

THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE THROUGH THE
AFTERNOON HOURS ACROSS PORTIONS OF TN VALLEY.  A FEW SEVERE STORMS
ARE POSSIBLE.  A WW WILL LIKELY BE NEEDED SOON.

LATEST VISIBLE SATELLITE IMAGERY SHOWS AN INCREASING CU FIELD WITH
ISOLATED THUNDERSTORMS BEGINNING TO DEVELOP ACROSS PORTIONS OF
MIDDLE TN AND NORTHERN AL.  THIS ACTIVITY IS INTENSIFYING AHEAD OF A
WEAK MID LEVEL SHORTWAVE TROUGH MOVING ACROSS AR/WEST TN...AND IN
REGION WHERE SUBSTANTIAL HEATING HAS ALREADY OCCURRED TODAY. 
DEWPOINTS IN THE MID 60S ARE YIELDING MINIMAL CINH AND MLCAPE VALUES
APPROACHING 2000 J/KG.  LOW LEVEL WINDS ARE NOT PARTICULARLY STRONG
IN THIS REGION...BUT FORECAST SOUNDINGS SHOW 35-40 KNOTS OF DEEP
LAYER EFFECTIVE SHEAR AND RELATIVELY STEEP MID LEVEL LAPSE RATES. 
THIS SHOULD PROMOTE ORGANIZED MULTICELL OR SUPERCELL STORMS CAPABLE
OF LARGE HAIL AND DAMAGING WINDS.

..HART.. 05/22/2011

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

ATTN...WFO...RLX...GSP...MRX...JKL...FFC...ILN...LMK...OHX...
BMX...HUN...PAH...

LAT...LON   37248706 37928613 38588381 38018267 37028234 35678301
            34928422 34178548 34118708 34268796 35688696 37248706

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 1:18 PM CDTSevere Thunderstorm WatchSPCColbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 7 more7 hr
May 22, 1:51 PM CDTMesoscale DiscussionSPCBoone, Boyd, Bracken, Campbell, Carroll, Carter and 8 more54 min
May 22, 3:44 PM CDTMesoscale DiscussionSPCBath, Bell, Bourbon, Boyd, Bracken, Breathitt and 44 more61 min
May 22, 4:40 PM CDTSevere Thunderstorm WatchSPCBoyd, Carter, Greenup, Lawrence5 hr
May 22, 6:26 PM CDTMesoscale DiscussionSPCBoyd, Carter, Elliott, Floyd, Greenup, Johnson and 4 more2 hr
May 22, 5:18 AM CDTMesoscale DiscussionSPCCrockett, Dyer, Fayette, Hardeman, Haywood, Lake and 3 more57 min
May 22, 7:03 AM CDTSevere Thunderstorm WatchSPCChester, Crockett, Decatur, Fayette, Hardeman, Hardin and 7 more7 hr
May 22, 1:09 PM CDTMesoscale DiscussionSPCChester, Fayette, Hardeman, Hardin, Haywood, McNairy and 3 more66 min

Nearby

Mesoscale Discussions in Kentucky, 2011Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Alabama, 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.