Alert archive / Kentucky / Mesoscale Discussions in 2011

Mesoscale Discussion 526

April 22, 20115 states

The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2011, 9:20 PM CDT for 5 states. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Apr 22, 2011, 9:20 PM CDT (02:20 UTC)
Expired
Apr 22, 2011, 10:15 PM CDT
In force
55 min
Issued by
the Storm Prediction Center
All 146 counties

Alexander County, IL, Clay County, IL, Clinton County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Madison County, IL, Marion County, IL, Massac County, IL, Monroe County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Clark County, IN, Crawford County, IN, Dubois County, IN, Floyd County, IN, Gibson County, IN, Harrison County, IN, Knox County, IN, Orange County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Washington County, IN, Adair County, KY, Allen County, KY, Anderson County, KY, Ballard County, KY, Barren County, KY, Bath County, KY, Bell County, KY, Bourbon County, KY, Boyle County, KY, Breckinridge County, KY, Bullitt County, KY, Butler County, KY, Caldwell County, KY, Carlisle County, KY, Casey County, KY, Christian County, KY, Clark County, KY, Clay County, KY, Clinton County, KY, Crittenden County, KY, Cumberland County, KY, Daviess County, KY, Edmonson County, KY, Estill County, KY, Fayette County, KY, Fleming County, KY, Franklin County, KY, Garrard County, KY, Grayson County, KY, Green County, KY, Hancock County, KY, Hardin County, KY, Harrison County, KY, Hart County, KY, Henderson County, KY, Henry County, KY, Hopkins County, KY, Jackson County, KY, Jefferson County, KY, Jessamine County, KY, Knox County, KY, Larue County, KY, Laurel County, KY, Lee County, KY, Lincoln County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Madison County, KY, Marion County, KY, Marshall County, KY, McCracken County, KY, McCreary County, KY, McLean County, KY, Meade County, KY, Menifee County, KY, Mercer County, KY, Metcalfe County, KY, Monroe County, KY, Montgomery County, KY, Muhlenberg County, KY, Nelson County, KY, Nicholas County, KY, Ohio County, KY, Oldham County, KY, Owen County, KY, Owsley County, KY, Powell County, KY, Pulaski County, KY, Robertson County, KY, Rockcastle County, KY, Russell County, KY, Scott County, KY, Shelby County, KY, Simpson County, KY, Spencer County, KY, Taylor County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Warren County, KY, Washington County, KY, Wayne County, KY, Webster County, KY, Whitley County, KY, Woodford County, KY, Bollinger County, MO, Cape Girardeau County, MO, City of Saint Louis, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Mississippi County, MO, Perry County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Claiborne County, TN

The radar

The Louisville radar (KLVX), 74 km from the middle of the area, began a volume at 02:20 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, 2.3 hours before the alert went out and 147 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 2011-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 719 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 2011-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 185 square meters per square second.193958Sfc1 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
719 J/kg
Mixed-layer CIN
-77 J/kg
Mixed-layer LCL
1368 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
185 m²/s²
0-3 km storm-relative helicity
309 m²/s²
Significant tornado parameter
0.4
Supercell composite
6.3

Open this sounding in Storm Lab

The text

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

216 
ACUS11 KWNS 230221
SWOMCD
SPC MCD 230220
VAZ000-KYZ000-TNZ000-INZ000-ILZ000-MOZ000-230315-

MESOSCALE DISCUSSION 0526
NWS STORM PREDICTION CENTER NORMAN OK
0920 PM CDT FRI APR 22 2011

AREAS AFFECTED...SERN MO...SRN IL...SRN IN...WRN/CNTRL KY

CONCERNING...TORNADO WATCH 181...

VALID 230220Z - 230315Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUPERCELLS THAT FORMED OVER CNTRL MO ARE CURRENTLY ENTERING WRN
PORTIONS OF THE WW AREA...CROSSING THE MO RIVER ATTM. ADDITIONAL
CONVECTION HAS DEVELOPED AHEAD OF THESE STORMS ACROSS SRN IL. LATEST
SFC SUBJECTIVE ANALYSIS PLACES A SFC LOW OVER WRN IL...WITH AN
EFFECTIVE WARM FRONT/BAROCLINIC ZONE EXTENDING SEWD ACROSS SRN IL
AND INTO SRN IN AND NRN KY. THE ENVIRONMENT DOWNSTREAM FROM THIS
CONVECTION REMAINS SUPPORTIVE OF PRODUCING DMGG WINDS...LARGE
HAIL...AND TORNADOES. REGIONAL VWP DATA CONTINUE TO SHOW CURVED
HODOGRAPHS WITH SUBSTANTIAL LOW-LEVEL VERTICAL WIND SHEAR /25-35 KTS
0-1 KM AGL/.

WITH TIME...MODEL GUIDANCE INDICATES A SLOW STRENGTHENING/VEERING OF
LOW-LEVEL FLOW. THIS SHOULD TEND TO FAVOR UPSCALE GROWTH INTO A
BROKEN LINE /WITH SMALL BOWING SEGMENTS/ CAPABLE OF PRODUCING DMGG
WINDS...THOUGH EMBEDDED SUPERCELL STRUCTURES WILL LIKELY STILL BE
OBSERVED WITH A CONTINUING POTENTIAL FOR TORNADOES.

..ROGERS.. 04/23/2011

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

ATTN...WFO...MRX...JKL...ILN...LMK...IND...PAH...ILX...LSX...

LAT...LON   36488355 36909084 38919085 38498354 36488355

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 22, 7:31 PM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Champaign, Christian, Clark and 22 more59 min
Apr 23, 1:04 AM CDTTornado WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 14 more4 hr
Apr 23, 3:41 AM CDTMesoscale DiscussionSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 10 more94 min
Apr 23, 4:22 AM CDTMesoscale DiscussionSPCHardin, Pope23 min
Apr 23, 1:04 PM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hardin, Johnson, Massac, Pope and 2 more86 min
Apr 23, 2:30 PM CDTTornado WatchSPCHardin, Massac, Pope5 hr
Apr 23, 5:09 PM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hardin, Jackson, Johnson, Massac and 5 more2 hr
Apr 23, 5:38 PM CDTSevere Thunderstorm WatchSPCAlexander, Johnson, Pulaski, Union6 hr
Apr 23, 10:51 AM CDTMesoscale DiscussionSPCBartholomew, Brown, Clark, Crawford, Daviess, Dearborn and 24 more84 min
Apr 23, 2:56 PM CDTMesoscale DiscussionSPCBath, Bourbon, Boyd, Bracken, Carter, Clark and 14 more64 min
Apr 23, 3:39 PM CDTSevere Thunderstorm WatchSPCBoyd, Carter, Greenup, Lawrence4 hr
Apr 23, 6:35 PM CDTMesoscale DiscussionSPCAdair, Anderson, Barren, Bath, Bourbon, Boyle and 37 more55 min
Apr 22, 7:29 PM CDTMesoscale DiscussionSPCRipley91 min
Apr 22, 11:04 PM CDTSevere Thunderstorm WatchSPCBarry, Barton, Camden, Cedar, Christian, Dade and 22 more7 hr
Apr 22, 11:10 PM CDTMesoscale DiscussionSPCBarry, Christian, Dade, Dent, Douglas, Greene and 13 more2 hr
Apr 23, 2:33 AM CDTMesoscale DiscussionSPCBarry, Barton, Christian, Crawford, Dade, Dallas and 20 more87 min
Apr 23, 5:06 AM CDTMesoscale DiscussionSPCBarry, Christian, Douglas, Greene, Howell, Lawrence and 8 more24 min

Nearby

Mesoscale Discussions in Kentucky, 2011Mesoscale Discussions in Illinois, 2011Mesoscale Discussions in Indiana, 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.