Alert archive / Kentucky / Mesoscale Discussions in 2012

Mesoscale Discussion 259

March 15, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Mar 15, 2012, 4:44 PM EDT for 4 states. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued
Mar 15, 2012, 4:44 PM EDT (20:44 UTC)
Expired
Mar 15, 2012, 5:45 PM EDT
In force
61 min
Issued by
the Storm Prediction Center
All 135 counties

Bartholomew County, IN, Clark County, IN, Dearborn County, IN, Decatur County, IN, Fayette County, IN, Floyd County, IN, Franklin County, IN, Hancock County, IN, Harrison County, IN, Henry County, IN, Jackson County, IN, Jefferson County, IN, Jennings County, IN, Johnson County, IN, Ohio County, IN, Ripley County, IN, Rush County, IN, Scott County, IN, Shelby County, IN, Switzerland County, IN, Union County, IN, Washington County, IN, Wayne County, IN, Adair County, KY, Allen County, KY, Anderson County, KY, Barren County, KY, Bath County, KY, Boone County, KY, Bourbon County, KY, Boyle County, KY, Bracken County, KY, Breathitt County, KY, Breckinridge County, KY, Bullitt County, KY, Butler County, KY, Campbell County, KY, Carroll County, KY, Casey County, KY, Clark County, KY, Clay County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Estill County, KY, Fayette County, KY, Fleming County, KY, Franklin County, KY, Gallatin County, KY, Garrard County, KY, Grant County, KY, Grayson County, KY, Green County, KY, Hardin County, KY, Harrison County, KY, Hart County, KY, Henry County, KY, Jackson County, KY, Jefferson County, KY, Jessamine County, KY, Kenton County, KY, Knox County, KY, Larue County, KY, Laurel County, KY, Lee County, KY, Leslie County, KY, Lincoln County, KY, Logan County, KY, Madison County, KY, Marion County, KY, McCreary County, KY, Meade County, KY, Menifee County, KY, Mercer County, KY, Metcalfe County, KY, Monroe County, KY, Montgomery County, KY, Nelson County, KY, Nicholas County, KY, Ohio County, KY, Oldham County, KY, Owen County, KY, Owsley County, KY, Pendleton County, KY, Perry 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, Trimble County, KY, Warren County, KY, Washington County, KY, Wayne County, KY, Whitley County, KY, Wolfe County, KY, Woodford County, KY, Butler County, OH, Clermont County, OH, Hamilton County, OH, Preble County, OH, Cheatham County, TN, Chester County, TN, Clay County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Hardin County, TN, Henderson County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Macon County, TN, Marshall County, TN, Maury County, TN, Montgomery County, TN, Perry County, TN, Pickett County, TN, Robertson County, TN, Rutherford County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Wayne County, TN, Williamson County, TN, Wilson County, TN

The radar

The Louisville radar (KLVX), 94 km from the middle of the area, began a volume at 20:47 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, 8.7 hours before the alert went out and 120 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 2012-03-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1726 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 2012-03-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 square meters per square second.1939Sfc1 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
1726 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
820 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

503 
ACUS11 KWNS 152045
SWOMCD
SPC MCD 152044
KYZ000-OHZ000-TNZ000-INZ000-152145-

MESOSCALE DISCUSSION 0259
NWS STORM PREDICTION CENTER NORMAN OK
0344 PM CDT THU MAR 15 2012

AREAS AFFECTED...TN/CNTRL OH VALLEYS

CONCERNING...SEVERE THUNDERSTORM WATCH 75...

VALID 152044Z - 152145Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 75
CONTINUES.

OVERALL SEVERE THREAT MAY HAVE PEAKED WITH NUMEROUS TO WIDESPREAD
TSTMS EXTENDING ACROSS THE CNTRL OH TO THE TN VALLEYS.
STILL...MARGINAL SEVERE HAIL SHOULD PERSIST FOR THE NEXT FEW HOURS
WITH PERHAPS LOCALLY DAMAGING WINDS WITHIN EMBEDDED MULTICELL
CLUSTERS. THE NEED FOR A WW ISSUANCE TO THE N/E OF WW 75 IS UNCLEAR
ATTM.

NUMEROUS DISCRETE CELLS HAVE LARGELY CONGLOMERATED INTO TWO DISTINCT
BANDS...ONE MOVING NEWD ACROSS SRN IND INTO N-CNTRL KY AND THE OTHER
MOVING EWD ACROSS WRN KY/TN. MID-LEVEL REFLECTIVITY CORES WITHIN THE
WRN BAND HAVE BEEN RECENTLY DIMINISHING AS ACTIVITY HAS PROPAGATED
INTO AN OVERTURNED AIR MASS. THE LEAD/NERN BAND MAY STILL REMAIN
STRONG TO LOCALLY SEVERE FOR THE NEXT COUPLE OF HOURS BEFORE
ENCOUNTERING THE OVERTURNED AIR MASS FROM AN EARLIER MCS THAT PUSHED
ACROSS SWRN OH/ERN KY. GIVEN THE WEAKLY SHEARED ENVIRONMENT AND
CONVECTIVE MODE BEING DOMINATED BY MERGERS/STORM-SCALE
INTERACTIONS...THE THREAT FOR SEVERE HAIL SHOULD BECOME INCREASINGLY
MARGINAL INTO EARLY EVENING.

..GRAMS.. 03/15/2012

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

ATTN...WFO...MRX...JKL...ILN...LMK...OHX...IND...PAH...MEG...

LAT...LON   35248894 35938809 36768723 37318695 38048660 38458614
            39058616 39658622 39978586 40098484 39768450 38758393
            37418309 37008310 36778335 36658457 36318552 35598649
            35208720 35108755 35018801 35158831 35248894

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 15, 2:08 PM EDTMesoscale DiscussionSPCBrown, Clark, Crawford, Daviess, Dubois, Floyd and 20 more2 hr
Mar 15, 3:06 PM EDTSevere Thunderstorm WatchSPCClark, Crawford, Dubois, Floyd, Harrison, Jefferson and 4 more6 hr
Mar 15, 5:28 PM EDTSevere Thunderstorm WatchSPCDearborn, Fayette, Franklin, Ohio, Ripley, Switzerland and 2 more3 hr
Mar 15, 6:02 PM EDTMesoscale DiscussionSPCAdams, Allen, Cass, DeKalb, Elkhart, Fulton and 19 more2 hr
Mar 15, 7:23 PM EDTMesoscale DiscussionSPCBath, Bell, Bourbon, Bracken, Breathitt, Campbell and 36 more97 min
Mar 15, 3:19 AM EDTMesoscale DiscussionSPCAllen, Ashland, Champaign, Clark, Coshocton, Crawford and 41 more86 min
Mar 15, 3:52 PM EDTMesoscale DiscussionSPCAllen, Defiance, Fulton, Hancock, Henry, Lucas and 8 more83 min

Nearby

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