Alert archive / Kentucky / Mesoscale Discussions in 2012

Mesoscale Discussion 25

January 17, 201256 counties in Kentucky; 43 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jan 17, 2012, 10:33 AM CST for 56 counties in Kentucky; 43 counties in Tennessee. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Jan 17, 2012, 10:33 AM CST (16:33 UTC)
Expired
Jan 17, 2012, 11:30 AM CST
In force
57 min
Issued by
the Storm Prediction Center
All 99 counties

Adair County, KY, Allen County, KY, Anderson County, KY, Barren County, KY, Bath County, KY, Bourbon County, KY, Boyle County, KY, Bullitt County, KY, Butler County, KY, Calloway County, KY, Casey County, KY, Christian County, KY, Clark County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Fayette County, KY, Fleming County, KY, Franklin 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, Jefferson County, KY, Jessamine County, KY, Larue County, KY, Lincoln County, KY, Logan County, KY, Madison County, KY, Marion 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, Owen County, KY, Pulaski County, KY, Robertson 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, Warren County, KY, Washington County, KY, Woodford County, KY, Bedford County, TN, Benton County, TN, Cannon County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Clay County, TN, Crockett County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Gibson County, TN, Giles County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Macon County, TN, Madison County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Perry County, TN, Pickett County, TN, Robertson County, TN, Rutherford County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Wayne County, TN, Weakley County, TN, Williamson County, TN, Wilson County, TN

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 4.6 hours before the alert went out and 60 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 2012-01-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2012-01-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 587 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
608 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
587 m²/s²
0-3 km storm-relative helicity
687 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.

889 
ACUS11 KWNS 171634
SWOMCD
SPC MCD 171633
KYZ000-TNZ000-INZ000-171730-

MESOSCALE DISCUSSION 0025
NWS STORM PREDICTION CENTER NORMAN OK
1033 AM CST TUE JAN 17 2012

AREAS AFFECTED...CENTRAL KY AND WRN/MIDDLE TN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 171633Z - 171730Z

WW IS BEING CONSIDERED FOR PARTS OF CENTRAL KY SWD INTO WRN AND
MIDDLE TN.

AT 16Z...WATER VAPOR IMAGERY INDICATED THE LEADING EXTENT OF
STRONGER FORCING WITH THE MIDWEST SHORTWAVE TROUGH WAS TRACKING INTO
THE GREAT LAKES REGION.  HEIGHT FALLS ALONG THE SRN EXTENT OF THIS
SYSTEM MAY CONTINUE TO PROVE SUFFICIENT TO SUSTAIN A LINE OF
CONVECTION ADVANCING QUICKLY EWD INTO CENTRAL KY AND WRN/MIDDLE TN
THROUGH THE EARLY-MID AFTERNOON.  DESPITE A VERY WEAKLY UNSTABLE
ENVIRONMENT WITH NRN EXTENT /MUCAPE 100-400 J PER KG/...STRONG DEEP
LAYER WIND FIELDS/EFFECTIVE BULK SHEAR ACCOMPANYING THE UPPER TROUGH
AND LOW LEVEL SPEED SHEAR/HODOGRAPH CURVATURE IN ADVANCE OF THE COLD
FRONT ARE SUPPORTIVE OF THREATS FOR ISOLATED DAMAGING WINDS/BRIEF
TORNADO DEVELOPMENT.

FARTHER S OVER THE TN PORTION OF THE DISCUSSION AREA...INSTABILITY
WILL BE GREATER GIVEN CLOSER PROXIMITY TO BETTER MOISTURE RETURN.
HOWEVER...FORCING WILL TEND TO BE WEAKER WITH SRN EXTENT AND RESULT
IN LOWER COVERAGE FOR ROBUST TSTMS.

FARTHER E...DEEP LAYER WIND FIELDS WILL BE STRONG WITH EWD EXTENT
TODAY INTO ERN KY/WV...BUT VERY WEAK DESTABILIZATION WILL LIMIT THE
SEVERE WEATHER THREAT...DESPITE THE POTENTIAL FOR SOME WIND THREAT.

..PETERS.. 01/17/2012

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

ATTN...WFO...JKL...ILN...LMK...OHX...HUN...PAH...MEG...

LAT...LON   38758467 38488341 36728490 35278643 35038714 35108894
            35408968 36128906 37098767 38758467

Nearby

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