Mesoscale Discussion 177

Issued

Feb 29, 2012, 3:40 AM EST (08:40 UTC)

Expired

Feb 29, 2012, 4:45 AM EST

In force

65 min

Issued by

the Storm Prediction Center

The Louisville radar (KLVX), 10 km from the middle of the area, began a volume at 08:40 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.

• Tornado Watch 45Feb 29, 4:20 AM EST
• Tornado Watch 46Feb 29, 5:40 AM EST

068 
ACUS11 KWNS 290841
SWOMCD
SPC MCD 290840
OHZ000-KYZ000-TNZ000-INZ000-ILZ000-290945-

MESOSCALE DISCUSSION 0177
NWS STORM PREDICTION CENTER NORMAN OK
0240 AM CST WED FEB 29 2012

AREAS AFFECTED...CENTRAL-ERN KY/SRN IND INTO SWRN-SOUTH CENTRAL OH

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 290840Z - 290945Z

WW ISSUANCE IS UNLIKELY OVER SWRN-SRN OH/NERN KY...THOUGH AREAS
FARTHER TO THE W/SW /PARTS OF CENTRAL KY INTO SRN IND AND MIDDLE TN/
WILL NEED TO BE MONITORED OVERNIGHT FOR A POTENTIAL WW ISSUANCE
TOWARD DAYBREAK.

08Z SURFACE/STREAMLINE ANALYSES SHOWED A WARM FRONT EXTENDING FROM
SRN IA SEWD THROUGH CENTRAL IL TO NORTH CENTRAL-NERN KY.  STRONG
SWLY LOW LEVEL FLOW ACROSS THE WARM SECTOR WILL MAINTAIN NWD
MOISTURE ADVECTION AND CONTINUED DESTABILIZATION FROM W-E ACROSS THE
LOWER OH VALLEY RESULTING IN LOWER THERMODYNAMIC PROFILES EVENTUALLY
BECOMING CONDUCIVE FOR SURFACE BASED STORMS.  OBJECTIVE ANALYSES
INDICATED A PLUME OF STEEPER MIDLEVEL LAPSE RATES /7-7.5 C PER KM/
SPREADING INTO WRN TN/KY AND FAR SRN IND ATOP THE MOISTURE RETURN
CONTRIBUTING TO MUCAPE OF 1000-2000 J/KG.

REGIONAL RADAR IMAGERY SHOWED CONVECTION CONTINUING TO DEVELOP
WITHIN A LOW LEVEL CONVERGENCE ZONE EXTENDING FROM NERN AR/WRN TN
INTO SRN IL AND WRN TN/KY TO SRN IND.  TSTMS HAVE BEEN DEVELOPING
ALONG THE ERN EXTENT OF THE CAP...NOW EXTENDING FROM CENTRAL KY INTO
SERN IND.  FORECAST SOUNDINGS SUGGEST THE ENVIRONMENT SHOULD BECOME
SUPPORTIVE FOR SURFACE OR NEAR-SURFACE BASED STORMS BY 12Z OVER
CENTRAL KY/ADJACENT NRN MIDDLE TN AND INTO SRN IND WITH THE
ADVECTION OF GREATER MOISTURE FROM THE SW.  IN ADDITION TO DAMAGING
WINDS...STRONG VERTICALLY VEERING WIND PROFILES WILL SUPPORT LARGE
CURVED HODOGRAPHS FOR A TORNADO THREAT.  ADDITIONAL SEVERE WEATHER
THREAT WILL EXIST WITH QLCS ADVANCING EWD INTO THE LOWER OH VALLEY
REGION BY 12Z.

MEANWHILE...AT THIS TIME...TSTMS MOVING INTO SWRN-SRN OH AND
ADJACENT FAR NERN KY SHOULD REMAIN ELEVATED N OF THE WARM FRONT
WHERE THE BOUNDARY LAYER REMAINS MORE STABLE GIVEN COOLER SURFACE
TEMPERATURES.  STRENGTHENING BULK SHEAR WILL SUPPORT SOME STORM
ORGANIZATION...BUT WEAK INSTABILITY/LAPSE RATES WILL PRECLUDE A
SEVERE WEATHER THREAT WITH ERN EXTENT.

..PETERS.. 02/29/2012

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

ATTN...WFO...RLX...JKL...ILN...LMK...OHX...IND...PAH...ILX...

LAT...LON   39698480 39438389 38888319 38268327 37148444 36058586
            35718714 35938812 36428794 36738719 38208684 38528708
            38578761 39148749 39698480

Mesoscale Discussions in Kentucky, 2012Mesoscale Discussions in Indiana, 2012Mesoscale Discussions in Tennessee, 2012Every mesoscale discussion in 2012

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.