[BNAWX] Severe Storm Outlook Narrative

[EMWIN Server]

ACUS11 KWNS 240107
SWOMCD
SPC MCD 240106
OHZ000-KYZ000-INZ000-TNZ000-240200-

MESOSCALE DISCUSSION 0341
NWS STORM PREDICTION CENTER NORMAN OK
0806 PM CDT FRI MAR 23 2012

AREAS AFFECTED...PARTS OF CENTRAL/SRN IND...CENTRAL KY AND NRN
MIDDLE TN

CONCERNING...TORNADO WATCH 103...

VALID 240106Z - 240200Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 103 CONTINUES.

REGIONAL RADAR TRENDS AND 00Z SURFACE ANALYSIS SHOWED A COLD FRONT
HAD ADVANCED INTO CENTRAL IND /INVOF INDIANAPOLIS/ AND EXTENDED SWD
TO ALONG THE IND/KY BORDER /HARRISON COUNTY IND AND MEADE COUNTY
KY/...THEN FARTHER SSWWD INTO MIDDLE TN /JUST W OF BNA/.

EARLY EVENING WATER VAPOR IMAGERY SHOWED A WELL DEFINED SHORTWAVE
TROUGH TRACKING NEWD THROUGH WRN TN/KY...AND APPROACHING SRN IND.
ALTHOUGH THERE HAS BEEN SOME REDUCTION IN AVAILABLE INSTABILITY...
DUE TO LOSS OF DAY TIME HEATING...THE APPROACH OF STRONGER ASCENT/
COOLING MIDLEVEL TEMPERATURES WITH THE WRN KY/TN TROUGH AND WITHIN
THE NOSE OF AN ACCOMPANYING 70 KT MIDLEVEL JET SHOULD OFFSET THE
DIMINISHING INSTABILITY TO SUSTAIN STRONGER UPDRAFTS AFTER DARK.
ACTIVITY IS BECOMING ORIENTED MORE PARALLEL TO THE SHEAR VECTORS
SUGGESTING A GREATER LIKELIHOOD FOR LINE SEGMENTS/BOW STRUCTURES.
HOWEVER...IF SURFACE WINDS ALONG AND E OF THE ONGOING STORMS CAN
REMAIN E/SELY...THEN LOCALLY ENHANCED LOW LEVEL SHEAR WILL SUSTAIN A
TORNADO THREAT.  IN ADDITION...OBJECTIVE ANALYSES SHOWED A CORRIDOR
OF SURFACE VORTICITY ALONG THE WIND SHIFT JUXTAPOSED WITH 0-3 KM
MLCAPE OF 100-150 J/KG FAVORING LOW LEVEL STRETCHING.

DESPITE A DRIER AIR MASS WITH SWD EXTENT INTO MIDDLE TN /PER
INVERTED-V TYPE SOUNDING AT 00Z AT BNA/...THE STRENGTH OF THE
FORCING FOR ASCENT ATTENDANT TO THE SHORTWAVE TROUGH /NOW TRACKING
NEWD THROUGH WRN TN/KY/ IS SUPPORTING CONVECTION/TSTM DEVELOPMENT
SWD ALONG THE COLD FRONT.  THE ONSET OF BOUNDARY LAYER COOLING
SHOULD RESULT IN A FAIRLY SHORT WINDOW FOR SUSTAINED UPDRAFTS ACROSS
MIDDLE TN...AND THUS A NEW WW IS NOT EXPECTED AT THIS TIME S OF WW
103.

..PETERS.. 03/24/2012

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

ATTN...WFO...ILN...LMK...IWX...OHX...IND...

LAT...LON   36588688 37498648 38218637 39588632 40438636 40388471
            39238471 38458471 37698496 36618528 35978579 35828657
            35878712 36588688



This weather bulletin was brought to you by:
http://www.nashvilleweather.net

Follow us on Facebook at:
http://www.facebook.com/nashvilleweather