[MCD] SWOMCD

Wed Feb 21 02:39:03 UTC 2007

ACUS11 KWNS 210243
SWOMCD
SPC MCD 210243 
TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-210415-

MESOSCALE DISCUSSION 0174
NWS STORM PREDICTION CENTER NORMAN OK
0843 PM CST TUE FEB 20 2007

AREAS AFFECTED...SERN MO...NERN AR...SRN IL...WRN KY/TN

CONCERNING...SEVERE THUNDERSTORM WATCH 26...

VALID 210243Z - 210415Z

SCATTERED SEVERE STORMS WITH THE POTENTIAL TO PRODUCE HAIL WILL
REMAIN A POSSIBILITY ACROSS PARTS OF THE LOWER OH VALLEY/MID MS
VALLEY FOR THE NEXT COUPLE OF HOURS. DESPITE MODEST FORCING FOR
ASCENT ACROSS THE REGION...RELATIVELY LIMITED INSTABILITY SHOULD
PRECLUDE THE NEED FOR ADDITIONAL WATCHES.

NUMEROUS SPLITTING SUPERCELLS CONTINUE TO SPREAD EWD TONIGHT FROM
THE BOOTHEEL OF MO TO SRN IL AND WRN KY. THIS CONVECTION WAS
OCCURRING AHEAD OF A WEAK FRONTAL WAVE CYCLONE TRACKING EAST ALONG
THE MO/AR BORDER. LOW LEVEL CONVERGENCE AHEAD OF THE LOW...AND ALONG
THE FRONTAL ZONE EXTENDING EAST TO THE LOWER OH VALLEY...SHOULD
CONTINUE TO SUPPORT SCATTERED SEVERE TSTMS OVER THE NEXT 1-2 HOURS.
A PLUME OF STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH POSITIVE TILT
LARGE SCALE MID/UPPER LEVEL TROUGH SHEARING EAST ACROSS THE REGION
WILL ALSO LEND SUPPORT TO ROBUST BUT PRIMARILY ELEVATED CONVECTION.
WHILE VERY STRONG SHEAR AND MODEST NEAR SURFACE-BASED INSTABILITY
EXIST ACROSS SRN PORTIONS OF THE WATCH...MOSTLY WRN TN...LATEST
GUIDANCE AND RADAR TRENDS SUGGEST LITTLE DEVELOPMENT OVER THIS AREA
IN THE NEXT FEW HOURS. HOWEVER...ENVIRONMENT OVER THE LARGER AREA
WILL REMAIN SUPPORTIVE OF ROTATING/PERSISTENT UPDRAFTS CAPABLE OF
PRODUCING LARGE HAIL FOR AT LEAST ANOTHER 1-2 HOURS. AFTER THAT
TIME...STRONGER FORCING BEGINS TO DECOUPLE FROM WEAKENING
INSTABILITY AND ADDITIONAL WATCHES ARE NOT ANTICIPATED.

..CARBIN.. 02/21/2007

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

ATTN...WFO...LMK...OHX...PAH...MEG...

35498727 35449097 36879106 37118983 37618942 37608805
37168773 37048703 36198711 

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