[MCD] SWOMCD

Wed Feb 21 00:23:04 UTC 2007

ACUS11 KWNS 210027
SWOMCD
SPC MCD 210027 
TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-210200-

MESOSCALE DISCUSSION 0173
NWS STORM PREDICTION CENTER NORMAN OK
0627 PM CST TUE FEB 20 2007

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

CONCERNING...SEVERE THUNDERSTORM WATCH 26...

VALID 210027Z - 210200Z

SEVERE STORMS WITH HAIL WILL CONTINUE TO DEVELOP GENERALLY EWD
ACROSS NRN/NWRN PORTIONS OF WATCH 26.

SEVERE TSTMS CONTINUE TO INCREASE NEAR SURFACE WAVE AND FRONTAL ZONE
FROM EXTREME NRN AR ACROSS THE MO BOOTHEEL REGION THIS EVENING.
LARGE HAIL HAS BEEN REPORTED WITH ACTIVITY ACROSS SCOTT COUNTY MO
OVER THE PAST HOUR. DEEP CONVECTION APPEARS TO BE DEVELOPING WITHIN
AN AXIS OF STRONG LOW LEVEL CONVERGENCE ASSOCIATED WITH THE FRONTAL
WAVE. AN INTENSE LEFT-MOVING STORM WAS TRACKING ENEWD TOWARD EXTREME
SRN IL ATTM...AND ADDITIONAL CELLS WERE STRENGTHENING WWD AND SWWD
ACROSS STODDARD...BUTLER...AND RIPLEY COUNTIES.

AIR MASS IN THE VICINITY OF THESE STORMS SHOULD REMAIN  SUFFICIENTLY
UNSTABLE TO MAINTAIN ROBUST UPDRAFTS WITHIN A STRONGLY SHEARED
ENVIRONMENT. RECENT STORM TRENDS AND LATEST LITTLE ROCK SOUNDING
INDICATED INTENSE UNIDIRECTIONAL EFFECTIVE SHEAR...ON THE ORDER OF
50-70KT...WAS RESULTING IN SPLITTING SUPERCELLS. GREATEST THREAT
WITH THIS ACTIVITY WILL CONTINUE TO BE LARGE HAIL FROM BOTH LEFT AND
RIGHT MOVING UPDRAFTS GIVEN STEEP MID LEVEL LAPSE RATES AND MODERATE
FORCING FOR ASCENT. IF RIGHT-MOVING CELLS CAN REMAIN DISCRETE WHILE
DEVELOPING INTO LOW LEVEL MOIST AXIS ALIGNED WITH MS RIVER OVER NEXT
HOUR OR SO...A BRIEF TORNADO CANNOT BE RULED OUT.

..CARBIN.. 02/21/2007

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

ATTN...WFO...LMK...OHX...PAH...MEG...LZK...SGF...

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