Mesoscale Discussion #840

AREAS AFFECTED...NRN MO...SRN IA
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 212225Z - 212330Z
   
   SEVERE THUNDERSTORM THREAT IS EXPECTED TO INCREASE 
DURING THE NEXT
   FEW HRS OVER NRN MO AND POSSIBLY SRN IA. 
A SVR THUNDERSTORM WATCH
   WILL LIKELY BE NEEDED OVER NRN MO. FURTHERMORE...
WW 317 MAY NEED TO
   BE EXTENDED EWD INTO PORTIONS OF SRN IA.
   
   22Z SURFACE OBSERVATIONS AND OBJECTIVE ANALYSIS 
SHOW THE AIRMASS
   ACROSS NRN MO/SRN IA HAS BECOME STRONGLY UNSTABLE...
WITH MLCAPE
   VALUES NOW AROUND 2000 J/KG. THIS WILL AID CLUSTERS 
OF STORMS OVER
   NERN KS TO PERSIST AS THEY MOVE E-NEWD ACROSS THE MO
   RIVER...RESULTING IN AN INCREASING 
SVR WEATHER THREAT OVER THE AREA.
   FAVORABLE SHEAR PROFILES WILL 
REMAIN IN PLACE FOR POSSIBLE
   SUPERCELLS...POSING A THREAT
 FOR LARGE HAIL/DAMAGING WIND GUSTS. A
   NEW WW WILL LIKELY BE NEEDED OVER 
NRN MO...WHILE WW 317 CAN BE
   EXTENDED EWD INTO SRN IA IF NECESSARY.