MESOSCALE DISCUSSION 2087
   NWS STORM PREDICTION CENTER NORMAN OK
   0407 AM CDT WED OCT 17 2007
   
   AREAS AFFECTED...PORTIONS CENTRAL/NRN OK...CENTRAL/ERN KS...SERN
   NEB...SWRN AND EXTREME W-CENTRAL MO.
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 170907Z - 171100Z
   
   CONVECTIVE COVERAGE AND INTENSITY EACH ARE FCST TO INCREASE ACROSS
   BROAD SWATH OF CENTRAL/SRN PLAINS THROUGH SUNRISE...PARTICULARLY
   BETWEEN SERN NEB AND N-CENTRAL OK.  THIS WILL INCLUDE MCS MOVING
   NEWD FROM NERN PORTIONS WW 706 AND SERN PORTIONS WW 707.  MAIN
   THREAT WILL BE LARGE HAIL...THOUGH ISOLATED DAMAGING GUSTS ALSO ARE
   POSSIBLE OVER PORTIONS N-CENTRAL OK.  TORNADO POTENTIAL APPEARS VERY
   CONDITIONAL FOR ANOTHER 4-6 HOURS...BUT INFLOW MAY BE CLOSE ENOUGH
   TO SFC BASED TO SUPPORT SOME PROBABILITIES WITH ANY
   SUSTAINED/DISCRETE STORMS OVER WRN/NRN OK.
   
   SFC MESOANALYSIS AND IR IMAGERY INDICATES LOW LEVEL MOISTURE
   RETURNING ROBUSTLY TO REGION FROM S-N...WITH SFC DEW POINTS
   MID-UPPER 60S F COMMON ACROSS SRN OK...LOW 60S NRN OK AND S-CENTRAL
   KS.  BOUNDARY LAYER THETAE IS EXPECTED TO INCREASE THROUGHOUT REGION
   AS MOIST/WARM ADVECTION CONTINUES TO OFFSET NOCTURNAL/DIABATIC
   STABILIZATION TENDENCY NEAR SFC...MAINTAINING OR INCREASING THETAE. 
   THIS WILL YIELD EFFECTIVE INFLOW PARCELS ROOTED VERY NEAR SFC OVER
   OK PORTION OF DISCUSSION AREA...WITH MUCAPES 500-1000 J/KG.  BROAD
   40-50 KT LLJ...ANALYZED FROM W-CENTRAL TX TO S-CENTRAL KS...WILL
   KEEP LOW LEVEL HODOGRAPHS ENLARGED ALONG WITH 0-3 KM SRH...FOR ANY
   TSTMS ABLE TO BECOME ROOTED NEAR SFC.  30-40 KT EFFECTIVE BULK SHEAR
   MAGNITUDES ARE FCST FROM E-CENTRAL KS INTO CENTRAL OK...MRGL FOR
   SUPERCELLS...HOWEVER STORMS SHOULD BECOME ORGANIZED/PERSISTENT
   ENOUGH TO SUPPORT HAIL PRODUCTION.  PRIND BUOYANCY AND SHEAR WILL
   WEAKEN AND BECOME MORE ELEVATED WITH NEWD EXTENT INTO NEB AND
   MO...BUT ALSO INCREASE WITH TIME...SUPPORTING STG/ISOLD SVR
   CONVECTIVE POTENTIAL.
   
   ..EDWARDS.. 10/17/2007
   
   
   ATTN...WFO...SGF...EAX...TSA...OAX...TOP...ICT...OUN...GID...DDC...
   
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