MESOSCALE DISCUSSION 0830
   NWS STORM PREDICTION CENTER NORMAN OK
   1148 AM CDT FRI MAY 15 2009
   
   AREAS AFFECTED...FAR SERN NEB...FAR NERN KS...NRN MO/FAR SRN IA INTO
   WEST CENTRAL IL
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 304...
   
   VALID 151648Z - 151745Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 304
   CONTINUES.
   
   THREAT FOR ELEVATED STORMS PRODUCING HAIL PERSISTS ACROSS FAR NERN
   KS AND EWD ACROSS FAR NWRN MO/SWRN IA WITHIN WW 304.  CONCERN IS
   INCREASING FOR STORMS TO BECOME SURFACE BASED WITH AT LEAST ONE
   BOWING STRUCTURE DEVELOPING ACROSS FAR NERN KS/ADJACENT NWRN
   MO...WITH THIS BOW THEN ADVANCING ESEWD THROUGH NRN MO.  NEW WW MAY
   BE NEEDED.
   
   LATE MORNING SURFACE ANALYSIS INDICATED AN AREA OF LOW PRESSURE OVER
   THE OK PANHANDLE WITH A SECOND WEAKER LOW LOCATED IN CENTRAL KS.  A
   WARM FRONT EXTENDED ENEWD INTO NERN KS/NWRN MO...NORTH OF A TOP-MKC
   LINE...AND THEN EXTENDING ESEWD THROUGH NRN MO TO WRN IL BETWEEN
   UIN/STL TO SRN IL.  12Z UPPER AIR ANALYSIS INDICATED A LEAD IMPULSE
   TRACKING EWD ACROSS CENTRAL NEB.  THE WRN MOST MCS OVER SERN
   NEB/NERN KS INTO SRN IA/NRN MO APPEARS TO BE TIED TO THIS MID LEVEL
   FEATURE...GIVEN THE EWD PROGRESSION OF THE WRN EXTENT OF THIS
   CONVECTIVE SYSTEM.  RECENT RADAR TRENDS INDICATED AN APPARENT BOW IS
   BEGINNING TO DEVELOP INTO FAR NWRN MO/NERN KS...WITH THIS TREND ALSO
   SUGGESTED BY THE 00Z HIGH RES WRF MODELS.  ALTHOUGH STRONG TO SEVERE
   STORMS HAVE THUS FAR BEEN ELEVATED...THIS BOWING STRUCTURE SHOULD
   TRACK ESEWD ALONG THE WARM FRONT/INSTABILITY GRADIENT...GENERALLY IN
   THE VICINITY AND NORTH OF I-70 WITH AN INCREASING THREAT FOR
   DAMAGING WINDS.  ONCE STORMS BECOME SURFACE BASED AS CAP WEAKENS...
   STRONG SWLY LOW LEVEL FLOW TRANSLATING EWD ACROSS NRN MO TO IL
   COMBINED WITH FAVORABLE LOW LEVEL SHEAR ALONG THE WARM FRONT WILL
   SUPPORT AN ISOLATED TORNADO THREAT.
   
   IN ADDITION TO THE SEVERE WEATHER THREAT...HEAVY RAINFALL RATES WITH
   TRAINING STORMS ACROSS FAR NRN MO INTO WEST CENTRAL IL ARE EXPECTED
   GIVEN 12Z OBSERVED PRECIPITABLE WATER VALUES RANGING FROM 1-1.5
   INCHES OVER THIS REGION.
   
   ..PETERS.. 05/15/2009
   
   
   ATTN...WFO...LSX...DVN...DMX...EAX...OAX...TOP...
   
   LAT...LON   39569652 40539689 41059570 40809479 40549454 40599210
               39649204 39329245 39279419 39429574 39569652