MESOSCALE DISCUSSION 0623
   NWS STORM PREDICTION CENTER NORMAN OK
   1033 PM CDT TUE APR 28 2009
   
   AREAS AFFECTED...PORTIONS W TX...ERN NM...TX PANHANDLE...TX
   SOUTH-PLAINS REGION...NW TX...SWRN OK.
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 205...206...
   
   VALID 290333Z - 290500Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   205...206...CONTINUES.
   
   CONTINUE WW 206.  WW 205 MAY BE CONTINUED FOR 2-3 HOURS BEYOND
   SCHEDULED 04Z EXPIRATION TIME FOR A FEW COUNTIES...OR A NEW WW MAY
   BE ISSUED.  THIS REMAINS TO BE COORDINATED W/AFFECTED WFOS.
   
   CONVECTIVE COVERAGE AND SVR POTENTIAL EACH ARE EXPECTED TO EXPAND
   SOMEWHAT IN AERIAL COVERAGE WITHIN BROAD/ELEVATED LOW LEVEL WAA AND
   MOISTURE TRANSPORT ZONE COVERED BY CENTRAL ERN PORTIONS WW 206 -- IN
   OTHER WORDS...NEAR AND E OF CAPROCK.  SOME OF THIS ACTIVITY MAY
   REACH PORTIONS SWRN OK BEFORE WEAKENING...HOWEVER AVAILABLE MOISTURE
   AND BUOYANCY EACH ARE EXPECTED TO BECOME GRADUALLY WEAKER WITH NEWD
   EXTENT...AWAY FROM DEEP MOIST AXIS AND NEARLY COLLOCATED LLJ CORE. 
   MOIST AXIS WAS EVIDENT IN ISOPLETHS OF GPS PW FROM
   GLS...AUS...BWD...40 W ABI...CDS.  ADDITIONAL COUNTIES OF NW TX AND
   SW OK MAY BE ADDED TO WW AS UPSTREAM CONVECTIVE TRENDS COMPEL.
   
   MEANWHILE...ISOLATED NODES OF SVR TSTMS -- INCLUDING A FEW
   SUPERCELLS...PERSIST ACROSS NRN...MIDDLE AND SRN PORTIONS WW 205 --
   I.E. MORA/SAN MIGUEL COUNTIES NM...CHAVES COUNTY NM...AND TX/NM
   BORDER AREA BETWEEN GDP-INK RESPECTIVELY.  MIDDLE AND SRN NODES HAVE
   MOST FAVORABLE AIR MASS IN THEIR PROSPECTIVE INFLOW REGIONS.  OLD
   DIFFERENTIAL HEATING BOUNDARY WILL BECOME MORE ILL-DEFINED FROM NOW
   ON AMIDST DIABATIC SFC COOLING...WHICH ALSO WILL ACT TO STRENGTHEN
   MLCINH AND ELEVATE EFFECTIVE INFLOW PARCELS ABOVE SFC WITH TIME. 
   THEREFORE...PRIND TORNADO POTENTIAL WILL DIMINISH WHILE SOME OF THIS
   CONVECTION MOVES EWD INTO ERN PORTIONS OF THIS WW AND WRN PORTIONS
   WW 206.  THAT AREA -- INVOF N-S SEGMENT OF TX/NM BORDER -- WILL BE
   CHARACTERIZED BY PROGRESSIVELY MORE MOIST LLJ WITH EWD EXTENT...AS
   WELL AS INCREASING STORM-RELATIVE INFLOW.  MUCAPE 1500-2000
   J/KG...ALONG WITH 40-50 KT EFFECTIVE SHEAR MAGNITUDES...WILL AID IN
   MAINTAINING TSTM ORGANIZATION IN SUPPORT OF CONTINUING POTENTIAL FOR
   LARGE HAIL.
   
   ..EDWARDS.. 04/29/2009
   
   
   ATTN...WFO...OUN...SJT...LUB...AMA...MAF...ABQ...
   
   LAT...LON   36480300 36450000 34719934 33409947 32960008 32710172
               32450195 31510226 31250341 31910473 34070499 35350500
               36480300