MESOSCALE DISCUSSION 0568
   NWS STORM PREDICTION CENTER NORMAN OK
   0616 PM CDT TUE APR 24 2007
   
   AREAS AFFECTED...PORTIONS CENTRAL/ERN OK...NW TX.
   
   CONCERNING...TORNADO WATCH 173...
   
   VALID 242316Z - 250115Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 173 CONTINUES.
   
   SFC MESOANALYSIS SHOWS DRYLINE WRN ALFALFA TO ERN BLAINE TO ERN
   TILLMAN COUNTY OK...WRN ARCHER COUNTY TX.  EXPECT ONLY
   LOCALIZED/ERRATIC DRYLINE MOTION NEXT 2-3 HOURS AS PRIMARY SFC
   CYCLONE DIGS SEWD ACROSS SWRN KS TO OK PANHANDLE.  ALTHOUGH
   SUFFICIENT CONVERGENCE MAY LINGER TO SUPPORT ISOLATED TSTM
   DEVELOPMENT...STRONGER ASSOCIATED LOW LEVEL FORCING SHOULD REMAIN N
   OF AREA -- ACROSS CENTAL KS.  TEMPORAL WINDOW OF OPPORTUNITY IS
   CLOSING FOR ROBUST HEATING BETWEEN OK/NW TX DRYLINE AND ANVIL CANOPY
   FROM ERN OK MCS...AMIDST RAIN-COOLED AIR.  VIS IMAGERY SUPPORTS THIS
   IDEA...WITH NO SIGNIFICANT CONVECTIVE DEVELOPMENT EVIDENT ATTM.  PER
   COORDINATION W/OUN...AIR MASS E OF I-35 APPEARS TOO STABILIZED AND
   NONCONVERGENT TO SUPPORT ADDITIONAL DEVELOPMENT BEFORE SCHEDULED 1Z
   WW EXPIRATION.  FARTHER W...REMAINDER WW MAY BE CANCELLED EARLY OR
   ALLOWED TO EXPIRE AS SCHEDULED...IF CONVECTIVE TRENDS CONTINUE AT
   PRESENT WITHOUT DEVELOPMENT ALONG DRYLINE.
   
   AFTER 1Z...ADDITIONAL DEVELOPMENT MAY BE POSSIBLE OVER PORTIONS OK
   ONCE SFC LOW AND ASSOCIATED ISALLOBARIC FORCING APCH...WITH SFC COLD
   FRONT OVERTAKING DRYLINE AND MOVING INTO FAVORABLY MOIST BOUNDARY
   LAYER.  THEREFORE THIS AREA WILL ME MONITORED FOR POSSIBILITY OF
   ADDITIONAL WW LATER THIS EVENING.
   
   ..EDWARDS.. 04/24/2007
   
   
   ATTN...WFO...TSA...ICT...FWD...OUN...DDC...SJT...
   
   36999942 36999586 33879597 33909797 33479797 33399950
   33839949 33909894 34209894 34199856 34519858 34499881
   34879880 34889855 36149864 36149885 36579889