MESOSCALE DISCUSSION 0666
   NWS STORM PREDICTION CENTER NORMAN OK
   0341 PM CDT SAT MAY 16 2015

   AREAS AFFECTED...CNTRL/ERN TX/OK PANHANDLES...FAR NW AND N
   TX...WRN/CNTRL OK

   CONCERNING...TORNADO WATCH 175...

   VALID 162041Z - 162215Z

   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 175 CONTINUES.

   SUMMARY...A BROKEN LINE OF INTENSE TSTMS IS PROGRESSING NEWD ACROSS
   THE ERN TX PANHANDLE AND NW TX. THE DOWNSHEAR ENVIRONMENT ACROSS OK
   IS BECOMING INCREASINGLY FAVORABLE FOR TORNADO POTENTIAL /POSSIBLY
   STRONG/. A NEW TORNADO WILL BE ISSUED SOON FOR WRN/CNTRL OK AND
   POSSIBLY PARTS OF NORTH TX.

   DISCUSSION...A BROKEN LINE OF INTENSE TSTMS WITH A FEW EMBEDDED
   SUPERCELLS CONTINUES TO MOVE NEWD ACROSS THE ERN TX PANHANDLE AND
   THE ROLLING PLAINS OF NWRN TX...WITH REPORTS RECEIVED RECENTLY OF
   LARGE HAIL AND A COUPLE TORNADOES. ADDITIONAL TSTMS ARE DEVELOPING
   FARTHER W WITHIN TORNADO WATCH 175...BUT WITH VEERED LOW-LEVEL WINDS
   AND A DRIER BOUNDARY-LAYER...LARGE HAIL AND DMGG WINDS WILL BE THE
   PRIMARY THREATS. 

   THE ENVIRONMENT ACROSS WRN/CNTRL OK IS ONLY MARGINALLY TO MODERATELY
   UNSTABLE /PER 18Z OUN AND LMN SOUNDINGS/...AND STILL CAPPED WITH A
   WARM LAYER NOTED NEAR 1.5 KM AGL. EXTENSIVE CLOUD COVER HAS ALSO
   LIMITED DIABATIC HEATING ACROSS CNTRL OK...WITH TEMPERATURES
   REMAINING IN THE LOW-MID 70S. DESPITE THESE POTENTIAL LIMITING
   FACTORS...LOW-LEVEL SHEAR WILL CONTINUE TO INCREASE INTO THE
   EVENING...AND WILL FAVOR THE RISK FOR TORNADOES /SOME POTENTIALLY
   STRONG/ ACCOMPANYING DISCRETE SUPERCELLS ACROSS WRN/CNTRL OK AND
   POSSIBLY INTO PORTIONS OF N TX. AS A RESULT...A NEW TORNADO WATCH
   WILL BE ISSUED SOON.

   ..ROGERS/DIAL.. 05/16/2015


   ATTN...WFO...TSA...FWD...OUN...LUB...AMA...

   LAT...LON   36479946 36769859 36859733 36539660 34939576 33469628
               33449938 33660075 36020212 36540157 36479946