MESOSCALE DISCUSSION 1786
   NWS STORM PREDICTION CENTER NORMAN OK
   0705 AM CDT FRI OCT 14 2016

   AREAS AFFECTED...NWRN OREGON THROUGH WRN WA

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 141205Z - 141430Z

   PROBABILITY OF WATCH ISSUANCE...20 PERCENT

   SUMMARY...ISOLATED TO WIDELY SCATTERED STORMS MOVING ONTO COASTAL
   OREGON AND WA WILL POSE A MARGINAL RISK FOR A BRIEF TORNADO OR TWO
   THROUGH THE EARLY MORNING. OVERALL THREAT IS NOT EXPECTED TO BECOME
   SUFFICIENT FOR A WW.

   DISCUSSION...COLD AIR ALOFT ASSOCIATED WITH VIGOROUS UPPER LOW OFF
   THE PACIFIC NW COAST HAS CONTRIBUTED TO STEEPENING MID-LEVEL LAPSE
   RATES AND WEAK INSTABILITY ALONG THE WA AND OREGON COASTS. THE RAP
   MODEL FORECAST SOUNDINGS SHOW MUCAPE AOB 400 J/KG ALONG WITH 7-7.5
   C/KM MID-LEVEL LAPSE RATES. WIDELY SCATTERED BUT LOW-TOPPED
   CONVECTION WILL CONTINUE DEVELOPING WITHIN CORRIDORS OF ENHANCED
   MESOSCALE ASCENT ACCOMPANYING VORTICITY MAXIMA ROTATING THROUGH THE
   UPPER LOW CIRCULATION. STRONG DEEP-LAYER WINDS ASSOCIATED WITH
   COUPLED LOW-MID LEVEL JET STRUCTURE ARE RESULTING IN STRONG /40+ KT/
   EFFECTIVE BULK SHEAR AS WELL LARGE 0-1 KM HODOGRAPHS. THIS
   ENVIRONMENT WILL FAVOR LOW-TOPPED SUPERCELL STRUCTURES AS STORMS
   MOVE ONSHORE BEFORE WEAKENING AS THEY MOVE EAST OF THE COASTAL
   RANGES AND AWAY FROM THE MARINE LAYER. WEAK INSTABILITY WILL
   CONTINUE TO SERVE AS AN OVERALL LIMITING FACTOR.

   ..DIAL/EDWARDS.. 10/14/2016


   ATTN...WFO...SEW...PQR...

   LAT...LON   48432444 47052357 45302377 45372423 46722431 47822476
               48432444