MESOSCALE DISCUSSION 1806
   NWS STORM PREDICTION CENTER NORMAN OK
   0858 AM CDT TUE OCT 25 2016

   AREAS AFFECTED...NWRN OREGON/WA COASTS

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 251358Z - 251600Z

   PROBABILITY OF WATCH ISSUANCE...5 PERCENT

   SUMMARY...A BAND OF OFFSHORE SHOWERS/STORMS WILL AFFECT COASTAL
   AREAS OF WA AND NWRN OREGON OVER THE NEXT FEW HOURS...WITH A
   WATERSPOUT AND/OR WEAK TORNADO POSSIBLE.  WW IS NOT ANTICIPATED.

   DISCUSSION...LATEST WV LOOP SHOWS A LOW OFF THE BRITISH COLUMBIA
   COAST...WHICH IS RETROGRADING SLIGHTLY NWWD WITH TIME.  S OF THE
   LOW...A LOBE OF VORTICITY IS NEARING THE WA/NWRN OREGON COAST
   ATTM...WITH A BAND OF COINCIDENT SHOWERS AND ISOLATED THUNDERSTORMS.
   VAD WIND PROFILES AND MORNING RAOBS ACROSS THIS AREA REVEAL FAIRLY
   STRONG/VEERING FLOW THROUGH THE LOWER AND MIDDLE TROPOSPHERE...WHICH
   IS CONTRIBUTING TO WEAK ROTATION WITHIN A FEW OF THE OFFSHORE CELLS.
   HOWEVER...THESE SAME RAOBS -- ALONG WITH MODEL POINT-FORECAST
   SOUNDINGS AND OBJECTIVE ANALYSES -- INDICATED MINIMAL SURFACE-BASED
   CAPE AT BEST ALONG THE IMMEDIATE COAST AND AN INCREASINGLY STABLE
   LOW-LEVEL AIRMASS INLAND.  AS SUCH...EXPECT LIGHTNING TO REMAIN
   LARGELY OFFSHORE.  WHILE GUSTY WINDS OR A WATERSPOUT OR TWO MAY
   OCCUR OFFSHORE WITH THE MORE ORGANIZED CELLS...ANY INLAND RISK
   APPEARS MINIMAL -- AND WOULD LIKELY BE CONFINED TO IMMEDIATE COASTAL
   AREAS.

   LATER...AS THE LOBE OF VORTICITY MOVES INLAND FOLLOWED BY WEAK
   SHORT-WAVE RIDGING/SUBSIDENCE -- AND A CORRESPONDING DECREASE IN THE
   LOW-LEVEL WIND FIELD...EXPECT RISK TO GRADUALLY DIMINISH THROUGH
   MIDDAY.

   ..GOSS/THOMPSON.. 10/25/2016


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

   LAT...LON   48402451 47872425 46912400 46042386 45252417 45282440
               46562449 47672484 48442503 48402451