Skip Navigation Links 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

Mesoscale Discussion 78
< Previous MD         Next MD >
MD 78 graphic

   Mesoscale Discussion 0078
   NWS Storm Prediction Center Norman OK
   0544 AM CST Fri Jan 20 2017

   Areas affected...Immediate coastal regions of southern Marin...San
   Francisco...and San Mateo counties

   Concerning...Severe potential...Watch unlikely 

   Valid 201144Z - 201245Z

   Probability of Watch Issuance...5 percent

   SUMMARY...Locally strong wind gusts (around 40-50 kt) will be
   possible as an eastward-moving line of storms reaches the coastal
   areas of southern Marin, San Francisco, and San Mateo counties by

   DISCUSSION...At 1125Z, radar imagery continued to show a fast-moving
   line of storms (speed close to 50 kt) approaching the Pacific
   coastal areas of southern Marin, San Francisco, and San Mateo
   counties, with this activity expected to reach the coast by 12Z.
   Area WSR-88D VWP data indicated south-southeasterly low-level winds
   of 40-50 kt.  Wind gusts associated with the line of storms could
   reach 40-50 kt at the surface, given momentum transfer in the
   downdrafts.  The threat for the locally strong/damaging wind gusts
   is expected to be confined to the coastal areas, since a more stable
   environment inland with surface temperatures in the upper 40s should
   support a diminishing trend in storm intensity.

   ..Peters/Thompson.. 01/20/2017


   LAT...LON   37852256 37852253 37752249 37642246 37542246 37432240
               37392239 37362244 37482252 37582256 37752256 37822259

Top/All Mesoscale Discussions/Forecast Products/Home
Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
Page last modified: January 20, 2017
Information Quality
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities