A storm is developing as expected off the Northern California coastline and will sweep northward off the Oregon and Washington coast tomorrow morning. This setup appears to be just about unprecedented in our area at this time of year. I could only find one example back in 1972. Mid-August that year a sudden windstorm arrived with very little warning along the Oregon/California border. Southerly wind gusts in the 60+ mph range sunk many boats and 12 fishermen died. Luckily nowadays we have much better satellite/radar and numerical modeling of storms. Yet, this may be the one “out of season” storm we talk about for years to come. We’ll see.
The Latest Highlights
High Wind Warning on the Oregon and southern Washington coast for Saturday morning:
Wind Advisory for the Willamette Valley and lowlands of SW Washington for Saturday morning”
Expect the wind to arrive in Salem/Portland sometime between 8am-10am. Note those peak gusts…I’ve never seen/forecast gusts over 30mph at the beaches in August! I can’t believe Hood-To-Coast relay has all those tents/tables set up along with a very high stage/backdrop too out in Seaside right now. If our forecasts are correct, I can see quite a bit of damage tomorrow morning out there when gusts 50+ arrive. I’m also concerned for the safety of runners moving through the North Coast Range after 8am. Many of those roads have trees overhead and even just a breeze and rain combined can bring down an old alder tree. We haven’t seen a gusty south wind since March. Be careful out there!
There is still a chance we don’t get gusts over 50 at the coast and over 30 in the valleys…models could still back off with the last runs this evening. That said, satellite imagery sure looks impressive off the California coastline.
I did notice on this morning’s runs the ECMWF has the low tracking slightly farther offshore, which could help to reduce the wind in the valleys. Yet this time of year the airmass is well mixed so stronger wind above will surface easily, counteracting weakness in pressure gradient or low location.
12z WRF/NAM/RPM all show a closed (or mainly closed) low coming right up against the Washington coastline by midday, around 990-993 millibars. They all indicate gusts 60-75 mph at the coast. Hard to believe that will happen in August, but we sure wouldn’t argue with that modeling in winter.
We’ll see what the 00z models show.
Chief Meteorologist Mark Nelsen