THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A HIGH WIND WARNING...WHICH IS IN EFFECT FROM 5 AM TO 6 PM PST TUESDAY. THE HIGH WIND WATCH IS NO LONGER IN EFFECT. * WIND...SOUTH OR SOUTHWEST 25 TO 40 MPH WITH GUSTS NEAR 60 MPH ARE POSSIBLE BEGINNING TUESDAY MORNING AND CONTINUING INTO THE AFTERNOON HOURS.
The forecasts for Northwest Washington are even stronger.
* WIND...WINDS MAY REACH 30 TO 45 MPH WITH GUSTS AS HIGH AS 65 MPH ON TUESDAY.
I suspect that this event will cause some power outages but will not cause major damage. One reason for optimism is that we already have had lots of wind and the leaves are substantially off the trees now. On the other hand, the ground is saturated and that will foster the failure of tree root systems.
My latest examination of the model forecasts suggest that at the height of the storm, somewhere between 10 AM and 2 PM Tuesday, the winds will reach sustained values of 22-30 mph over land and 25-37 mph over water, with gusts reaching 30-50 mph over land and 50-65 mph over water.
Looking at the latest infrared satellite picture you would hardly think a windstorm is brewing, with no low center obvious off our coast.
8 PM Monday infrared satellite image
A modest low center will move into southern B.C. tomorrow (Tuesday) AM, while much higher pressure exists to its south (see image). The result is a large pressure differences north to south. Air tends to accelerate from high to low pressure near terrain and in this case it will produce strong southerly winds.
The updated NOAA SREF ensemble (many forecasts) is going for sustained winds of roughly 20 knots (23 mph) at Seattle Tacoma Airport.
And did I mentioned the rain? LOTS of it. Here is the rain prediction over the next 24h. 5-10 inches in the mountains, while locations to the east of the terrain will enjoy substantial rain shadowing.
I know what I will be doing...