Update on Surface Low

November 21, 2009
10:07 P.M.

Hey everybody. I just got back from eating some delicious Indian food so I thought I’d make an update on the forecast as far as winds are concerned for tonight.

Here is the water vapor imagery for . This satellite shot shows the amount of water vapor in the atmosphere. Notice the “dry slot” behind the storm headed towards us. A pronounced dry slot is a telltale sign of an intense low pressure system or one that is still developing. Even when the storm is not visible on the infared satellite, a dry slot can often be observed on the water vapor one.

Here is the infared satellite. In the past few hours, a “bent back occlusion” has developed, which is where the occluded front wraps around the low pressure center. This is also conductive of a vigorous and intensifying low pressure system.

I really can’t give a straight forecast (a coastal radar would really help here!) but I don’t think the Seattle area will be too windy. Still, we have a wind advisory from midnight till 10 A.M. tommorow I think for gusts up to 45 miles per hour. The southwest interior and coast still have high wind warnings. Also, something I forgot to mention earlier was that this storm will bring a very strong westerly surge of wind down the Strait of Juan de Fuca after it passes early Sunday. Expect winds up to 70 miles per hour there as well.

Charlie