Huge eddy today: Satellite animation

[windfind]

Hi Gang,

Below is my satellite animation of todays large eddy and the southerly coast winds that will dominate our winds.

20 years ago such eddies happened maybe 1-2 times per season. Now they often occur several times per week.

My forecast last night went into proximal causes of today's eddy:

1. Overnight the North Pacific High ridge expands over far Northern California and helps produce an inland high pressure in the Columbia and N. Great Basin.

This event has a flock of consequences that caused...
1. Our NW ocean surface winds west of the Farallon Islands turn NNW.

2. While the winds just aloft over the Bay turn a weak NNE creating wind shear that helped an eddy form.

3. Plus an upper ridge also encourages the Central Valley thermal low to expands way over the coast and strong low-pressure forms over Sonoma and Napa making an S. to N. pressure gradient.

4. The sum of these events helps stir up a 300-mile long elongated eddy that produces southerly coast winds from Monterey to The Lost Coast and a foggy marine layer streams into the Bay.

The low pressure retracts to near the East Bay in the afternoon so the pressure gradient goes way up but the eddies southerly winds never die so we see weak WSW coast winds all day. Inside the Bay these winds accelerate towards Sacramento and we see upper-teens to mid 20's SSW winds strongest in the mid Golden Gate to Larkspur/ Pt. Isabel zone to Sherman Island zone.

Mike Godsey
iwindsurf.com/ikitesurf.com
Weatheflow.com

[windward1]

That eye is pretty dramatic! If we could just get out there to its eye-wall we could sail in circles instead of just back and forth...

[SwellRipper]

That's a funny but interesting thought windward1!

Post your GPS track if you get out there and do it, ha ha