Wind Forecast Write Up

WNDZRFR · Posted: Sat Sep 02, 2023 12:14 pm Post subject: Wind Forecast Write Up

Mike,

The only people that have knowledge to access all of the following are usually those that don't pay for iwindsurf! If you are going to say the following then you need to include links to each item. Thanks

Todays Assignment: 1. Go to any page that shows the Surface isobars over the eastern Pacific. 2. Notice the huge hungry North Pacific High extending from near Japan and over Hawaii to about 200 miles from your house. 3. Notice the tiny 100-mile-wide low-pressure centered just off Pt. Arena blocking the NW ocean winds. 4. Ponder how such a tiny critter could block such a massive beast. 5. Now go to a page that shows the eastern Pacific but at the 500 MB. level. 6. Sort of scary, huh, That Cut Off Low is only 1000 miles wide but its 40-70 mph winds are centered right over Pt. Arena to San Francisco creating and reinforcing that tiny surface low. 7. That Cut Off Low departs Monday. So why am I forecasting NW clearing winds for that day?

windfind · Joined: 18 Mar 1997 Posts: 1902

windsrf · Joined: 01 May 1998 Posts: 464

Mike,

Just noticed that your Daily Briefing for Pt. Isabel differs dramatically from "Gray Line" on the Classic site? I'll try to attach a screenshot for clarity.

I recall you informed us long ago of why this happens, but would appreciate a reminder?

Thanks, David

WNDZRFR · Posted: Sun Sep 03, 2023 3:50 pm Post subject:

This links drawing is Greek to me - https://ocean.weather.gov/Pac_tab.php and not very helpful for someone who went through the Oakland Public School system.

Now your West Coast Blog is quite understandable and a link to it should be included in your forecasts when these conditions are present!

Thanks

windfind · Joined: 18 Mar 1997 Posts: 1902

windfind · Joined: 18 Mar 1997 Posts: 1902

windsrf · Joined: 01 May 1998 Posts: 464

Mike,

All makes sense - including the dart board.... Smile

Lately Some of us have decided that the PI sensor has been reading "low" due to winds heading north over by Brooks, rather than continuing eastward towards the sensor.

We finners have compensated by assuming we will have to slog out closer to the "structure" to access that more westerly windline. The steam from a refinery stack also informs us at times - as does Berkeley Reef sensor.

I suppose we should consider launching from Vincent or Shimada, but those are further for driving, plus hate the Shimada steps, plus harder to get offshore from launch, plus low tides don't work there due to muck.

Anyway, appreciate the details as always.

Thanks, David

WNDZRFR · Posted: Mon Sep 04, 2023 1:38 pm Post subject:

Mike,

For those of us regulars at PI we whole heartedly agree with your GUES Model Wink

! It is known that forecasting PI is not an easy task like other bay sites.

Over the last so many years we have noticed the East Bay wind direction has clocked more towards PI (SW, SSW) than Berkeley (W, SW). Take my PI/HLS sessions this year - 82 planning sessions with only 5 at HLS. In the not so distant past it was closer to 60/40 PI/HLS. Do you have any thoughts on the changing wind direction for this to occur or do we just chalk it up to climate change like everything else?

And as for the PI sensor readings and location (south of the launch, high up on a pole and inland) I feel the local consensus is it reads low, not high to the actual wind we sail in not very far from the launch.

dllee · Joined: 03 Jul 2009 Posts: 5329 Location: East Bay

I wonder if direction of wind is as important as neighboring highs and lows....
At least 5 of my best windsurfing days this season are on SW to slightly SSW wind directions when both Berk and PI are blowing 5.5 sail weather.
At least 10 days if "no wind" at Berk, when PI is 5.0 weather, but most of those would gave been fine on foils and 5.5-6.5 sails.
We all know PI blows stronger than Berk, and has for over 40 years.
Just Berk's lower winds can start in mid March, and go into early Oct most years...

WNDZRFR · Posted: Tue Sep 05, 2023 12:07 am Post subject:

I agree to disagree! HLS always blew stronger than PI until maybe the last decade. Before that I hardly ever needed to (get in the traffic) and go to PI because the Berkeley wind was always stronger and more consistent.

I don't think I have seen you at PI more than a hand full of times and if the wind is soo much better at PI why aren't you there on your small sails taking advantage of it?

Now a days when the wind goes SSW, PI is mediocre at best which by the way has been happening very frequently this season. The wind used to come through the gate and head straight for Berkeley, now it comes in the gate and curves up the bay.

Maybe over the years the max gradient to Sac has just become stronger than the gradient to Stockton and Bakersfield, well that and Eddy who seems to be a mainstay now.