by WeatherFlow ForecasterPosted on Posted in Baja California, Columbia River Gorge, Puget Sound, San Francisco, Southern California

by Mike Godsey

In normal years the bulk of the strong wind at the kite and windsurf sites in the Los Barriles and La Ventana areas comes from high pressure in the Great Basin area of the USA. However, the 2019-2020 winter season has seen lots of days when an unusually robust North Pacific High (NPH) has sent strong NNW winds down the Sea of Cortez.

The NNW angle of this NPH wind is not ideal for reliable wind at the beach but if there is good inland valley heating this wind does curve into the beaches.

But sometimes this season both the North Pacific High and the high pressure in the Great Basin have either been absent or too far away to help the Baja Sur winds.

Typically when this happens and we have blue skies we see kiteable mid to upper-teens winds from the local sea breeze as the inland valleys heat. These winds usually are strongest in the Rasta Beach area north of El Sargento and weaker for the La Ventana beaches and weaker yet for Los Barriles.

But there is another wind machine in our area that can ally with the local sea breezes to brings upper-teens to about 20 winds to the area. And that is the thermal trough just south of Baja’s East Cape.

Let’s look at today, February 21, 2020 as an example of this pattern.

by WeatherFlow ForecasterPosted on Posted in Baja California

by Mike Godsey, mikeATiwindsurf.com

Pretty good wind quality for La Ventana today as the morning clouds in far Los Planes Valley cleared allowoing the local pressure gradient to climb helping the sea breezes and encouraging the El Norte winds to reach the beach. You can see this clearly in the animation today Dec. 21!

But notice how the clouds lingered north of El Sargento and how they turned westerly at times making for unreliable El Norte winds at the beaches below the bluff.

by WeatherFlow ForecasterPosted on Posted in Baja California

by Mike Godsey, mikeATiwindsurf.com

I think the daily wind forecast and the wind graphs below from Tuesday, Dec. 17 capture the wind quality in the late morning and early afternoon pretty well.

BUT… if you ventured about 1/2 mile outside at La Ventana you got away from the shifty up and down N to WNW winds inside and found:

“2 hours of solid 6m kiting. Guessing 30ish+ . Good wind about a half mile off shore. Lot of west near shore but pretty solid north offshore. Clouds disappeared for the most part.”

 

by WeatherFlow ForecasterPosted on Posted in Baja California, Columbia River Gorge, Puget Sound, San Francisco, Southern California

by Mike Godsey, mikeATiwindsurf.com

Many years ago I spent 3 months per year doing underwater research on Pomacentrids around the islands of the Sea of Cortez. One thing that always struck me was how incredibly fast the weather could go from calm to strong winds.

The next 24 hours will brings such a change as this you can see in this graphic:

by WeatherFlow ForecasterPosted on Posted in Baja California

by Mike Godsey, mikeATiwindsurf.com

Take at this Baja California forecast valid for Thu, Dec 12 2019

Once again our ikitesurf.com sensor network and the ASCAT satellite imagery show continued El Norte winds coming down the Sea of Cortez. Unlike a typical El Norte these winds are from 3 sources: 1. NNE winds from the North Pacific Hig, 2. ENE winds at 1000 feet aloft that may sometimes transfer energy to the surface as gusts and shifts. 3. Weak high pressure in the Great Basin. Plus, of course, our mild local sea breezes. All this suggests gusty shifty winds which may be aggravated by the low-level clouds curving into the El Sargento mountains. Gusty upper-teens to around for Baja’s East Cape with fewer clouds than yesterday.

Why was the forecast for such GUSTY winds?

First looking at the model streamlines for today on the left side of this animation. It looks a great day. Note the very strong El Norte winds north of La Pacific and a bit weaker for Los Barriles to the south and weaker yet for La Ventana.  But still, who is going to complain about upper-teens to weak low 20’s winds.

But now look at the 2 wind graphs from our sensors in the area. Notice how jagged the graphs are indicating gusty winds near the shore. Once you got a bit outside the wind quality went way up.

Today the cause of that gustiness is largely the cloud build-up you see in the mountains N. of El Sargento and in the Los Planes Valley. The day was not anywhere near as bad as recent days but it was still not the rock study winds La Ventana used to be famous for years ago.

by WeatherFlow ForecasterPosted on Posted in Columbia River Gorge, Puget Sound, San Francisco, Southern California

by Mike Godsey, mikeATiwindsurf.com

Do you like gambles? So here is a big meteorological gamble. Today Dec. 1, 2019, I am forecasting a big El Norte winds event for the entire Sea of Cortez for Monday, Dec. 16. Normally I would not stick my neck out so far but this is a major event and the upper-level steering winds seem promising. I could be a day or so off on this forecast. And, as always, we need good sunshine in the inland valleys to create the local pressure gradient to suck those El Norte winds reliably to shore. But my bet is still there are strong winds.

Why? Follow this animated graphic carefully a few times and you will see the recipe for a big El Norte blow.

1. Note the isobars around the North Pacific High and the NW winds it is creating near the California coast.

2. Notice how there is low pressure in the Great Basin so there are few isobars near Baja’s Sea of Cortez

3. This produces very WEAK large scale winds for La Ventana and Los Barriles. There may be weak local sea breezes as the inland valleys heat.

4. Next is a critical step. Watch as a lobe of high pressure extends from the North Pacific High towards the Great Basin and

5. Watch the high-pressure move into the Great Basin as it enlarges steadily.

6. Notice how the low pressure exits to the east.

7. Now watch the Great Basin high pressure become stronger with more isobars moving towards Baja.

8. Watch isobars stack up over the Sea of Cortez

9. Watch El Norte winds fill in down the Sea of Cortez towards La Ventana

10. With high pressure ruling the Great Basin and 4 corners we see several days of El Norte winds if the clouds over Baja’s East Cape are not too thick.

 

 

 

 

 

 

 

 

by WeatherFlow ForecasterPosted on Posted in Baja California

by Mike Godsey, mikeATiwindsurf.com

If the cloud band you see in this animation keep moving towards La Ventana it could spoil winds today.

All models have the clouds only reaching near La Paz today but watching the satellite imagery it looks to me that they might get further south.

So watch the skies to the north and if you see thicker clouds be ready for a forecast bust. Below is the Loreto cam image at 12:10 PM today

by WeatherFlow ForecasterPosted on Posted in Baja California, Columbia River Gorge, Puget Sound, San Francisco

by Mike Godsey, mikeATiwindsurf.com

Sometimes you will notice a caveat in the forecast that a band of high clouds streaming from SW or WSW may come over us and spoil the wind but stopping the inland valleys from heating weakening the local pressure gradient.

Usually when I mention clouds I am talking about low-level clouds that are often extremely difficult to forecast so I will use weasel words like “Upper-teens winds IF the clouds do not block heating in the inland valleys” Since these clouds form locally or nearby they often develop and move over the valleys after the forecast is published.

Whereas, when I am talking about the higher clouds of the subtropical jetstream I am much more confident about their impact on the winds.   This is because these clouds are in a narrow band extending for hundreds of miles and their location later in the day is far easier to gauge.

This animation of the satellite imagery for Dec. 4, 2019, shows these clouds of the jet completely missing La Ventana and Los Barriles today. Hence the upper-teens or stronger winds.

Now, Thursday Dec. 5, those clouds are much closer to La Ventana making the mid to upper-teens forecast iffy since these clouds may kill the pressure gradient to the inland valleys.

by WeatherFlow ForecasterPosted on Posted in Baja California, Coastal South Carolina, Puget Sound, San Francisco, Southern California

by Mike Godsey, mikeATiwindsurf.com

With a bit of luck and a Cut-Off Low that behaves according to the models we see a 3-5 day El Norte blow for La Ventana and Los Barriles, Baja Sur.

This graphic for Saturday Nov. 30, 2019, shows the setup.

1. First, notice the huge storm over the mid-USA. This low-pressure system, that brought crazy winds, rain and snow to much of the west coast a few days ago is now tracking eastward.

2. Now note the second large storm out in the Pacific just off the west coast of the USA. Normally this storm would bring a day or two of stormy weather to the west coast and then move into the Great Basin displacing the El Norte wind creating high pressure located there. But far above this surface storm at ≈ 18,000 ft. is a near Cut-Off Low that is mostly disconnected from the upper winds that steer weather systems from west to east. This means this surface storm is likely to just loiter off the west coast for a few days.

3. Check out the small high pressure area in the Great Basin. This high pressure should cause El Norte winds today that augment the La Ventana local sea breezes today.

4. Notice the isobars extending from that high pressure. The closer those isobars are to each other the stronger the pressure gradient making for stronger winds.

4. This is creating the El Norte winds indicated in green in the Sea of Cortez. If that Cut-Off Low above storm#1 holds station while storm #2 departs eastward then the high pressure#3 can stay over the Great Basin and we see days of El Norte winds.

 

 

by WeatherFlow ForecasterPosted on Posted in San Francisco, Southern California, Weather Blog

by Meteorologist, Kerry Challoner Anderson

The media is talking about a “Bomb Cyclone” on the West Coast.  Does this mean imminent destruction?  View the following presentation for more info on this very interesting storm and how it relates to all the eddies we had this past summer.

https://spark.adobe.com/page/kya0DDY4Zytm3/