It is Baja meteorology 101 gospel that the strongest winter Sea of Cortez winds are created by high pressure in the USA’s 4-Corners region.
You can see this high-pressure area in the circle of white isobar lines in this first image.
Notice how those lines get closer together over the Sea of Cortez. The closer the lines are, the stronger the pressure gradient and winds.
But where does all this northerly wind go?
And why are there some days with no high-pressure to the north but there are fairly strong winds in the Rasta Beach, La Ventana, and Los Barriles zones far stronger than the weak local thermal winds?
This happens due to a frequent winter low-pressure area, or what Mets call a “low-pressure trough,” south of Cabo San Lucas at the tip of Baja California.
Frequently, you will see that a low-pressure trough is mentioned in forecasts as an ingredient in a day’s wind recipe.
The winds from the high-pressure in the USA are accelerated down the Sea of Cortez when that low-pressure is south to southeast of Cabo San Lucas at the tip of the Baja Peninsula is in the right location.
The shape and location of this low-pressure system are critical to the strength of the winds on Baja’s East Cape.
1. If the low-pressure is too far south it does not help our winds at all.
2. If the low-pressure moves too far north then it covers the Sea of Cortez. This location destroys the pressure gradient and kill the winds.
3. But if the low-pressure is mostly south of Cabo, then it works with high pressure to create very strong El Norte winds for much of the Sea
of Cortez.
4. On days with no high-pressure in the USA, the Rasta Beach, La Ventana, and Los Barriles launch sites normally only have weak local thermal winds caused by Coastal Valley heating. These weak winds struggle to reach above the low teens.
But sometimes, the winds reach into the upper teens without a hint of high pressure in the USA. That difficult-to-forecast pattern happens when the low-pressure trough south of Cabo is perfectly positioned.
Unfortunately, most of the higher-resolution models do NOT cover that area, so it is hard for us to pinpoint the location of that low-pressure. This leads to crappy forecasts.