Winter of 2019-2020 vs. the NPH vs the unusual 4 corners high pressure.
When it comes to mild winds in the mid to weak upper-teens wind Baja’s East Cape has several wind machines. These include 1. the mild local sea breezes created by the inland valleys. and 2. The mesoscale winds from the cooler Sea of Cortez to the persistent thermal trough just south of the Baja Peninsul
But when it comes to the famed El Norte winds in the low to upper 20’s range that made La Ventana and Los Barriles a mecca for kiters and windsurfers the main wind machine has always been the high pressure in the Great Basin especially if it was centered over the 4 corners region.
This first animation shows this El Norte wind pattern. Frist a storm passes over the west coast and then the Great Basin. Then high pressure develops in the Great Basin and typically lingers for several days. This causes isobars to align over the Sea of Cortez which combined with the persistent trough to the south creates strong N wins that augment the local sea breezes.
The problem with this N wind is that it is not at the perfect angle to fill into the beaches since there is mountainous terrain to the north putting the beaches into a partial wind shadow.
The key to getting this wind to the beaches is heating in the inland valleys that curves the N. wind so it makes it to the beaches. As you can see in the next graphic.
Winter of 2019/20
This winter we often saw a different strong wind pattern. Frequently there was low pressure in the Great Basin so the classic El Norte winds were uncommon.
Instead, the North Pacific High was closer to the west coast and often more northerly in position. This placed in near the Baja Peninsula.
This means that the winds in the Sea of Cortez were often from the NPH and had a more NNW rather than N. angle.
Since this angle is slightly offshore it was harder for the wind to curve into the beaches. This made inland valley heating and the local pressure gradient even more critical. And since the subtropical jet often had clouds over southern Baja the winds often did not make it to the beaches reliably.