Matt Broze's story about getting stuck on Coronado Island in the Sea of Cortez got me to thinking about those winds, known as "Gulf Northers" to the yachties in the area. We've been stuck in anchorages down there for a few days so I guess it's worth talking about what causes them so anyone planning to go paddle there can get a leg up on the competition. With global climate change and the current drought in California you're likely to see more of these in the future. In the 1970s you could expect two gulf northers in any month between November and March and each one would typically last 3 to 5 days. Sue and I cruised there for a couple of years in the 1970s and one of the amateur radio weather men (good weather reports on the local ham nets down there so it's worth taking a radio that can receive single sideband) finally figured out the mechanism. Gulf northers are almost completely a winter phenomenon and correspond with high pressure over NV, AZ, western NM and the high deserts of CA along with a "thermal low" over the Sea of Cortez. (A thermal low is low pressure caused by air heating up and rising.... this gives colder, denser air a chance to flow in to fill the void.) So here is the mechanism. The sun shines a lot over the area between Baja California and the mainland of Mexico. This heats the air up and since warm air rises there is a low pressure area over the water and lower land elevations. Normally the cooler air at the mountain ridges that line each side of the Sea of Cortez simply flows downslope and fills this thermal low in. So in the winter you can often expect mild offshore breezes in the afternoon. But when a cold dense ridge of high pressure settles in over the higher desert areas of the southwest corner of the USA (NV, AZ, NM, and CA) that normal downslope mechanism of the area is overpowered. The inland desert areas all slope downwards to the south (e.g.: the Colorado River watershed) right into the northern Sea of Cortez where they get funneled between the high mountains on each side of the Sea. This flow continues until either the high pressure ridge moves east and across the Rockies or the pressures equalize. This also explains why the northerly winds subside some at night. It's worth noting that a gulf norther is also noticable on the west coast of Baja (on the Pacific side) at the southern end of the peninsula west of La Paz. The mountainous spine of the Baja disappears here and the winds can flow over the land to make the ocean pretty rough. The typical gulf norther winds disappear only a few miles south of Cabo San Lucas. So, basically, you can expect no winter northerly gales in the Sea of Cortez if there is rain or low pressure over the high desert southwest. If there is a ridge over the desert sw and sunshine over the Sea of Cortez you can expect northerly gales. You can often listen to LA radio station KFI down in the Baja area to hear weather reports. If there are offshore winds (the "Santa Anas") in LA then you are certain to get a gulf norther in the Sea of Cortez. It's the same mechanism. Craig Jungers Moses Lake, WA www.nwkayaking.net *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:33:51 PDT