For those of you already in Mazatlan, or expected to arrive in the next couple of days, a strong word of caution. There was a very, very early season winter storm last week off the coast of Antarctica. So what the heck does does a storm in Antarctica with it's penguins and ice, have to do with Mazatlan where it's sunny and clear?
They've just finished up their summer in the Southern Hemisphere, so the ice pack off Antarctica is currently at it's smallest point of extension out to sea. This leaves more open water for wind to blow across. Consequently the open ocean swells generated by that storm had more area to build up their power, and there's nothing between those swells and Mazatlan but open ocean. Eventually they're going to crash on shore.
Starting sometime tomorrow and certainly by Saturday you can expect some very good sized, to potentially large waves hitting the beaches of Mazatlan. For reference it should be bigger than the waves that visitors like Sunseeker mentioned last week. I would not recommend anyone go swimming over the weekend as there's going to be a lot of current moving from left to right as you look out to sea.
In addition if you love your walk on the sand, make your path farther....much farther.... up away from the crest of the water being pushed up on top of beach. These are what is called long period swells, which means more time passes by between each individual wave. In addition because they've traveled literally thousands of miles getting to North American, the time between the larger groups of waves (called sets) can get quite long. Think of throwing a pebble into a pond and how you see the ripples get farther and farther apart as they travel away from the initial splash.
Between the sets it can appear relatively calm and people are often lulled into walking right next to the water. Or worse they walk at low tide on the wet sand inside, having no idea that next big surge may to turn that shallow area or dry sand into a river of moving water. More than once I've seen people walking at the edge of the berm...the last of the flat sand, just where it starts angling downhill to the water. Only to get knocked down or even dragged outside into the deep water, as a huge surge recedes back out to sea.
Be very careful where you start your walk, and be particular cautious if you intend on going into the ocean. Take your cue from the big wave surfers around the world who would never just show up and launch themselves into the water. They'll watch and wait for sets of waves to arrive to see what the conditions will be like, and where the dangers are. Like where the riptides are...how far the biggest waves will surge the water up on top of the beach...how bad the current looks...etc.
Mazatlan is a wonderful place to let your mind relax and have a carefree vacation. Just don't let yourself get too relaxed around the water for the next few days.