Had a bit of a wake-up call on Thursday with a charter group. We left Palma under blue skies, 8 knots from the south, flat sea — a textbook September morning. By 14:00 we had 22 knots gusting 28 from the northwest and a short chop building fast off Dragonera. Two of my crew had never reefed under pressure before and it got lively.
This is the thing about September that catches people out. The stable summer pattern is breaking down and the transitional weather can turn much faster than in July or August. The embat (sea breeze) is less reliable, the first cold fronts start pushing down from the north, and the temperature contrast between the still-warm sea and cooler air masses can trigger squalls that barely show up on the morning GRIB files.
A few things I am drilling into my crews right now:
- Check the forecast at 06:00 AND again at 12:00. The morning forecast in September is a suggestion, not a promise.
- If the barometer drops more than 3mb in 6 hours, take it seriously even if the sky looks fine.
- Reef early. Nobody has ever regretted putting a reef in too soon. Plenty of people regret putting one in too late.
- Know where your bolt holes are. If you are sailing the west coast, Andratx and Sóller are your friends. East coast, Porto Cristo and Cala Ratjada.
Anyone else noticed the weather getting twitchier this week? Curious what conditions have been like up in Pollença, @james_wheeler.
This is slightly terrifying but also exactly what I needed to read. We had perfect conditions on my last course day and I think I was starting to believe September was always going to be like that.
Katrin, stupid question maybe — when you say check the barometer, do you mean an actual barometer on the boat? Or is there an app? I have been using Windy but I am not sure I would know what a 3mb drop looks like on it.
Katrin is right about this and I will add something from years of watching September weather here. The pattern to watch for is when you get a day or two of unusually calm, hot conditions — that is often the setup for a sudden shift. The sea breeze builds and builds with nowhere to go, and when the gradient wind finally arrives from the northwest it all happens at once.
Anna, to answer your question — yes, a proper barometer on the boat is worth having, but the Windy app pressure graph works fine for learning to spot the trends. The number to watch is not one specific reading, it is the direction and speed of change. If you see pressure dropping steadily through the morning — say 2-3mb in 4-5 hours — that is your signal to start thinking about your plan B. I keep the pressure widget on my phone home screen from September onwards. Old habit.
Just a quick heads up for anyone planning to go out mid-week — AEMET is showing a possible low pressure system moving in from the northwest around Wednesday or Thursday. Nothing dramatic but could bring 20-25 knots and some rain, which after this summer would actually be quite welcome on land. On the water, less so.
Worth keeping an eye on. These early autumn systems can wobble a lot in the forecasts so check again Tuesday evening before committing to anything.
Carlos thanks for the AEMET heads up — I have been watching that system too. Looks like Thursday might be properly grotty which is actually fine by me, could do with a day in the office without staring longingly at the marina.
The barometric pressure thing is interesting. I never used to pay attention to it but since getting my Day Skipper I have become slightly obsessed with watching the numbers on my little Clipper barometer. Dropping 3-4mb in a few hours definitely gets your attention.
Carlos, thank you for the AEMET warning — I just checked and it does look like Thursday could be rough. My next course session is actually on Thursday afternoon so I am secretly hoping it gets moved to Friday instead. Is that terrible to admit?
Serious question though — at what point does the school cancel a session because of weather? And if we do go out in 20 knots, is that actually a good learning experience or just scary? My husband keeps saying I should want to sail in bad weather to learn but I think he has been watching too many YouTube videos about Atlantic crossings.
Anna, definitely not terrible to admit — even experienced sailors are relieved when a rough day gets postponed. No shame in that.
To answer your actual question though, 20 knots is not automatic cancellation territory for us. It depends on direction, sea state, and what we are teaching that day. A westerly 20 in the bay is very different from a northerly 20 with a big fetch. For Competent Crew we would probably still go out in 20 if it is steady and the forecast is not showing gusts much above that — it is actually brilliant learning conditions because you really feel the boat respond and your tacks get purposeful fast. We would stay closer to shore and keep things simple.
Where we draw the line is usually around 25 sustained or if there are gust warnings above 30. Or if the sea state is ugly and confused, which can happen when these autumn systems come through quickly.
Honestly some of my best teaching days have been in 18-22 knots. Students learn more in one breezy afternoon than in three calm ones.
Worth adding that September is also when the sea temperature is at its peak, which means the thermal contrast when a cold front arrives can be extreme. I have seen the wind go from 5 knots to 30 in under an hour up near Cap Formentor when a tramuntana sets in behind one of these early autumn systems.
Anna, to your question about sailing in 20 knots on a course — Katrin is spot on. Controlled exposure with an instructor is genuinely the best way to build confidence. My only advice is make sure you eat properly beforehand. Nothing makes rough weather worse than being hungry and cold, and in September people forget the cold part because the mornings are still warm.
James, that 5 to 30 knots in under an hour is exactly the kind of thing that keeps me up at night. We had a session last week where the instructor pointed out a line of clouds building over the Serra de Tramuntana and said we would be reefing within the hour — he was right almost to the minute. Starting to understand why everyone here watches the mountains as much as the forecast.