Just saw the AEMET warnings for the eastern mainland coast this week and it got me thinking. We are properly into gota fría season now and while Mallorca usually gets off lighter than Valencia or Murcia, when it does hit us it hits hard.
Last October we had that system that dropped 80mm on Palma in about four hours. My friend had left his dinghy tied alongside at the Club Nàutic and it was underwater by the morning. The drainage in the port could not cope and half the pontoon was floating debris.
For anyone who has not been through an autumn here before — the weather can turn very fast from now through November. The sea temperature is still 25 degrees and when cold air moves in from the north the instability is brutal. You can go from flat calm sunshine to 40 knot gusts and zero visibility rain in under an hour. The AEMET app and their avisos page are your best friends this time of year.
A few things I always do from now until December: check the 5-day forecast every morning before deciding anything, keep the boat secure even on good days because things change fast, make sure the cockpit drains are clear, and avoid being caught in the south of the island in an exposed anchorage if there is any yellow or orange warning.
Anyone else got DANA stories or prep tips?
Oh god yes. We arrived back from the UK last week and the first thing Tom checked was the AEMET page. Old habits from living aboard — you learn quickly that September sunshine can be a trap.
Good reminder about the cockpit drains Carlos. We had a near miss two years ago when leaves from the palm trees at the marina clogged ours overnight during a heavy downpour. Woke up to six inches of water in the cockpit.
Okay so this is probably obvious to everyone else but what exactly is a DANA? I keep hearing people at the marina mention gota fría and I just nod along like I understand. Is it basically a really bad storm? And does MSA cancel courses when one is forecast or do you just go out anyway?
I am slightly terrified of the idea of being out on the water when one of these hits.
Anna, great question and no need to pretend you already know — I wish more people asked instead of nodding along!
DANA stands for Depresión Aislada en Niveles Altos, which basically means a pocket of cold air that gets cut off high up in the atmosphere. When that cold air sits over the warm Mediterranean in September and October, the contrast creates incredibly violent storms — we are talking 100mm of rain in a couple of hours, hail, waterspouts, the works. Gota fría is the older name for the same thing, people use them interchangeably here.
The mainland coast around Valencia and Murcia gets it worst because the mountains trap the moisture, but Mallorca absolutely gets hit too. The key difference from a normal thunderstorm is the intensity and how fast conditions change. You can go from flat calm and sunshine to zero visibility in thirty minutes.
MSA will definitely cancel if there is a serious DANA forecast, nobody is sending students out in that. But the tricky days are the ones where the forecast says maybe — those are the ones where you need to be watching the sky yourself.
Carlos has given you a solid explanation Anna. The only thing I would add from the liveaboard perspective is that DANA events can come with very little warning compared to what you might expect. The forecast will say scattered showers and then suddenly you are dealing with 50 knot gusts and zero visibility.
I have been through three proper ones in Pollença now. The worst was in 2023 when the wind shifted 180 degrees in about twenty minutes and half the boats in the anchorage started dragging. The key is always having a plan before the season starts — know your escape routes, keep your engine ready to go, and if you are on a mooring make sure it is inspected.
For you as a student I would not worry too much. MSA will not send you out in anything dangerous. But learning to read the AEMET forecasts yourself is a skill worth developing early.
Thank you James, that is really helpful and also slightly terrifying. The idea that the forecast can say scattered showers and then you get 50 knots is… well, it makes me appreciate having proper instruction before going out.
Quick practical question — is there a specific weather app or website that people here trust most for these DANA warnings? I have been using Windy but I am not sure I would know what to look for in terms of the really dangerous patterns Carlos described.
Anna, I use AEMET as the official source — their app is a bit clunky but the warnings are reliable. For day-to-day I check Windy like you do, but during DANA season I also keep an eye on the Predictia DANA tracker and the AEMET meteoalerta page specifically.
Honestly the biggest lesson I have learned is just to not go out if there is any doubt. Last autumn I had a Day Skipper practice session cancelled because of a DANA warning and I was annoyed at the time, but we watched from the marina bar as the sky turned black over the bay in about fifteen minutes. Very glad we were on dry land with a cold beer instead.
Sophie thank you for the app tips! I downloaded the AEMET app and set up the meteoalerta notifications. The interface is… well, it is very Spanish government website, but it works. Feeling much better knowing I will actually get a proper warning now instead of just checking Windy and hoping for the best.
The AEMET alerts are the only thing worth trusting when it gets serious. Windy is fine for planning a weekend sail but when there is a real DANA forming you want the official source.
I will say this — I have sailed through nearly 30 autumns here and the pattern is always the same. End of September into October the sea temperature is still very warm, the air starts cooling, and that energy has to go somewhere. Last year we had three DANA events between the end of September and mid-November. Two were manageable if you were paying attention, one shut the whole bay down for two days.
The thing that catches people out is the speed. You can have a beautiful morning and by 1400 the sky looks like someone pulled a curtain across it. If you are out near Cabrera or the south coast and you see towering cumulus building to the west after lunch, do not wait to see what happens. Turn around.
Just checking in on this — did anyone else see the AEMET yellow warning for tomorrow afternoon? Looks like there might be some heavy showers coming through from the southwest. Not full DANA territory but enough that I have postponed a practice sail I had planned off Portals.
Carlos, you mentioned three events last autumn. Are we due for the first proper one soon or is it still early?
Sophie, to answer your question — yes, we are right in the window now. Historically the first serious DANA event tends to hit somewhere between mid-October and early November, though of course it does not follow a calendar. What I watch for is the sea surface temperature off the east coast of Spain getting above 22-23 degrees while the first proper cold air drops start coming down from the north. That collision is what triggers the worst of it.
I had a proper fright in October 2019 anchored in Cala Figuera when a DANA that was supposed to track further south shifted at the last minute. Went from flat calm to 40 knots in about ninety minutes. Got the anchor up and ran for Portocolom with the engine wide open. Not my finest seamanship but sometimes getting out of the way is the right call.
The yellow warning for tomorrow looks manageable but keep an eye on it. These things can escalate.
James, that is really useful context about the sea surface temperature trigger — I had not thought about it that way before. Makes total sense though.
So I have been checking AEMET obsessively since that yellow warning last week (which turned out to be nothing much in the end, just a few heavy showers over Palma that cleared by evening). Is there a good rule of thumb for when to actually cancel a sail versus when a warning is just being cautious? I know the answer is probably “always err on the side of caution” but I am trying to calibrate my decision-making as a relatively new skipper.