top of page
hbanziger

D - 20: Can We Use 800 Years Old Weather Reports?

Updated: Mar 26, 2021

Would we need a weather report for our trip from Genoa to Tunis given that neither the Genovese nor the Pisan merchants had any such thing? They just sailed with the prevailing winds during the summer and knew they would be alright. My piece on our weather in July and August should thus be quick to write. Or so I thought. But looking for information on Mediterranean Climate gets you buried in an avalanche of climate change articles! Not that climate change is not important but does it really have to replace everything else?

Have to do this from memory then. It is basic and simple. The atmosphere over our planet’s surface has some degree of inertia and does not fully follow the seasons. It remains mostly in place whilst the earth below moves. Which means that the Sahara Heat and the Azores High Pressure Area move north thereby blocking the westerly depressions from reaching the Mediterranean basin. They are pushed over Scotland and Scandinavia instead and ensure that these parts of Europe remain lush and green.

The climate in the Mediterranean for the summer months is stable – of course there are exceptions as we experienced last summer in the Adriatic when a depression crossed our path. But it blew over quickly. We sat it out in Albania. One day in a harbor is not the end of the world.


Forecast for Temperature Anomalies July 2020 – same amount of sunshine as on average

After a good hour of searching, I found some weather data from the European Center for Medium-Range Weather Forecast. They provide data for this summer - it looks promising!

Rain Anomalies in July 2020

There is not only a high probability for lots of sunshine but also for little rain. It will be wet and rainy in Russia and Scandinavia this July, but the Mediterranean should just be fine. Our entire route from Genoa to Tunis is white (=average). This means less than 5% probability of rain. The same is true for August.

Average Temperature for July for Corsica

Due to the constant water temperature all the way down to Tunisia, the weather will be more or less like in Corsica for which I found a chart showing data from 2019. It will be hot during the day – mitigated by the fact that we are on the sea – but cooler in the evening. Bring a sweater or a jacket - we are going to have dinner at the back of the boat.

CEAM Sea Temperature in August 2019 – very consistent on our sailing route

The wind pattern this summer will be more benign than last year. Who does not remember our dashes to avoid the Bora and we got still caught – our two boats almost collided!

Typical wind pattern in July

There are only two places where we possibly are exposed to stronger winds. The strait of Bonifacio between Corsica and Sardinia and the Punic Sea between Sardinia to Tunisia. However, the first distance is short and the second follows a westerly course to Tabarka right on the border to Algeria. We should be fine.

More noticable will be the thermal winds during the day. The mornings will be calm as when we sailed along the Anatolian coast in summer 2018. By 10 am the winds will pick up and by 4 pm we should probably reach a safe bay. Thunderstorms or gales are not frequent but possible.

In a nutshell, our travelling will follow the same daily routine as the sailing of the Genovese or the Pisani a few hundred years ago. Doing 30 – 40 miles per day, putting into a safe place for staying overnight and continue the next day. Had the Genovese or the Pisani had a weather report, we could borrow theirs – of course there was not any!

11 views0 comments

Recent Posts

See All

Comments


bottom of page