Subject: MISTRAL Date: Mon, 25 May 1998 14:28:31 +0200 From: "Michael Tommasi"The Mistral is a strong wind from the NW affecting the eastern Mediterranean coast of France, from Marseille to St. Tropez. The Mistral is one of the key weather-makers of this charming and relatively undiscovered part of the French Riviera, situated in the départements of the Var and extending to the Bouches-du-Rhône (Marseille), away from the overcrowded Nice-Cannes-Antibes area. The Mistral is responsible for the exceptionally sunny conditions, the desert-like vegetation (reminiscent of Southern California), and perhaps even the local temper. Most of the time, in between bouts of Mistral, the coast is gently swept by pleasant breezes, which make summer days more bearable than the hot conditions inland, while winters are mild compared even to Aix-en-Provence, only a half-hour drive inland. These calm periods are punctuated by short violent bouts of Mistral, which clear the air and prepare for the next mild spell, ensuring that this area maintains its sunny conditions. The towns of Bandol-Sanary-Six Fours boast the largest number of sunny days per year in France.
Hello, I found you Web page to be very useful. I live in the Mistral area, although I originally come from the Bora area (!), please find enclosed an article I wrote on Mistral, you might find it useful. It has a few non-meteorological items which you might skip. Bye Michele Tommasi
The risk of a Mistral of force 6 or greater is about 30% in the peak period from November to April. In the summertime that risk drops to 18%, but the warm sea temperature increases its speed significantly. Force 7-8 is not uncommon, and at least once a year it reaches force 10 (that's 89 to 102 km/h average; to put the feeling in perspective, it's like leaning out of the window while driving legal speed on a US highway). Navigators and hikers must be particularly aware of the Mistral. Although the locals are fond of embellishment (the Marseillais have the same reputation as the Texans), one should never underestimate their descriptions of Mistral. It does occasionally reach 70 knots, it does appear suddenly, it does drive you to making rash decisions.
If you are driving southward along the Rhône on a Mistral day, you will begin to feel it around Montelimar, the city which marks the dividing line between cloudy and clear conditions. As you continue southward, the cypresses that protect gardens and orchards from the wind are bent over, leaning permanently towards the Mediterranean. At Marseille the Mistral blows from the north, but a cyclone effect twists it as it reaches the Mediterranean, so that it actually follows the coast eastward all the way to St. Tropez, while also pushing out to Corsica and even the north of Sardinia.
Why the Mistral evokes such romantic dreams in visitors, why these quaint bed-and-breakfasts in the heart of Provence are inevitably named Le Mistral, is hard to explain. When the Mistral blows, it sets most people on edge or gives them migraine, maybe due to lack of sleep, caused by the howling noise it makes gusting up to 120 km/h onto a provençal tiled roof. The dry cold air blows hard and evenly, leaving the sky clear and tinged in an unbelievably luminous blue colour unique to Provence, the air is brisk and the sunshine is harsh and blinding. In the summertime, a day of Mistral is enough to make the soup-warm Mediterranean drop to the serving temperature of vichyssoise.
The Mistral blows dust in your eyes and leaves your teeth gritty with sand. They say that during a Mistral you can see Corsica from atop the appropriately named Mont Ventoux in Northern Provence; unfortunately, nobody has ever proven that, because it is impossible to stand up in Mistral on the Mont Ventoux. Do not try the "Route des Crêtes" drive in a Mistral, your car will feel like it is about to fly off the ridge of the Calanques, Provence's version of the "fjords" with a 300m vertical drop overlooking the Mediterranean and the town of Cassis.
The Mistral's effects develop along the Rhône valley, as a consequence of the cold front that sweeps France once a low pressure area has formed around the English Channel. The cold front advances in a SSE direction, passing under high altitude warm air layers, hits the Alps and spills out by funneling down the Rhône valley at high speed, often helped by low pressure in the Tyrrhenian Sea.
While the conditions outlined above are necessary, they are not sufficient, and other complex triggering mechanisms are involved. For the Mistral to blow, it is also necessary to have a pressure gradient along the coast, however slight, from higher pressure in the Pyrenees to lower pressure in the Appennines. If you are in the Mistral area, that pressure is hard to detect, because you are smack in the middle of the gradient, so you must rely on the isobars furnished by weather services.
Mistral effects on the coast can be amplified if the air is much cooler than the sea. Mistral can get a further boost from the Tramontane, another strong fall wind which can simultaneously blow out of the west, generated by conditions similar to the Mistral, by the funneling effect of the Pyrenées. The Tramontane can blow alone, and it is often confused with Mistral by the inexperienced.
Another wind affecting the area is the East wind, which brings the rain to this dry area. The East wind is not a fall wind. Its arrival is pre-announced by the movement of the sea's current towards the west. Exceptionally, violent storms can be carried by southern winds, although these are more often the result of instability in North Africa, and carry prodigious amounts of desert sand, coating everything in thick yellow mud.
The Mistral is what Bowditch defines as a fall wind, occuring when cold air is dammed up in great quanityt against the windward side of a mountain ridge. The Bora is an eastern Mediterranean example of fall wind, when cold air moves in a NW direction up Yugoslavia and hits the Alps, spilling out onto the Adriatic, hitting Trieste with great force and reaching as far as Venice. The Bora is not as dramatic as it used to be up to the '60s, when the pavements of Trieste were even fitted with rope railings to help pedestrians.
On rare occasions, if the volume of cold air is sufficient, it may also spill down the Argens and the Var valleys (the Var river is not in the Var départment at all, it flows through Nice), hitting the Nice Riviera directly from the land side. Technically speaking though, the Mistral must come from the Rhône valley. But the wind the Niçois most often call Mistral is in fact the Ponant, which is not a fall wind at all. The Ponant always begins around mid-day and ends just after tea-time on the Boulevard des Anglais. So remember, contrary to what they tell you there, Nice is not in Provence and hardly ever gets the Mistral.
Accurate forecasting is very hard indeed, do not expect anything more than a short notice if any. It often builds up in the night, after midnight, or early in the morning, especially in the summer. It very rarely appears on a summer afternoon. Once established, the Mistral generally peaks in the afternoon and weakens in the evening. Most Mistrals last one to three days, sometimes extending to a full week. Tales abound about it always lasting a multiple of 3 days, but this notion, often quoted by landlubbers as some form of venerable ancient mariner's knowledge, is in fact utter nonsense.
The sky in the NW can show telltale signs several hours before a Mistral. Wispy high-altitude cirrus may appear, but the typical signs are lens-shaped alto-cumulus, looking like cuttlefish bones. These appear the evening before, with a red sunset, the clouds are golden at first, turning to pink and then gray. The faster they turn gray, the harder the wind will be, force 8 or 9 is not uncommon. After sunset, short gusts of wind appear, at first in long intervals, then coming more often, while the sea current starts to flow towards the east. Expect full development between midnight and sunrise.
When the Mistral is blowing, you can often see a large cloudy area waiting far away to the west of Marseille, prevented from advancing by the airflow down the Rhône. If the Mistral subsides, those clouds will quickly invade your area.
While it is blowing, the Mistral creates short deep waves, making navigation unpleasant and definitely very wet. Sea conditions are generally extreme around the numerous capes that make up the coast in Mistral country. The shallower waters and the rocky coast create havoc with the waves, creating crossing patterns which are hard to negotiate. The waves can be one to two metres long, 3 metres at most, in places like Almanarre.
When navigating, be aware that not all ports are suitably protected against all winds. Some are well oriented for protection against the Mistral, but may be rough spots during an East wind.
Several aids are available to navigators. Flashing lights are used in certain ports or navigation areas, for daytime warnings of expected winds of force 6 and over. Weather warnings are issued in SSB on short wave by stations at Grasse, Marseille and Monaco. The "CROSS" centre in La Garde broadcasts special bulletins and warnings on VHF, plus you can request a rebroadcast of a weather bulletin. Other sources are local radio stations, Radio France International, NAVTEX, Weather-fax, as well as many meteorological centres and semaphores with automated telephone response, reachable by GSM mobile phone.
The Mistral makes our part of the coast a wind-surfer's paradise. All of the dangers to navigation mentioned above are in fact a plus to wind-surfers. Few people refer to the beach of Six-Fours by its real name "Plage de Bonnegrace", the more popular "Brutal Beach" is more descriptive. Another favourite spot is the beach of Almanarre, in Hyères. In both places the waves are short and treacherous for a pleasure boat, but ideal for wave jumping on a 2.6 m long funboard. Expect to see amazing acrobatics being performed here.
In calm weather you will not see them, but wind-surfers from all over Europe are there, camped out somewhere, waiting. When the Mistral hits, they all come out at once, their campers invading the coast. The Italians have the fanciest gear, their custom boards splashed with "Giorgio" or "Roberto" in large script, smartly tied on top of their sleek German cars. The Germans have the most gear, plus mountain bikes, so they need extra-large campers. The Dutch also have oversized campers, because they are in the habit of bringing along all their food needs for the entire trip, including those beautiful but totally tasteless watery greenhouse tomatoes that they grow.
Summer dry conditions and Mistral combine to create a high risk of forest fires, making hiking dangerous. Such fires are rarely accidental, usually deliberately set in pine forests by deranged people or by contract arsonists on motorcycles, using such imaginative devices as incendiary tennis balls and a raquet. The perpetrators are often known by the police but never held for more than a few days, the police here being mainly in the business of giving parking tickets. The fires rapidly assume alarming proportions and become difficult to control, advancing in the forest faster than you can run, unimpeded by rivers or highways as glowing pinecones get flung across these ineffective obstacles. All the firefighters can do in these conditions is concentrate on protecting the inhabited areas.
The pine trees burn very quickly, fuelled by resin and wind, while the pinecones explode and spread burning shrapnel to nearby trees, aided by the burning underbrush and thus extending the fire to the cork oak forests. The growth on the ground used to be kept under control by large flocks of sheep and goats, but somehow the shepherd's profession has become even less attractive than accounting. When a pine forest burns, it rarely regenerates itself, the more rugged cork oaks eventually replacing them. Cork oak trees also appear to burn to a crisp, but in fact the scar is only on the surface, caused by the underbrush and the leaves, the trunk and main branches being protected by the cork bark, which does not burn. Remarkably, the following spring these blackened skeletons develop pristine new green buds and leaves, while the tree keeps growing stronger than ever, fed by the minerals in the ash deposited on the ground.
Fires of this magnitude can cloak huge areas of the coast in smoke. This can be awesome (in the pre-1980's sense of the word), the sky gets completely overcast. The tourists think it's a storm coming until they notice their cars are covered in ash, the sun is invisible but for an eerie orange-brown glow, and bright yellow and red Canadair water bombers are buzzing all around.
The Canadair CL-415 is rapidly replacing the piston-engine CL-215, but despite its variable pitch prop and turbine engine it is still basically the same design as the original WW II bomber that it was developed from. The plane can scoop over 6000 litres in a quick 12-second skim over water, and in a typical 2.5 hour mission it will drop 91000 litres of water. Canadians will never stop telling you about Canadian airplane designs that never saw service because they were 10 years ahead of their time. It is ironic that one of their biggest successes is a WW II bomber still in production 50 years later. Officially called a firefighting amphibious craft, the French refer to any such plane as a "Canadair". They are stationed at Marseille airport, watch for them as you land, admire them during the 45 minute wait for your luggage.
Places in the Mistral's path
The Mistral is like an endurance test, but once it has finished its business it will leave the air clean and fresh, allowing you to enjoy the rest of your stay here. There are many things to see and places to visit on and around the coast. Avoid the months of july and august at all cost, that's when Parisians come down and invade the place, recreating the traffic jams of the capital, just so they can keep their stress from dropping to unnaturally low levels.
Starting from the West, as you probably will arrive at Marseille airport, always head East. You could venture into Marseille, there is nothing wrong with the place, it just has a bad reputation which the Paris-based media scrupulously maintains, but in truth, despite the rough veneer, the place is totally harmless and actually quite a place for contemporary culture, mainly theater and music.
As you leave Marseille head for Cassis, but do not take the highway, use the spectacular road which goes along the coast, with great views of the islands, and then continues through the garrigue, the patch of mediterranean brush which covers the Calanques. Take a detour to the Presqu'île of Cassis and see the view from the Calanques. As you leave Cassis, look for the Route des Crêtes, and follow the ridge of the Calanques. Drop into La Ciotat and see the station, so you can see where the Lumière brothers shot the first film ever made. The first cinema hall is also in La Ciotat. Take the coast road again and go to Bandol if you like sitting at a café people-watching, or if you are searching for some night-life, otherwise go to Sanary, one of the best preserved fishing villages on the coast. A side trip to Castellet will provide great views from this medieval village.
Beyond that you can skip Toulon altogether, unless you want to see France's only major city with a mayor from the fascist and overtly racist National Front. The infamous Toulon-La Seyne-Hyères triangle is the capital of mafia and corruption on the coast, the highest level politicians are in jail and so are some of the neighbouring town mayors. Toulon is home to the French fleet, which was self-destroyed in the harbour when a couple of German subs blocked the port entrance in WW II. If the Germans were prevented from taking the city, nobody was able to prevent post-war French architects, inspired by Stalin, from defacing the waterfront with nightmarish blocks of concrete, simultaneously choking the old town and blocking any view of the sea. The got the coveted "Prix de Rome" prize for this work.
Hyères is next, and consider a day-trip to the island of Porquerolles. The coast drive will take you to wonderful spots, such as Bormes les Mimosas, and the nearby beaches of Bregançon, the nicest of the entire coast. Continue to Lavandou and through to Ramatuelle, ending up in St. Tropez. This is a very beautiful village, but its discovery by Brigitte Bardot has made it incredibly crowded between Easter and September. Look for immense yachts in the minuscule port, but also walk through the tiny streets and see the fishermen's houses. The aging Ms. Bardot has lost her marbles, she has married a member of the National Front and advocates saving the seals and being nice to dogs, while spouting the nastiest remarks about the humans of every race, including her own, who have ruined her little village. She has forgotten who started the whole invasion.