The mistral ( ca, Mestral, el, Μαΐστρος, it, Maestrale, mt, Majjistral, Corsican: ''Maestrale'') is a strong, cold, northwesterly

wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ...

that blows from southern France into the Gulf of Lion in the northern

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

. It produces sustained winds often exceeding , sometimes reaching . It is most common in the winter and spring, and strongest in the transition between the two seasons. Periods of the wind exceeding for more than sixty-five hours have been reported. In France, it refers to a violent, cold, north or northwest wind that accelerates when it passes through the valleys of the

Rhône The Rhône ( , ; wae, Rotten ; frp, Rôno ; oc, Ròse ) is a major river in France and Switzerland, rising in the Alps and flowing west and south through Lake Geneva and southeastern France before discharging into the Mediterranean Sea. At Ar ...

and the

Durance The Durance (; ''Durença'' in the Occitan classical norm or ''Durènço'' in the Mistralian norm) is a major river in Southeastern France. A left tributary of the Rhône, it is long. Its drainage basin is .Camargue region. It affects the northeast of the plain of

Languedoc The Province of Languedoc (; , ; oc, Lengadòc ) is a former province of France. Most of its territory is now contained in the modern-day region of Occitanie in Southern France. Its capital city was Toulouse. It had an area of approximately ...

and

Provence Provence (, , , , ; oc, Provença or ''Prouvènço'' , ) is a geographical region and historical province of southeastern France, which extends from the left bank of the lower Rhône to the west to the Italian border to the east; it is bo ...

to the east of

Toulon Toulon (, , ; oc, label= Provençal, Tolon , , ) is a city on the French Riviera and a large port on the Mediterranean coast, with a major naval base. Located in the Provence-Alpes-Côte d'Azur region, and the Provence province, Toulon is th ...

, where it is felt as a strong west wind. It has a major influence all along the Mediterranean coast of France, and often causes sudden storms in the Mediterranean between

Corsica Corsica ( , Upper , Southern ; it, Corsica; ; french: Corse ; lij, Còrsega; sc, Còssiga) is an island in the Mediterranean Sea and one of the 18 regions of France. It is the fourth-largest island in the Mediterranean and lies southeast of ...

and the

Balearic Islands The Balearic Islands ( es, Islas Baleares ; or ca, Illes Balears ) are an archipelago in the Balearic Sea, near the eastern coast of the Iberian Peninsula. The archipelago is an autonomous community and a province of Spain; its capital is ...

. The name ''mistral'' comes from the

dialect of the Occitan and means "masterly". The same wind is called ''mistrau'' in the Provençal variant of Occitan, ''mestral'' in

Catalan Catalan may refer to: Catalonia From, or related to Catalonia: * Catalan language, a Romance language * Catalans, an ethnic group formed by the people from, or with origins in, Northern or southern Catalonia Places * 13178 Catalan, asteroid #1 ...

, ''maestrale'' in Italian and Corsican, ''maistràle'' or ''bentu maestru'' in Sardinian, and ''majjistral'' in Maltese. The mistral is usually accompanied by clear, fresh weather, and it plays an important role in creating the climate of Provence. It can reach speeds of more than , particularly in the Rhône Valley. Its average speed during the day can reach about , calming noticeably at night. The mistral usually blows in winter or spring, though it occurs in all seasons. It sometimes lasts only one or two days, frequently lasts several days, and sometimes lasts more than a week.Internet site of Meteo France, article on the mistral.

Cause

The mistral takes place each time there is an

anticyclone An anticyclone is a weather phenomenon defined as a large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere as viewed from ...

, or area of high pressure, in the

Bay of Biscay The Bay of Biscay (), known in Spain as the Gulf of Biscay ( es, Golfo de Vizcaya, eu, Bizkaiko Golkoa), and in France and some border regions as the Gulf of Gascony (french: Golfe de Gascogne, oc, Golf de Gasconha, br, Pleg-mor Gwaskogn), ...

, and an

area of low pressure In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible ...

around the

Gulf of Genoa The Gulf of Genoa (''Golfo di Genova'') is the northernmost part of the Ligurian Sea. This Italian gulf is about wide from the city of Imperia in the west to La Spezia in the east. The largest city on its coast is Genoa, which has an importa ...

. When this happens, the flow of air between the high and low pressure areas draws in a current of cold air from the north which accelerates through the lower elevations between the foothills of the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...

and the Cevennes. The conditions for a mistral are even more favorable when a cold rainy front has crossed France from the northwest to the southeast as far as the Mediterranean. This cold, dry wind usually causes a period of cloudless skies and luminous sunshine, which gives the mistral its reputation for making the sky especially clear. There is also, however, the mistral noir, which brings clouds and rain. The mistral noir occurs when the

Azores High The Azores High also known as North Atlantic (Subtropical) High/Anticyclone or the Bermuda-Azores High, is a large subtropical semi-permanent centre of high atmospheric pressure typically found south of the Azores in the Atlantic Ocean, at the H ...

is extended and draws in unusually moist air from the northwest. The long and enclosed shape of the Rhône Valley, and the

Venturi effect The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. The Venturi effect is named after its discoverer, the 18th century Italian physicist, Giovanni Battista ...

of funnelling the air through a narrowing space, is frequently cited as the reason for the speed and force of the mistral, but the reasons are apparently more complex. The mistral reaches its maximum speed not at the narrowest part of the Rhône Valley, south of Valence, but much farther south, where the Valley has widened. Also, the wind occurs not just in the Valley, but high above in the atmosphere, up to the troposphere, above the earth. The mistral is very strong at the summit of

Mont Ventoux Mont Ventoux (; oc, Ventor, label= Provençal ) is a mountain in the Provence region of southern France, located some northeast of Carpentras, Vaucluse. On the north side, the mountain borders the department of Drôme. At , it is the highest ...

, 1900 meters (6300') in elevation, though the plain below is very wide. Other contributing factors to the strength of the mistral are the accumulation of masses of cold air, whose volume is greater, pouring down the mountains and valleys to the lower elevations. This is similar to a

foehn A Foehn or Föhn (, , ), is a type of dry, relatively warm, downslope wind that occurs in the lee (downwind side) of a mountain range. It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of ...

wind, but unlike a foehn wind the descent in altitude does not significantly warm the mistral. The causes and characteristics of the mistral are very similar to those of the

Tramontane Tramontane ( ) ; french: tramontane ; el, τραμουντάνα, tramountána, ; it, tramontana ; la, trānsmontānus ; mt, tramuntana ; sl, tramontana ; sh, tramontana ; es, link=no, tramontana . is a classical name for a northern wind ...

, another wind of the French Mediterranean region. Bell Tower La Cadiere d'Azur Provence France

In France, the mistral particularly affects

east of

Montpellier Montpellier (, , ; oc, Montpelhièr ) is a city in southern France near the Mediterranean Sea. One of the largest urban centres in the region of Occitania, Montpellier is the prefecture of the department of Hérault. In 2018, 290,053 people l ...

, as well as all of the Rhône Valley from

Lyon Lyon,, ; Occitan: ''Lion'', hist. ''Lionés'' also spelled in English as Lyons, is the third-largest city and second-largest metropolitan area of France. It is located at the confluence of the rivers Rhône and Saône, to the northwest of ...

Marseille Marseille ( , , ; also spelled in English as Marseilles; oc, Marselha ) is the prefecture of the French department of Bouches-du-Rhône and capital of the Provence-Alpes-Côte d'Azur region. Situated in the camargue region of southern Fra ...

, and as far southeast as Corsica and Sardinia. The mistral usually blows from the north or northwest, but in certain pre-alpine valleys and along the

Côte d'Azur The French Riviera (known in French as the ; oc, Còsta d'Azur ; literal translation "Azure Coast") is the Mediterranean coastline of the southeast corner of France. There is no official boundary, but it is usually considered to extend fro ...

, the wind is channelled by the mountains so that it blows from east to west. Sometimes it also blows from the north-north-east toward the east of Languedoc as far as Cap Béar. Frequently, the mistral will affect only one part of the region. In the Languedoc area, where the tramontane is the strongest wind, the mistral and the tramontane blow together onto the Gulf of Lion and the northwest of the western Mediterranean, and can be felt to the east of the

, in

Sardinia Sardinia ( ; it, Sardegna, label=Italian, Corsican and Tabarchino ; sc, Sardigna , sdc, Sardhigna; french: Sardaigne; sdn, Saldigna; ca, Sardenya, label= Algherese and Catalan) is the second-largest island in the Mediterranean Sea, aft ...

, and sometimes as far as the coast of Africa. When the mistral blows from the west, the mass of air is not so cold and the wind only affects the plain of the Rhône delta and the Côte d'Azur. The good weather is confined to the coast of the Mediterranean, while it can rain in the interior. The Côte d'Azur generally has a clear sky and warmer temperatures. This type of mistral usually blows for no more than one to three days. The mistral originating from the northeast has a very different character; it is felt only in the west of Provence and as far as Montpellier, with the wind coming from either a northerly or north-northeasterly direction. In the winter this is by far the coldest form of the mistral. The wind can blow for more than a week. This kind of mistral is often connected with a low pressure area in the Gulf of Genoa, and it can bring unstable weather to the Côte d'Azur and the east of Provence, sometimes bringing heavy snow to low altitudes in winter. When the flow of air comes from the northeast due to a widespread low pressure area over the Atlantic and atmospheric disturbances over France, the air is even colder at both high altitudes and ground level, and the mistral is even stronger, and the weather worse, with the creation of cumulus clouds bringing weak storms. This kind of mistral is weaker in the east of Provence and the Côte d'Azur. The mistral is not always synonymous with clear skies. When a low pressure front over the Mediterranean approaches the coast from the southeast, the weather can change quickly for the worse, and the mistral and its clear sky changes rapidly to an east wind bringing humid air and threatening clouds. The position of the low-pressure front creates a flow of air from the northwest or the northeast, channeled through the Rhône Valley. If this low-pressure area moves back toward the southeast, the mistral will quickly clear the air and the good weather will return; but if the cold-weather front continues to approach the land, bad weather will continue for several days in the entire Mediterranean basin, sometimes transforming into what French meteorologists call an ''épisode cévenol'', a succession of torrential rains and floods, particularly in the areas west of the Rhône Valley: the

Ardèche Ardèche (; oc, Ardecha; frp, Ardecha) is a department in the Auvergne-Rhône-Alpes region of Southeastern France. It is named after the river Ardèche and had a population of 328,278 as of 2019.Gard Gard () is a department in Southern France, located in the region of Occitanie. It had a population of 748,437 as of 2019;Hérault Hérault (; oc, Erau, ) is a department of the region of Occitania, Southern France. Named after the Hérault River, its prefecture is Montpellier. It had a population of 1,175,623 in 2019.Lozère.Jean Vialar, ''Les vents régionaux et locaux'', 1948, republished by

Météo-France Météo-France is the French national meteorological service. Organisation The organisation was established by decree in June 1993 and is a department of the Ministry of Transportation. It is headquartered in Paris but many domestic operations ...

in 2003 The summer mistral, unlike the others, is created by purely local conditions. It usually happens in July, and only in the valley of the Rhône and on the coast of Provence. It is caused by a thermal depression over the interior of Provence (The Var and Alpes de Haute-Provence), created when the land is overheated. This creates a flow of air from the north toward the east of Provence. This wind is frequently cancelled out close to the coast by the breezes from the sea. It does not blow for more than a single day, but it is feared in Provence, because it dries the vegetation and it can spread forest fires.

Effects

The mistral helps explain the unusually sunny climate (2700 to 2900 hours of sunshine a year) and clarity of the air of Provence. When other parts of France have clouds and storms, Provence is rarely affected for long, since the mistral quickly clears the sky. In less than two hours, the sky can change from completely covered to completely clear. The mistral also blows away the dust, and makes the air particularly clear, so that during the mistral it is possible to see mountains and farther away. This clarity of the air and light is one of the features that attracted many French impressionist and post-impressionist artists to the South of France. The mistral has the reputation of bringing good health, since the dry air dries stagnant water and the mud, giving the mistral the local name ''mange-fange'' (Eng. "mud-eater"). It also blows away pollution from the skies over the large cities and industrial areas. The sunshine and dryness brought by the mistral have an important effect on the local vegetation. The vegetation in Provence, which is already dry because of the small amount of rainfall, is made even drier by the wind, which makes it particularly susceptible to fires, which the wind spreads very rapidly, sometimes devastating vast expanses of mountainside before being extinguished. During the summer, thousands of hectares can burn when the mistral is blowing. In the Rhône Valley and on the plain of la Crau, the regularity and force of the mistral causes the trees to grow leaning to the south. Once the forest has been razed by fire, the strong wind makes it difficult for new trees to grow. The farmers of the Rhône Valley have long planted rows of cypress trees to shelter their crops from the dry force of the mistral. The mistral can also have beneficial effects—the moving air can save crops from the spring frost, which can last until the end of April. As summer visitors to the beach in Provence learn, the summer mistral can quickly lower the temperature of the sea, as the wind pushes the warm water near the surface out to sea and it is replaced by colder water from greater depths.

Beyond France

The mistral regularly affects the weather in Sardinia and sometimes also affects the weather in North Africa,

Sicily (man) it, Siciliana (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = Ethnicity , demographics1_footnotes = , demographi ...

and

Malta Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...

and other parts of the Mediterranean, particularly when

low-pressure area In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible ...

s form in the

. The winds create a physically cold, salty ocean body that sinks in the Gulf of Lion when certain weather conditions are present.

Maestral or maestro in the Adriatic

Similar names—''maestral'' or ''maestro''—are used for (although also mostly northwestern) a quite different wind in the

Adriatic Sea The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to th ...

. It is an anabatic sea-breeze wind which blows in the summer when the east Adriatic coast gets warmer than the sea. It is thus a mild sea-to-coast wind, unlike the mistral. The strong katabatic wind there is the northeastern bora. In Greece, it is also known as ''maïstros'' or ''maïstráli''. In southwestern Crete, it is considered the most beneficial wind, said to blow only in daytime.

In Provençal culture

The mistral played an important part in the life and culture of Provence from the beginning. Excavations at the prehistoric site called Terra Amata, at the foot of Mount Boron in

Nice Nice ( , ; Niçard: , classical norm, or , nonstandard, ; it, Nizza ; lij, Nissa; grc, Νίκαια; la, Nicaea) is the prefecture of the Alpes-Maritimes department in France. The Nice agglomeration extends far beyond the administrative ...

, showed that in about 40,000 B.C. the inhabitants had built a low wall of rocks and beach stones to the northwest of their fireplace to protect their fire from the power of the mistral. The '' mas'' (farmhouse) traditionally faces south, with its back to the mistral. The bell towers of villages in Provence are often open iron frameworks, which allow the wind to pass through. The traditional Provençal

Nativity scene In the Christian tradition, a nativity scene (also known as a manger scene, crib, crèche ( or ), or in Italian ''presepio'' or ''presepe'', or Bethlehem) is the special exhibition, particularly during the Christmas season, of art objects rep ...

usually includes a figure of a shepherd holding his hat, with his cloak blowing in the mistral. A Fête du Vent (Festival of Wind) is held periodically on the Prado Beach in Marseille.

References

Notes Bibliography * Lumley, Henry de (2007) ''La Grande Histoire des premiers hommes europeéns'', Odile Jacob.() * Valar, Jean (2003) 948''Les vents régionaux et locaux''.

External links

Local Mediterranean winds
{{DEFAULTSORT:Mistral (Wind) Winds Provence Climate of Malta