You are watching: A valley or anabatic breeze is created when
The main varieties of local winds space sea breezes and also land breezes, Anabatic and also katabatic winds, and Foehn winds.
You can discover different ways to measure wind speed on our Experiments and also Demonstrations page, or ~ above our Top 10 principles for Weather Fieldwork page.
Find out about Weather Folklore
Katabatic wind speeds carry out not commonly not exceed 3 or 4 m/s. However, where the ground is spanned with snow or ice, katabatic winds can take place at any type of time of job or night through speeds often reaching 10 m/s, or even more if funnelling v narrow valleys occurs. Katabatic winds may bring about the formation of frost, mist and fog in valleys.
Sea breezes space the result of differential heater of the land and also the sea. Sea breezes happen by day, when the land becomes warmer than the sea.
Warm air from the soil cannot broaden into the sea together the air is cooler and much more dense, therefore it expands up right into the atmosphere. Cumulus clouds have tendency to form as the warm air rises over the land to about 500-1500m.
The diagram below shows the whole sea breeze process.
Air in sea breezes is cool and moist compared to the air over the land. Sea breezes can move 70km inland in warm climates by 9pm in the evening. Sea breezes deserve to be noticed several kilometres out to sea. In the tropics they deserve to be felt 20km native the land. Wind speed from sea breezes deserve to be around 4-8m/s however can be also stronger.
Land breezes take place at night and in the beforehand morning, when the floor is cooler 보다 the sea. This is since as the waiting cools in the night time (as over there is less heating from the sun) that contracts. Press is higher over the land than the sea. This reasons the waiting to circulation from the land come the sea which is known as a soil breeze. The circulation is completed by air rising and also moving towards the land at 100-300m.
This is shown on the diagram below.
Cumulus clouds from whereby there is increasing air. Soil sea breeze fronts have tendency to only affect a small area that 10-15km out to sea, in comparison to the much larger effect of sea breezes. Wind speed are additionally lower in ~ 2-3m/s.
As fine as regional winds and also local weather phenomena, the following list includes seasonal winds with neighborhood names:
A cold dried wind i m sorry blows from the north-east, phibìc or north-west in the mountainous regions of southeastern France and also western Switzerland in winter months. The bise is attach by heavy cloud.
The bora begins suddenly and without warning and the cold air commonly descends to the coastline so swiftly that the has small time to warmth up.
The bora have the right to reach speed of much more than 100 km/h and has been recognized to overturn vehicles and also blow people off their feet.
The Chinook Wind
A warm, westerly wind uncovered in western phibìc America – Canada and the USA, once air indigenous the Pacific blows over the Rocky Mountains and also other upland areas. Top top January 15th, 1972, the Chinook brought about the temperature in Lorna, Montana to climb from -48°C come 9°C in 24 hours! The faster wind rate recorded throughout a Chinook was 107mph, in Alberta, Canada.
The name provided to the drizzling weather v low stratus, mist or fog which occurs from time to time during the duration January to April over the China Sea and in coastal areas between Shanghai and also Cape Cambodia. The occurs once cool, moist waiting from the north encounters warm, moist air, and also it is intensified by orographic lifting and/or by coastal convergence.
The Etesians/ Meltemi
The strong northerly winds which punch at times over the Aegean Sea and eastern parts of the Mediterranean Sea throughout the duration May to October. The winds are recognized as meltemi in Turkey.
The Föhn (or Foehn)
An explanation that the Föhn result in the UK indigenous BBC weather.
The Gregale (or Grigale)/ Euroclydon/ Euraquilo
A notorious wind that the western Mediterranean which additionally blows across central parts of the Mediterranean Sea. That is a solid and cold wind native the north-east and also occurs mainly in winter. It is most pronounced on the island that Malta, whereby it occasionally reaches hurricane force and also endangers shipping.
The bible tells united state that the delivery which brought St Paul and other prisoners throughout the Mediterranean en path to Rome was moved by a storm from Crete to Malta, wherein it was eventually wrecked.
The ship collection sail native a bay called Fair Havens close to Lasea top top the south coastline of Crete, having put into this bay come wait because that favourable problems after being delayed by contrary winds. Together the bay was exposed to storms, it was not thought about a safe location to continue to be at the time of year in question, which to be either late September or beforehand October. The harbour in ~ Phoenix ~ above the south-western coastline of Crete was taken into consideration a safer place to invest the winter. Soon after the ship left same Havens, however, a serious gale began to blow. Therefore violent to be the storm that the sailors could do no an ext than drift through the wind. The bible tells us that the ship got to Malta fourteen days later.
Paul proficient a gregale. Together these winds usually last no much more than 4 or five days, the storm the experienced appears to have actually been person that is abnormal persistent.
A dry and also comparatively cool wind i beg your pardon blows from the eastern or north-east on the coast of north Africa in between Cabo Verde and the Gulf of Guinea throughout the dry season (November come March). It bring dust and sand indigenous the Sahara Desert, regularly in sufficient quantity to form a thick fog which hinders navigating on rivers. Dust and also sand room sometimes brought many thousands of kilometres the end to sea.
The Helm Wind
An easterly wind discovered in Cumbria, N. England, wherein the winds blow over overcome Fell and then descend into the Eden Valley. A financial institution of cloud forms over the hill tops, and also the roaring of the wind have the right to be heard as far away together Penrith.
Discovering brother A go across great Dun dropped from the RGS, trying out the Helm wind and also lots of other weather, and stories that sheep, socks, snow and also spies and also a relevant post from Weather: The Helm wind that Cross dropped .
The name given to the south-easterly winds i m sorry prevail in winter (December come April) in the Persian Gulf. They room accompanied by gloomy weather, rain and squalls and also are sometimes followed by very strong south-westerly winds dubbed suahili.
A hot, dry, dust-laden, southerly wind end Egypt, the Red Sea and eastern components of the Mediterranean Sea ahead of eastward-moving depressions. It occurs throughout the period February come June, being most constant in March and April. The Khamsin is a Sirocco wind, whose name comes from the Arabic word because that ‘fifty’, i beg your pardon is around the length of time the wind blows for. In the nineteenth Century, the pester was worst in Egypt when the Khamsin was blowing.
A solid south-westerly wind which blows everyday over the Gulf of Aden from about 22:00 hrs until around noon the adhering to day. It wake up in June, July and also August (during the south-west monsoon) and also frequently will gale force.
A hot, dry, southerly wind which wake up in winter and also spring in between Madeira and also Gibraltar and along the shore of north Africa ahead of an progressing depression.
A moist wind which blows native the eastern over the Strait that Gibraltar. It is generally accompanied by haze or fog and may happen at any type of time of year, though it is most usual in the period June to October. A feature is the incident of a ‘banner cloud’ prolonging a kilometre or much more downwind indigenous the summit of the rock of Gibraltar.
The stamin of the Levanter go not normally exceed Beaufort pressure 5. Once it is strong, however, complex and vigorous atmospheric eddies type in the lee that the Rock, causing an overwhelming conditions because that yachtsmen and also the pilots that aircraft. The levanter can additionally cause persistently foggy weather top top the coast of Spain.
A hot, dry, southerly wind i beg your pardon blows ~ above the south-east coastline of Spain front of an advancing depression. It is frequently laden v sand and dust, and its technique is frequently heralded by a belt the brownish cloud on the southerly horizon.
A strong, squally, south-westerly wind which wake up over main parts that the Mediterranean Sea, most common in winter.
The name provided to north-westerly winds over the Adriatic Sea, the Ionian Sea and coastal regions that Sardinia and Corsica.
A solid south-easterly wind over the Golfe du Lion. The is usually accompanied by warm, cloudy weather through rain.
It might blow continuously for a work or two and also attain speed of 100 km/h, causing significant damage come crops and making driving conditions difficult in the Rhône Valley. It gets rid of clouds and pollution out of the air. In the Rhone valley in France, trees lean to the South since of the force of the Mistral.
This surname for a wind is provided in much more than one place. In Chile, a Norther is a northerly gale through rain. It typically occurs in winter however occasionally occurs at various other times the year. Typically, it deserve to be determined by falling air pressure, a cloudy or overcast sky, an excellent visibility and also water levels below normal follow me the coast.
Over the Gulf of Mexico and also western parts of the Caribbean Sea, Northers are strong, cool, northerly winds i m sorry blow largely in winter. Over the Gulf that Mexico, they are occasionally humid and also accompanied by precipitation, however over the Gulf that Tehuantepec they are dry winds.
The name provided to major line squalls in Argentina and also Uruguay, particularly in the Rio de la Plata area. Castle are connected with marked cold fronts and also are normally accompanied through rain, thunder and also lightning, a spicy drop in temperature and also a sudden adjust of wind direction indigenous northerly or northwesterly come southerly or southern westerly. They room most likely to occur throughout the period June come September.
Strong westerly winds found in the southerly Hemisphere in between 40 and also 50 levels South. Sailing ships have always made usage of them. The winds are lot stronger in the southerly Hemisphere since there is very small land to slow-moving them down – just Tasmania, new Zealand and also the an extremely bottom of southern America.
The Santa Ana
A hot, dry, strong, blustery, föhn-type wind i beg your pardon blows indigenous the north-east or eastern over southerly California and carries v it huge quantities that dust. The is most frequent in winter however may additionally occur in feather or autumn. The may acquire its name from the Santa Ana hills or the Santa Ana Canyon yet other possibilities are that that derives native santanas, definition ‘devil winds’, or the Spanish Satanás, definition Satan. These winds can cause a good deal the damage. As they room hot and also dry, they reason vegetation to dry out, so enhancing the hazard of wildfires; and also once fires begin the winds fan the flames and hasten the spread of the fires. In spring, Santa Ana winds can cause considerable damages to fruit trees.
Strictly, the shamal is any north-westerly wind end the Persian Gulf and Gulf of Oman, however the term commonly refers not to the typical prevailing winds but to the squally gale-force winds attach by rain and also thunder which occur in winter.
The Scirocco/ Sirocco
A hot, dried wind southerly wind i m sorry blows native the Sahara in north Africa right into the southerly Mediterranean. It choose up moisture together it crosses the Mediterranean and also can reach Spain, France, Italy and Greece pass Saharan dust and also hot, windy, wet weather, often with fog or low stratus cloud. In spring, the Sirocco can lug gale force winds. There are countless local names because that the Sirocco, consisting of chom, arifi, Simoom, Ghibli, Chili, Khamsin, Solano, Leveche, Marin and Jugo.
An easterly or south-easterly wind, through rain, which wake up in the Strait that Gibraltar and also over south-eastern coastlines of Spain.
The name offered to the violent squalls i beg your pardon are associated with well-defined active cold fronts over coastal regions of southern and south-eastern Australia. They are accompanied by lightning, thunder and gale-force winds and are similar to pamperos. They room most frequent in summer yet may likewise occur in spring and also autumn.
These room characteristically squally regional winds which take place over the Malacca Strait numerous times a month throughout the duration April to November. Castle are constantly accompanied by heavy rain indigenous cumulonimbus clouds and also are nearly always accompanied by lightning and thunder. They room initiated by katabatic winds and also therefore have tendency to occur at night.
A violent squally wind from the north or north-east in the Gulf that Tehuantepec in winter. It originates in the Gulf the Mexico together a norther and blows across the Isthmus that Tehuantepec.
The trade wind
Easterly winds in the Tropics (between the Tropic of Cancer and also the Tropic of Capricorn). The trade winds assisted European explorers with America.
A cold, dry, northerly or north-westerly wind end the coastline of Catolina and also a cold, dried northerly or north-easterly wind over the west shore of Italy and also the north shore of Corsica. It is commonly a strong wind however does not regularly reach gale force.
Strong, squally, south-westerly winds off the east shore of Spain and also in the Strait the Gibraltar. They happen mainly during the duration September to March and are often accompanied by violent squalls, heavy rain and thunderstorms.
A sudden, cold, violent wind found in Alaska and also Cape Horn which blows native the mountains to the sea.
A willy-willy is a dust storm over north-west Australia. Much more information.
See more: What Happens In Chapter 13 Of Lord Of The Flies Chapter 13 Summary
This term applies to two various phenomena. The usually describes a dry and often dusty föhn wind that occurs end the eastern slopes the the Andes in main Argentina in winter months. The is likewise the name (or sondo) given to a hot, humid, northerly wind over the Pampas region of southern America in advancement of an eastward-moving depression and also preceding a pampero occurrence.