THE MAIN WEATHER AND CLIMATE FEATURES OF THE NORTHERN HEMISPHERE IN FEBRUARY 2018

Air Temperature.

February weather in Russia was intricate. It would seem that the closer to the spring, the warmer the weather should be. But everything has happened vice versa. In the first half of the month the air temperature in the most part of the country exceeded the norm noticeably. Over the first decade the average decade air temperature anomalies from west border to East Siberia have set +2…10°. New warmth records were registered in Krasnodar district and Crimea, in Russian North, Kamchatka, Chukotka and all Russian Arctic. In the middle of the month the abnormal warmth was kept only in the south of ETR and to the east of Urals. In the third decade all Russian territory, except north-east, Arctic territories and part of North Caucasus republics was captured by abnormally cold air. Temperature norms in the third decade became lower than real values by 4-10°. Record colds were registered in European territory, it was lower than -30°. The single country region with exceptionally warm weather during all month was north-east (Kamchatka, Chukotka, Kolyma). Here in all decades the average monthly air temperature exceeded the norm by 6-12° and more.
As a result, the average monthly air temperature of February in the north of Far East federal district is the second highest on the record. It succeeds only to the February 1934, i.e. the year which became the part of the period of the first instrumentally fixed Arctic warming. In other Russian regions the change of the warmth and cold caused the proximity of the average monthly air temperature to the norm. It was slightly colder the norm in the most part of ETR and in the south of Far East, warmer – to the east of Urals, where the Arctic coast, as before, showed the warmth records.

February closed the calendar winter of 2017-2018, which in Russia became warm. It has 3-6 rank amongst all warm winters since 1891. The warmest winter is 2015-2016, then is its predecessor. The last winter in the north of Far East federal district is among the temperatures close to the highest one. It is the warmest winter among the XXI century winters. In the most part of the country the average air temperature of the last winter is higher the norm by 2° and more, in the Arctic region – by 4-8°. Only in the south-west of Siberia (Novosibirsk area, Altai district, republic of Altai) the winter was colder than usual, in some places by 1-3°.
Cold weather in the south of Far East expanded also to the north-east areas of China, Korea and Japan. Here the average monthly air temperature is below the norm. In Hokkaido the new daily temperature minimums were registered. However, in the most part of Celestial empire the average monthly air temperature was close to the norm, and in some places, as in neighbouring Mongolia, exceeded the norm by 1-3°.
In the South Asia it was colder than the usual.
All Middle East and most part of the Central Asia were in conditions of abnormally warm and sometimes – hot weather. Here the temperature norms were exceeded by 2-4° and more. In Atyrau (Kazakhstan) the anomaly is +2.2°, Andijon (Uzbekistan) and Dushanbe (Tajikistan) - +3.1°, Amman (Jordan) - +3.3°, Eilat (Israel) and Shiraz (Iran) - +3.5°, Al-Jawf and Rafha (Saudi Arabia) - +4.4°.
In the most part of North Africa is was warmer than usual. In Egypt, east of Libya and to the south of Sahara – even substantially (by 2-3° and more). But cold from Europe from time to time penetrated to the north-west of the subcontinent. In Morocco the air temperature before the morning dropped to zero. From Algeria to Mauritania the average monthly air temperature was below the norm by 1-2°.
February did not pamper Europeans with warm weather. Although in some days the cyclones brought to Europe the wet and warm air and in Spain and France the temperature rose up to +15-20°. But in the second half of the month the Arctic cold penetrated to the continent. Heavy frosts locked Europe. In the west (Spain, France) it was getting cold to -10°, in the centre and east of continent – to -20…-30°, in Scandinavia – to -32°. In Italy the fountains were frozen, in Holland – the channels. Cold caused the cancellation of many planned events and human losses because of hypothermia. The average monthly air temperature in all continent was below the norm. In Spain, France, Germany, Poland, Baltic countries in some places by 2-3°. However, such cold February is not seldom during the last years. Over the past 18 years of XXI century it happened for the sixth time.
In USA the temperature in February had the sharp contrast between south and south-east from one side and north, north-west from another. In San-Francisco the air got cold to +2°, whereas in Boston – was heated to +20°. From Texas to Atlantic ocean the average air temperature of February exceeded the norm by 2-6°. Warm air was transferred deeply to Atlantic ocean, and its average temperature above the surface exceeded the norm by 2-4°. In states which are situated to south from Virginia to Florida and Alabama it was the warmest February in history, and to the north from it to Great Lakes and Canadian border came to five of the warmest ones. At the same time, to the west of Great Lakes and to Pacific ocean the month is colder the norm, in some places by the same 2-4°.
Most part of Canada was in the colder weather than usual. Only in the east and Polar north of the country the temperature exceeded the norm.
In Arctic February 2018 became the warmest on the record. Its average temperature exceeded the last record achievement of 2016 by 0.5°. At the end of the month the transfer of the warm air from Atlantic ocean to Pacific one caused the unprecedented event. First time during the height of the winter its temperature (according to the data of Danish Meteorology Institute) rose above zero. Ice cover, which had to increase during this time of the year, started to decrease. As a total during the week, ice coverage in Bering sea was decreased by one third. Meteorological phenomenon in Arctic during the last days of February testifies on early spring in Polar Circle.
Last winter in the Northern Hemisphere became the third warmest one on the record. In all Arctic the average monthly air temperatures in winter exceeded the norms substantially and last winter became here the warmest on the record. The average winter air temperature in East Europe, Middle East and in the west part of Atlantic ocean along Gulfstream is higher the norm. In California it was the second warmest winter in history. Vice versa, in south-east of Atlantic ocean, including equatorial part of Pacific ocean, in Kazakhstan, Korea, south of Japan and in equatorial part of Pacific ocean, where La-Niña is observed, the winter became colder the norm.
In Moscow the average February air temperature is -9.1°. The month became colder the norm by 1.4°. Only in the last days of winter the air temperature dropped below -20°, in Moscow area even -30°. As long as December and January in the capital were noticeably warmer than usual, all winter also became warm. Its temperature exceeded the norm by 3.2°.

Ocean Surface Temperature.

The main peculiarity within the field of surface temperature anomalies of Pacific ocean in the Northern Hemisphere is the gradual decreasing of the negative anomalies of equatorial area, which means slow weakening of La-Niña. La-Niña climax was apparently passed and by the end of spring – beginning of summer one should expect the transition of Southern oscillation to the neutral phase. In the Pacific ocean the abnormally cold water was spread along the Asian continent, whereas central and east part of the ocean have the water temperature above the norm.
In the Atlantic ocean the large positive anomaly was extended from Gulf of Mexico along the US coast far to the central part of the ocean. At the same time in tropical zone, especially near the African coast and in the north, the negative SST anomalies were observed.

Precipitation.

In the European territory, except the Polar North areas, there were a lot of precipitations in February, especially in the central area. It was not only snow, which is natural for winter, but rain also. So, in the first decade the rains fell in the central areas and south of Russia. At the same time in the capital area and in Upper Volga in some places it was a record amount of snow, or close to this (Kostroma, Nizhniy Novgorod, Kazan), which caused huge snow drifts on the roads. Monthly precipitations sums over the month exceeded the norms in Kostroma and Ivanovo areas in 2 times, in Moscow, Vladimir and Bryansk areas in 1.5 times. In the other territory of Central federal district the precipitations have set the norm. Substantially more than the norm the precipitations fell in the south of ETR (Volgograd and Rostov areas, republic of Kalmykia, republic of Kabardino-Balkaria). In Crimea in the end of the month the heavy snowfalls fell, having blocked the road traffic.
To the east of Volga, in Urals and West Siberia it was few precipitations. In the most part of Krasnoyarsk district, Irkutsk area and republic of Buryatia they have set the norm or slightly more of it. Far East federal district was divided to the wet north and dry south. Heavy snowfalls brought a lot of precipitations to republic of Sakha (Yakutia), Magadan area, Chukchi autonomous area and Kamchatka district. In some places the norms were exceeded in 2 times and more. In the south of the region and neighbouring Transbaikalia the monthly precipitations sums did not reached even to the half of the norm, in some places were entirely absent.
All North and Central China have only several millimetres of precipitations over the month. In many areas it was entirely dry, also in Beijing. Since last November it was not even one day with precipitations more than 0.1 mm. This is the longest period without precipitations in the Chinese capital. Some rains fell only in the south of the country, snowfalls – in the north-west. In Japan it was few precipitations also. But some snow showers caused traffic incidents and human losses.
Heavy showers fell in some areas of Thailand and Laos. Dry weather was in India, but neighbouring Bangladesh was inundated by rains. Here the monthly precipitations norms were exceeded in 2.5 times.
Middle East had the cyclones full of water, which have got by the Mediterranean countries (Israel, Lebanon, Jordan) and Saudi Arabia. In some places there were up to the half of monthly precipitations norms and more. In Armenia in Ararat valley the last winter did not see the snow at all, it allowed to begin the spring field work earlier by one month.
Mediterranean cyclones brought a sufficiency of precipitations to the coastal areas of Tunisia, Algeria and Libya. In some West African countries, most part of which the Sahara desert is included, the precipitations norms were exceeded in several times. The reason of this is than the norms are very small itself (only several millimetres) and even light rain can cause substantial excess above the norm.
In Sahara the snow fell for the second time since the winter begins. Firstly it happened in January. Snow in Sahara appeared the second winter in a row. Before this it was observed in December 2016, and before this only one time – almost 40 years ago.
Rains and snowfalls tormented Europe in this month. Although the monthly quantity of precipitations exceeded the norm in general in south-east and east of the continent, but some of them brought a great amount of snow and rain. In Malta 109mm of rain fell over the day, which is more than monthly norm. Spain, Italy, Greece, Croatia have got 40-80mm of rain over the day. In the beginning of the month snow covered Paris with depth of 10 cm. But apocalypse was at the end of February, when abundant snowfalls came to Europe together with Siberian cold. In Croatia snow blocked the roads, in Greece the sleet caused the landslide, which descended to Korinthos channel and blocked it. In Rome schools and kindergartens were closed because of snowfalls, tourist posed at the background of snow-clad Colosseum, shortages of electricity took place. Firstly over the last half-century the snow laid down on the Napoli streets. Heavy snowfalls fell in Ukraine.
In USA February 2018 became sixth “wettest” on the record. East and south states have got a lot of precipitations. In states, situated to the south of Great Lakes and in the Middle West, monthly precipitations sums reached maximum and exceeded the norms in 2-3 times. In the first decade bad weather captured the north-east of the country. In New York and Washington two thirds of monthly norm fell over the day. Heavy snow covered also states of Wisconsin, Illinois and Michigan. In the third decade the rains came here, which together with warm weather caused intensive snow melting with floods in the mentioned states and areas of river valleys of Ohio and Mississippi. In the west of the country in the Pacific coast states the month was dry. In California it is second driest on the record.
In the most part of Canada it was dry weather. Only in south-east, closer to US border and in extreme north the precipitations have set the norm and more. Mexico has got a lot of rains. In the central areas of the country their monthly sums exceeded norms in 1.5-3.0 times.
In Moscow in February it was 64mm of precipitations, or 177% of norm. Although last February one can undoubtedly consider as very snowy, however, it is far to February 1966, in which the monthly sum of precipitations was in 1.5 times more – 97mm. As to the last winter, it has cumulated 216mm of precipitations (161% of norm), this is second result on the record in the capital. It was more only in winter of 1965-1966 – 244mm.
Hydrometcentre of Russia