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

Air Temperature.

The last October was exceptionally favourable for the Russia’s inhabitants regarding the temperature comfort. “Indian summer” dominated the most part of the month. In the beginning of the first decade in the European territory in some places the light frosts were noted, in the other decades the exceptionally warm weather was everywhere, which was very rare for this time of the year. The information on the new temperature maximums came from everywhere, they were registering during the several days successively and repeatedly. In the ETR, this was happened in the second decade, beyond the Urals – during all month.
And as a result, this wonderful month became the warmest in Russia on the record, i.e. since 1891. The previous record of the maximum average October air temperature, registered almost 50 years ago, was overcame by 0.5°. Absolute maximum of the October average air temperature was reached in Siberia and Far East. Here the largest average temperature anomalies were registered - +4…9°. In any point of the country, the average monthly air temperature appeared above the norm.
In the most part of China, the average monthly temperature conditions corresponded to the norm. Here are the areas, where it was noticeably colder than usual (south and west of the country), but in some areas it was noticeably warmer than usual (eastern provinces Shandong, Henan, Jiangsu, Anhui). Air temperature in Mongolia and Japan is above the norm (in some places by 2-3° and more) and below the norm – in Korea.
Slightly higher the norm the average monthly air temperature in the South-East Asia and India. In the Middle East, this superiority of the warmth is more obvious. Here are the areas (in Iran, Arabia, Jordan, Israel, east of Turkey and Transcaucasia), where the average monthly air temperature anomalies reached +2…3°.

In the North Africa, the heat in the continent centre was opposed by the cold in the Atlantic and Mediterranean coasts.
Weather in the Central Asia demonstrated high volatility. It was noticeably warmer than usual in the beginning of the month, the new temperature maximums were registered. However, in the second decade the cold came here. Now the temperature minimums were registered, at the average over the decade it became lower the norm by 2-4°. In the third decade, the warmth turned back and caused the record values, average temperature anomalies have set +2…5°.
In the most part of Europe once again, like in the summer and beginning of the autumn, it was substantially warmer than usual, although the average monthly air temperature anomalies became not so valuable, as during the previous months (+1…3°). The summer was continuing in the centre and east of the continent. Air temperature during the day reached +20…25°. In Germany, Poland, Czech, Montenegro, Baltic countries and Scandinavia, in Ukraine the new air temperature maximums were registered. At the same time, in the extreme west of the continent (north-west of Spain, Ireland, west areas of England and Scotland) the temperature conditions in month at the average became colder than usual.
The last month became cold for the North America countries. In Canada, this October became the coldest one over the last 10 years. Except the polar regions, everywhere the average monthly air temperature was below the norm – in the most part of the territory – by 2-3°, in some places – by 4° and more.
In US Great Plains and Rocky Mountains, the air during the month at the average was heated by 2-3° below the norm. It was warmer than usual in the Pacific coast and in the east of the country. In the last case, the average monthly air temperature was situated in the first ten of the highest values in the ranged row since 1891. Here the air was heated warmer the norm by 2-4°. Approximately the same anomalies are in Alaska, where the average monthly air temperature has the 2-3 rank amongst the highest values, succeeding only to October 2013.
The cold penetrated also to heat-loving Mexico. In the centre of the country, the average monthly air temperature is below the norm by 1-3°.
Abnormally warmth is kept in Arctic. The last September became the second warmest on the record. Only October two years ago was warmer. The positive anomalies of the average monthly air temperature took place almost in all territory of the Arctic area, except some areas in the north-east of Canada. In the west Arctic, the air was heated by 2-6°, in the east – by 4-10° above the norm.
The average monthly air temperature in the last October in the Northern Hemisphere repeated the record of October 2015 (with 0.1° accuracy).
In Moscow, the average monthly air temperature is +7.3°, anomaly is +2.2°. Although, according to the Muscovites appearances, the last October was very warm, as a matter of the fact, its average temperature did not come to the first ten of the highest values. But in XXI century this is the second warmest October after the October 2008 record. During the month, the daily air temperature maximums were registered twice.

Ocean Surface Temperature.

In the Pacific ocean, the rising of the SST anomaly of the Northern Hemisphere is continuing. In general, it is rising because of mid-latitudes and north latitudes, where the SST anomalies are more than 1°, in the polar latitudes – more than 2°. But, equatorial latitudes make their contribution, where in the east the abnormally warm water takes place. This, together with simultaneous decreasing of the Passat, could cause the new El Niño during the 1-2 months ahead.
In the Atlantic ocean, the average SST anomaly is kept at the previous months’ level. Abnormally warm water is being observed along North America coast, abnormally cold one – in the north latitudes from America to Europe, also partially in the centre of the ocean.
Noticeably above the norm is the water temperature along the Northern Sea Route. In Barents and Kara seas, East-Siberian and Chukchi seas it succeeds the norm by 1-2°.

Precipitation.

In the European territory of Russia, the precipitations prevailing over the norm was observed only in the north and south. In Komi republic, it has set more than 150%, in the south of Krasnodar district and Adygea republic – near 200% and more. Heavy rains inundated Kuban and Black sea coast in the third decade of the month. In Tuapse the two-month precipitations norm has fallen over the day, which caused electricity shortage, casualties were registered. Another peculiarity of October in ETR became unusually dry autumn weather in the second decade of the month. Majority of meteorological stations have “zero” precipitations in their decade records.
The Urals and Siberia have noticeably more precipitations in the national autonomous regions in the north, in the Far East, vice versa – in the south (Primorye and Amur area). Khakassia republic, Kemerovo, Irkutsk area and Kamchatka regions have precipitations less the norm. Heaviest showers fell in the end of the first decade in the south of Primorye.
It was dry in the most part of China and neighbouring Mongolia. Rains were only in the south provinces of the Celestial Empire. The same situation in Japan – it is dry in the most part of the country and rains in the southern islands. In the south of Korea the precipitations norms were exceeded in 1.5-2.0 times.
In the South-East Asia countries the monthly precipitations have set the norm and less the norm. Abundant rains fell in some places in Myanmar, Malaysia, south of Vietnam and Indonesia. In delta of Mekong and north of Sumatra, they caused the floods and casualties.
Indian monsoon has finished. In the most part of India, it was dry. Some rains fell only in the in the south of the country and neighbouring Sri-Lanka, where tens of thousands people suffered from the heavy rains. It was informed on human losses.
Mediterranean cyclones brought a lot of rains to the Middle East. Precipitations norms in the countries of this region were substantially exceeded. Some showers had a catastrophic character. In Jordan, the rain floods inundated the valleys and gorges in the east coast of the Dead Sea. Disaster caused the human losses.
In the African coast, the same cyclones inundated the Mediterranean countries coast, where the monthly precipitations sums in some places exceeded the norm in 1.5-2.0 times. Sub-Saharan countries have got a lot of rains. In Uganda, they caused the landslides with tens of human losses.
Mainly dry weather was in the Central Asia countries. The winter came here early. In the middle of the month, the snow covered Kazakhstan and Kirgizia.
In the Central Europe and Balkans, the month was dry. Here the precipitations have set only half of the monthly norm. But in the south of Spain, France, Italy the norms were exceeded in some places in 2.5-3.0 times and more. The rains actually inundated the most part of the Apennine Peninsula, Sicily, south departments of France. In Mallorca, they were named as “biblical flood”. The rains blocked the road traffic. The water level in the Venetian fleet reached the highest mark over the last 20 years. The raged disaster caused the huge damage to this touristic European centre.
Canada and USA became antipodes by the amount of the precipitations. In Canada, except Ontario and Quebec provinces, it was absence of precipitations, whereas the rains inundated the USA. The precipitations exceeding in 1.5-2.0 times was the routine phenomenon. Atmospheric precipitations sum, averaged in all country territory, has set the 6th highest value in the ranged row on the record, in some areas this range is even more. From Arizona, Utah, Louisiana and Arkansas in the south to both Dakotas and Michigan in the north such present amount of precipitations takes place approximately one time over the 20 years.
Mexico and the Central America countries have got a lot of rains. They caused numerous floods and torrents. The disaster destroyed the infrastructure and caused the numerous casualties.
In Moscow the monthly precipitations norm is 56mm, which is 95% of the norm. On 26 of October, a first snow fell in the capital, and first snow cover was formed on 30 of October.