The key weather and climate features in the northern hemisphere in October 2015

Air temperature

Last October was memorable with the abnormally cold weather in the European part of Russia. A record cold was registered in Ryazan, Lipetsk, Tambov, Belgorod, Kursk, Smolensk, in the Volga region and the Stavropol Territory. During any decade, and in general for the month, the average monthly air temperature was below the norm (in the Perm region - approximately  by 2ºC). In European Russia so cool October is no longer an uncommon thing. At about the same cold it was in the previous year. Over 15 years of 21 century, 3 Octobers were among the ten coldest in the past 125 years of weather observations.

Warm weather prevailed most part of the month beyond the Urals. In the first decade in the Irkutsk, Kemerovo, Novosibirsk, Altai Territory, the Altai Mountains and the Republic of Tuva new temperature maximums were recorded. The same thing happened in the north of Yakutia and Chukotka.  In the south of Siberia, the Trans-Baikal Territory and along the Arctic coast of Russia the October temperature norm was considerably exceeded. In Chukotka, Taimyr and Arctic islands - by 4-6ºC. However, on some days severe frosts occurred in the Polar Urals and the lower reaches of the Ob River. Thermometer drops below -20ºC, in Yakutia below -30ºC.

In Eastern Europe, after a long and hot summer hosting here in September came the abnormally cold weather. In Belarus and Latvia was recorded new minimums. Some of them came close to the mark of -10ºC. In Poland and in eastern Germany anomalies of mean monthly temperature -1.0 ºC ... -1.5ºC. In Western Europe, the September cold even more intensified. In France and the Benelux countries, in the daytime it was only about + 5ºC, which is almost 12-15ºC below the norms usual for this time of year. However, in the south of the continent, the weather matched the norm, and further southwards in Africa the heat even prevailed. Across the African continent over the last month, the average temperature was above normal. In Algeria, Tunisia, Morocco, Mauritania, Mali - sometimes by about 2ºC.

Even larger anomalies were in Egypt and throughout the Middle East. Here they reach + 3ºC, while in Saudi Arabia and the Gulf countries - + 4ºC.

In the north of the Central Asia in Kazakhstan last month it was cooler than usual, and in the south of the Central Asian republics and Afghanistan still remained abnormally warm weather, which did not prevent, however, the frost to -1 ... -3ºC to appear in Tajikistan.

A few above-normal temperature was in South Asia, Indochina and China. In some places the norm was exceeded by 2ºC or more. This primarily refers to the southern areas of Pakistan, Central India, Mongolia and eastern provinces of China. Record heat prevailed in Indonesia. The absolute maximum temperature in the country was repeated.

In Canada, the average temperature was generally close to normal. In the east of the country in the provinces of Quebec,

Ontario and Labrador it was slightly less than it (by 1.5-2.0 °C), and in the west and north – even more. This is especially noticeable in the Polar Regions, where the norm was exceeded by 2-4°C.

Abnormally warm was in the United States. Except for the northeastern states, where in general over the last month was colder than usual (in Washington anomaly -0.7°C), the rest of the country was dominated by heat. In the west, in the states of Washington, Oregon, California, Arizona, Texas last October was warmer than usual by 3-4°C. Even larger anomalies (up to + 4 ... 5°C) were in Alaska. The average temperature for the month in the United States came in the top five highest values for the entire period of meteorological observations. Such a warm October in the country was not seen since 1963.

Higher than normal temperatures were in Mexico. In the north of the country anomaly up to +2 ... 4°C.

Arctic remains abnormally warm. Norm temperature was exceeded here by an average of 3.5°C, and in some areas, as already mentioned, by 4-6°C (polar territory of Russia and Canada, and Alaska).

In equatorial latitudes of the Pacific Ocean, where abnormally warm underlying surface formed because of El Niño, there were large positive anomalies of air temperatures exceeding 2°C.

Last October in the Northern Hemisphere wa the warmest in the entire 125-year history of meteorological observations in the world, so as the entire 10-month period in 2015.

In Moscow, the average temperature for the month + 4.4°C, anomaly of -0.7°C.

The temperature of the ocean surface

In the Pacific, strengthening of El Niño continued. The anomalies of sea surface temperature (SST) in the equatorial and tropical latitudes constitute +2 ... 3°C. The average value of the surface temperature of the Pacific Ocean in the Northern Hemisphere has reached the absolute maximum for October. At almost all the waters from the equator to the Bering Sea monthly average SST was higher than normal, and only in the west of the temperate latitudes in the Yellow, Japan, Sea of Okhotsk and east of Japan in October were negative SST anomaly.

The average value of surface temperature anomalies of the Atlantic Ocean in the Northern Hemisphere remained at level of last month. Still above the normal temperature of the water was in the Gulf Stream. In polar latitudes along the coast of

Scandinavia and the southern Barents Sea ocean surface warmed by about 1.0 - 1.5°C above normal.

Very warm water was observed in the resorts of the Eastern Mediterranean. It was by 1-2°C higher than normal.

Precipitation

The northern and central regions of European Russia, in October received less rainfall than they had to. In Novgorod, Pskov, Tver, Moscow, Vladimir, Smolensk, Belgorod region there was only one-fifth of the norm, and in other regions of the federation about a half or a little more. So dry October in Central Russia appeared for the third consecutive year. In the east of European Russia in the Volga Federal District the norm of precipitation was reached, and in the republics of Tatarstan and Bashkortostan, the Perm region, Samara and Saratov region - even 1.5-2.0 of the norm. In the Southern, North-Caucasian and Crimean Federal District total precipitation for the month exceeded the norm 1.5-2.5 times, and only in the Astrakhan Region and the Republic of Kalmykia there were a few of it - about a half of the norm. The cold weather has led to the snow in the early month in the Middle Volga. In the Saratov region, first snow fell on October 8, which is a new early record for this phenomenon. The snow was so abundant that the thickness of the white curtain in some places reached 10 cm.

In the Urals and Western Siberia was norm of precipitation and more, whereas in the south of Siberia in the Altai, Khakassia, Tuva, as well as in the territories around the Baikal Lake there were a few of them.

Kamchatka and Sakhalin, Primorsky and Khabarovsk Territory and Amur region received 1.5-2.0 times more than the norm of rainfall, only Chukotka has been deprived of them.

In China, the amount of precipitation in October mostly conform to the norms. Only to the north along the Mongolian border and in Tibet, there were few of them. The same pattern occurred in Mongolia and Japan.

In Southeast Asia for the norm of rainfall was accounted. Some days bring to Thailand, Vietnam and Malaysia to 50-70mm of rainfall. It was quite dry in Indonesia, which is common during the development of El Niño.

In India, where monsoon has ended, was dry weather. Only in the extreme south of the country and in the neighboring Ceylon rains continued. Mostly their intensity reached 90 mm in an hour. Heavy rains have passed from the north of India to Pakistan. In the capital Islamabad, in a day has dropped 122mm of precipitation, which is 4 times higher than the monthly norm. In some parts of the country were observed landslides and mudflows.

A similar pattern was in Afghanistan and in the south of Central Asia. There rainfall was exceeded by 2-3 times. In Tashkent in the past month fell 89mm of precipitation at norm of 34mm. The rest of the territory of Central Asia got about norm of precipitation, and only in northern Kazakhstan, there were few of them.

As usual, the dry Middle East last October got excessively much rain. From the Mediterranean to the Caucasus and from Iran to Oman, it actively poured the land. Norms of precipitation there were exceeded by 2-4 times. In Yerevan, the norm exceeded by 3.5, in Lenkoran – by 2, in Eilat – by 2.5, in a number of cities Iran - by 1.5, and in Saudi Arabia and Oman - by 2-3 times. Downpours led to numerous destruction of infrastructure and loss of life of in these countries. In the mountains the first snow fell.

The Mediterranean coast of Africa received rainfall sufficiently. Heavy rains were observed in the popular resorts of Egypt. The Sahara was almost out of precipitation. However, to the south of it, the rains prepared the ground very well for future harvests. In Senegal, Guinea, southern Mali, Burkina-Fassi, Nigeria, Sudan, monthly norm of precipitation was exceeded by 2-4 times.

In southern Europe, the rains in October were a common thing. Earlier this month they hit the Western Mediterranean. For the exceptional intensity of their, they were named tropical storms. During the day, it dropped out up to 300 mm of precipitation and more. In Cannes, in an hour recorded 107mm of rain, and in 3 hours - 174mm. Rains of such intensity was not mentioned there from the middle of the last century. Hundreds of people lost their homes. The amounts of precipitation in the past month closed the norm by 2-3 times. In the middle of the month, the rains hit Italy and the Balkan countries. Rivers burst their banks, numerous buildings were flooded and roads washed away, thousands of residents were evacuated. Landslides were registered not only in rural areas but also in major cities, including Rome. For a month in these areas dropped to 2.5-3.0 of the norm. At the same time, heavy rains struck the south of Portugal and Spain. There the total precipitation for the month amounted to 1.5-2.5 norm. And finally, at the end of the month, it affected Greece. In a matter of hours 170mm of rain fell down. Rivers washed away houses and bridges, destroyed roads. There monthly norm of rainfall was exceeded 1.5-2.0 times. In the rest of Europe, it was mostly dry and only in Germany the rainfall was close to norm.

The United States has got a lot of atmospheric moisture. With the exception of the Pacific coast precipitation was about the norm and more. And this "more" is increasing from north to south, in the states of Kansas, Colorado, New Mexico, Texas, Louisiana, Mississippi, it totaled 2-4 norm. However, especially South Carolina was poured, where the monthly norm was exceeded by more than 4 times. The state was declared a zone of disaster.

In most of Canada, precipitation was normal. Only in the west to British Columbia and in the east at Labrador and in the area of Hudson Bay they have accumulated over the last month less than 50% of the norm. Although the winter is far in southern Canada, the residents of Toronto, Montreal, Ontario, Quebec in the middle of the month witnessed a heavy snowfall. The thickness of the snow cover sometimes reached 10 cm.

Heavy rains in October have fallen in the Mexico and the countries of Central America. They have caused landslides, which severely disrupted traffic and business activities in these countries. In Mexico, the total precipitation for the month exceeded the norm by 1.5-2.5, and Guatemala - by 2 times.

In Moscow in the past month fell 21.0 mm of rainfall, which is 35% of the norm. Such dry in the capital in October for the last time was seen 30 years ago.