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

 

Air temperature

June was abnormally warm in most parts of the Russian Federation. Only on Sakhalin Island, in the north of Primorye and the south of Kamchatka, partly in Kaliningrad, Pskov, Arkhangelsk Region and the Republic of Karelia mean monthly air temperature was a little lower than normal. In the rest of the country, it has exceeded the norm. In the Urals, western Siberia and the Lower Volga - by 4-6ºC. New temperature maxima during the month were many times recorded throughout the territory. On certain days in the Republic of Kalmykia, the Astrakhan Region and the eastern areas of the Volgograd and Saratov Regions the thermometer rose to the level of +40ºC and above. Also there was frost during the month, sometimes it comes up to new daily temperature minima. Thus, in the first decade of the month frosts happened in the north of the European territory, in Bashkiria, in the south of the Krasnoyarsk Territory, the Irkutsk region and the Trans-Baikal region, in the second decade - in the central region of Russia, and in the third decade - again on Sakhalin and in Trans-Baikal. Still the warm weather in June significantly prevailed over the cold the mean month temperature received the second rank among the highest values for this indicator yielded only by June 2012; the first half of the year was the warmest in the history of regular meteorological observations in the country.

Heat prevailed in Central Asia. This refers particularly to Turkmenistan, Uzbekistan and the Western Kazakhstan. Here, the monthly rate of temperature is exceeded by 4ºC and more. The weather in Ashgabat last June was the hottest in history; in the last day of the month the air heated to + 47.2ºC, which became the new absolute maximum temperature for the capital. More than thousand of lives were taken by the heat in southwestern Pakistan; the monsoon still have not reached this country. Thermometer for a long time held around the mark of + 45ºC.

In neighboring India, with the arrival of monsoon heat was gone, and the air temperature, which reached in May 45-48ºC, dropped by 10-15 points. Moreover last June in India almost all over the country turned out to be colder than normal, in some places by 1.5-2.0ºC.

The average temperature in China is the same as in the last June, i.e. the norm is slightly exceeded by less than 1ºC. In the north of the country, it was noticeably cooler than normal (anomaly to -1.5 ... -2.0ºC), and in the south the temperature was about of the same heat as in the neighboring countries of Southeast Asia. The temperature turned out to be higher than normal in Mongolia, Korea and Japan.

It was hot in the Middle East. In Iran, the mean monthly temperature anomalies were + 2 ... + 4ºC. In the Middle East, the situation was non-uniform. If in Arabia mean month air temperature warmed by 1-2ºC above normal, in the countries of the Mediterranean basin (Turkey, Syria, Jordan, Lebanon, Israel) it was cooler than usual; it was significantly cold in Turkey (anomaly to -2ºC).

In general the temperature was close to normal in most parts of North Africa. Only in northeastern Egypt it was cooler than usual, while in Central African countries (Niger, Chad, Burkina Fassa) in some areas it was hotter by 2ºC or more.

It was quite hot in the significant part of Europe, especially in its central and western areas. The temperature of 30º here was a common occurrence; in the traditionally hot Spain, Portugal and the south of France, the thermometer stayed above 40ºC. This is where the mean month air temperature exceeded the norm by 2ºC or more. At the same time in the north of the continent in the Scandinavian countries and parts of the UK, as well as in the south-east Greece last month turned out to be cool. In Trondheim (Northern Norway) anomaly -2.3ºC, Stockholm (Sweden) - -1.7ºC, Thessaloniki (Greece) - -1.3ºC.

In the US and Canada the month can be considered abnormally warm. Almost all over the country (US), except for the Northeast and parts of the Rocky Mountains, the average air temperature exceeded the norm. In the West, it is particularly noticeable (anomalies of + 2 ... + 5ºC). In Washington, on June 28 thermometer recorded temperature of + 44˚C. Nevertheless, in the north-east June turned out to be cool (an anomaly of -2.3ºC in Boston). The average air temperature throughout the country (except Alaska) entered the top five highest values in the history of meteorological observations, in Alaska it reached a new record. Moreover, in this state the record was set for the second month in a row.

In most parts of Canada the mean month temperature was above normal. The exception were Quebec, Newfoundland, southern Ontario and areas adjacent to the Davis Strait and Baffin Sea, where it was colder than usual by 1-2ºC.

The average temperature of the Arctic has 3-4 rank among the highest value. In Alaska and Chukotka, in northern Canada, Spitsbergen and Novaya Zemlya in the Barents and Kara Seas were noticeably warmer than usual (anomalies + 2ºC and more).

The average temperature in the hemisphere up to 0.1º repeated record achievement first established in June 2010 and then repeated twice in 2012 and 2014.

The first half of 2015 for the hemisphere was the warmest in the world history of meteorological observations.


The temperature of the ocean surface

The development of El Niño continues in the Pacific. Throughout the equatorial zone of the Western Hemisphere temperature anomalies on the ocean surface were over +1°C, in some places more than +2°C. The area of the waters in which sea surface temperature anomalies (SST) were over 1ºC, markedly increased. WMO reported that most of the models indicate further growth of SST and development of El Niño in the following months to the strong stage. Now the average surface temperature of the Pacific Ocean in the Northern Hemisphere is at the level preceding the El Niño of 1997-98, known as the most powerful El Niño in the XX century.

Large positive anomalies in the Pacific Ocean formed near the coast the United States, while in the west of Okhotsk, Japan, Yellow, East China Sea, as well as along the Kuroshio jet SST were below normal.

The average temperature of the surface of the Atlantic Ocean in the Northern Hemisphere was close to normal. Northern latitudes of the ocean are still occupied by large negative anomalies: especially in the area of Newfoundland, south of Greenland, Iceland and Baffin Bay. Temperatures in the Gulf Stream were above normal, however, the transfer of heat to the northeast seemed difficult.

Precipitation

In the most part of European Russia territory last June was very rainy. In the third decade rains hit the Central District. In Lipetsk, Tambov, Ryazan, Moscow, Belgorod, Kursk, Voronezh, Vladimir, Ivanovo, Tver, Yaroslavl regions it fell  from one-third to half of the monthly norm of precipitation per day or less. Cities and towns were flooded. New daily highs were established. In Lipetsk, Tambov, Ryazan, and Vladimir regions in the past month more than 2 norms of precipitation fell. The cyclone that hit central Russia, at first raged in the south of the country. In Sochi within 12 hours fell almost 180mm of precipitation when the monthly rate is about 100mm, and per day - 212mm, which is a new record. In the Krasnodar Territory and the Republic of Adygea monthly precipitation exceeded the norm by 1.5 times. The north of European Russia was marked by heavy rains. In the Komi Republic, the Nenets Autonomous Okrug and Arkhangelsk region total precipitation for the month amounted to 1.5-2.0 standards and more. In the Volga Federal District in the northern regions the norm of precipitation was reached, and sometimes it was more, while in the East - only about 50% of it or less.

In Ural precipitation was normal in general and sometimes higher. The latter refers to the Yamal-Nenets and Khanty-Mansi Autonomous District, where the rainy cyclones have caused the river level rise to 90 cm per day, which caused massive flooding, the strongest over the past 10 years. In Siberia, a lot of precipitation was only on the Taimyr Peninsula (up to 2 standards, and more), and the further south it became less and less. In the Kemerovo region, Republic of Khakassia, Tuva, Buryatia the precipitation amount for the month reached to only about half of the monthly norm. In the north of the Far East (Chukotka Autonomous District, Kamchatka region) precipitation was about 1.5 times more than the norm, and the rest of the approximately normal, except for the northern regions of the Khabarovsk Territory, where it was not enough.

In Primorye and Sakhalin "rainy season"came. For a day or two in some places it fell by half to the monthly norm of precipitation. In Sakhalin sometimes it was wet snow.

The northern branch of the Asian monsoon has covered not only the Russian Far East, but also China and Japan. In the north-eastern China rainfall exceeded the monthly norm by 2-3 times. In the center of the country in Hubei province and in the south in Guangdong province houses of thousands of people were flooded. A similar pattern can be seen in Japan, especially in the south, where the island of Kyushu, received more than 200mm of rain per day. Only Korea was bypassed by the rainwater front. Here, precipitation was significantly less than normal. The media reported that North Korea is experiencing the severes drought in the past 100 years. In the south-eastern branch of the Asian monsoon the rainfall fell about the norm, just to the north of Thailand it was approximately 1.5-2.0 times more than usual.

On the territory of India the monsoon was coming very active. Pausing in the beginning, by the end of the month it covered the entire country, as well as Nepal, northern and central regions of Pakistan. In many places rainfall exceeded the norm by 2-4 times. Only the south-east of Pakistan, where monsoon has not arrived, it was still extremely hot and dry. As usual at this time of year the weather was dry in most parts of the Middle East and the Central Asian republics. Only Turkey and the countries of the South Caucasus had a lot of rains. In Turkey, their amount sometimes exceeded the norm by 2-3 times. Heavy rain that hit Tbilisi on June 14 caused the most severe floods in the past 50 years, the cause of which was a landslide blocked the river.

In most of Europe, there was little rain. Their amount for the month, as a rule, do not exceed half of the norm. Only in the north in the Scandinavian countries, they amounted the norm, while in Greece, the Balkans and part of the north-eastern Spain they have exceeded it (sometimes 2-3 times).

Dry weather prevailed in Africa, only in the Sahel and Gulf of Guinea there were rains that totaled the monthly norm of precipitation.

In the US in June, there were a lot of rains. Except for the western states, they amounted around normal or exceeded it. In some areas. the excess was 2-3 times. The latter particularly applies to the northeast of the country. In the capital, Washington, fell 3.5 norms of precipitation. In the West, the in the states of the Pacific coast of Washington, Oregon and California there were areas without rain.

In the central and western provinces of Canada it was mostly dry. In the east, total precipitation for the month amounted approximately the norm and in the north in the Arctic in some places, it significantly exceeded the norm (2 times or more).
Many precipitations went to Mexico. In the central and northern areas of the country, their amount exceeded the norm by 2-3 times.

In Moscow in the past month fell 93mm of rainfall, which is 124% of norm. With the result of June 2015, the month entered the top ten most "wet" Junes since 1891. During the month, rainfall fell unevenly. For example, more than 40% of monthly norm fell in one day.

Atmospheric Circulation

In the upper stratosphere (at the level of AT-10) in June continued strengthening of the stratospheric anticyclone centered over the north pole. It reached maximum intensity in the third decade, and this intensity was close to normal.

In the equatorial stratosphere winds persisted eastern phase of quasi-biennial cycle with a tendency to weaken.

In the middle troposphere (at the level of AT-500) in in the past month positive anomalies dominated at the averaging field of geopotential. The most intensive tropospheric ridges in early June formed over Europe and Western Siberia, in the second decade - over the north Pacific Ocean, the Atlantic and Western Siberia, in the third - on the west of Europe, Urals, Western Siberia, the Pacific and western of the North America. As a result, the mean monthly anomalies of geopotential to + 7 ... + 8 dam were mentioned over Europe, +9 dam over the Urals, +11 dam over Western Siberia and the North Pacific Ocean, + 4 ... + 7 dam over western part of North America and western Atlantic. Enhanced geopotential was in the Canadian Arctic (anomalies to +8 dam), in which during the first two decades of June ridges continually extended through the North American and Pacific. In connection with this, polar vortex was significantly deformed, on average for the month all its centers turned out to be shifted relatively to their climatic situation. The main circumpolar center was also bifurcated: one of his focus has shifted to the north of Scandinavia (anomalies to -9 dam), the other - to the area of the East Siberian Sea (anomalies -2 -3 dam). Their intensity was normal. Bifurcated and weakened was the center, which normally resides over the Bering Sea: geopotential anomalies of over Kamchatka amounted +3 dam, and over the Gulf of Alaska - +6 dam. Canadian Centre from Ellesmere Island shifted to the Labrador Peninsula (anomalies to -2 dam). The related to him tropospheric troughs had normal position and depth. The exceptions were parts of Western Siberia and the North Pacific, where the troughs were substantially weakened and deformed. Their removal promoted the formation of negative anomalies of geopotential in the Kuril Islands (-5 dam) and in the central subtropical Pacific (-3 dam). Unusual for June active cyclogenesis in the eastern Mediterranean, because of which anomalies of geopotential amounted here -4 dam, also should be noted.

The position of the planetary high-altitude frontal zone over North America and the Atlantic almost corresponded to the climate norm; over Europe, it was located slightly to the south from normal position. Over Siberia and the Pacific Ocean, the position of the planetary high-altitude frontal zone was completely abnormal. In West Siberia, its deviation to the north was about 8°C. Sharp and frequent changes in position of planetary high-altitude frontal zone over the Russian Far East and the Pacific Ocean led to its constant breaks. Therefore, during a significant general deviation to the north (more than 15°C) planetary high-altitude frontal zone at the Kuril Islands often located to the south of the usual, and in the Gulf of Alaska was almost at the normal position.

Zonal and meridional circulation indices in the whole hemisphere was not much different from the climate. However, in the I NSR the zonal transfer was slightly disturbed: in the higher latitudes, it was 20% more intense than usual, and in moderate - 26% attenuated. Meridional transfer was noticeably different from the norm only in the high latitudes of the II and III NSR, where the indices was above the norm by 31% and 23%, respectively.

In the averaged for the month Atlantic steam surface pressure field atmospheric centers of action looked quite traditional. Both centers had normal position. It is possible to mention higher than normal in June intensity of the Azores maximum: at the southern periphery of the anticyclone pressure anomalies amounted +3 hPa. Throughout the month the northeast ridge were active, it influenced the central and in the northwestern regions of Europe, where pressure anomalies amounted + 3 ... + 4 hPa. Quite often ridges combined with continental anticyclone that regularly formed over the Urals and Western Siberia (anomalies of +1 to +4 hPa). A vast area of high pressure forced the Atlantic cyclones move eastward through the north of Eurasia and the Arctic seas (anomalies of -3 to -8 hPa). Therefore on mean monthly map formed quite unusual for this time deep cyclone over the Barents Sea, and the pressure anomalies in northern Scandinavia reached -8 hPa. Moving eastward cyclones have caused negative pressure anomalies in the northern part of Yakutia (-3 hPa), and over adjacent Arctic seas (-5 hPa). Troughs of Atlantic cyclones often had an impact on European Russia, therefore the background of pressure there a little lowered. Another area of cyclonic activity in the past June was the eastern Mediterranean (anomalies to -2 hPa). By shifting to the east fronts with waves caused pressure anomalies to -7 hPa over the Caspian Sea and to -4 hPa over Central Asia. The excess of rainfall was noted in the Balkans, Turkey, eastern Ukraine, the Caucasus and in the Krasnodar region, as well as in some parts of Central Asia.

Asian seasonal minimum fully appeared at the June map. One of its centers, the Manchurian one, had its normal position and depth. Active cyclones transported from the northern China and southern polar frontal waves and cyclones contributed to its formation. Hainan center of Asian low, dislocated to the south of China, turned out to be deeper than usual. Therefore monsoon over Southeast Asia moved actively, causing heavy rains in southern and eastern China and southern Japan.

Monsoon depression in position and depth fully conform to the standards. Negative pressure anomalies over Oman (-4 hPA) was associated with the impact of a tropical cyclone. The Indian monsoon was advancing very unevenly. Over the Bay of Bengal, it initially lagged climatic terms, while over the Arabian Sea moved faster pace. In mid-June, its movement stopped, but at the beginning of the third decade it resumed, until June 26, the entire territory of India was under the rain, including its northwestern regions and eastern Pakistan, where monsoon usually arrives in mid-July.

Hawaiian anticyclone dominated in the Pacific pair of atmospheric centers of action in June. An extensive in size, it influence vast areas. Its western ridges reached southern Japanese islands (pressure anomalies +3 hPa), northern formed anticyclones over the Bering Sea (anomalies 7 hPa), northeastern and eastern determined the weather in the western half of North America (anomalies to +3 hPa), where June was very dry and hot. Especially large temperature anomalies were observed in the northwest of the United States and southwest Canada: Aleutian Low was dramatically weakened and appear on the map in the form of mean monthly small throughs over Alaska. Pacific cyclones moved north than usual (mainly in Canada), the negative pressure anomalies to -3 hPa in the eastern half of Canada and the cyclonic center on the mean monthly map over Hudson Bay were an evidence of this activity. The central and eastern United States were regularly influenced by their fronts: there were heavy rains. A large amount of rainfall was also associated with the passage of ex-tropical cyclone in the southern and eastern states.

In the tropical zone of the northern hemisphere tropical occurred 6 cyclones at a normal rate of 4.8.

Two cyclones formed in the western Pacific (norm for 4.7). Cyclones were not intense. One of them was on Hainan Island and then went out on the coast of Vietnam, without causing serious damage.

There were 2 cyclones in the northeast Pacific (norm for 2.0). Both reached the stage of a hurricane, and one of them, "Blanca" - the stage of super-hurricane (Pmin = 943 hPa, vmax = 60 m / s, gusts up to 75 m / s). Their path took place near the Mexican coast, but in both cases cyclones weakened before landfall and did not cause great damage.

A cyclone formed in the Gulf of Mexico near the coast of Texas (the norm for Atlantic 0.6). Despite the short existence, it had managed to develop to the stage of a strong tropical storm that hit the coast with heavy rains.

There was a tropical cyclone in the north of the Indian Ocean (the Arabian Sea) in June (norm for 0.5). Cyclone was pretty weak and collapsed before reaching the coast of Oman. Nevertheless, on June 11 in Oman dropped 200mm of rainfall per day.

However, the most unusual was the tropical cyclone in the southern hemisphere, which arose on June 30 to the east of the Solomon Islands. For 45 years of observations of tropical cyclones - it's only the fourth event of the cyclone in the South Pacific in June. Its wind speed did not exceed 20 m / s, so it was not dangerous for the islands.