MAIN WEATHER AND CLIMATE TRAITS IN THE NORTHEN HEMISPHERE AS OF JULY 2020
Air temperature
Air temperature
With the beginning of July, the heat in the ETR intensified and spread as far as the Urals and the coast of the Kara Sea in the north. The anomalies of decade-averaged temperature were +2-3° in the central region, +4-5° in the south and +5-8° in the north. New daily temperature maxima were recorded in the Volga Region, in the Urals and in the Rostov, Volgograd and Lipetsk Regions. The air heated up to +40° or above in places. The decade-averaged air temperatures were close to normal in the west of the ETR only including Karelia and the Leningrad, Pskov and Novgorod Regions. The weather became colder in the second decade, and the decade-averaged air temperatures returned to their normal values over the most part of the ETR already. The anomalous heat solely survived in the south, in the Volga Region and in the Urals. Hot air fluxes from the Western Kazakhstan resulted in record-breaking temperatures in the Middle and Southern Urals where the thermometer readings rose above +40° sometimes. In Orenburg, a new absolute maximum of air temperature in July was set. The temperatures in the Sverdlovsk and Orenburg Regions and in Bashkiria remained extreme for 5-7 days in succession. There, the average air temperature in the second decade was 6-8° above the normal value. The weather grew colder in the third decade. The average air temperature in the centre and the west of the ETR was subnormal. New daily temperature minima were recorded in the Pskov, Yaroslavl, Tula, Ryazan and Tambov Regions. The anomalous warmth remained solely in the south and along the coasts of the Barents and Kara Seas. Yet, considering the overall monthly figures, the air temperatures in the South, Volga and Western Ural Federal Districts were 2-4 or more degrees above the normal values. In the rest of the ETR, they were approximately normal, and in the Leningrad, Pskov and partly Novgorod Regions, lower than that. In the Volga Region, this July was the fourth warmest in the history of meteorological observations.
The monthly-averaged air temperature in most of Siberia was close to normal. Only in the central regions of the Krasnoyarsk Territory, this value was somewhat lower than the normal one: cold weather prevailed there for most of July. The anomalies of decade-averaged air temperatures in the second and third decades reached -2° or more.
The weather in the Far East was very varied. Even though the air temperature averaged for the month over the whole territory excluding the northern areas of Sakhalin was above-normal (notably, by 2° or more in Yakutia and Trans-Baikal), the waves of heat and cold often replaced one another. For example, on some days, new daily temperature maxima above +35° were set in Yakutia, but on other days, new record-breaking minima provided an early evidence of real light frosts (down to -2°). A similar picture was observed in Chukotka, in the Magadan Region and in the Khabarovsk Territory. Everywhere from Chukotka to Primorye, unprecedented colds were swapping with unprecedented heats of up to +30° or more.
Regarding Russia as a whole, the averaged temperature in this July is the fifth highest recorded in the history of meteorological observations, but is still much lower than the one during the unrivalled heat in July 2010.
In Mongolia and north-eastern China, the month was 2-3° warmer than usual, whereas in the east of China, colder than that. In Taiwan, the temperature above +36° persisted for 17 days in a row. In South Korea and Japan, the air temperature was slightly below its normal value, although the thermometer readings exceeded +30° on some days.
In South-East Asia, the air temperature was 1-3° above the normal value.
Roughly the same anomalies were observed in India and Pakistan.
The heat reigned in the Near and Middle East. From the Levant to Iran, the monthly-averaged air temperature was higher than normal by 2-4° or more, and the thermometers indicated 40 or more degrees sometimes.
In Central Asia, the weather was also hot. The average temperature was two or more degrees above the normal value in Kazakhstan, Uzbekistan and Turkmenistan, and four or more degrees above it in the west of Kazakhstan. Numerous daily temperature maxima were recorded.
In North Africa, the air temperature was normal in general, with the only exceptions of Algeria, Morocco, Tunisia and Egypt where it exceeded the normal value by 2-3° and more.
In most of Europe, the weather remained hot during July, and new daily temperature maxima were recorded in many countries. The thermometer readings often crossed the 40° mark. Importantly, the record-breaking values pertained not to the daylight periods alone, but to the night hours as well. The monthly-averaged temperature was 2-3° above the normal value in the Iberian Peninsula, in the south of France and in Ukraine. The abnormal cold came to the north of the continent only (Scandinavian countries) where the air breakthroughs to its east and west originated occasionally to result in new daily temperature minima in a number of countries (Czech Republic, Serbia and France).
The weather in Canada was very warm, especially in the east of the country where the monthly-averaged air temperature was 2-4° above the normal value and on the Arctic islands where it was six or more degrees above it. In the west of the country, the temperatures were close to normal or even slightly lower in places, but the eastern heat was still stronger than the cold, and July 2020 in Canada became the second warmest in the history of meteorological observations, yielding to July 2012 only. This month was also warm in the USA: its monthly-averaged temperature entered the Top Ten of the highest July values in the entire meteorological chronicle. The weather was especially hot in the east of the country where the anomalies exceeded 2-4°; in New England, this July was the hottest in history. In the south-east of the country (Arizona, New Mexico, Utah, Colorado), the temperature was also noticeably higher than normal (by 2° or more), and its monthly-averaged value was ranked the third highest in the meteorological records. The air temperature in neighbouring Mexico was also above-normal, remarkably in the south where the normal value was exceeded by 2° or more.
In the Arctic, the record-breaking monthly-averaged air temperature of July 2016 was observed again. On Svalbard Islands, the absolute maximum air temperature equal to +21.7° was recorded. The sea ice in the Arctic started rapidly melting due to very warm weather, and its area shrank to the minimum less then ever recorded for this month in all satellite observations in this region. The previous minimum was observed in July of the last year.
In Moscow, the average air temperature was +18.7° demonstrating an anomaly of +0.5°.
Ocean Surface Temperature
The surface of the World Ocean in the Northern Hemisphere heated up to extreme values. The average July temperature reached an absolute maximum in the Pacific Ocean, and became the second highest after July 2003 and July 2005 in the Atlantic Ocean.
In the Pacific, the above maximum was recorded against the background of negative anomalies in the equatorial belt which were precursors of a new La Niña (cold episode of the Southern Oscillation). Almost all the remaining surface of the Ocean excluding minor water bodies in the Sea of Okhotsk, Sea of Japan and Yellow Sea or in the central parts of the Pacific was occupied by positive anomalies higher than +2…3° or more over a large area.
In the Atlantic, the area of positive anomalies was smaller but significantly larger than that of negative ones now traditionally present at the temperate latitudes of the Ocean. High positive anomalies took place along the coast of the USA and Canada, as well as in the north – in the Norwegian and Greenland Seas and further eastward in the Barents and Kara Seas where they exceeded +4…5° and more. Abnormally warm water was observed in the Black Sea and in the west of the Mediterranean Sea.
Precipitation
In the ETR, certain territories were distinguished by larger precipitation amounts, specifically, in the north, north-west and south. But everywhere between, the weather was basically dry all July. In the North-West Federal District, the precipitation was generally normal, but increased by 1.5 or more times in the Arkhangelsk and Vologda Regions and in the Republic of Karelia. In the Central Federal District, the situation was similar: 1.5 or more times the normal precipitation amounts in the Tver, Yaroslavl and Smolensk Regions, but little rain to the south of Moscow – less than half the normal total in the Lipetsk and Tambov Regions. The Volga Federal District followed the same pattern with much precipitation in the north, viz., the Republics of Udmurtia and Mari El, and quite small quantities in the southern regions. In the south of the ETR, the normal precipitation total was only achieved in the Krasnodar and Stavropol Territories and in the Republics of Crimea and Dagestan, while in the remaining territories, the precipitation was scarce. From time to time, rains were very intense. For example, as much as 105 mm of celestial moisture, which is almost the normal monthly total, poured down for 2.5 hours in Tuapse, or for a single day in some regions of Crimea. These rains caused flooding in Rostov-on-Don. Heavy showers took place in the Krasnodar and Stavropol Territories. In the north of the ETR, rains were also very abundant in places. The normal monthly precipitation amount was exceeded for just one night in some districts of the Moscow Region, and up to half the monthly quantity of rainwater accumulated for twelve hours in the suburbs of Saint-Petersburg.
In the Urals, the precipitation was scarce everywhere save for the south of the Chelyabinsk Region and the north of the Yamalo-Nenets Autonomous District where it reached the normal monthly value. Normal or increased precipitation quantities were recorded in a significant part of the Siberian Federal District. Showers in the Republic of Tyva caused floods that destroyed residential buildings and bridges, and swamped roads. The Altai Territory still suffered from the lack of moisture. Agrarians remarked on co-existing soil and atmospheric droughts and on developing dry winds. Such progressing of these three natural phenomena at the same time had not been observed for years in the previous droughts. In the Far Eastern Federal District, the precipitation amount was normal in Trans-Baikal and Yakutia, in the Amur River Region, and partially in Kamchatka and the Khabarovsk Territory. Very few rains came to the rest of the Far East. Heavy downpours (in excess of 20 mm of rainwater per day) occurred in Yakutia: in its centre and along the lower courses of the Lena River.
The whole month was rainy in the east of Asia. Heavy showers flooded the Yangtze River Valley. The river level in some places rose to critical heights. The epicentre of the natural disaster was in the provinces of Anhui, Hunan and Hubei. Certain meteorological stations reported the values three or even five times greater than the normal monthly amount of precipitation. No such quantities of rainwater have been seen for the past sixty years here. The Yunnan province in the south-west of China was also afflicted by showers. According to the Ministry of Emergency Situations, floods affected about 38 million people, and almost 140 of them died. More than 500 cultural heritage sites were destroyed or damaged in the Yangtze Delta. At the same time, almost no rains were observed in the north of China in the areas bordering Mongolia, Russia and Kazakhstan. White flakes flew from the sky during thunderstorms. In fact, a very rare natural phenomenon was observed – a soft fluffy hail called the graupel.
At the same time, rains flooded Kyushu, the island in the south of Japan. According to the Japan Meteorological Agency, such a large amount of precipitation has not been seen there before. Up to 100 mm of rainwater could fell per hour, 400-500 mm per day, and more than 1000 mm per week. Rivers overflowed their banks and destroyed roads, houses and bridges. More than 50 people were killed, and more than 300 thousand residents were evacuated.
Showers pounced upon South Korea. The streets in its southern city of Busan became turbulent rivers with water levels reaching 2.5 m. For a day and a half, 202 mm of rainwater poured out there, given the normal monthly rate of 130 mm.
In South-East Asia, rains were rare in Vietnam, Laos, Cambodia and Thailand. On the other hand, they were abundant in Myanmar, Indonesia and Malaysia. Intensive showers on the island of Sulawesi (Indonesia) caused flooding which was quite unexpected because the weather is usually dry at this time of year. The height of flood waters in various places reached one to four metres. Houses and roads were inundated by mudflows. Fatalities were reported. On the Malacca Peninsula in Malaysia, scores of settlements sank under water.
India was deluged by monsoon showers. Here and there, daily rainwater topped 100 mm, reaching 434 mm, which is above the normal monthly value, in the state of Gujarat). The precipitation totals were either normal or above-normal almost everywhere in the country. The neighbouring Republic of Bangladesh also suffered from rains, and was hurt by showers that were most strong for the past ten years and affected more than 1.5 million people. Intense rains that continued for a week in Nepal led to landslides and floods destroying houses and roads, and killing more than 50 humans. Rains were surprisingly rare in Pakistan. Monsoon showers in the Indian subcontinent occur from June to September each year, and have a significant impact on the life of population. This year, rains in the past two month of the monsoon were especially plentiful. In the Indian city of Mumbai, this July became the rainiest in the history of observations: rains did not stop for a single day. The monthly precipitation total was almost 1,500 mm, nearly two times higher than the normal value.
In the Near and Middle East, it was dry as it should at this time of year. Yet, occasional showers did take place there. Heavy mid-July rains in the north-west of Iran and in Armenia resulted in floods that forced many residents to leave their homes and caused temporary blackouts. In Georgia, driving rain at the end of the month triggered flooding and raised the water level in rivers by two metres. Water inundated roads and destructed bridges.
In the northern regions of Kazakhstan, a lot of precipitation was observed: in some places, the total monthly figures were 2-3 or more times higher than normal. Further to the south, and in the other countries of Central Asia, a lack of rains was perceived. On the last day of the month, pouring rains hit Afghanistan, targeting its central regions. Fatalities and injuries were reported.
In most of North Africa, the weather was dry. Rains were observed to the south of Sahara only: there, the normal precipitation amounts were exceeded by 1.5-2.0 times or more in places. Showers in Niger caused a devastating flood that affected over 20 thousand people.
Most of Europe was in arid conditions this July, with rains chiefly resorted to the east and the north of the continent where their monthly rate was about normal or higher. Heavy showers led to floods in Romania, and new maxima of daily precipitation were recorded in Moldova. Torrential rains descended upon Sicily where the normal annual precipitation amount of 611 mm in Palermo was gained just in two hours. Roads turned into rivers, tunnels were flooded, and casualties were reported. Local authorities claimed that no such precipitation had been seen for the entire period of observations, i.e., since 1790. Hot weather with no rains caused fires in the south of France.
In most of Canada, in the east and the centre of the USA and in the north of Mexico, the monthly precipitation totals were normal or exceeded, e.g., by 2-3 times in Kansas and Oklahoma in the US. The weather was altogether dry in the west of the USA. From Washington and Montana to California and Arizona, the monthly rainwater added up to few millimetres, or was not present at all in some places. Fires were observed in California. Snow fell in the mountains of Wyoming on the first day of July.
In Moscow, 170 mm of rain, i.e., 226% of the normal value, was recorded in July. This was the third wettest July in the entire history of observations in the capital: more precipitation was observed in July 1965 and July 2008 only. The normal monthly total was surpassed by the middle of the month already. The quantity of atmospheric moisture accumulated from January to July was as large as 657 mm – only 34 mm less than the annual normal value – with usually wet autumn still ahead. Hence, much more precipitation than normal should fall in Moscow this year.