World Extremes & Global Round-up APRIL 2012
Posted 05 May 2012 - 10:25
April 2012 - Record heat in Central and Eastern Europe
Central and Eastern Europe had record high temperatures at the end of the month, which was hot, even extending to north-western Asia and much of the Arctic. In the eastern United States the month was not as warm as the previous and the Antarctic was cold.
Parts of western Europe and Scandinavia were generally slightly colder than normal in April while it was warmer to the east. Pressure distribution with low air pressure over the UK pushed the warm air to the east of it and the cooler air swept down the west. Britain had its wettest April since records began in 1910 and most of the precipitation fell in the south. The month was on average cooler than March, which was the first time since 1998. It was also the first time since 1998 that Norway had on average slightly lower temperature than normal. It was mainly in the mountains that it was cold. More than 175 stations in Norway recorded a warmer March than in April and that is a new record when 125 stations did so in 1973.
At the end of the month records fell in several countries, in some cases the national record, as the hot and dry air carried up from the Sahara on southern winds. Along with föhn helped the temperature reach over 30 ° in areas north of the Alps. For example, 32.0 ° C in Waidhofen / Ybbs, Austria on the 28th and it was new April record for the country, the old was 31.0 ° in Obersiebenbrunn in 1968. In Munich, Germany, the temperature reached 32.2 ° on the same day and thus was broken the national record of 32.1 ° in Zehdenick from 22 April 1968. A few stations north of the Alps in Switzerland had a "Tropical Night" on the 29th, the minimum temperature was then 20 ° in Zurich and Ebnat-Kappel; 21.3 ° in Wädenswil, 22.3 ° in Luzern and 22.9 ° in Altenrhein.
On the 17-18th Greece and western and central Turkey were hit by a major storm . In the inner parts of Turkey it was mainly a dust storm. The 18th measured wind gusts of 38 m/s (85 mph) in Datça in western Turkey, and up to 42 m/s (94 mph)in Elmadag in inner Turkey. A low pressure area in Brittany gave strong winds during the night of 28 & 29th of in central France. A supercell formed over the Pyrenees in the warm unstable air, and moved to the Massif Central. In the Toulouse region a tornado was observed on the 29th.
At the beginning of the month, a few stations in Alaska's set a new record for the largest amount of snowfall for a season. For example, Anchorage, on the 7th reached a total of 339 cm, the old record was 294 cm from 1983-1984. Several tornados were formed in the U.S. during the month. An intense low pressure system over the Rocky Mountains contributed to storms in the midwest U.S., on the 14-15th struck by lightning and more than 70 tornados. Hail the size of tennis balls was reported and associated with a vortex in the city of Woodward in northeastern Oklahoma six people were killed. A powerful high pressure brought for the month a return of record high temperatures in the southwestern United States on 20-25th. In Death Valley measured 45.0 ° on the 22nd, which broke the station's April record from 24 April 1946. A late snowfall of the season hit the northeastern U.S. and Ontario, Canada, from 22nd-24th. At Laurel Summit, Pennsylvania measured with a total snowfall of 60 cm. In general, though at most about 20cm of snow fell.
A powerful storm hit Buenos Aires and surrounding areas in Argentina, on the 4th the wind velocity varied between 25 and 36 m / s ( 56 - 80 mph ). The storm caused major damage and 17 deaths.
Between 2nd and 3rd a low-pressure developed fast as it moved out over the Okhotsk Sea from northern China to Japan. In 24 hours the pressure decreased by 42 hPa, bringing high winds. The mean wind reached 32 m / s ( 72 mph ) in Tomogashima, Japan, 3rd and Ryotsu early on the 4th, with also squalls of just over 43 m / s ( 96 mph ) measured. A cold front that belonged to the low pressure gave large amounts of rain and in Yakushima recorded 156 mm on the 3rd. At least four people died in the storm and hundreds of airline flights were cancelled. In particular, southern Japan was influenced by a number of low pressures over the month. Large amounts of rain fell, for example, on Okinawa, 19-20th, and further north the following days.
It was warmer than normal in many parts of the Arctic, mainly in the Russian sector of Arctic and southern Greenland. In an area in northeastern Greenland, the temperature was however somewhat below normal. Melting in the Arctic was slower in the first weeks of April compared to previous years and in the middle of the month the ice cover was on average close to normal. In the last week, however, melting increased again. During the month the ice cover in the Bering Strait remained larger than normal and the Barents Sea less.
Australia / Oceania
The only tropical storm that formed during the month was Daphne, which remained in the south Pacific and passed about 500 miles southwest of Fiji, on the 2nd/3rd. In April, Australia as a whole had less precipitation than normal. In eastern Australia a contributing factor to this was weakening of La Niña in the Pacific. Northern Territory was the only state or territory which recorded an average precipitation. The temperature was on average slightly above normal in southern Australia and about the normal in the north.
April was colder than normal in Antarctica and on the 6th at the South Pole, the temperature dropped to -73.4 °C. It was the first time such a low temperature has been measured so early in the year.