Sunday, March 11, 2012

February 2012 Global Weather Extremes Summary



February was notable weather-wise for the extreme cold wave and snow that affected a large part of Europe, excessive rains and flooding in Australia, two strong tropical storms that caused flooding and fatalities, in Madagascar, and a major snowstorm in Colorado that occurred in spite of a generally warmer than normal month in the United States. California wrapped up its 2nd driest climatological winter on record. 


Below is a summary of some of the month’s highlights.

NORTH AMERICA

In the U.S. temperatures averaged above normal for every state in the nation, including Alaska which had endured a brutally cold January. In Massachusetts it was the warmest February on record (tied with 1998) and it was also the warmest February on record for the New York City metropolitan area. February was the 11th consecutive month of above normal temperatures for the Northeast region. Most of the East Coast and West Coast were also much drier than normal. California wrapped up its 2nd driest climatological winter (Dec.-Feb.) on record (the driest was that of 1975-1976). Welcome rainfall, however, drastically improved drought conditions in Texas where the area under extreme drought conditions shrank from 43.3% in early December to just 14.8% by the end of February. Last year’s drought killed off 10% of the entire state’s urban shade trees.



A massive snowstorm enveloped Colorado on February 2-4 depositing up to 52” at one location west of Boulder and providing Denver with its single greatest February accumulation on record: 15.9”. Lincoln, Nebraska received 11.1” of snow on February 4th, its fourth greatest single-day total on record.


A map shows the snow accumulations in the Denver area during the early February snow event. A peak point total of 52” was measured in the mountains about 20 miles west of Boulder. Map from NWS Denver office.

A tornado outbreak on the last two days of the month, (February 28-29), killed 13 in Illinois and Kentucky. This was a precursor to the even deadlier massive tornado outbreak several days later on March 2nd (to be covered in next month's summary).

The coldest temperature measured in the northern hemisphere during February was -83.9°F (-64.4°C) at one of the Summit RAWS sites atop the Greenland ice dome on February 29th.

SOUTH AMERICA and CENTRAL AMERICA

Heavy rains continued in the normally arid Atacama Desert of northern Chile. The Pan-American Highway had to be closed near the border of Peru after flash floods unearthed land mines (put down in the 1970s during a conflict between the two nations) and swept them on to the highway.

EUROPE

The biggest weather story of the month was the intense and prolonged cold wave that enveloped most of Europe for most of the month. It was the most severe such since 1987. For details on the event see my recent posted in February. The only, all-time cold record, however, was set at Astrakhan, Russia when the temperature fell to -28.8°F (-33.8°C) on February 8th.

The U.K. experienced an amazing wild swing of temperatures for the normally temperate country. On February 11th a national low reading for the month of -0.9°F (-18.3°C) at Chesham and Chipstead Valley (both on the outskirts of London) was followed by a national high of 65.7°F (18.7°C) at Coleshill near Birmingham on February 23rd. The latter figure was within one degree centigrade from the warmest February reading on record in the U.K. Following many months of abnormally dry weather, southeastern England is now officially suffering drought conditions. Authorities are concerned that if beneficial rainfall does not occur later this spring, visitors to the Olympic Games (as well as local residents of course) will be facing severe water restrictions. The greatest 2-hour rainfall in the U.K. during February was 2.78" (70.6mm) at Achnagart, Highland on Feb. 17-18. The highest measured wind gust was 74mph at Fair Isle on Feb. 24th.

AFRICA

Tropical Cyclone Giovanna, at one point a CAT 4 storm, slammed into the north coast of Madagascar on February 20th killing 32. Fortunately, the storm weakened prior to reaching the coast, otherwise the toll could have been much worse. 


A satellite image of Giovanna when the storm was at its maximum strength on February 13th several hundred miles east of the coast of Madagascar. Peak sustained winds were estimated at 140 mph at this point. Image from NASA Earth Observatory.

Another tropical cyclone, Irina, affected Madagascar on February 29-March 2nd with deadlier results. Flooding in the southern interior of the island has claimed at least 72 lives according to early reports. See Jeff Master's recent blog for more on this developing story.

The hottest temperature measured in the northern hemisphere during February was 109.4°F (43.0°C) at Abu Na’Ama, Sudan on February 9th. The hottest temperature in the southern hemisphere was 114.3°F (45.7°C) at Redelinghuys, South Africa on February 5th (a similar reading also occurred in Australia during the month).

ASIA

A blizzard impacted the Tibet region of China February 7-9 isolating towns and shutting down the Lhasa-Kathmandu highway along which hundreds of travelers were stranded for several days. Heavy snow also blanketed the Japanese prefecture of Yamagata where up to 4 meters (150”) of snow accumulated during the first 10 days of the month. 


A snow plow struggles to keep the Lhasa-Kathmandu Highway open during the blizzard that struck Tibet on February 7-9. Photo from China News TV.

In Siberia the temperature fell to -71°F (-57.2°C) at the perennial cold town of Oimyakon on February 10th, the coldest reading at an inhabited site in the northern hemisphere for the month.

AUSTRALIA

February saw the coldest average minimum for the nation since February 1990. Although precipitation averaged slightly below normal for the country as a whole, it was the wettest February on record for portions of New South Wales. Some sites reported their heaviest single-day rainfalls on record: Mulwala 3.68" (94mm) on Feb. 28 (105 period of record), Tungamah 4.90" (124.4mm) on Feb. 28 (122 period of record), and Coolamon 4.87" (123mm) on Feb. 29th among others. The heaviest calendar day rainfall in Australia during February was 10.68" (264.6mm) at Noosaville, Queensland on Feb. 25th.

Persistent heavy rainfall over much of Australia during the current La Niña event has resulted in the years 2010-2011 being the wettest two-year period on record for Australia.



Top map shows deciles of departure from normal for precipitation across Australia during February, and the bottom map the deciles of departure from normal for the average minimum temperatures. In this regard, it was the coldest such February since 1990. Maps from the Australian Bureau of Meteorology.

The hottest temperature during the month in Australia and the world (tied with South Africa) was 114.3° (45.7°C) at Roebourne, Western Australia on Feb. 16th. The coolest reading was 31.3°F (-0.3°C) at Liawenee, Tasmania on Feb. 24th.

NEW ZEALAND/SOUTH PACIFIC

New Zealand endured an unusually cloudy and cool month for summer. The highest temperature measured in the country was 87°F (30.4°C) at Hastings, North Island on Feb. 23rd and the lowest 31.6°F (-0.2°C) at Chateau Tongairiro, Mount Ruapehu, North Island on Feb. 28th. The greatest calendar day rainfall was 10.80” (275mm) at North Egmont, North Island on Feb. 22nd. A peak wind gust of 98mph (158km/h) was reported at Cape Turnagain, North Island on Feb. 1st.

A powerful tropical storm, Jasmine, strengthened to CAT 4 status in the open waters between New Caledonia and Vanuatu in early February. Both islands experienced damaging winds from the cyclone.

ANTARCTICA

The coldest temperature in the southern hemisphere and the world during February was -84.5°F (-64.7°C) recorded at Dome A site.

KUDOS Thanks to Maximiliano Herrera for global temperature extremes data, Stephen Burt for the U.K. extremes, and Jeremy Budd for New Zealand weather extremes.

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