April 2011 Global Weather Extremes Summary
April 2011 Global Weather Extremes Summary
Extreme weather highlights for this past April include the almost unbelievable tornado outbreak of April 25-28 in the Deep South of the U.S.A., wild fires in Texas, record warmth and drought in portions of Western Europe, and more flooding in Columbia.
Below are some of the month’s highlights.
Of course, the tornado outbreak of April 25-28 was the defining extreme weather event of the past month anywhere in the world. As of this writing the death toll is still undetermined ranging somewhere between 318 (latest NOAA estimate) to 350 (according to some media outlets). In any case, it was one of the most catastrophic natural disasters in U.S. history and perhaps the 3rd deadliest tornado outbreak of such. At least three of the tornadoes were rated as EF-5s, the first so rated since 2008 and only the 2nd time since 1900 that three or more F-5 or EF-5 tornadoes have ocurred during a single outbreak, the other time being on April 3-4, 1974 when six were recorded.
This is F-5 tornado damage in the Hackelberry, Alabama area following the tornado outbreak of April 27th. Note that there is just the bare slab of what was once a structure and the scouring marks in the surrounding fields. Photo a still from an aerial survey made by an ABC affiliate.
Another tornado outbreak killed 26 in North Carolina and Virginia on April 17th. More than another dozen were killed by tornadoes in other parts of the country during the month, with the total number of tornadoes counted being the most ever for any April on record.
Meanwhile, a severe drought combined with excessive heat and winds fueled massive wildfires in Texas. So far 1.5 million acres have been consumed destroying dozens of homes and killing at least one firefighter. Temperatures peaked at 111°F in Laredo on April 26th (although Richard Berler informs me the actual temperature was 110°F since the airport site thermometer is over exposed). Never the less, this was just shy of the 113°F April state record for Texas set at Catarina on April 20, 1984.
In Mexico the temperature peaked at 48.8°C (119.8°F) at Matlapa, San Luis Potosi on April 27th. This was the warmest temperature measured in the world during the month of April.
Ironically, the month closed with a fierce blizzard in North Dakota on April 30th. 14” of snow fell at Trotters and winds gusting to 78mph blew down 100 power poles between Berthold and Stanley. The 7.9” of snow that fell at Williston brought the seasonal snowfall to an all-time record amount of 107.2” (previous record was 94.7” in 1894-1895).
NOTE: Record flooding of the Mississippi River will likely be a lead story for my May summary.
The coldest temperature in the Northern Hemisphere during April was -57.3°C (-71.1°F) at Summit Station on Greenland on April 21st, an unusual value for so late in the season.
Columbia continued to be plagued by deadly floods and mudslides during April with over 20 dying in the city of Manizales during the week of April 10-17. Torrential rains have been pounding the country since last November, a result of the strong La Nina condition that prevailed this past winter.
April was the warmest such on record for many parts of Western Europe including London where the temperature averaged 4.0°C (7.2°F) above normal and peaked at 27.2°C (81.0°F) on April 23rd. A reading of 27.8°C (82.0°F) at Wisley was the 2nd warmest April temperature ever measured in the British Isles (the record remains 29.4°C/84.9°F at Camden Square, London on April 16, 1949). It as also the warmest April on record nationwide for the United Kingdom with a departure from normal of +3.7°C (+6.7°F). The warmest April temperature ever measured in all of Europe occurred at Orihuela, Spain on April 9th with a 39.0°C (102.2°F) reading. Other national April records included readings of 33.9°C (93.0°F) in France and 32.0°C (89.6°F) in Switzerland. In Switzerland wildfires broke out in several locations burning thousands of acres of forest. Drought has reached critical levels in both Switzerland and the Low Countries, especially Holland where outdoor burning and smoking have been banned. In the United Kingdom the March-April period has been the 4th driest on record since 1766 (the driest such period was in 1938).
A forest wildfire consumes a mountainside near Visp, Switzerland on April 27th. Photo by Jean-Christophe Bott.
I am unaware of any significant extreme weather events in Africa during the month (see note about Mexico above concerning the hottest temperature in the Northern Hemisphere). The warmest temperature in the Southern Hemisphere for the month occurred at Vredenal, South Africa on April 10th with a 41.3°C (106.3°F) reading measured.
Heavy early monsoon thunderstorms resulted in the deaths of six by lightning in Nepal on April 12-13. The deaths occurred at three different locations in Sindhuli, Makwanpur, and Udaypur Districts.
In early April the Burmese media reported that 700 fishermen remained missing following the severe storms that affected the Andaman Sea on March 14-17. It is unclear at this time if they have yet been accounted for.
Tropical Storm Errol lashed East Timor on April 16-17 resulting in torrential rains and gusty winds. It was a minimal tropical storm and quickly dissipated, but it is quite unusual for tropical storms to strike Timor which lies just 10° south of the equator. There were no reported injuries or significant damage.
Wet and cool weather continued over much of Australia during April although not nearly as much as March. Extreme temperatures ranged from -5.1°C (22.8°F) at Perisher Valley, New South Wales on April 23rd to 40.0°C (104.0°F) at Roebourne, Western Australia on April 14th. The wettest day was recorded at Mt. Hart, Western Australia when 206mm (8.11”) was measured.
While portions of northern Western Australia experienced their wettest April on record, most of the country received close to normal precipitation with the national average running just 18% above normal. Map courtesy of the Australian Bureau of Meteorology.
The coldest temperature in the Southern Hemisphere and the world occurred at Dome Fuji on April 26th with a -70.9°C (-95.6°F) reading.
KUDOS Thanks to Maximiliano Herrera for temperature data, Richard Berler for Laredo information, and Paul Simons for U.K. data.