Friday, September 12, 2014

August 2014 Global Weather Extremes Summary

By: Christopher C. Burt , 9:33PM,GMT on September 12,2014

August 2014 Global Weather Extremes Summary

August featured a record heat wave in the Baltics and Belarus, record cold in Northern Ireland, extreme rainfall events along the U.S. East Coast and in Michigan. Deadly flooding in Nepal and India killed at least 200 and Typhoon Halong hit Japan. A rare tropical storm struck the Big Island of Hawaii. Perth, Australia had its warmest August on record while Darwin measured its coldest August temperature on record.

Below are some of the month’s highlights.

NORTH AMERICA

The U.S. August national temperature averaged 72.2°F (23.3°C). Although this was 0.1°F (0.2°C) above the long-term average it was the coolest August since 2009. Precipitation was well above normal (the 11th wettest August on record) and the wettest since 1977.





State-by-state temperature (top map) and precipitation (bottom map) rankings for the contiguous U.S. for August. It was the wettest August on record for Montana and close to such for all of the northern Plains and inter-mountain West states. The summer heat continued along the west coast from Washington to California (where it was the 3rd warmest climatological summer on record). Maps from NOAA/NCDC.

Sioux City, Iowa (which recorded its wettest month on record just this past June) received 10.12” (257 mm) in August, a new monthly record (old record 9.07”/230 mm in 2007) and thus bringing their summer (June-August) total to an astonishing 30.38” (772 mm). This beat the previous wettest-summer-on-record by 51% (20.13”/511 mm during the summer of 2010). In sharp contrast was the normally wetter Tallahassee, Florida that had a dry August (2.26”/57 mm) and the driest summer ever observed when just an 8.99” (228 mm) accumulated (previous record 10.89”/277 mm during the summer of 2011). In Idaho, Twin Falls had its wettest month (any month) on record with 5.57” (141 mm). The normal August rainfall here is 0.32” (8 mm). Saco, in northeastern Idaho, measured 10.41” (264 mm), smashing its previous August precipitation record of 3.51” (89 mm) set in 1975. The summer monsoon has been very active in the Southwest this year. Needles, California had its wettest summer on record with 4.43” (113 mm) of precipitation. This improved drought conditions in Arizona and southeastern California but not for the rest of the state. By the end of August the drought index remained in the ‘exceptional’ category for 58.4% and ‘extreme’ for 81.9% of California. Also, the January-August period has continued the warmest-year-on record trend

A phenomenal rainstorm swept up the East Coast on August 12-13 breaking non-tropical storm-related 24-hour rainfall records in Baltimore, Maryland (6.30”/160 mm) and Portland, Maine (6.43”/163 mm). Most amazing, however, was the 13.57” (345 mm) that deluged Islip, New York (central Long Island). This established a new all-time 24-hour record rainfall for the state of New York (although unofficial higher amounts were measured during the passage of Hurricane Floyd in September 1999). You can read more about this storm here.

The Detroit area also experienced a flooding rain on August 11-12 that resulted in the deaths of 3 and paralyzed much of the city’s metropolitan region. 4.57” (116 mm) in 24 hours was measured at the airport, the 2nd greatest 24-hour total on record (since 1875). The all-time record was 4.75”/121 mm on July 31-August 1, 1925.



Scenes like this were common along Detroit-area freeways on August 12th following the city’s 2nd greatest 24-hour rainfall on record. Photographer not identified.

Tropical Storm Iselle struck the Big Island of Hawaii on August 7th with 65 mph winds and over 12” of rain. It was the strongest (and only the 2nd) tropical storm to hit the island. Little damage was done aside from some ruined crops and fallen trees.

The highest temperature observed in the U.S. during August was 122°F (50°C) at Death Valley, California on August 2nd and the coldest 12°F (-11.1°C) at McGill, Nevada on August 27th. The latter figure, if verified, would be the coldest temperature ever observed in the state of Nevada during the month of August (previous record 15° at Charleston in 1964).

It was another very warm month in Northeastern Canada with near record heat for Baffin Island and Newfoundland. Resolution Island, Nunavut measured its warmest temperature on record (for any month) with a 22.7°C (72.9°F) reading on August 23rd.

Hurricane Marie became the first CAT 5 hurricane in four years to develop in the Eastern Pacific Ocean when its winds reached 160 mph off the coast of Mexico on August 24th.



CAT 5 Hurricane Marie on August 24th when her winds peaked at 160 mph. NASA image.

The coldest temperature observed in the northern hemisphere during August was -38.5°C (-37.3°F) at GEO Summit, Greenland on August 28th.

SOUTH AMERICA and CENTRAL AMERICA

A winter heat wave occurred in northern Argentina on August 2-3 bringing temperatures as high as 38.5°C (101.3°F) to Chilecito, one of the warmest winter temperatures ever observed in country. The hottest temperature measured in the southern hemisphere during August was 40.4°C (104.7°F) at Villamontes, Bolivia on August 23rd.


EUROPE

The biggest weather story during August in Europe was the record heat wave in the Baltics, Belarus, and Scandinavia. The temperature peaked at 37.8°C (100.0°F) at Ventspils, Latvia on August 4th, a new national record and the hottest temperature ever observed in any of the Baltic nations. The city of Minsk in Belarus also measured its hottest temperature on record with a 35.6°C (96.1°F) on August 3rd. In Sweden a temperature of 35.1°C (96.1°F) was observed at Falun on August 4th. This was the hottest August temperature seen in the country since 1992. In Norway, it was so warm that reindeer took refuge from the heat in a 1.4 mile-long highway tunnel (the Stallogango Tunnel) near the Arctic outpost of Hammerfest, some 250 miles north of the Arctic Circle. For more about this historic heat wave, see this blog on the subject posted last August.

In contrast to the Baltics and Scandinavia, the U.K. and Ireland were much cooler than normal. An all-time monthly record low temperature for Northern Ireland of -1.9°C (28.6°F) was observed at Katesbridge on August 25th. For the U.K. as a whole it was the coolest August since 1993. Precipitation was also much above normal (7th wettest on record), and it was the wettest August on record for Scotland (since 1910). The coldest temperature measured during the month was -2.1°C (28.2°F) at Braemer, Aberdeenshire, Scotland on August 25th and the warmest 27.2°C (81.0°F) at St. James Park, London on August 7th. The remains of Hurricane Bertha swept over the nation on August 10-11 bringing the heaviest 24-hour precipitation total of 132.6 mm (5.22”) to Fair Isle and a wind gust of 64 mph at Needles Old Battery on the Isle of Wight.



August was the wettest August on record for Scotland and 7th wettest for the U.K. as a whole. Map courtesy of the U.K. Met Office and Crown copyright.

AFRICA

Some very hot weather in the Sahara Desert during August. In fact, at Ouarla, Algeria, the temperature peaked at 50.4°C (122.7°F) on August 2nd. This was the 3rd hottest temperature ever reliably measured in Africa.

ASIA

The hottest temperatures measured in the world during August were two 51.5°C (124.7°F) readings on August 15th, one at Kanaquin, Iraq and the other at Mitribah, Kuwait. Georgia also saw some very hot temperatures with 42.2°C (108.0°F) measured at Kutaisi on August 18th, quite close to the national record of 43.0°C (109.4°F) observed at Charnali and La’ta in previous years.

Monsoonal rains pounded northern India and Nepal during the middle of the month resulting in floods that killed at least 200 in western Nepal and the northern portions of India’s Uttar Pradesh State.

Typhoon Halong struck southern Japan on August 10th bringing torrential rainfall and deadly flash floods and mudslides. 17” (425 mm) of rain fell in one 24-hour period at Hakusan, Mie Prefecture. At least 10 storm-related fatalities were reported and 100 injuries.



Typhoon Halong had weakened to tropical storm strength by the time it came ashore in southern Japan on August 10th but high surf pounded this torii gate shrine in Hayama, Kanagawa Prefecture and flooding resulted in 10 fatalities. Photo by Kimimasa Mayama.

AUSTRALIA

August was a “mixed” month temperature-wise in Australia. It was the coldest on record for portions of the Northern Territory and the warmest on record for portions of Western Australia. For example, it was the warmest August on record for Perth with an average of 16.0°C (60.8°F) surpassing the 15.7°C (60.3°F) previous record set in 1983. The normal average August temperature is 13.6°C (56.5°F). The POR for Perth dates back to 1897. On the other hand, the Northern Territory experienced its 4th coldest August on record. Darwin dropped to 13.0°C (55.4°F) on August 23rd, its coldest August temperature ever measured.





Temperature (top map) and precipitation (bottom map) deciles for Australia during the month of August. Note the wide variability in temperatures across the country. Maps courtesy of the Australian Bureau of Meteorology.

The warmest temperature measured during the month in Australia was 36.3°C (97.3°F) at Wyndham Aero, Western Australia on August 2nd and the coldest -13.0°C (8.6°F) at Perisher Valley, New South Wales on August 3rd. The greatest calendar day rainfall was 181.4 mm (7.14”) at Beaumont (The Cedars), New South Wales on August 18th.

Heard Island, an uninhabited Australian Territory located in the very southern portion of the Indian Ocean about halfway between Australia and Africa but closer to Antarctica, recorded its lowest temperature on record August 23rd with a reading of -11.5°C (11.3°F). In a similar vein and at Port Aux Francais in the French Territories of the South Atlantic Ocean, the coldest temperature on record, -9.5°C (14.9°F) was measured on August 11th. This surpassed the previous record of -9.4°C (15.1°F) observed in June 1953.

NEW ZEALAND

An unusually warm mid-winter warm spell affected New Zealand on August 1-2. Both Christchurch on the South Island and Auckland on the North Island measured their warmest August days on record (previously these occurred towards the end of the month not the beginning!). Christchurch reached 23.6°C (74.5°F) and Auckland 21.2°C (70.2°F) on August 2nd. The Christchurch figure was the warmest temperature observed anywhere in New Zealand during August with the coldest being -7.0°C (19.4°F) at Middlemarch, South Island on August 4th. The greatest calendar day rainfall was 157.2 mm (6.19”) at Tolaga Bay, North Island on August 4th.

ANTARCTICA

The coldest temperature in the southern hemisphere and the world during August was –80.8°C (-113.4°F) recorded at Vostok on August 20th.


KUDOS Thanks to Maximiliano Herrera for global temperature extremes data and Jeremy Budd and NIWA for New Zealand data.


Christopher C. Burt
Weather Historian

No comments:

Post a Comment