Tag Archives: Christopher Burt

Siberia heat Wave, South America Cold, Thailand Rains

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Cold Snap hits southern South America. UPDATE: (and ‘Big Fish in Living Room’ story!)

It has been a wild week for temperature extremes with the amazing heat wave in north central Siberia juxtaposed with an unusual cold spell in portions of Brazil, Bolivia, and Argentina occurring simultaneously almost exactly opposite one another on the planet. Scroll down to end of blog for my fishy story! It actually has some context considering the amazing rainfall record set at Chantaburi, Thailand this past week.

South American cold snap

Between 20-25th July a mass of very cold air suddenly froze a large area of southern South America (where temperatures had been running above average for weeks prior to the abrupt change).

Snow was recorded for the first time since 1996 at Catamarca, Argentina (28°S and located at about 500m/1,650’), and cold rain (temperatures of 5-6C/41°-43°°F) at sea level altitudes like Florianopolis, Brazil. Montevideo, Uruguay also experienced rain with temperatures as low as 3C (37°F). The town of Campos Novos, Brazil (at an elevation of 947m/3,100’) had a high temperature of just 3.6°C (38.5°F) and low of -2.7°C (27.1°F) on July 23rd, a daily average of almost freezing (0.9°C/32.8°F). There was no precipitation at the site that day, if so it probably would have been snow. In fact, a little snow was reported in Brazil in the hills above nearby Curitiba for the first time since 1975.

Snowfall in the mountainous region of Santa Catarina, Brazil is not so unusual. Above is an image of a deep snowfall near Rio Grande do Sul during the cold wave of July-August 2010. Ironically, this occurred at the same time as the famous Moscow heat wave of that summer, a somewhat similar situation as is now occurring. Photographer not identified.

There were incredible temperature contrasts in Bolivia (which isn’t unusual given the complex Andean topography) but what was unusual was that it was actually colder at the low elevations in the Amazonian jungle than in the higher mountainous terrain of the country: temperatures at Bolivian locations above 4000m (13,000’) on 23 July were higher than those in the Bolivian portions of the Amazon jungle at low elevations. For instance, the temperature at Reyes (located at 14°S and 140m/462’ elevation) had a maximum of 9.3C/48.8°F while at El Alto Airport, La Paz (elevation 4,000m/13,200’) the temperature maximum reached 13.9°C (57°F). Temperatures in the Chaco region of Bolivia were remarkably chilly with a reading of -5.8°C (21.6°F) observed at Villamontes.

Some places in the middle of the Andes, protected by mountains on all sides, like Cochabamba didn’t experience a single degree drop in temperature, while low areas experienced drops as high as 22-25°C (40-45F) in 24 hours. In Paraguay sleet was recorded in Itapua and the minimum temperature reached -5.2C (21.6°F) at Prats Gill on 24th, not far from the all-time national record of -7.5C (18.5°F) (also set in Prats Gil) on July 13, 2000

The cold air actually filtered as far north as the western part of the Amazon jungle near the Equator, with 7°C (44.6°F) at Rio Branco, Brazil (10°S latitude) and 16°C (60.8°F) at Leticia, Colombia (4°S latitude). Both are low-level sites in the Amazon Basin.

The most exceptional cold wave, in regard to how north cool air has ever penetrated, was that of July 1975 when air of polar origin reached the Caribbean affecting the whole of South America (including the extreme western part of Amazon in Peru, Brazil, Colombia, Venezuela, the Guyanas, and even Trinidad and Tobago. Unlike other cold waves (such as those of 1955, 1973 and 2010) the July 1975 event didn’t stop south of the Equator, but continued well into the Northern Hemisphere. This remains unique and the only documented occurrence of such an event. The surface high pressure reached 1044 hPa (30.82”) over central South America on July 15, 1975, the highest yet measured (modern records) on the continent (REF: Markgraf, Vera Interhemispheric Climate Linkages p. 37)


500 mb MAP

Surface air temperature anomaly for the week of July 19-24 (top map) and 500 mb height anomalies for the same period (bottom). Note how the cold air over South America is almost exactly on the opposite side of the world from the heat dome over north central Siberia. NCEP/NCAR maps, courtesy of Stu Ostro.

The cold snap this past week was caused by a strong upper-level low centered over the southern third of the continent. Curiously, it has been unusually mild over the portions of Antarctica opposite South America with a high of 7.8C (46.0°F) being recorded at Base Esperanza (63°S), higher than the normal summer average maximum and just 1.5°C less than the Amazonian maximum of Reyes in Bolivia at 14°S latitude!

Meanwhile on the other side of the world…

The unrelenting heat wave in north central Siberia continues with Svetlogorsk (on the Arctic Circle) recording its 13th consecutive day (as of July 26) with temperatures above 30°C (86°F). Meanwhile, all eyes are turning to Western Europe where a potentially historic heat wave is expected to develop this weekend and continue into next week! There is a chance that some all-time national heat records may fall in some countries like Germany, Liechtenstein, Austria, Slovakia, Slovenia, and Hungary when all is said and done.

Phenomenal Rainstorm in Thailand

On a side note, a historic rainstorm has caused serious flooding in portions of southeastern Thailand. Chantaburi picked up 445.7mm (17.55”) of rain on July 23rd with an amazing 385mm (15.16”) of this falling in just 12 hours and an even more amazing 297 mm (11.69”) in just 6 hours! This may be one of the (if not the) heaviest 24-hour rainfall on record for Thailand (previous record was 414.8mm (16.33”) at Ko Samui on March 28, 2011. A famous flood in Bangkok occurred on May 9-10, 1986 when 401.1 mm (15.79”) of rain fell in just 8 hours. The ensuing floods almost cost the mayor (Chamlong) his job.

My ‘fish story’

I lived a few blocks from the Bangkok Met office at the time (during the storm of 1986) on Soi 49 Sukhumvit Rd. and caught a 15″ fish that swam through a break in the screen porch door off my living room which flooded about half a meter deep at one point. My girlfriend at the time and I trapped the sucker hiding under the water-logged couch in the living room. We grilled it later that same day (after the water receded) and it was delicious (no idea what kind of fish it was). I think I must be one of the only people who have caught a large live fish swimming around their living room and then cooked it in their kitchen just 10 feet away hours later :-). I’d love to hear from other WU friends if they have had a similar experience!

METARS for Chantaburi, Thailand July 22-23 when a peak 24-hour rainfall amount of 445.7 mm (17.55”) accumulated, a possible national record. Flooding continues as more rain has since fallen over this region of southeastern Thailand. From OGIMET.

KUDOS: Thanks to Maximiliano Herrera for much of the above information about the cold wave in South America.

Christopher C. Burt
Weather Historian

from:    http://www.wunderground.com/blog/weatherhistorian/show.html

ANomalous Snow Events

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Strange Snowfalls
Published: 8:54 PM GMT on February 04, 2013

Strange Snowfalls

Although there were no spectacular snowstorms in the contiguous U.S. this past January there were a couple of interesting snow events. On January 20th the residents of Vermont were amazed to find their yards and fields covered with large snow rollers. A week later, on January 27th, giant snowflakes “the size of cotton balls” were observed near Moline, Illinois. Here is a summary of some strange snow events.

A Vermont TV station, WCAX, reports on the snow roller event that occurred in Vermont on January 20, 2013.Video still from WCAX and rebroadcast on CNN and The Weather Channel.

Snow Rollers

This rare and interesting phenomenon occurs when surface conditions are just right following a fresh snowfall. The surface snow must be light and sticky but not too wet. Strong, gusty winds in excess of 30 mph must then ‘scoop’ the fluffy snow into small balls on the surface and then blow the balls along forming small barrels. The stronger the winds and deeper the snow, the larger the barrels or ‘rollers’ become. Of course, the process is the same as making a snowman. Reports of snow rollers up to five or six feet in diameter (the “size of rolled hay bays”) have been reported in the Great Plains but cannot be substantiated.

Perhaps the largest snow rollers ever photographed were these barrels some 20” in diameter and three feet long that formed in Vermont’s Lamoille River Valley in February 1973. Photo by Ronald L. Hagerman.

For some reason New England and especially Vermont seem to be where snow roller formation is most often observed, as was the case in January. The event received national media attention being widespread and photographed by thousands in the Mad River Valley area and towns of Plainfield, Craftsbury, and St. Albans.

A beautiful shot of the recent snow roller event taken near Plainfield, Vermont in January. Photo by Janet Steward.

Giant Snowflakes

Reports of large snowflakes of 2” in diameter, as observed near Moline, Illinois on January 27th, are relatively common. Of course, these are not individual snowflakes but rather aggregates of entwined snowflakes. These aggregates normally occur when the temperature at the surface is near or just above freezing causing the wet flakes to bump into and stick to one another as they fall through the sky. Sleet often accompanies these giant flakes. The wind must be near calm in order for the aggregates to stick together.

A couple of close up images of large snowflake aggregates. One can see how these are composed of many different individual snowflakes entwined with one another. Top photo taken by Ruth Zschomler in Vancouver, Washington in 2010. Bottom photo by Thomas Niziol, the Weather Channel’s Winter Weather Expert.

Some truly extraordinary giant aggregates up to 5” (14 cm) in diameter and even larger have been verifiably observed. On January 24, 1894 ‘snowflakes’ of this size were observed in Nashville, Tennessee. In Berlin, Germany flakes up to 4” in diameter were seen on January 10, 1915. A weather observer noted:

On this occasion a large number of snowflakes had diameters of 8 to 10 centimeters (3-4″), and these giant flakes fell with both a greater speed and more definite paths than did the smaller flakes. They did not have the complicated, fluttering flight of the latter. In form the great flakes resembled a round oval dish with its edges bent upward. During flight they rocked to this side or that, but none were observed to turn quite over so that the concave side became directed downward.

There is a report from Fort Keogh, Montana of snowflake aggregates reaching a diameter of 15”/38 cm (the “size of sauce pans”) on January 28, 1887. If true, these would be the largest such ever recorded.

Giant snowflakes up to 2-3” in diameter blanket Kashgar, China during the winter of 2001. Photo by Michael Yamashita.

Colored Snow

I devoted a few paragraphs of my book ‘Extreme Weather: A Guide and Record Book’ to this phenomena and quote myself herein:

In Dr. Seuss’s The Cat in the Hat Comes Back, the Cat and his Hat’s mischievous inhabitants, Little Cats A, B, and C make a terrible pink mess in the home of two children. The Cat and the Little Cats manage to get the pink stains out of the house—and into the snow, which then becomes bright pink.

Preposterous as it may seem, it has, on very rare occasions, snowed pink. Not only pink but other unnatural shades as well. Pink snow was reported to have fallen in Durango, Colorado on January 9, 1932. Red snow coated the Alps on October 14, 1775, and again on February 3–4, 1852, over a wide area from Bergamo, Italy, to Zurich, Switzerland. Brown snow was reported on Mt. Hotham in the Snowy Mountains of Victoria, Australia, in July of 1935.

In the above cases, the coloring factor in the snow was dust which had risen into the atmosphere during desert dust storms. The dust that mixed with the snow in Europe was carried there by winds from the Sahara; the coloring in Australia originated in its interior desert.

Black and blue snowfalls have been reported on several occasions in New York State. The N.Y. State Weather Service report for April 1889 records black snow falling over Lewis, Herkimer, Franklin, and Essex Counties. Upon examination, the snow was found to contain a “sediment consisting principally of finely divided earth or vegetable mold.”

A blue snowfall was reported in many towns of western New York State during January of 1955. Yellow snow that fell on South Bethlehem, Pennsylvania, on March 16, 1879, was found to contain pollen from pine trees that were in bloom throughout states further to the south. Unfortunately, there are no known verifiable photographs documenting these rare and unusual events.

This photograph purports to be of a colored snowfall that occurred in Saaksjarvi, Finland on January 16, 2010. However, it is difficult to tell if this is actually colored snow or just a lighting effect. Photo from Flikr page by ArtemFinland.

Christopher C. Burt
Weather Historian

from:    http://www.wunderground.com/blog/weatherhistorian/article.html

August 2012 Weather Extremes

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August 2012 Global Weather Extremes Summary
Published: 5:52 AM GMT on September 04, 2012

August 2012 Global Weather Extremes Summary

There is never a dull month when it comes to extreme weather and August 2012 was no exception. The month began with a massive flood in Manila, Philippines and an intense heat wave in the south-central U.S. Two very sharp heat waves affected much of Europe during the 2nd and 3rd weeks of the month smashing records from Spain to Poland and the Ukraine. Typhoons walloped coastal sections of China and Hurricane Isaac thrashed the U.S. Gulf Coast.

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

NORTH AMERICA

An intense heat wave in the southern plains exacerbated the on-going drought conditions and the temperature at Oklahoma City reached 113°F (45°C), the warmest temperature ever measured in the city. By mid-August, however, a very cool air mass invaded most of the central portion of the country and temperatures even fell to freezing at a few locations in Minnesota and Wisconsin. In spite, of the mid-month cool down some sites have ended up enduring their hottest summer on record. Denver, Colorado has averaged 76.3° for its climatological summer (June-August) beating its former warmest summer of 1954 by a full 2°F (old record was 74.3°F). The warmest temperature in the world during August was 126°F (52.2°C) measured at Death Valley, California on August 9th.

Sub-tropical moisture brought intense rainfall to portions of the desert southwest on August 22nd. Las Vegas, Nevada recorded its 2nd wettest calendar day on record with 1.68” that caused flash flooding resulting in one drowning death in the city. (Mesquite, near Las Vegas, picked up 2.04”, its greatest 24-hour rainfall on record/since 1992). Some other desert locations measured over 4” of rain in just a few hours (4.03” at Mid Hills RAWS in San Bernardino County, California—about what this site might expect in an entire year). One site in Nevada’s Mohave County, Wikieup, received 1.42” of rain in just 30 minutes. Ironically, Seattle, Washington (normally perceived as wetter than Las Vegas!) received no measureable precipitation during the entire month of August, and of this writing, is approaching its record of 51 rain-free days set in 1951 (last rainfall this summer was on July 22nd).

Hurricane Isaac made landfall in Louisiana on August 27 as a CAT 1 storm although its large size, strong storm surge (as high as 13’,) and central pressure (as low as 966mb) was more indicative of a strong CAT 2 cyclone. Seven storm-related deaths were reported mostly associated with the 15-20” rainfalls that fell along the path of the slow moving storm. The damage (at least US$2 billion) caused by Isaac is still under review as of this writing.

Flooding reminiscent of Hurricane Katrina ravaged some New Orleans-area neighborhoods like Plaquemines Parish southeast of the city. Ironically, Isaac struck virtually on the 7th anniversary of Katrina. Photo by Carolyn Cole, Los Angeles Times).

Hurricane Ernesto struck the western coast of Mexico on August 9th resulting in the deaths of two.

The Arctic measured its lowest sea ice extent since observations began in 1975. By August 26th the ice extent had shrunk to 1.58 million square miles, about 277,000 square miles less than the previous record low set in September 2007.

The coldest temperature measured in the northern hemisphere during August was -36.1°C (-33.0°F) at Summit AWS, Greenland on August 30th.

SOUTH AMERICA and CENTRAL AMERICA

Tartagal, Argentina recorded a temperature of 38.8°C (101.8°F) on August 22nd a record for the month at that location.

EUROPE

Europe experienced its most intense heat wave since the famous heat wave of 2003 and, in fact, many locations measured even higher temperatures than that occasion. All-time national heat records were set in the Czech Republic (40.4°C/104.7°F at Dobrichovice on August 20th), Moldova (42.4°C/108.3°F at Falesti on August 7th), and Montenegro (44.8°C/112.6°F at Danilovgrad on August 8th). In the Pyrenees along the French and Spanish border virtually every site recorded its warmest temperature on record. For more details on the European heat waves of August see my previous blog on the subject. Wild fires have raged out of control in both Spain and Greece with several fatalities reported from the Spanish resort area around Marbella.

August weather extremes for the United Kingdom are not yet available.

An intense wild fire threatens a beach resort on the island of Chios in the Greek archipelago on August 18th. Photo from EPA archives.

AFRICA

Monsoonal rains resulted in deadly floods in Nigeria and Cameroon during the month. At least 14 flood-related deaths were reported in Cameroon’s north region and at least 15 in Nigeria’s central provinces.

On August 25th and 26th the temperature peaked at 42.5°C (108.5°F) at Mtunzini, South Africa. This was not only a winter record for South Africa but also close to the warmest temperature ever measured in the southern hemisphere during the winter months (44°C has been recorded at Villamontes, Bolivia during previous Augusts). Needless to say, this was the warmest temperature measured in the southern hemisphere during this past August.

ASIA

Although this years summer monsoons have failed to materialize in much of South Asia, heavy rains in the mountains of northern Pakistan on August 20-23 resulted in flash floods that drowned at least 26.

It was a very active month typhoon-wise in the Western Pacific. Notable typhoons struck Macao and Hong Kong including Typhoon Kai-tak that caused winds to gust to 87 mph at Hong Kong’s International Airport on August 23 and 27 lives were lost in China’s Guangdong and Guangxi Provinces. It was the strongest typhoon to hit Hong Kong since 1999. Typhoon Bolaven was the strongest typhoon to hit the Korean Peninsula since 2002 when it roared ashore on August 28th. At least 18 deaths (mostly fisherman) were reported as a result of the storm with at least a further 48 fatalities reported just recently from North Korea.

The biggest weather story of the month in Asia, however, was the tremendous flood that engulfed Manila in the Philippines between July 31-August 8th. Up to 1000 mm (40”) of rain was reported to have fallen in Quezon City during the week of rains and there were some 60 fatalities reported. For details about the flood see Angela Fritz’s August blog on the subject.

Manila’s streets turned into lakes during the phenomenal flood that affected the city the first week of August. Photo by Jof Cubol.

AUSTRALIA

Australia had a warmer and drier August than normal, reversing (temperature-wise) the cold weather endured over much of the country the previous July. It was Western Australia’s driest August since 1995 and 2nd warmest August on record.

A very warm month virtually nation-wide for Australia this past August (top map). Precipitation was also below normal in most of the country, especially in portions of Western Australia where it was the driest August on record (bottom map). Maps courtesy of the Australian Bureau of Meteorology.

The warmest temperature recorded in Australia during this past August was 38.5°C (101.3°F) at Fitzroy Crossing, Western Australia on August 27th and the coldest -4.9°C (23.2°F) at Thredbo Top Station, New South Wales on August 6th. The greatest calendar day precipitation was 73.0mm (2.87”) at Mount Sabine, Victoria on August 18th.

NEW ZEALAND/SOUTH PACIFIC

It was generally a mild and wet August in New Zealand although there was a sharp contrast in precipitation totals on the South Island where anomalies ran the gamut from 10% to 400% of normal!

The extreme anomaly between very dry and very wet weather that affected the South Island in August can be seen in this map above. Map courtesy of NIWA.

The highest temperature recorded was 22.7°C (72.9°F) at Christchurch, South Island on August 26th and the lowest -5.3°C (22.5°F) at Ranfurly on August 23rd. The greatest calendar day rainfall was 198 mm (7.80”) at Akaroa on August 25th.

ANTARCTICA

The coldest temperature in the southern hemisphere and the world during August was -80.0°C (-112.0°F) recorded at Vostok on August 7th.

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

from:    http://www.wunderground.com/blog/weatherhistorian/article.html