Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 3:13 PM GMT on August 09, 2010
The Great Russian Heat Wave of 2010 brought temperatures of 37°C (99°F) to Moscow today, and smog and smoke from wildfires blanketed the city for a sixth straight day. Air pollution levels were 2 - 3 times the maximum safe level today, and peaked on Saturday, when when carbon monoxide hit 6.5 times the safe level. The death toll from heat and air pollution increased to approximately 330 people per day in Moscow in recent days, according to the head of the Moscow health department. Yevgenia Smirnova, an official from the Moscow registry office, said excess deaths in Moscow in July averaged 155 per day, compared to 2009. The heat wave began on June 27. These grim statistics suggest that in Moscow alone, the Great Russian Heat Wave of 2010 has likely killed at least 7,000 people so far. A plot of the departure of July 2010 temperatures from average (Figure 1) shows that the area of Russia experiencing incredible heat is vast, and that regions southeast of Moscow have the hottest, relative to average. Moscow is the largest city in Russia, with a population just over ten million, but there are several other major cities in the heat wave region. These include Saint Petersburg, Russia's 2nd most populous city (4.6 million), and Nizhny Novgorod, Russia's 5th most populous city (1.3 million people.) Thus, the Russian population affected by extreme heat is at least double the population of Moscow, and the death toll in Russia from the 2010 heat wave is probably at least 15,000, and may be much higher. The only comparable heat wave in European history occurred in 2003, and killed an estimated 40,000 - 50,000 people, mostly in France and Italy. While the temperatures in that heat wave were not as extreme as the Russian heat wave, the nighttime low temperatures in the 2003 heat wave were considerably higher. This tends to add to heat stress and causes a higher death toll. I expect that by the time the Great Russian Heat Wave of 2010 is over, it may rival the 2003 European heat wave as the deadliest heat wave in world history.
Figure 1. A comparison of August temperatures, the peak of the great European heat wave of 2003 (left) with July temperatures from the Great Russian Heat Wave of 2010 (right) reveals that this year's heat wave is more intense and covers a wider area of Europe. Image credit: NOAA/ESRL.
Worst Russian heat wave in 1,000 years of history
The temperature at Moscow's Domodedovo Airport hit 99°F (37°C) today. Prior to this year, the hottest temperature in Moscow's history was 37.2°C (99°F), set in August 1920. The Moscow Observatory has now matched or exceeded this 1920 all-time record five times in the past two weeks. Temperatures the past 27 days in a row have exceeded 30°C in Moscow. Alexander Frolov, head of Russia's weather service, said in a statement today, "Our ancestors haven't observed or registered a heat like that within 1,000 years. This phenomenon is absolutely unique." There is some slight relief in sight--the latest forecast for Moscow calls for high temperatures of 31 - 33°C (88 - 91 °F) Wednesday though Sunday.
Belarus records its hottest temperature in history for the second day in a row
The Russian heat wave has also affected the neighboring nations of Ukraine and Belarus. All three nations have recorded their hottest temperatures in history over the past few weeks. Belarus, on the western border of Russia, recorded its hottest temperature in history on Saturday, August 7, when the mercury hit 38.9°C (102°F) in Gomel. This broke the all-time record for extreme heat set just one day before, the 38.7°C (101.7°F) recorded in Gorky. Prior to 2010, the hottest temperature ever recorded in Belarus was the 38.0°C (100.4°F) in Vasiliyevichy on Aug. 20, 1946. As I described in detail in Saturday's post, Belarus' new all-time extreme heat record gives the year 2010 the most national extreme heat records for a single year--seventeen. These nations comprise 19% of the total land area of Earth. This is the largest area of Earth's surface to experience all-time record high temperatures in any single year in the historical record. Looking back at the past decade, which was the hottest decade in the historical record, Seventy-five countries set extreme hottest temperature records (33% of all countries.) For comparison, fifteen countries set extreme coldest temperature records over the past ten years (6% of all countries). Earth has now seen four consecutive months with its warmest temperature on record, and the first half of 2010 was the warmest such 6-month period in the planet's history. It is not a surprise that many all-time extreme heat records are being shattered when the planet as a whole is so warm. Global warming "loads the dice" to favor extreme heat events unprecedented in recorded history.
July SSTs in the tropical Atlantic set a new record
Sea Surface Temperatures (SSTs) in the Atlantic's Main Development Region for hurricanes had their warmest July on record, according to an analysis I did of historical SST data from the UK Hadley Center. SST data goes back to 1850, though there is much missing data before 1910 and during WWI and WWII. SSTs in the Main Development Region (10°N to 20°N and 20°W to 80°W) were 1.33°C above average during July, beating the previous record of 1.19°C set in July 2005. July 2010 was the sixth straight record warm month in the tropical Atlantic, and had the third warmest anomaly of any month in history. The five warmest months in history for the tropical Atlantic have all occurred this year. As I explained in detail in a post on record February SSTs in the Atlantic, the Arctic Oscillation (AO) and its close cousin, the North Atlantic Oscillation (NAO), are largely to blame for the record SSTs, though global warming and Atlantic Multidecadal Oscillation (AMO) also play a role.
The magnitude of the anomaly has increased slightly since June, because trade winds over the tropical Atlantic were at below-normal speeds during July. These lower trade wind speeds were due to the fact that the Bermuda-Azores High had below-normal surface pressures over the past month. The Bermuda-Azores High and its associated trade winds are forecast to remain at below-average strength during the next two weeks, according to the latest runs of the GFS model. This means that Atlantic SST anomalies will continue to stay at record warm levels during the remainder of August, and probably during September as well. This should significantly increase the odds of getting major hurricanes in the Atlantic during the peak part of hurricane season, mid-August through mid-October.
Figure 2. The departure of sea surface temperature (SST) from average for August 9, 2010. Image credit: NOAA/NESDIS.
A area of disurbed weather (94L) over South Florida is generating disorganized heavy thunderstorms over Florida and the adjacent waters, but is not a threat to develop today due to high wind shear of 20 - 30 knots. The latest SHIPS model forecast predicts that wind shear will fall to the moderate range, 10 - 20 knots, tonight through Thursday. This relaxation in shear may allow 94L to begin to organize. However, 94L will not have much time over the Gulf of Mexico to become a tropical depression or tropical storm, as steering currents favor a westward or west-northwestward motion over the Gulf that would bring the storm ashore over the northern Gulf coast by Wednesday or Thursday. NHC is giving 94L a 20% chance of developing into a tropical depression by Wednesday morning. The Hurricane Hunters are on call to investigate 94L on Tuesday afternoon.
A tropical wave (Invest 93) in the middle Atlantic Ocean is close to tropical depression status. The disturbance has a well-defined surface circulation, but only a limited amount of heavy thunderstorm activity, thanks to dry air and wind shear of 10 - 20 knots affecting it due to a large upper-level low pressure system to the west. Wind shear is expected to stay in the moderate range, 10 - 20 knots, over the next two days, which should allow 93L to become a tropical depression by Tuesday. NHC is giving a 70% chance 93L will become a tropical depression by Wednesday morning. Both the GFDL and HWRF models predict 93L will develop, and the GFDL predicts the storm will become a hurricane. A strong trough of low pressure moving across the central Atlantic should force 93L to turn northward on Wednesday, and 93L should only be a concern to shipping interests. None of the reliable computer models are forecasting tropical cyclone development in the Atlantic over the next seven days, other than for 93L.
A exceptionally slow-starting typhoon season
There is one bit of good weather news to report. Over in the Western Pacific, typhoon season has been remarkably quiet this year. Prior to yesterday's formation of Tropical Storm Dianmu, just three named storms had formed this year--Tropical Storm Omais, Typhoon Conson, and Typhoon Chanthu. The average for this point in the season is ten storms. Sunday's total of three named storms in the West Pacific tied 2010 with 1998, 1954, and 1975 as the slowest starting Western Pacific typhoon season on record, for the date August 8. Now that we have Tropical Storm Dianmu in the Western Pacific, 2010 ranks as the 4th slowest start to a typhoon season as of August 9. Reliable records of typhoon activity go back to 1951.
Figure 3. Heavy downpours triggered landslides and mud-rock flows in China's Gansu Province, early Sunday morning. Image credit: www.news.cn.
The deadly 2010 monsoon kills hundreds more in China, India, and Pakistan over the weekend
The Asian Southwest Monsoon has been exceptionally deadly this year. Northwest China's Gansu province was hard hit over the weekend with torrential monsoon rains, and the resulting flooding and landslides claimed at least 127 lives. At least 1300 people are missing in the disaster. Fresh monsoon rains in Pakistan over the weekend triggered landslides that killed sixty more people, in addition to the 1,500 - 1,600 people who died in monsoon floods that began in late July. At least 137 died in floods and landslides in the neighboring Indian state of Kashmir over the weekend, with 500 people missing. Monsoon flooding and landslides have also killed at least 65 people in Afghanistan in the past two weeks. Dave's Landslide blog has some great discussions of the flooding and destruction wrought by the terrible monsoon rains this year in Pakistan, India, Afghanistan, and China. I plan to write much more about this year's deadly monsoon on Tuesday.
I'll have an update Tuesday.
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