Colin takes aim at Bermuda; the Great Russian Heat Wave of 2010: 102°F in Moscow
A reborn Tropical Storm Colin is taking aim at Bermuda, and should bring tropical storm force winds to the island by Saturday afternoon. Colin continues to pass through an unfavorable environment for development--an upper-level low pressure system with dry air and high wind shear. High wind shear of 20 - 25 knots has exposed the surface circulation to view, as seen in recent satellite imagery. Colin's heavy thunderstorm activity is all on the east side of the storm, and the associated rains can now be seen approaching the island on Bermuda radar.
Forecast for Colin
The latest SHIPS model forecast predicts that wind shear will drop to the low to moderate range, 5 - 15 knots, tonight through Saturday afternoon. This relaxation of shear prompts the intensity models to predict that Colin will strengthen to a 50 - 70 mph tropical storm by Sunday. With the forecast path of the storm predicted to take Colin just west of Bermuda, the island will be in the strong right front quadrant of the storm, and may see wind gusts in excess of hurricane force, 74 mph. After its encounter with Bermuda, Colin will head towards Newfoundland, and it is possible the storm could bring tropical storm force winds to the island on Monday. However, wind shear will be on the increase again beginning Saturday night, and it is unlikely Colin will be a hurricane when it makes it closest approach to Newfoundland.
Figure 1. Morning satellite image of Colin.
A tropical wave (Invest 93) about 700 miles west of the Cape Verdes Islands off the coast of Africa is moving northwest at 10 mph. Wind shear is a moderate 10 - 20 knots over 93L, which is low enough to allow some slow development. This system currently does not appear to be a concern to any land areas over the next seven days. NHC is giving a 40% chance of this disturbance developing into a tropical depression by Sunday morning. The GFS and NOGAPS models predict 93L will become a tropical depression.
Figure 2. Smoke from fires in Russia on August 4 covers an area over 3,000 km (1860 miles) across. If the smoke were in the United States, it would extend approximately from San Francisco to Chicago. Visibility in Moscow dropped to 20 meters (0.01 miles) on August 4, and health officials warned that everyone, including healthy people, needed to take preventative measures such as staying indoors or wearing a mask outdoors. Image credit: NASA.
The Great Russian Heat Wave of 2010 continues
One of the most remarkable weather events of my lifetime is unfolding this summer in Russia, where an unprecedented heat wave has brought another day of 102°F heat to the nation's capital. At 3:30 pm local time today, the mercury hit 39°C (102.2°F) at Moscow's Domodedovo Airport. Moscow had never recorded a temperature exceeding 100°F prior to this year, and today marks the second time the city has beaten the 100°F mark. The first time was on July 29, when the Moscow observatory recorded 100.8°C and Baltschug, another official downtown Moscow weather site, hit an astonishing 102.2°F (39.0°C). 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 eleven days, including today. The 2010 average July temperature in Moscow was 7.8°C (14°F) above normal, smashing the previous record for hottest July, set in 1938 (5.3°C above normal.) July 2010 also set the record for most July days in excess of 30°C--twenty-two. The previous record was 13 such days, set in July 1972. The past 24 days in a row have exceeded 30°C in Moscow, and there is no relief in sight--the latest forecast for Moscow calls for high temperatures near 100°F (37.8°C) for the next seven days. It is stunning to me that the country whose famous winters stopped the armies of Napoleon and Hitler is experiencing day after day of heat near 100°F, with no end in sight.
Thousands of deaths, severe fires, and the threat of radioactive contamination
The extreme heat has led to thousands of premature deaths in Russia. According to Yevgenia Smirnova, an official from the Moscow registry office, "We recorded 14,340 deaths in Moscow in July, that is 4,824 deaths more than in July, 2009." Undoubtedly thousands of additional premature deaths have occurred in the rest of Russia as a result of the heat. The heat has also caused the worst drought conditions in European Russia in a half-century, prompting the Russian government to suspend wheat exports. The drought has caused extreme fire danger over most of European Russia (Figure 3), and fires in Russia have killed at least 50 people in the past week and leveled thousands of homes. The fires are the worst since 1972, when massive forest and peat bog fires burned an area of 100,000 square km and killed at 104 people in the Moscow region alone. Smoke from the current fires spans a region over 3,000 km (1,860 miles) from east to west, approximately the distance from San Francisco to Chicago. Dozens of flights were canceled at Moscow's airports today, thanks to visibilities of 300 meters in smoke. Also of concern is fires that have hit the Bryansk region of western Russia, which suffered radioactive contamination from the Chernobyl nuclear disaster in nearby Ukraine. There are fears that fires may burn through the contaminated area, releasing harmful radiation into the atmosphere.
Figure 3. Fire danger in Russia for August 5, 2010. Extreme fire danger (Category 5, red colors) was seen over much of the European portion of Russia. Image credit: Hydrometcentre, Russia.
Why has Russia's heat wave been so long and intense?
Dr. Rob Carver has done a detailed analysis of the remarkable Russian heat wave in his latest post, The Great Russian Heat Wave of July 2010. A persistent jet stream pattern has set up over Europe, thanks to a phenomena known as blocking. A ridge of high pressure has remained anchored over Russia, and the hot and dry conditions have created helped intensify this ridge in a positive feedback loop. As a result, soil moisture in some portions of European Russia has dropped to levels one would expect only once every 500 years.
I'll have an update on Saturday morning.