Summer Heat Returns, Baking New York City Streets, U.S. Open Through Week

The heat that descended on the U.S. East Coast yesterday is forecast to affect New York City all week, according to the National Weather Service, baking workers, back-to-school students and U.S. Open tennis players and fans.

High temperatures in Central Park are expected to be 11 to 15 degrees Fahrenheit (6 to 8 Celsius) above normal through the end of the work week, said Joe Pollina, a weather service meteorologist in Upton, New York.

“A high-pressure system has been sitting over us for quite a few days now,” Pollina said. “That is the main culprit. The air just warms up.”

The high in Central Park was 94 yesterday and temperatures will be in the 90s four more days, he said. Officially, a heat wave is three consecutive days with highs of at least 90, according to the weather service.

In July, high temperatures in New York and the rest of the U.S. Northeast drove energy use close to record levels as people used air conditioners to cool off. New York set its third- highest hourly peak electrical load, 33,542 megawatts on July 6, according to the New York Independent System Operator in Rensselaer, New York.

The record was 33,939 on Aug. 2, 2006.

Natural gas for October delivery gained 10.7 cents, or 2.9 percent, to settle at $3.812 per million British thermal units on the New York Mercantile Exchange. The gain was the first in nine days.

Inventory Surplus

Hot weather has helped erode a surplus to five-year average inventories. The surplus peaked in April at 18.8 percent above the five-year average and declined to 6.2 percent Aug. 20.

“The heat is a major factor here,” said Peter Beutel, president of energy adviser Cameron Hanover Inc. in New Canaan, Connecticut. “We have some hot weather that’s going to give us decent demand.”

Yesterday’s cooling degree days value in Central Park was 16, or 8 above normal, according to the weather service. Since June 1, the value has been 1,168, or 260 above normal.

Cooling degree days, calculated by subtracting a base of 65 degrees from the average daily temperature, is a value designed to show energy demand, according to the weather service. The larger the value, the warmer the weather, and thus the more energy is probably being used to cool homes and businesses.

Since June 1, many U.S. cities have experienced values higher than normal. In Philadelphia, the value since June 1 is 1,334, or 372 above normal. In St. Louis, it is 1,531, or 378 above normal.

U.S. Open Tennis

Play at the U.S. Open in New York started today and ends Sept. 12. Players will be battling poor air quality as well as each other.

An air quality alert stretches from New York to Virginia for elevated levels of ground-level ozone.

The alert, which expires at 11 p.m. in New York, means people should limit their outdoor activities, according to the weather service. Those with asthma or other respiratory ailments are most at risk.

The air quality index is expected to be near 100 today. Quality is considered good in the 0-to-50 range, according to the U.S. Environmental Protection Agency. Today’s rating is the second-lowest on the six-step index, which goes to 500.

A warning is issued when the index reaches 100.

Ozone is produced by the chemical reactions of hydrocarbons and other gases in the atmosphere, especially in urban areas, and can build up when winds are calm, according to the weather service. At lower levels of the stratosphere, ozone is a classified as a pollutant, while at higher levels it helps filter out the sun’s ultraviolent rays.

Hurricane Earl

The tournament may also have to contend with Hurricane Earl, a Category 3 storm in the Atlantic with winds of 125 miles per hour.

Earl is projected to move parallel to the eastern seaboard. Some forecasters say it may make landfall anywhere north of North Carolina or spread high winds and rains even if it doesn’t strike the coast directly.

The heat wave will ease at the end of the week as a cold front moves from the Great Lakes to the southeast, said Jim Rouiller, senior energy meteorologist at Planalytics Inc. in Berwyn, Pennsylvania.

That front may also protect the East Coast from a direct hit from Earl, he said.

To contact the reporter on this story: Brian K. Sullivan in Boston at bsullivan10@bloomberg.net.

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