Portions of 33 states may have a heat index, which measures air temperature and humidity, above 100 degrees Fahrenheit (38 Celsius) tomorrow, according to the National Weather Service. The index reached 131, a level common only along the Red Sea in the Middle East, in Iowa on July 18, according to Weather Underground Inc. in Ann Arbor, Michigan.
“You’re seeing a sustained level of heat and humidity, and you’re not seeing a lot of relief overnight,” said Travis Hartman, a meteorologist at MDA EarthSat Weather in Rockville, Maryland. “Power demand is going to be very high.”
The high temperature in New York the day after tomorrow may be 98 degrees Fahrenheit, 13 above normal, and feel like 114, according to AccuWeather Inc. The high in Washington may be 101 and feel like 113, the forecaster said.
“While it’s already hot on the East Coast, the worst is on its way,” said Heather Buchman, a meteorologist at AccuWeather in State College, Pennsylvania, in blog post today. “Areas along the Northeast’s heavily populated Interstate 95 corridor will have highs near or higher than 100 by the end of the week as the steamy air spreads eastward from the Plains.”
Jack Hayes, director of the National Weather Service, called the heat “dangerous on many levels.” The combination of high temperatures, high humidity and a lack of respite “make this an unhealthy situation,” he said in a statement yesterday.
Cooling demand in the Northeast may be almost double the normal level on July 22, said David Salmon, a meteorologist at Weather Derivatives in Belton, Missouri, in a note to clients today.
The extreme heat will last through July 24 in the mid- Atlantic, ending on July 25 when a cold front sweeps across the region, said Jeff Masters, co-founder of Weather Underground, in blog post yesterday.
“Detroit has hit 100 degrees Fahrenheit 18 different years in its 137-year record, and New York City 22 years out of the past 140 years, so this heat wave is expected to be about a one- in-seven-year event,” he said.
Hotter-than-normal weather may return to the Midwest next week, Masters said.
Forecasts of above-normal temperatures drove natural gas futures to their biggest weekly gain since November last week. Gas for August delivery on the New York Mercantile Exchange rose 3.8 percent as meteorologists predicted hotter-than-normal weather in the eastern and central U.S. through the end of July.
Power plants use about 30 percent of the nation’s gas supplies, according to the Energy Department.
Corn prices rose to a five-week high yesterday as U.S. crop conditions deteriorated, and hot, dry weather this week may erode prospects for Midwest yields. In the week ended July 17, corn rated in good or excellent condition fell to 66 percent from 69 percent a week earlier, the U.S. Department of Agriculture said July 18.
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