Summer heat, which has so far been “more impressive and widespread than anticipated,” will continue to blanket most of the country in August and into the autumn, according to forecasters at Andover, MA-based WSI Corp.

“The extreme drought across the southern Plains has resulted in record heat in that part of the country. The drought has also acted to anchor the heat across much of the eastern two-thirds of the country, while the West has remained relatively cool, so far. We don’t foresee a significant change in pattern for the remainder of the summer, although the focus of the heat may shift slightly farther to the west in August,” said WSI Chief Meteorologist Todd Crawford.

“As we progress into fall, the pattern will generally be driven by the northern Pacific Ocean signal, which strongly argues for very warm temperatures across much of the eastern two-thirds of the U.S., especially in the north-central and northeastern states. For the August-October period as a whole, we are forecasting 587 population-weighted cooling degree days. This is much higher than the 1971-2000 average of 498, but slightly lower than last year’s extreme value of 603.”

In its previous forecast, WSI said much of the country could expect temperatures to average warmer than normal throughout the summer, with population centers in the Northeast likely to experience increasingly intense and widespread heat into September (see Daily GPI, June 21). WSI’s steamy outlook is significantly different than MDA EarthSat Weather’s forecast of summer temperatures averaging 14.5% cooler than last year (see Daily GPI, May 18), while AccuWeather.com forecasters have said they expect the lingering effects of a recent La Nina event to translate into a “year without a summer” for the nation’s midsection (see Daily GPI, June 1).

According to WSI, warmer-than-normal temperatures will dominate all of the country in August except Florida, coastal California and the Northwest, which will be cooler than normal. But the cooler weather in those areas won’t be enough to offset the bullish underpinnings across the rest of the country, according to Energy Securities Analysis Inc. Senior Analyst Chris Kostas.

“With natural gas inventories running 7.7% below last year’s level (and 2.0% below the five-year average) through mid-July, the forecast for warmer-than-normal temperatures over most of the country in August will make it difficult for inventories to close the gap,” Kostas said in a statement issued in conjunction with WSI’s outlook.

“Increased gas demand from [electricity grid operators] ERCOT, MISO, New York, New England and PJM should keep natural gas prices firm, despite the huge increases in year-over-year gas production.”

With WSI’s temperature forecast map unchanged for September, gas prices are likely to remain relatively firm, Kostas said.

“Implied market heat rates and power prices in ERCOT, MISO, PJM, New York and New England should run high in September, as above-normal power demand combines with the beginning of the generator maintenance period to push prices up the supply curve,” he said. “Power prices in California and Florida are likely to be spared from the higher implied market heat rates seen east of the Mississippi, as cooler-than-normal temperatures combine with seasonal decreases in weather-related demand.”

Warmer-than-normal temperatures will remain in place over most of the country in October, with the Northwest, coastal California and Florida remaining the only exceptions, according to the WSI outlook.

“While cooling demand tapers off significantly in October, the generator maintenance period typically takes a great deal of generation offline. Even a minor increase in weather-related demand could have a meaningful effect on heat rates as a result,” Kostas said. “With warmer-than-normal temperatures expected in ERCOT, MISO, PJM, New York and New England in October, increased power demand and the onset of the generation maintenance period should keep gas demand firm. Implied market heat rates and power prices are also likely to be firm on marginal late-season cooling demand.

“With a much warmer-than-normal August to October period expected for most of the country, we now expect inventory levels to have trouble challenging last year’s record 3,840 Bcf by the end of the injection season. Natural gas prices are also unlikely to collapse significantly in October due to the much warmer-than-normal temperatures that are expected this summer.”

WSI is scheduled to issue its next seasonal outlook on Aug. 23.

While temperatures in the East were relatively cool Monday compared with the record-setting triple-digit highs reached in many areas late last week, more very hot weather is on its way, AccuWeather.com senior meteorologist Alex Sosnowski said Monday.

“At least for the northern mid-Atlantic and New England, the heat will neither be as long-lasting, nor as extreme as that of recent days,” Sosnowski said.

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