Forecast says winter will be colder than in recent years

~ However, meteorologists are uncertain of that projection because of two competing forces.

One of the largest weather authorities in the world predicts the upcoming winter in the Midwest and on the East Coast will be colder than in recent years, but that means temperatures will actually be about average.

Senior AccuWeather.com meteorologist Dale Mohler said that December, January and February in Southeast Missouri should be right around their historic average temperature of 36 degrees. The previous three winters had above-average temperatures; last winter, for example, was four degrees warmer than normal, Mohler said.

The forecast comes with a caveat. "It should be cooler, but we probably have less confidence in this forecast than at any time in the past," Mohler said. "We'll know a lot more in mid-October."

The uncertainty, forecasters say, comes from two competing forces. Meteorologists point to El Nino, the cyclical warming of surface waters in the Pacific Ocean that has a domino effect on weather across North America. The coming winter will likely be an El Nino-affected winter, something that occurs every three to seven years.

Observers are also expecting a "blocking pattern" -- that is, a cold jet stream that will flow farther south than normal. In most years, the jet stream flows through southern Canada, but this year, AccuWeather says, it will shift to the northern United States.

"It's going to be a tug of war between El Nino in the south and the blocking pattern in the north. Cape Girardeau will be right at the cusp of where the impact of those two forces is felt," Mohler said.

El Nino, said Mohler, may result in colder, wetter winters from St. Louis north to the Great Lakes and warmer, drier winters from Memphis to the Gulf Coast. Southeast Missouri lies in the middle.

"It could go either way in your area," he said.

Wednesday morning's temperature of 38 degrees at the Cape Girardeau Regional Airport was an all-time low for Sept. 20, according to KFVS12 meteorologist Bob Reeves.

But Reeves said the low temperature, though unusual, is not indicative of a larger trend. Reeves said he won't play the game of predicting a winter's strength before it hits.

"I have a very low confidence in these seasonal outlooks," he said.

Reeves said the information he has seen regarding El Nino winters indicates they result in warmer than average winters half the time and colder than average winters the other half of the time in Southeast Missouri.

"We've found little correlation around here," he said.

Reeves added that the course of warm, El Nino-produced jet streams will settle somewhere in the Midwest. If they settle to the east of Missouri, the area could experience a mild winter. But if they shift to the west, a colder winter is more likely.

"It's easy to predict what the effect will be on the West Coast, but it becomes much harder here in the Midwest," said Reeves, who added he believes this year's El Nino will be weaker than past years and will not have a drastic effect.

tgreaney@semissourian.com

335-6611, extension 245