Drought theories abound

August 17, 1999|By JULIE E. GREENE

Global warming, La Niña, sunspots, the alignment of the planets ...

While most people just want the Tri-State area's prolonged drought to end, others are analyzing and debating the cause.

[cont. from front page]

In general, weather experts blame a combination of displaced weather patterns: The jet stream is farther north than usual, the Bermuda high pressure system is farther west than normal, and then there's La Niña.

Normally during a La Niña year the Tri-State area would be wetter than normal, said Ken Pickering, acting state climatologist for Maryland.

Instead, the Tri-State area has suffered from drought conditions since May.

Since August 1998, Hagerstown has seen 29.81 inches of rain when normally 37.96 inches would have fallen, according to local weather observer Greg Keefer. So far this month, only 1.54 inches of rain have fallen.


"We don't have any grand theory on this one, not really. Basically it's just a very persistent pattern that's set up since April this year blocking the high pressure to the west," said Douglas LeComte, senior meteorologist at the National Oceanic and Atmospheric Administration's Climate Prediction Center in Camp Springs, Md.

The Bermuda high normally would pump humid air across our region, bringing in moisture from the Gulf of Mexico that would cause periodic showers or thunderstorms, weather officials said.

Since at least June, that high pressure system has been farther west than normal, as far west as the Plains states, said Bill O'Toole, weather prognosticator for the Hagers-Town Town and Country Almanack.

Acting in concert with the displaced Bermuda high is the jet stream, which is further north than usual and has carried the bulk of storm systems to the north. This has left the Tri-State area with hit or miss scattered showers from weak cold fronts, Pickering said.

The result has been flooding out West and an East Coast drought.

Making matters worse, the drought is feeding on itself.

The ground is so dry that there's less moisture to evaporate into the atmosphere, in turn making it harder for the atmosphere to produce rain, LeComte said.

For the situation to improve, the area needs a drenching coastal rain of the type usually associated with autumn, and which broke a 1960s drought, he said.

O'Toole forecast below average precipitation for July and August, but didn't think it would be as dry as it is.

"I thought it would be rather hot, especially early on, but I didn't expect August to be above average in temperature," said O'Toole, who uses the phases of the moon to help him formulate his weather predictions.

There is some good news.

About two weeks ago the weather pattern changed. While there was no immediate relief, the area soon should begin getting periodic rain, O'Toole said.

Astrologer Jeanne Mozier, of Berkeley Springs, W.Va., agreed.

Mozier said the drought should peak today, and then weather conditions should improve.

Today's the day the planets assemble in a cross pattern, known as the Grand Fixed Cross, Mozier said.

In preparing her predictions for 1999 Mozier called for a "summer from hell."

"I never quite imagined it quite so literally," she said.

Nicer, new energy will come onto the scene in September, Mozier said.

But Mozier doesn't think we've seen the end of "bizarre" weather.

"I think the weird weather patterns are definitely in place and will probably continue through the next decade," she said.

There is high sunspot activity now, but weather experts are divided over their effect, she said.

One camp says droughts are associated with low sunspot activity, while another says high sunspot activity could be related to the dry weather.

The acting state climatologist for Maryland didn't want to comment on sunspot activity.

Ken Pickering, who also is a research faculty member in the University of Maryland at College Park's Department of Meteorology, did comment on another controversial theory - cloud seeding.

"There's not too much of that going on in this part of the country," Pickering said.

Jerry Ditto, a Washington County resident who has researched cloud seeding, said the drought is too widespread to know for sure if cloud seeding could be behind it.

Cloud seeding involves using a plane to drop chemicals in developing thunderheads to induce rain.

It's important to remember when discussing the drought that it's summer, said Kevin Trenberth, head of Climate Analysis for the National Center for Atmospheric Research in Boulder, Colo.

"There's a drought in the United States somewhere every summer and the size of the drought this year is not unusual," he said.

What is unusual is that the most concentrated area of this drought is often the worst on record, he said.

Normally meteorologists would be expecting drought-breaking storms this time of year, but there has been little activity such as hurricanes or tropical storm remnants moving out of the Gulf of Mexico or the Atlantic, Trenberth said.

Some people blame global warming, but that isn't what caused the drought, Trenberth said.

He said, however, that global warming does make droughts set in quicker, be more intense and last longer.

The Herald-Mail Articles