ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Monday, August 19, 1996 TAG: 9608190099
SECTION: VIRGINIA PAGE: C-1 EDITION: METRO
SOURCE: DWAYNE YANCEY STAFF WRITER
WHERE'S SUMMER? The jet stream takes the blame. Does that mean a harsh winter lies ahead?
Nancy King has some explaining to do as she bites into a ripe, red tomato the way some people sink their teeth into an apple.
Ummmm.
Oh, not for the way she's consuming the delectable treat - just for having the thing in the first place. "I'm sitting here eating a tomato, and ours aren't ripe yet," she said. "Somebody gave me this one."
That's how this Bent Mountain farmer sums up the summer of '96: Here it is mid-August, and she still doesn't have any tomatoes.
"They're just not ripening," she said. "They need hot days and hot nights."
And this summer, there have been precious few of either.
* Last summer, Virginians sweated; this summer, we need sweaters. In July and August 1995, Roanoke sweltered through 26 days when the mercury pushed into the 90s, or beyond - almost twice the average for the two hottest months of the year.
In those same two months this year, Roanoke has recorded just three days of 90 degrees or more. Blacksburg hasn't had any.
* Last summer, many Virginia communities set record highs; this summer, we're setting record lows. Roanoke recorded 54 degrees July 21; Bluefield shivered at 50 degrees that same morning.
* Oh yes, and it's been wet, too. Last August, only 0.24 of an inch of rain wetted down Roanoke; a normal August sees 1.82 inches fall on the city. So far this August, we've been inundated by 5.46 inches.
Pat Michaels can explain all that, although he'll have to talk about the Micro-Waving Sounding Unit satellite and maybe the North Atlantic Oscillation Pattern to do it.
Virginia's state climatologist is almost beside himself when it comes to talking about weather patterns, and here he's got some big-time trends to talk about.
So how come Nancy King's tomatoes aren't ripening? Let's talk about the jet stream. Let's talk about global cooling.
"After the heat and dry conditions last summer, the weather patterns changed dramatically," Michaels said.
You've heard of the movie classic "Seven Days in May''? This scientific thriller might be called "Nine Days in November."
In late November 1995, the seasonally adjusted temperatures in the Northern Hemisphere plummeted - for no apparent reason. Before, they were running 1/2 degree above average; after this hemispheric cold snap, the meteorological equivalent of a small stock market crash, they were 1 degree below. That may not sound like much to tomato growers, but in scientific terms, that's an abrupt climatic shift - and the biggest one-month drop the Micro-Waving Sounding Unit satellite has measured since it went up in 1979.
Put another way, the only other time the Northern Hemisphere's seasonally adjusted temperatures - computed by averaging temperatures from just about everywhere between the equator and the North Pole - were this cool came when the drifting ash from the Mount Pinatubo volcano darkened the skies in 1992.
But this time, there was no volcano to blame. The earth somehow simply turned down the global thermostat, and fast.
"This happened mostly during a nine-day period at the end of November, and the temperatures have really never recovered from that drop," Michaels said. They're still running below the hemispheric average.
No need to fear, Michaels said. An Ice Age isn't at hand - these kinds of small-scale climatic shifts have happened before, even though the reasons for them remain a mystery.
Some scientists say we've entered a new phase in the North Atlantic Oscillation Pattern, in which weather in the Northern Hemisphere has historically wobbled back and forth between cool spells and warm spells that may last a decade or more. Some climatologists suspect that after a run of hotter-than-usual summers during the 1980s and '90s, we're now back into a period when the summers will run cooler.
"The climate changes all by itself, and so far we haven't been able to predict these changes," said Roy Spencer, an atmospheric scientist for NASA who has written a paper on the drop in hemispheric temperatures. "I just chalk it up to variability."
That's a scientific way of shrugging your shoulders and saying, in effect, whichever way the wind blows.
And right now, our winds are blowing out of the Arctic.
The boundary between the hemisphere's cold air and warm air is marked by the jet stream. Usually, it blows across southern Canada in the summer, dips into the American South during the winter, then heads back home again in the spring.
This year it didn't, and it hung around in Dixie like a houseguest who's overstayed his welcome.
"What we have is a jet stream that looks more like a winter pattern, except it's summer," Michaels said. "That's why we're getting what look like third-time carbon copies of Northeasters - in August."
And that's why Nancy King's tomatoes aren't ripening.
And that's why her peaches aren't as sweet, her hay is molding, but her cucumbers are about to burst.
Heck, that's even why the customers at her Roanoke City Market stall are in a better mood. "People's attitudes are just nicer when it's cool," said her sister-in-law, Gladys King. "When the temperature gets past 92, they begin to get cranky."
The natural question to ask, then, is how long the jet stream is going to stay out of kilter. Or, more to the point, does this mean we're going to have a bad winter?
"If I gauge it by the trees in West Virginia, I think I'm going to stock up and hole up," joked Dave Keller at the National Weather Service office in Blacksburg. "The dogwoods are already changing. They started changing one to two weeks ago. And the acorns on the trees - man, they're full of them. That usually doesn't happen until September."
Folklore also warns that we ought to make a run on snow shovels: For every fog in August, there's supposed to be one snow in winter. A bank in Bridgewater even posted that reminder on its sign last week.
But the official scientific line is ... nobody knows.
"And if anyone says they know," Michaels said, "have them give me a call."
LENGTH: Long : 113 lines ILLUSTRATION: GRAPHIC: Chart by staff: Not hot enough for you?by CNB