Whither The Weather
By Cynthia Macgregor
An oft-heard quote goes "Everybody talks about the weather, but nobody does anything about it." (Although the quotation is generally attributed to Mark Twain, the originator may have been Charles Dudley Warner.) While it may have been true in Twain's (or Warner's) day, and though we still can't create rain in drought-parched regions or steer hurricanes harmlessly out to sea, we can predict the weather with much greater accuracy. Longer-range forecasts are also possible. With that in mind, and with the hurricane season underway on the heels of an anomalous winter, The Parklander talked to two weather experts. We wanted to get their take on both the 2012 hurricane season in south Florida and this year's weather for the U.S. in general.
|Mike Smith is a board-certified consulting meteorologist, a fellow of the American Meteorology Society, and the author of two books, Warnings: The True Story of How Science Tamed the Weather and When the Sirens Were Silent. He is senior vice president of AccuWeather Enterprise Solutions.
Smith says that AccuWeather is predicting this hurricane season to be normal or featuring slightly fewer storms. But he reminds us that what's important to any given area is not the number of storms but whether one makes landfall in the region. Hurricane Andrew occurred in a below normal season, but no one in the Homestead/Miami area would describe 1992 as a mild hurricane season.
"All it takes is one storm to disrupt a person's life, so it's important to be prepared and not be lulled by the comparatively mild forecast," Smith says.
What's behind his forecast? The main factor is that La Niņa, in the Pacific, is gone. The water in the equatorial eastern Pacific is neutral in temperature, a condition that usually brings a mild season.
But since the real question for us is whether any hurricanes will make landfall in this area, what are the factors affecting that likelihood? According to Smith, we need to look at the Bermuda high, an area of high pressure typically near or a little east of Bermuda, which is what principally steers the storms. "A hurricane is like a block of wood floating on a river," he says. "Where that Bermuda high is centered orients the flow of air toward south Florida. If the high is farther east than usual, hurricanes tend to curve north and parallel the U.S. east coast, while if the high is farther west, it will steer the hurricanes more toward south Florida."
Unlike some weather conditions that can offer a clue to long-range forecasts, the Bermuda high's location is predictable no more than four to five days out. The likelihood of a hurricane making landfall in our area this season is not something Smith is able to forecast.
In terms of other weather events, he says that in neutral (as now) and El Niņo conditions, south Florida tends to be wetter, so we are likely to have a rainier-than-usual rainy season. (This in no way predicts, however, the likelihood of a hurricane hitting here.)
Smith was asked about the weather anomalies of the past winter, when this region and much of the rest of the nation had a downright balmy winter. As we turned the corner into spring, the Midwest saw an early outbreak of severe tornadoes. "What people don't realize," Smith pointed out, "is that while the U.S. east of the Rockies had a much milder than usual winter, Europe was having one of its coldest winters ever, and world temperatures in January and February were actually colder than normal.
"The tornado season got off to a pretty fast start but has been mild in late April and early May. There is no reason to assume we are in for a more severe weather pattern than usual this summer nationwide."
Asked what, if anything, the winter's anomalies portend for the rest of the year, he says that there are no signs of anything unusual. "Because we have neither a strong El Niņo or La Niņa, there is no indication of an unusual weather pattern this year," Smith says, adding that it is too early for an opinion of next winter.
Chris Orr is a certified consulting meteorologist with 32 years of long-range weather forecasting. He is a consulting meteorologist with Weather Briefings.
Orr concurs that the number and intensity of Atlantic storms this season should be normal or slightly below the usual number. "I wouldn't expect to see more than six or seven actual hurricanes," he says.
He adds this caveat, "We may see a higher than normal number of hurricanes this year -- perhaps three to five -- develop over the Gulf of Mexico."
The reason? "The Atlantic is cooler than normal, but the Gulf is warmer than normal," says Orr. "Extra ice in the Arctic areas has been brought down by the currents along Europe, and these cooler waters extend down to West Africa. The cooler water will keep the number of hurricanes down, as they feed off warm water. In the Gulf, however, the warm weather [of this past winter] didn't allow enough cool air to get into the Gulf to cool the waters, so we're starting out with warm waters."
Among the factors that affect the likelihood of storms making landfall here, Orr cites the question of whether there is enough warm water to direct a hurricane right toward south Florida. "It almost looks like the tropical storms and hurricanes that form over the Atlantic will tend to move toward the middle of the Atlantic but not so much toward Florida," he says.
He sounds a reminder, "We're not used to seeing a lot of Gulf storms in recent years, so we're going to be seeing something different."
As for this year's weather nationwide and in south Florida, Orr points to something called the North Atlantic Oscillation, a pressure difference between Iceland and the Canary Islands. "The jet stream flew straight across the Atlantic without any ripples," he says. "Ripples cause the variation in temperatures and storms, and we didn't have those, so we wound up with long periods of warm weather and not as much cold air coming down from the Arctic...The tornadoes resulted because there was more moist air available than usual because the Gulf of Mexico was warmer than normal."
Looking ahead, he sees above normal temperatures nationwide and around normal rainfall. For the balance of the year, the northeast should be drier than normal, and this coming winter should be a lot stormier nationwide. The upcoming winter will be wetter than normal in south Florida.
All in all, it is not the worst of forecasts for us here. But remember what Mike Smith warned in connection with Hurricane Andrew -- all it takes is one.