Everybody was told this Spring that this would be one very busy hurricane season—- perhaps rivaling 2005 which brought us Katrina and Rita. However, not much as happened this year. Alex formed early and seemed to be right in line with the predictions. But then Bonnie fizzled as it made landfall and Colin died almost as soon as it formed. So what is the deal? Are we out of the woods? Or are we about to be slammed by hurricane threat after hurricane threat during September and October? Recent article by Eric Berger in the Houston Chronicle gives us a glimpse into the hurricane possibilities over the next two to three months. His article ran in the August 18th edition of the newspaper:
Slow Hurricane Season May Quicken
The peak of hurricane season is nigh, but glancing about the tropics one would hardly know it. So far the Atlantic season has missed the fevered expectations of forecasters who predicted this year might become one of the most active on record. It’s been 11 days since weak little Tropical Storm Colin died in the deep Atlantic, a long stretch to pass without a storm in mid-August.
Although the tropics remain quiet for now, there are indications that may soon change, with the season’s first major hurricane potentially developing next week. “Some models are indicating as many as three storms will develop over the next few weeks,” said Chris Hebert, lead hurricane forecaster for Impact Weather, a Houston-based private forecasting service.
“Several of these are predicted to be strong hurricanes by the models. I think that this will really be the start of the hurricane season.”
The 2010 season began in late June with a bang. Alex, which struck Mexico, became the first Category 2 hurricane to develop in June during the Atlantic hurricane season since 1966. But since then it’s been incredibly quiet out there, with only two minimal tropical storms. Historically, for a normal season with 10 or 11 named storms, we’d expect to have had three by now.
Another measure of seasonal activity is accumulated cyclone energy, or ACE, which essentially sums up total storm activity across a basin. During a normal hurricane season the ACE value is around 100. Before the season began the National Oceanic and Atmospheric Administration predicted an ACE value of around 210 this year.
It’s still early in the season — most of the strongest hurricanes come in late August, September and early October – but the 2010 season’s present ACE value of 10.7 is still 50 percent below a normal year at this time, according to Ryan Maue, who recently received his doctorate in meteorology at Florida State.
Hebert attributed the season’s sluggish start to a strong ridge of high pressure over the eastern U.S. for much of the summer. In addition to giving Houston its warmest start to August ever, the ridge generally has brought sinking air across the western Atlantic Basin, and sinking air makes it hard for storms to develop.
As cool fronts begin pushing into the northern United States, however, the ridge is weakening, Hebert said. In the tropical Pacific Ocean La Niña is strengthening as predicted, which also favors storm development. And finally, sea surface temperatures in the Atlantic where most storms develop remain at record levels, even higher than during the record 2005 season.
“So there is a tremendous amount of heat energy available,” Hebert said.
Hebert said instead of initial predictions of 18 named storms and an ACE value of 200, more realistic predictions with the season’s slow start are 15 named storms and an ACE value around 150. At present forecasters are watching a tropical wave in the central Caribbean Sea, which isn’t expected to develop, and a vigorous tropical wave coming off the African coast. Some models forecast this wave to become an intense hurricane next week, although it appears increasingly likely the system will turn north into the open Atlantic.
For Houston, time is running out to see a hurricane strike this year. Although hurricane season does not officially end until Nov. 30, the state of Texas has been hit by a hurricane just three times in the past 150 years after Sept. 24.
So, bottom line, keep monitoring the tropics. Make sure you have a plan and you have an emergency kit. Be ready!