When we first spoke with Adam Moyer, meteorologists were predicting an active 2007 hurricane season.  Obviously, the season has been very calm. Caribbean Travel News wanted to check back in with Adam and get more details.  Adam spoke with us from Bermuda, where he has been working for the Bermuda Weather Service.

CTN: When we last checked in, it looked like it was going to be a La Nina summer with plenty of Atlantic hurricanes.  Yet we've only had 3  tropical storms so far.  Why has it been so quiet?

AM: Indeed, last time we spoke it seemed as though the Eastern Pacific was going to be cooler than usual, which would be indicative of La Nina conditions. Since that time, however, sea-surface and below sea-surface temperatures have warmed in the East Pacific to near normal, and therefore neither El Nino nor La Nina, conditions. It goes to show how poor meteorologists and climatologists are at forecasting the state of ENSO (El Nino-Southern Oscillation) many months out.

It should be pointed out, though, that this season is only slightly below normal for this time of year. As the calender turns to the middle of August, the tropics begin to heat up and the frequency of tropical storms and hurricanes increases dramatically.

To answer why this season has been relatively quiet, especially compared to predictions, the answer is two-fold. First, June and July were very active months for Saharan Air Layers (SALs). Essentially, storms over Africa deposit dust from the Sahara Desert in the middle troposphere (about 15,000 feet up). The Saharan dust dries and heats the middle troposphere. Both of these conditions tend to inhibit the creation of tropical cyclones. Secondly, sea-surface temperatures have been merely average across much of the Atlantic. In 2004 and 2005, sea-surface temperatures were some 2-3C (3-5F) degrees above normal in the regions where we expect storms to form. All else being equal, regions of warmer sea-surface temperatures should have higher frequency of tropical storms.

That said, one shouldn't be too liberal with that statement and try to apply it to global warming. In a global warming sense, all things are not equal to what they currently are, and the latest research is divided as to whether global warming causes an increase in hurricanes.

CTN:  Will this relative calm continue?

AM: Relatively speaking, I would forecast the progression of the season to be near normal. Totals for the season should be expected to fall somewhere in the neighborhood of twelve to fourteen tropical storms, seven to nine hurricanes, and three to five major hurricanes. I expect that the season from here on out will start to become more active than we have seen. Just this week, Tropical Storm Chantal formed and a vigorous tropical wave is producing 55 mph winds in the Caribbean Sea. I think these events portend what the next two or three months will be like.

CTN: Travelers watch weather sites, like Weather.com, TheStormTrack.com, etc for hurricane predictions/reports.  Are there key indicators that we can follow to help monitor potential storms.  Like water temperatures in the Caribbean, etc.

AM: For long term forecasting, keep an eye on sea-surface temperatures and sea-surface temperature differences from normal. As the sea-surface temperatures hit their maximum in September, more hurricanes will form.

For short-term forecasting, read the National Hurricane Center's Tropical Weather Outlook, which they have expanded to a graphical product this year. The Tropical Weather Outlook will provide information as to where NHC thinks regions of disturbed weather could form into tropical storms. Also, my website, thestormtrack.com will be up and running smoothly once I get back to the States from Bermuda in September. Bryan has been busy with research and I have been forecasting for the Bermuda Weather Service all summer, so updates have been few and far between. That will change as the season heats up and the fall semester gets moving.


CTN: At what point can we stop worrying about hurricanes in the Atlantic? November?

AM: The National Hurricane Center defines the end of the Atlantic Hurricane Season to be November 31. This is mainly an arbitrary date, however. Some years, no storms form after the middle of October. Other years, like 2005, tropical storms were forming after Christmas. Obviously, 2005 was the busiest year on record, but I think the public can generally stop paying attention in November. If anything forms after that, it's usually strange enough that the mainstream media will pick up on it rather quickly.

CTN: Thanks, Adam.  Keep track of Adam's forecasts via www.thestormtrack.com.

Adam Moyer's background: Adam is a Ph.D. candidate in meteorology at Penn State University.  Adam is currently in Bermuda, forecasting for the Bermuda Weather Service. Website: TheStormTrack.com.