Atlantic Sat Image

Atlantic Sat Image
Clouds over Atlantic

Monday, August 30, 2010

Hurricane Models like Athletes?

Many questions have arisen regarding the potential track of Earl and rightfully so. We all remember Hurricane Andrew with a similar track in 1992 and Hurricane Charlie in 2004. Charlie was expected to hit Tampa , but at the last minute changed course making landfall father South near Punta Gorda.

I have received countless e-mails, calls and texts regarding this question... "are you sure Earl wont hit us?" The truthful answer is no. Nothing is ever certain.

We rely heavily on highly complex and specialized computer models. Their forecasts are as good as the information given to them. Many, like athletes go on streaks. Some models will nail down every forecast one year, and fail miserably the next. Its up to us to figure out which one is at the top of its game. This year, in my opinion, it's the CMC.

I have been following the CMC model since the beginning of the hurricane season, and thus far, it is performing the best. Accurately forecasting all the tracks ( even the loop that TD 5 made over the Southeast ) and possible landfall sites.

It has been showing Earl getting pushed along to the west by the Bermuda high and then at the same time, a trough ( a weak front, accompanied by an elongated area of low pressure ) moving off the Atlantic seaboard. This traps Earl and sends it to the north becoming a worry for the middle Atlantic states down the road.

Check out the CMC model run on this link:

Everything in blue are areas of low pressure, in orange high pressure. You will find Earl as a tight circle east of Puerto Rico. On the right hand of the page (on some it may be way at the bottom) click on fwd and see the animation take Earl to the East Coast of the USA.

Because the CMC has been accurate so far, I feel confident in its track. Still, models like athletes, can have an unexpected injury or slump so keep monitoring is track just in case mother nature throws us a curve ball.

Thursday, August 19, 2010

Get a Grip!

NASA is really getting into hurricanes! Within the next few months they will deploy a handful of planes to study how hurricanes form and why they grow in strength so rapidly. The program is called GRIP. G for Genesis (relating to the beginning or birth of hurricanes) R for rapid, I-intensification and P for process.

The research will take place over the peak of hurricane season between August and September. It is hoped that the data will help forecasters determine the recipe for hurricanes, and that it will provide the keys for determining how and why they grow in strength.

The research will take months, but it will be worth it for all of us.

Link to the site below for a small video from NASA regarding GRIP.

Tuesday, August 17, 2010

Quiet Cape Verde, so far....

Hurricane season began June first and runs through the end of November. This of course is a man made timeline as storms can brew at any time of year as long as there is sufficient energy.

The primary source of fuel for hurricanes is warm ocean water of at least 80 degrees. Obviously the span from June through November is when the sea surface temps are the warmest and thus this is our hurricane season.

Hidden within this season is a smaller and more active grouping of months known as Cape Verde Season, usually kicking off around August and coming to an end by October. It is so called, because hot pockets of air come off the West Coast of Africa, move over the Cape Verde Islands, and then if the conditions are right, can grow into hurricanes. They move over the entire Atlantic picking up plenty of energy turning many of these Cape Verde Systems into monsters.

One great example was hurricane Andrew in 1992.

If we narrow our focus, we can see that activity picks up in August and reaches its peak in September. This search shows the amount of tropical systems sprouting between 1851 and 2009. In AUGUST there is a total of 352 systems while in SEPTEMBER it skyrockets to 540.

Experts are still predicting an active 2010 with around 20 tropical storms , above the seasonal average of 11. So far we've only seen Alex, Bonnie, and Colin. Up to this point it has been a rather dull and quiet season. Why? A few items come to mind. A strong Bermuda high, an expansive SAL or African dust plume in the atmosphere, and an unimpressive La Nina event.

Top scientist still warn that La Nina will rear its head soon making conditions better for hurricanes to grow, so we must remain vigilant. Some long range models, specifically the CMC has been on the mark this year forecasting activity and its calling for something to develop off the Cape Verde islands within the week. Hopefully it will be wrong. I would hate for our uneventful season so far, to come to an end.

Sunday, August 1, 2010

Why we should watch INVEST 91

A wave that came off Africa on Saturday has already developed a low pressure center of circulation. It appears it will not meet the same fate that a previous wave did on Saturday. Late last week a vigorous wave pushed into the eastern Atlantic, only to be choked by dry air, suffocated by African dust and squeezed by this new wave.

This new low , known as INVEST 91, will stay South of all that hostile activity steering over warm ocean waters with very little shear ahead of it. Most models intensify the low taking it near the Lesser Antilles as a Tropical Storm in 5 days. If it does grow into a storm, it will be called "Colin".

The models are pretty much in agreement over its future path, but not so much in its intensity. This worries me a little more than usual and here is the reason why. It may travel through the "Hebert Box". What in darnations is that?

This Box was named after Paul Hebert, once a director of the local National Weather Service office, and former forcaster for the National Hurricane Center. I was fortunate to be proctored by him during my early Weatherman days in the 19... lets say a while ago.

His research of past hurricane tracks lead him to a theory that says: Nearly every Major Hurricane that has hit South Florida since the start of the 20th century went through these boxes.

The boxes are located in the Atlantic and Caribbean. The first box is found east of Puerto Rico and the second box is located over the Cayman Islands. He adds that storms don't have to go through the boxes to hit us but if they do you have to watch out.

The pattern has proven accurate for 9 out of 10 storms that developed & hit Dade,Broward & Palm Bch Counties.

Now compare Box 1 with the latest model runs regarding INVEST 91... it just makes you wonder.
So what does this all mean? Right now nothing. But it is worth watching as INVEST 91 makes its way closer to the Hebert Boxes.