Archive for May, 2009

World of Hurricane Protection Show in Tampa

Friday, May 15th, 2009

It was good to see so many of our dealers at the WOHP Trade Show in Tampa last week and we trust you found it as worthwhile as we did. It was especially good to see our representatives from Texas and Louisiana and hear that business is picking up in those areas. Business has also been picking up steadily the past few months throughout Florida. We had a very good April and May has started out strong. We anticipate another very good month as we move into our busiest time of the year.

We received a great deal of interest in our new dual screen system that incorporates a solar screen and a hurricane screen together in one unit. We have received many inquiries over the years about using our Storm Catcher screens to provide shade, keep out bugs and even sold them in northern Canada to keep snow off people’s decks during blizzards. The display we had at the show featured two motorized screens in a dual track; the solar screen in front and the hurricane screen behind. The solar screen requires a less powerful motor than the hurricane screen and the motor we used is powered by a small solar panel and battery. Though the solar screen is in its developmental stages, we believe this is the wave of the future and we will soon have it available for our dealers.

Thermohaline Circulation And Its Relation to Hurricanes

Friday, May 15th, 2009

From: Colorado State University

Net Hurricane Activity, Atlantic Conveyor Belt Are Factors In Colorado State University’s Landfall Prediction Model

FORT COLLINS-Hurricane records since 1900, estimates of damage potential and a theory that a period of more intense hurricane activity may be beginning all contribute to a new statistical model that predicts hurricane landfall probabilities along the U.S. coast.

Developed by William Gray, Colorado State University professor of atmospheric sciences, the model charts landfalls along the entire coastline from Brownsville, Texas to Eastport, Maine; 11 arbitrary segments of coast; and 100 kilometer (62 mile) stretches of coast, assigning each a probability.

These probabilities, expressed as percentages, indicate the chance of occurrence in 1998. For example, a 2 percent chance that a hurricane will make landfall upon a given 100-kilometer coastal section means there is a 1-in-50 chance that a hurricane will strike that area this year.

An important element in Gray’s model is the Atlantic Ocean “conveyor belt,” or Atlantic thermohaline. This circulation system moves Atlantic waters northward from the vicinity of the Caribbean to an area east of Greenland. There, the current sinks to deep levels, moves southward and flows into the South Atlantic Ocean and beyond.

Warm water in the conveyor belt – perhaps one degree Fahrenheit above the average North Atlantic sea surface temperature of about 45 F in the regions west of the British Isles – is associated with more intense hurricanes and more landfalls along the eastern seaboard, Gray said. Cool water tends to dampen hurricane activity.

During the period from the late 1920s to the late 1960s, generally warmer sea surface temperatures led to processes that produced more intense hurricanes than did the quarter-century periods from 1900-25 and 1970-94, Gray’s data show.

Gray’s model requires a seasonal forecast of “Net Tropical Cyclone” (NTC) activity, a statistical averaging of overall hurricane activity for a given year, in combination with sea surface temperature anomalies in the North Atlantic. Gray calls the latter “a good proxy measure for the strength of the Atlantic Ocean thermohaline circulation.”

An increasing NTC forecast number and strengthening thermohaline circulation increases the probability of major or intense (Category 3-5 on the 1-5 Saffir-Simpson scale) hurricanes’ landfall.

“When the season’s especially active you get many more intense storms making landfall than you would during an average season,” he said. “In general, the more hurricane activity you have, the greater the probability of landfall.

“While it’s been suggested that our general forecasts (Gray heads a research team that has been issuing seasonal hurricane forecasts for the Atlantic Basin for the past 15 years, with above- average success) have no meaning in relation to landfall, they certainly do. With active seasons, you get a much higher probability of landfalling storms of Saffir-Simpson 3-5 categories.”

Gray took hurricane activity for the past 98 years and calculated the ratio of the most active 33 years to the least active 33. The ratio was eight to one. He says that simple comparison, and the historical record, support his contention.

“We got so many landfalling intense storms along the U.S. East Coast in the 1940s through the 1960s that the NTC simply doesn’t explain it all,” he said. “You also have to take into account the Atlantic Ocean thermohaline circulation.”

And, since North Atlantic sea surface temperatures and salinity contents have been rising since 1994, Gray believes the Atlantic conveyor belt may again produce conditions that will generate more intense hurricane landfalls in coming years.

Curiously, the connection between the conveyor belt and Gulf Coast landfalling hurricanes is very weak to non-existent, Gray said. Nonetheless, in an active year, the Gulf Coast remains more prone to landfalls by major hurricanes than in a weak year.

Gray said that while the NTC and Atlantic thermohaline circulation are fundamental features of landfall probability, they do not work in all years.

“Andrew came into South Florida in an inactive year (1992), and Alicia (1983) came into Houston in an otherwise inactive year and did a billion dollars worth damage,” he said. “Those are exceptions to the general rule, however. Most of the landfalling storms this century come in active years. For example, 1985, 1989, 1995 and 1996 were all active years with intense hurricane landfalls by Elena in 1985, Hugo in 1989, Fran in1995 and Opal in 1996.

“Despite the exceptions, the model does mean something in terms of long-term probability.”

2009 Hurricane Season Preparedness

Friday, May 1st, 2009

The following story was written by Dr. Steve Lyons of The Weather Channel and appears on www.weather.com

Many of you are familiar with the Atlantic seasonal forecasts of named storms and hurricanes. At The Weather Channel we do NOT make seasonal forecast, instead we have tried to provide the message that it only takes one to hit your area so be well-prepared every hurricane season regardless of these forecasts. But each late winter/spring leading up to the June 1st start of hurricane season it happens, first whispers of the season outlook that turn into talking about them and finally preoccupation with them. Often there is a slant toward how terrible hurricane season is going to be; more rarely how mild it will be. Just remember it will be a very bad and memorable hurricane season, even if there is a total of only one Atlantic hurricane, if that one strikes your area! Below I attempt to give a perspective on the early forecasts for 2009 and how one might interpret them. Keep in mind that there is some sound (although highly volatile) science involved in making some of these forecasts, in others I am uncertain how the numbers are arrived at. In any event, this is not an attempt to demean these forecasts or the people or companies that make them. Instead it is written for you and how you might react/respond to them.

OK, we first have to examine some of the 2009 forecasts that have been put out there thus far; so I list some of them you may find in the news or on the web. I am sure you can find additional forecasts, but I will focus on these for simplicity.

# Named # Hurricanes # Major Hurricanes
Colorado State/Bill Gray
NOAA/National Weather Service
Weather Services Inc.
Accuweather
Wx Research Center
14
**
13
13
7
7
**
7
8
4
3
**
3
2
-

** Not yet released.

As a reference frame for you to relate to these forecasts, I show below a long-term approximately 50 year, the average since the Atlantic “active era” began in 1995, and the active era minus 2005. Keep in mind that the huge 2005 hurricane season was extremely anomalous with 27 named storms, so I also show the active era average excluding this very anomalous year.

# Named # Hurricanes # Major Hurricanes
Long term average
Average 1995-2008
Average 1995-2008 (minus 2005)
11
15
13
6
8
7
2/3
4
3/4

Now it becomes clear that three of four 2009 hurricane season forecasts currently available are close to a climatological forecast of “average” relative to the past 14 years minus 2005. The Weather Research Center forecast is only about 60% of that average. Their forecasts have seemed to consistently be lower than most other forecasts, but because of that they did better than others in 2006! One interesting thing is that within the 14-year period since 1995, the actual number of named storms has routinely departed from average with a low of 9 named storms in 2006 to a high of 27 name storms in 2005 (19 in 1995); so there are very large year-to-year variations in the number of Atlantic Basin named storms.

Note that all of these forecasts are for the entire Atlantic Basin and do not necessarily have anything directly to do with how many might strike the U.S. coastline. It turns out that within the recent active era (1995-2008), the relationship between the number of Atlantic storms that formed and the number that struck the U.S. was poor; for example, only about 15% of U.S. storm and hurricane landfall variations are explained by knowing “exactly” how many storms and hurricanes formed in the Atlantic Basin after the season ended (this assumes a perfect seasonal forecast)! More importantly, Atlantic Basin forecasts say nothing about how strong or where a storm or hurricane might strike. Wording within some of these seasonal forecasts provides general information about U.S. strikes and/or strike probabilities, but verification of them in a scientific manner would take years of forecasts and verifications to identify any meaningful skill of being correct compared to chance/guessing. Of course someone “could” take an approach of forecasting landfall in a specific area over and over again year after year, and just by basic climatological probabilities of where storms/hurricanes hit the U.S. coast, eventually they will be successful in one year, but they will have provided many forecasts of false alarm to the public, there is “no skill” in this approach.

So where does this leave us? IF I could tell you with 100% certainty a hurricane will strike your coast on September 10, 2009, would you do anything between now and then? Obviously no one can make such a forecast with any skill. So you should be ready, ready just as well every year for a potential hurricane strike. Eventually one will come to your coast, it could be in 2009 or it may be 100 years from now, but the potential for great disaster requires you to be ready just like when you put on your car seatbelt each time you start your car, never expecting to get in a crash. Be ready to put on those house shutters and get out your pre-prepared hurricane plan of action. Then you can sit back like I do and muse at how each seasonal forecaster and each media outlet feeds you these curious, but relatively inapplicable long-range forecasts.