Friday, April 22, 2011

Hurricane Conference 2011

The week-long hurricane conference held in Atlanta this year has come to an end. It was nice to run into some old friends and fellow meteorologists like Brian Norcross, now at the Weather Channel, Dr. Richard Knabb, formerly of NHC and now also with the Weather Channel, and former NBC6 and PLG 10 meteorologist John Gerard, now working in San Antonio. Hurricane guru Bill Gray was there as was former NHC director Max Mayfield. It was great to be surrounded by great minds and I made the best of it soaking up all the wisdom they offered.

Many things were discussed during the conference, from improving hurricane forecasting, to better communication of important information. Here is a summary of the conference:

Behind the scenes :
A clearer "Storm Status" identification will be issued for each advisory. In the past, even if a hurricane had downgraded to a tropical storm, the advisory would still say "Hurricane Name" and then in the following text it would say,"has been downgraded." Starting in May, all advisories will give the exact status of the system. Not a biggie, but very important when one is tracking multiple storms.

New this year, all The Tropical Cyclone Discussions will include both km/ and mph conversions. This is normally not a big issue until you've been on the air for 19 hours straight.

NHC is now offering a pronunciation guide for Storm Names. Remember Noel? Or was it No-el? Well NHC has eliminated the confusion by providing a list of the correct pronunciations. Here is this year's list.

Arlene ar-LEEN
Bret bret
Cindy SIN-dee
Don dahn
Emily EH-mih-lee
Franklin FRANK-lin
Gert gert
Harvey HAR-vee
Irene eye-REEN
Jose ho-ZAY
Katia ka-TEE-ah
Lee lee
Maria muh-REE-uh
Nate nait
Ophelia o-FEEL-ya
Philippe fee-LEEP
Rina REE-nuh
Sean shawn
Tammy TAM-ee
Vince vinss
Whitney WHIT-nee

Important information:
Nothing causes more damage in hurricanes than the storm surge. In the past, storm surge height was tied into the Saffir Simpson wind scale but this had a huge inherited problem... no coastline is identical. A cat 3 storm surge will be different in Miami as compared to New Orleans. Over the past few years NHC has been working on how to present the risk of storm surge to your coastal community.

Storm Surge Exceedance products will become operational this year. The exceedance graphics show the storm surge height, in feet above normal tide level, which has a specific probability of being exceeded in the next 3 days. The available probability thresholds range from 10 to 90 percent, at 10 percent intervals.

The cone is shrinking!
Due to the great work the forecasters have accomplished over the years... the forecast swath will be smaller. Forecasters tell me that since 1990 track errors have decreased by 60%. With this impressive stat, they are now reducing the dreaded cone.

At 12 hours out there is no change from before, but at 24 hours, the cone will be reduced by 59 nm, at 36 hours by 79 nm, at 48 hours by 98 nm , at 72 hours by 144 nm, at 96 hours narrowed by 190 nm, at 120 hours down to 239 nm. Keep this in mind, even though this is an enormous leap forward there is still risk.

Experts tell me that no forecast is ever perfect. Even today, track errors may be as large as 40-50 miles per day and with huge gaps in data out in the Atlantic it is a bit more difficult to gain full understanding of any system. As a matter of fact forecasters expect storms to go out of their forecast path a third of the time.

The intensity of a storm is another matter all together. While progress has been made since 1990 on track forecasting, no progress has been made on how strong a storm will be. Experts tell me that 48 hours into a forecast the intensity of a hurricane could be off by as much as one category.

The problems forecasters face are 1) The evolution of large scale environments 2) Oceanic environment 3) Structure of cyclone's inner core 4) Physical processes within the storm - ie warming of the hurricane. Experts say they need to understand more the ocean's impact on the storm to better forecast it's intensity. They are working on this and will hopefully have more tools and better forecasts in the next few years.

2011 season forecast: The official outlook will be released in May from NHC. You can expect another above average season as has been typical over the last few years, what we will never know is where any one of them will make landfall.

Please stay tuned to WSVN, on air, on the web, or on your smart phone for the very latest. We will try our hardest to keep you up to the minute when any system threatens.

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