06 September 2004

Frances exits stage left, another storm that may be known as 'Ivan the Terrible'...

From Jonathan Vigh: 
 
Hurricane Frances was downgraded to Tropical Storm Frances at 5 pm EDT. What
is remarkable about this fact is that she made it nearly to the other side
of Florida before being downgraded. Lumbering along at 5-7 mph, her large
circulation has been very slow to weaken. Frances has now affected nearly
the entire Florida Peninsula, bringing at tropical storm force gusts all the
way from the Lower Keys up to Jacksonville. Hurricane-force gusts have been
felt along Florida's east coast from Palm Beach county all the way up to
Saint Augustine. There have not been very many reports of peak winds yet,
but there have been anecdotal reports (or estimates) by the media and others
of 100+ mph winds right along the coast. Port Canaveral reported a 124 mph
gust, but it is not known at what height this measurement was taken. Winds
almost always increase rapidly with height just above the ground, so if this
was measured on a tall tower it would not be representative of the actual
winds (the standard height to take wind measurements is 10 meters). Inland,
Orlando's main airport reported gusts as high as 69 mph (in contrast, they
had gusts to at least 105 mph in Charley), and wind gusts of 95 mph were
reported around and on Lake Okechobee. 

Most of the damage so far seems consistent with a cat 1/2 hurricane. It is
likely that the most severe damage occurred on barrier islands which have
not been surveyed yet. Needless to say, Frances hit Florida hard. Unlike
Charley, where damage was extreme, but mostly confined to a 10-mile wide
swath, Frances left spotty damage across the entire state, but a general
swath of moderate damage about 100 miles across, mostly along the coast (not
very many people live inland in the path taken by the eye after landfall).
Beach erosion has been considerable. Frances has also been much less deadly
than Charley (so far -- however, many storm deaths happen afterwards due to
accidents, electrocutions, carbon monoxide poisoning, and the like). 2 were
reported killed in the Bahamas and 2 or 3 deaths are blamed on the storm in
Florida so far. Power is out to over 2 million households and businesses.
The total damage will likely be in the billions, but it is unclear whether
it will be more or less than Charley. 

But wait, the story is not done -- no, not even yet has Frances relinquished
her desire to cause grief to the state of Florida. She is just now emerging
out into the Gulf of Mexico north of Tampa and will have 12-18 hours over
open water before making a second landfall, possibly near Apalachicola. She
is forecast to restrengthen to a minimal hurricane by this time, so more
trouble is ahead. Since she is so broad, the actual point of landfall
doesn't matter very much and winds and more heavy rains will spread far
inland over Georgia and Alabama afterwards. The bend of Florida is very
susceptible to storm surge flooding, so this will be a factor as well.
Hurricane warnings are in effect from south of Tampa all the way to Destin.
Tropical Storm Warnings are in effect for nearly the rest of Florida except
the southeast coast.   

At 03Z, Frances was at 28.3N  82.7W, moving west-northwest at 7 kt with
sustained winds of 55 kt and a central pressure of 976 mb.

If anyone is getting hurricane fatigue, they may want to skip the next
section. Unfortunately, Africa has given birth to a monster. Just a few days
ago, cute little Ivan rolled off the coast with an interesting umbilical
cord stretching back to the motherland. Now, just a few days later, Ivan is
poised to become one of the strongest storms ever seen in the Atlantic.
Here's a brief recap of the amazing developments of the past day:

Sun 03Z 991 mb 60 kt
Sun 09Z 987 mb 65 kt Ivan becomes 5th Atlantic hurricane of the year
Sun 15Z 980 mb 75 kt Ivan rapidly strengthening
Sun 17Z 960 mb 100 kt Ivan becomes the 4th major hurricane of the season
Sun 21Z 950 mb 110 kt Ivan is now perhaps the strongest hurricane on record at such a low latitude in the Atlantic basin (preliminary)
Sun 03Z 948 mb 115 kt Ivan now a cat. 4 hurricane

It should be noted that all of these intensity measurements are based
completely on satellite estimates. A plane is scheduled to investigate Ivan
about 24 hours from now. By then, it may in all likelihood be a cat. 5
hurricane, as there is not much of anything that would bring a stop to its
rapid intensification. It wouldn't hurt to say a prayer for the safety of
the Hurricane Hunters and NOAA scientists that fly into these storms. 16
years ago, the first plane to investigate Hurricane Hugo was nearly lost
(you can read the story at:
http://www.wunderground.com/hurricane/hugo1.asp). 

The potential effects of Ivan could be indeed terrible. The first island in
the path is Barbados, where appoximately 278,000 people live. Under the
current track forecast, the storm may pass between Saint Lucia (pop.
164,000) and St. Vincent and the Grandines (pop. 117,000), sparing either
the deadly core (hurricane-force winds are only 35 miles across). Of course,
a slight deviation could produce a direct hit for either of these island
groups. The confidence in this forecast is quite high, and Barbados should
prepare as best as possible for a direct hit from a cat. 5 hurricane 36
hours from now. After passing the windward islands, the forecast track of
Ivan takes it over Hispanola, one of the poorest and most vulnerable areas
you could find (just this year, extreme flooding from an early season
tropical disturbance killed approximately 2000 people there). The extreme
rains are caused by mountains that reach up to 10,414 feet (and the
deforestation). Hispanola has torn apart many mighty storms in the past
(David, Cleo, Inez). It is still too early to say if this will tame Ivan, or
whether Ivan will even pose a threat to the United States. Regardless of the
ultimate effects of Ivan on the U.S., trouble is rapidly approaching the
Carribbean. 

At 03Z, Ivan was at 10.8N  49.4W, moving west-northwest at 18 kt, with
estimated maximum sustained winds at 115 kt and estimated minimum central
pressure of 948 mb. 


Please visit my tropical Atlantic headquarters.

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