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[aprssig] RE:Need Help in Fla

WB4GQK at aol.com WB4GQK at aol.com
Sat Sep 11 21:40:08 UTC 2004


>Jim,

>Good read..but tell 'em about your boat in Tampa (mud) Bay.. :)

>Clay AA3JY
>(via Winlink)


Hi All,

This message really has nothing to do regards ham radio much less APRS, but I 
believe it does carry some very important information regards Hurricane storm 
surge.

Clay and I go back a number of years when he was also sailing. Occasionally 
we would make contact on a marine oriented ham net and exchange comments. As a 
consequence we still exchange email to each other and that is the connection 
regards his message above.

The key point of this discussion is just how fast a storm surge can arrive 
and depart! My input deals with Frances which was a strong tropical storm whose 
"eye" passed just east of Tampa FL, crossing the upper reaches of Tampa Bay 
and exiting into the Gulf of Mexico near Dunedin. We began having winds out of 
the NE for several days before Frances passed just ENE of our house. Winds were 
in the 25-35 MPH steady with gusts to 45-50MPH. The wind began blowing the 
water out of Tampa Bay and pushing our boat away from the dock. Even when high 
tide arrived the water was 2-3 ft below normal high tide water mark. 

At my dock when the so-called "Spring Tides" arrive and then at low tide I 
have about 1 ft of water under the keel. The general range is 4ft for these big 
tides.  Otherwise about 2 ½ is normal range. 

As Frances approached the winds grew stronger and the Bay level went further 
down. When the "eye" was perpendicular to our location the winds were in the 
40-50 steady range with gusts to 65 out of the NE. Our boat was aground! In the 
21 years we have lived in St Petersburg I had never seen the water in the Bay 
this low!

Within a period of 1-2 hours the wind gradually clocked from the NE to the SW 
and started blowing water into Tampa Bay! Over the next 4-5 hours the water 
rose until it was 1 ft over my dock, and this correlated with low tide! The 
principal point is the water level changed close to 8 ft in 5 hours! Of course 
NOAA concluded we had a 3 ft storm surge in Tampa Bay. The 3 feet corresponds to 
1 ft over my dock at normal water level. But the point that seems to be 
overlooked is just how fast the total water level changed in Tampa Bay! It was a 
real eye opener (excuse the pun)

As the tide started rising  the wind kept pushing the boat into the pilings 
on our dock. By the time the dock was a foot under water one of my fender 
boards broke. I was using two 4ft long 2X4s secured to two 16inch X 24 inch 
fenders. So the 2X4s were pressing against the piling. The problem was the boat was 
heeling at the dock and the top fender board was taking the brunt of the force. 
It broke.  As a consequence the boat got some scratches right at the toe 
rail. 

I hope you find the reference to wind surge informative. This just gives me 
something to do while we wait for IVAN.

73 de Jim wb4gqk




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