Good Grief, Cat. 5 Hurricane

[DeepFrz]

There are some phenomenal pictures of the power lines and transformers exploding on the weather channel. Hardened power grid? I think not.

[DeepFrz]

National Data Buoy Center for ocean buoy data. I've noticed this in other storms as well. Even buoys directly in the path of the storm do not show hurricane force winds at any time during their passing. Anyone know why this might be?

Its the effect of surface drag. Go up to mast height and the wind will be significantly stronger. Go up 100 ft. and it will be stronger still.

[jimbunyard]

Originally Posted by SVNeko

National Data Buoy Center for ocean buoy data. I've noticed this in other storms as well. Even buoys directly in the path of the storm do not show hurricane force winds at any time during their passing. Anyone know why this might be?

There are many factors in play. For instance, the buoy at Settlement Point in the Bahamas (actually a [nomimally] land station) showed a peak wind of 91 knots yesterday, with the pressure still dropping rapidly (i.e. before the eye got there), before going off-line, probably due to power or equipment failure.

The size of the wind field within the storm has a very large effect also. Mathew at several points seemed tightly wound up; while the peak winds were very strong, they were very limited in area, with hurricane force (over 70 knots extending 'only' 20 miles on either side of the eye. This means that, even given the comparatively abrupt velocity changes within the eyewall, one must take into account a gradient of some sort between that 70 kt minimum and the 140 kt maximum closer to the inner edge of the eyewall.

For actual, floating buoys there are just as many variables. For starters, the violence of the sea in a hurricane will rarely let the smaller buoys remain on line throughout a hurricane, even the large ones rarely do, so they usually don't get to tell the actual complete story. Also, being on the waters' surface has a pronounced effect, normal sea state in a minimal hurricane is going to be at least 25-30 ft, so the wind at the (relative) surface is not going to be close to the actual sustained wind because of wave interference. In a strong, slow moving storm, swell of 40 feet is common. In Katrina I remember seeing 52 feet significant wave height on buoy 42040, 70 miles south of the mouth of Mobile Bay. This translates into a calculated 100 ft maximum wave height. Maximum wind speed recorded at this buoy was 72.55 kt.

An idea of the violent seas in that storm; a mid-gulf 10 meter buoy, 42003, capsized during it, a first for the NDBC's history in the Gulf.

The point is, I suppose, that the numbers given for 'maximum sustained wind' should be taken as a proxy measurement for a storms' relative strength. This value is generally calculated and/or extrapolated from a variety of factors, including dropsondes, flight level winds and pressure observations. While it's human nature, at least for me, to have a hard fast number ("I measured 64 knots on my anemometer"), sometimes "it was blowin' its' ass off" is a more accurate assessment...

[a64pilot]

Originally Posted by DeepFrz

There are some phenomenal pictures of the power lines and transformers exploding on the weather channel. Hardened power grid? I think not.

An issue is, do you want to pay say a 20% higher utility bill for years and years so that one day maybe 10 yrs down the road the power will stay on?

Yeah, I wouldn't either.

[HopCar]

Driving to work this morning I passed a big parking lot filled with bucket trucks.
There must have been at least fifty of them. There were also several big flat beds loaded with lights and generators. The trucks were owned by various electrical and tree trimming contractors. I passed more trucks headed that way.

I'm sure they will be forming a big convoy heading north to help with the recovery.
This is just Miami. I'm sure similar convoys are forming in many cities on the East coast.

After Andrew, it was a crew from Georgia that restored power to my street.

[HopCar]

Originally Posted by DeepFrz

There are some phenomenal pictures of the power lines and transformers exploding on the weather channel. Hardened power grid? I think not.

There is no practical way to prevent the power grid from going down in a hurricane. All you can do is make it as easy to repair as possible.

I know, you're going to say bury the power lines. That certainly helps but there are draw backs. It's horribly expensive and it still doesn't prevent large portions of the system from going down. Parts of the system have to be above ground and they are vulnerable. Even buried lines are torn up by the roots of falling trees. A buried line takes much longer to replace than an overhead line.

My neighbor shares the same transformer with me. His line from the pole to the house is buried, mine is overhead. We both lost the connection to the pole during Andrew. The same falling tree that took out my overhead line, pulled up his buried line. My power was restored in ten days. He was without power for over a month. He now has a whole house generator and a big tank of propane. I hope to do the same soon.

Yes once I got power we ran an extension cord to his house to help out.

[a64pilot]

Originally Posted by HopCar

After Andrew, it was a crew from Georgia that restored power to my street.

As of this morning it was reported that there were "hundreds" of trucks filled with "thousands" of linemen in Adel Ga determining which way to head when the storm is past, either East or South is the bet.

Now the news has a tendency to exaggerate that is why I put the numbers in parenthesis, but the fact is that pretty much all of Georgia Power's linemen and equipment is standing by ready to go, of course I don't think anyone expects them to rush headlong into the Hurricane.

[HopCar]

Originally Posted by a64pilot

As of this morning it was reported that there were "hundreds" of trucks filled with "thousands" of linemen in Adel Ga determining which way to head when the storm is past, either East or South is the bet.

Now the news has a tendency to exaggerate that is why I put the numbers in parenthesis, but the fact is that pretty much all of Georgia Power's linemen and equipment is standing by ready to go, of course I don't think anyone expects them to rush headlong into the Hurricane.

After Andrew I bought a commercial ice maker and hooked it up in my store which still had power and water. I started carrying ice down to my friends in Homestead which was very badly hit. I ran across a convoy of church folks from Georgia that had come South to help. They asked me for directions. I pointed them in the right direction, handed them my map and thanked them profusely.

[charlystsimons]

Guys,
sure would like to know how the east coast fared the storm. We are waiting to get back into Brunswick to check on our boat. The reports we have seen are that the marina there is fine with little or no damage.
Anyone have any first hand news from florida or south carolina? Savannah?

[Boatguy30]

Many boats sank and damaged at conch house when docks broke up and topped the pilings. It appears several boat also broke loose in mooring field.

It looks like only one anchored south of 312 went ashore.

Lots of homes flooded on the island and businesses downtown.

Really pretty minimal wind damage all storm surge which was only about 4-5' in my canal.

[charlystsimons]

Thanks for that. Hope you got through OK. Is the Conch house downtown there at
the old Santa Maria?

[Boatguy30]

We have some water in Florida room and outbuildings. Boat is good.

Conch house is on salt run. Very exposed similar situation to the place that broke up near you. But more damage to boats

[Mikado]

Originally Posted by charlystsimons

Guys,
sure would like to know how the east coast fared the storm. We are waiting to get back into Brunswick to check on our boat. The reports we have seen are that the marina there is fine with little or no damage.
Anyone have any first hand news from florida or south carolina? Savannah?

My boat is at the Titusville city marina on the ICW in Florida where 106 MPH winds were reported. Fortunately the marina is in a basin with a large natural seawall and we are in an area on the ICW with very little tide. As far as I know, none of the 200 or so boats in slips were damaged. The city just had huge dock pilings installed a few years ago so I'm guessing that really paid off.

A couple hundred yards outside the marina entrance is the mooring field. Several boats ended up on the rocks. Not sure if they were at anchor or on mooring balls.

[skipmac]

Originally Posted by GoingWalkabout

Sorry to disagree. This storm was very well tracked with little to no uncertainty a week out.

Sorry but I have to disagree with this. My boat is just south of Jacksonville and I have been tracking the storm since it was a depression, 4-5 times every day. Until a few days ago the track was a good bit further off the coast. Not hundreds of miles but far enough to greatly reduce the winds and impact at least along the FL coast. It was just a few days before it hit that the track was moved west to hug the coast and to make the 360 degree loop and head back to south Florida instead of tracking north to possibly impact the NE.

[skipmac]

Originally Posted by charlystsimons

Guys,
sure would like to know how the east coast fared the storm. We are waiting to get back into Brunswick to check on our boat. The reports we have seen are that the marina there is fine with little or no damage.
Anyone have any first hand news from florida or south carolina? Savannah?

I was in Green Cove Springs, about 30 miles south of Jacksonville and 20 miles from the coast. Of the 21-22 boats in the main mooring all but 8 broke free or dragged. I saw no boats toppled that were hauled out.

I have family in Savannah, mostly the west side so not so close to the ocean. On land at least it wasn't too bad there. I heard it was pretty bad in Charleston.

In Florida along the coast it was very bad. Lots of flooding, lots of power outages, A1A washed out.