Wednesday, October 10, 2018

Hurricane Michael As A Worst Case To Consider

Some time during the mid '80s  or early '90s, after Mrs. Graybeard and I had moved into this house, the newspaper we got at the time (The Orlando Sentinel) published an article on a county Emergency Operations Center planning event.  The scenario was designed to tax the area's ability to respond to a worst case hurricane.  The scenario had the storm coming into central Florida from the east over open Atlantic to maintain strength the most until impact.  Then (IIRC) the storm slowed to a stop far enough off the coast to start lashing us with hurricane force winds while the hurricane intensified over the warm Gulf stream to chart-topping strength.  I think it intensified to a category 5 hurricane then came ashore slowly crossing the state east to west in the middle. 

The projected destruction was mind blowing.  Virtually nothing along the barrier island - what locals call "beach side" - survives a direct hit from a Cat 5 hurricane.  Very little within 10 miles of the coast survives.  Even very few of the buildings and launch structures on Cape Canaveral Air Force Station and the Kennedy Space Center were said to be able to survive a category 5 storm with a 15-20 foot storm surge.  I thought that blockhouses designed to survive an exploding rocket falling on them would laugh off a little 160 mph wind; the EOC said otherwise.  Or said they didn't do well under 15 feet of water. 

Long time readers might recall we caught a lucky break with Hurricane Matthew two years ago and had only tropical storm force conditions.  We had a Cat 1 storm conditions with Irma going up the other side of the state last year.  Before that, we had hits from Hurricanes Frances and Jeanne in 2004 (a few weeks apart) and Erin in 1995.  Going back to childhood, I lived through Cleo, Betsey and Donna.  Over the years, we've had more tropical storms than I recall because they're not really worth counting.  So I claim some level of "cred" when it comes to these storms. 

Today's Michael is the worst case I can recall.  The thing only got named on Sunday the 7th, three days ago!  Yeah, the precursors were there a few days longer, but only us weather geeks who check the tropical weather every morning know that.  The vast majority of people who got hammered today probably heard about it on Monday.  Or yesterday.  They either heard "evacuate NOW" or "your preparations must be rushed to completion.  Tuesday evening was too late.  This morning the storm was starting and it was way too late.  Then the storm did the worst thing it could possibly due, it explosively intensified right up to the moment of landfall.  Early reports are calling it Category 4 with winds at 155, which is 2mph below the low end of Cat 5, and the third lowest central pressure in history.  It's truly a storm for the record books. 

Yesterday, it was still a category 2 and then cat 3 storm until as late as 11PM (bottom of that page) with 125 mph winds.  Just 14 hours later the winds were 155.  Wind damage scales as wind speed squared, so the factor is 155^2/125^2, over 1.5 times as strong in 14 hours. 

When I look at storms like this, I try to figure out what I can learn from it.  Would I stay or would I go? 

The storm surge reports I've seen have been 9 feet or less, compared to forecasts of 12 feet.  Most of that is due to the shape of the gulf bottom helping the winds pile up the water along the shores of the panhandle east of Apalachicola.  One of the reasons I bought this house is that we drove around looking for neighborhoods that don't flood.  We're high enough above sea level that it would take much more storm surge to reach us.  Facing a cat 2 storm that everyone was saying should make 3, I would have stayed.  If I was on the beach a couple of feet above sea level looking at a storm surge higher than my house?  Aside from the fact I wouldn't live there, yeah, I'd get out. 

What if I had known it would make it to the cusp of Cat 5?  I don't think I could have known that in time, because we would have needed to be out by Tuesday evening.  I probably would have stayed until this morning when it was too late to go and treated it more like something serious.  Maybe camp out in an inner hallway with a mattress in case the roof leaves. 



15 comments:

  1. I've been following the radar returns of the storm and it looks like a whopper.

    Good to hear that at this time you dodged one. But like my buddy in Houston, you both *carefully* shopped for houses in areas that DIDN'T flood

    ReplyDelete
  2. Bless you and yours, SiG. Michael obviously decided to go fast and go heavy, no doubt taking cues from Trump. (That's a joke there, son, said Foghorn Leghor, voiced by, of course, Mel Blan_). I got through Harvey with the water fractions of an inch from my threshold, my son got through Florence there at LeJuene. Gonna hit God up for another solid for you.

    ReplyDelete
  3. Denninger says winds couldn't have been that strong, the damage doesn't match. I recall you showing data from official offshore buoys from some landfall, which were much lower than the official reports.

    But taking the question as stated, a retired guy could putter around all Winter installing 500 pounds of Simpson Strong-Tie type metal straps up in his attic, and no one would notice. What about burglar bars maybe spaced a little closer, and behind them the 3M retrofit plastic film which keeps the glass pieces in place after the glass is cracked.

    ReplyDelete
    Replies
    1. You mean to hold the roof to the trusses? Our house was built that way. After Hurricane Andrew hit south Miami in '93, there was a rush to improve the building codes. This house was built to the post-Andrew codes 15 years before they existed.

      Delete
    2. The building codes don't matter. Builders don't bother to build to them! In Andrew, it was discovered that a large number of houses had roof plywood held on by four or five nails per sheet (when code is every 8" along the middle-crossing trusses and every 6" along each end truss).

      Builders typically have flunkie-class people stick up the panels with just enough to hold them down, followed by higher-paid people who put in the rest of the nails. Clearly, they just don't want to bother with the second step.

      In the construction of a neighborhood I'm familiar with in Clearwater, the inspector would come in to pass all the steel in the concrete floor and foundation, and as soon as he left the whole crew would pick it up and carry it to the next house and they'd pour the first one without rebar.

      Codes are a meaningless tax as long as we allow fraudulent builders the freedom to screw us. And the inspectors don't care (or are bribed). They get paid either way.

      Delete
  4. Good luck sir, I hope the after effects are minimal. Michael sounds like quite the storm, Florida will be feeling the after effects for quite a while.

    ReplyDelete
  5. Just to be clear, we are so far from Panama City Beach area that we didn't even get a sprinkle of rain and no winds.

    It's a long, long way to where the storm came ashore. My son and daughter in law lived there for a year and we went up to visit. It's about an 8 hour drive, and you change time zone from eastern to central. After that, you're still an hour away from the west end of the state.

    This was just an exercise to make sure I think of what I can learn from the situation.

    ReplyDelete
    Replies
    1. It is 832 miles from Key West to Pensacola, but it is only 827 miles from Beaumont TX to El Paso. I prefer the drive in Texas, because at least the scenery changes. Florida is a huge, hot, damp, bug-ridden, boring place. I get to say that because I lived there for over a dozen years and paid my dues in the south, west, and north regions of it.

      Delete
    2. Florida is a huge, hot, damp, bug-ridden, boring place.

      Hard to disagree with that. A favorite story is my wife works with a woman who emigrated out of Africa. She said she preferred Africa because we have too many bugs - or "creep crawlies" as she put it. We have more annoying bugs than Africa??

      Delete
    3. Yep, you do!

      The most disgusting discovery I made was that cockroaches could fly, when one flew into my mouth as I left the house one evening. I have since thought that you could significantly alter the population of Florida by introducing a genetic modification that caused the cockroaches (ok, sorry, "Palmetto Bugs") to glow in the dark.

      Once people saw just exactly how surrounded they were, they would run screaming to somewhere else – anywhere else!

      Delete
    4. I've never caught one in the mouth, but have had one fly into my hair. Or seen them flying in the house.

      One of my earliest memories - must have been like 3 or 4 - is jumping on palmetto bug at a gas station one night. My parents bought into a place about as far SW in Miami as was populated in those days. I was roaming around while the car was being filled, saw this big roach and jumped on it. The BFR just kept on walking as if I hadn't done anything to it.

      Delete
    5. They are indestructable. I completely believe the research that says that if any life survives all-out global thermonuclear warfare, it will be these little guys.

      One spring, in the garden shed, I noticed that a dozen or so had fallen into a quart jar containing about an inch of motor oil and drowned. Not having the time to deal with it, I just set a quart oil can (remember those?) on top to seal it, then promptly forgot about it.

      Next spring, a complete year later, I was horrified to discover a thriving colony of mutant roaches (elongated, white, weird bits) living in the jar. Apparently, the eggs the others had when they drowned in oil had hatched and the population had been living on them and oil ever since.

      Think about that. It was well-sealed.

      Delete
    6. Oh, and: "BFR"! I love it!

      Delete
    7. Oh, and: "BFR"! I love it!

      Almost snuck that by. ;-)

      Delete
    8. Y'all are too hung up on them roaches and palmetto bugs. Hell, Biketoberfest is coming up. If you want to tell who the REAL bikers are, just count the number of cockroaches or palmetto bugs in their front teeth. The rest of them are merely poseurs and wannabes...

      Delete