Tuesday, September 5, 2017

"I Keep a Weather Eye on the Horizon"

To borrow a line from Mark Knopfler's "Cleaning My Gun".  Lots of my fellow Florida bloggers are keeping an eye on Irma and feeling a bit uncomfortable.  This morning, Irma has gone fully beast mode with sustained winds at 180 mph.  That said, it's not expected to stay Cat 5 for more than the next couple of days, and the models are having difficulty predicting what it does beyond three days. It's important to remember the area of the highest winds is actually pretty small, just the eyewall of the storm, but that lower winds can cover a large area over water.  McThag posts some computer runs from one of the good models (the GFS) for a couple of days that show how the wind fields can work out.

The current National Hurricane Center guys put up this 5-day forecast this morning:  
The way this is supposed to be read is that the storm can be anywhere in the stippled area at 8AM on Sunday.  The end location is about 500 miles in diameter, saying the center could be over the center of the state, or over southern Cuba which is the difference between hurricane winds over all of south Florida or not even having a nasty day.  

The morning spaghetti plot of all the models shows almost unanimous agreement that the storm is going to get picked up by an approaching low pressure system and turn north; the question is how soon it gets picked up and where it ends up hitting. 
Several of the models; the consensus if you will, have it turning right in the last 24 hours of that plot, and coming ashore somewhere on the southern tip of the state.  Some models have it turning much sooner, a few have it turning in the Gulf.  The largest difference is just where it tracks.  If it tracks along the center of the state it will weaken markedly.  If it tracks off either coast, it will be over some rather warm water and will weaken less.   

There's a difference between forecasting and reading computer models, but the NHC is pretty good.  Granted, they have a tendency to be melodramatic when a storm is close, they forecast a much, much worse scenario for Hurricane Matthew last October than we really got, but they still get pretty close.  I've read that they overstate the forecasts deliberately, saying that people won't evacuate unless they overstate it, but IMO that just feeds the cycle.  People see the overstated forecast (cat 4 hurricane onshore, death and destruction) vs. the reality (cat 3 storm well offshore, barely hurricane force winds onshore) and ignore the "official" forecasts. 

It takes two days to evacuate the keys, so folks down there should be getting out of town by Friday, maybe Thursday.  For us, midway up the East Coast, evacuation depends on what kind of storm we're getting and I don't see a way to know that for a few days.  I really doubt it could be a Cat 5 with any substantial land interfering with wind inflow, but if it stays off the East Coast, it could remain a Cat 4.  That would be exceedingly unpleasant, but I'm pretty sure the house would make it barring bad flying debris, a tornado, or something like that.  If it comes up the center of state, or rides the coast, I think it's cat 2 or cat 3.  I recall some storm in around '07 or '08, maybe Fay in '08, where the forecast called for it to intensify coming up the center of the state - I remember joking about that with co-workers wondering what planet something like that could happen on.  It did not intensify.

To steal a meme from Gunfree Zone
It looks like the next few days are going to be spent watching the path and how the big picture steering pattern develops.  Waiting to see when the storm turns right.  I think I've spent a couple of months of my life watching storms like this and trying to see when they turn right. 


16 comments:

  1. My step-mother in Cocoa Beach remained in her third floor condo during the one that ran up the coast during Matthew, when almost all of the other residents in her complex (~100 units in four or five buildings) evacuated. She said it got a little exciting at one point during the night, but otherwise she "weathered the storm" easily, and was glad she had elected to stay home.

    I'll echo Irish: stay safe. I 'm sure you and the missus have go-bags ready on the off chance things get pear-shaped. However, I'm told that the DNC has stated that - should the storm turn Left - they have arranged for a "safe space" for all of Bernie's people. Somewhere at Guantanamo.

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  2. I do not feel good about this one. Most of the shutters going up tomorrow - I have someone do it for me now. I will put the last few up. At least I don't have a boat in the water like 2004. My biggest fear is storm surge. I am about 10 miles from the inlet but have water just behind my property - no view though, it is a mangrove swamp.
    Do you have shutters? (For other readers, I am 65 miles South of SiG)

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    1. I do - the aluminum corrugated sheet system (look up POMA system at Home Depot). The addition we put on in '14 has hurricane windows that are rated for a 2x4 shot at 150 mph, so we haven't added shutters for it.

      I'm on the sand ridge that the FEC built its railroad tracks on - generally the highest land on the east coast. I think we're 22' above sea level, so only a monster storm surge would get here. Tropical storm Fay dumped 24" of rain here, the most we've ever had, and more than the '04 hurricanes combined. That didn't make it as high as the front yard.

      The shutters will probably go up Thursday. Maybe Friday, depending on what the track does.

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    2. Same ones I have. When I was a bit younger I put them up but it is just too much for me now. They are going up early because of the handy man's schedule.
      The railroad guys knew what they were doing.

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  3. Batten down the hatches and prepare for the worst would be my modus operendi.

    I'm sure you have been around long enough to know when to hold 'em and when to fold 'em.
    We are all keeping an eye on the weather lately, even us clear across the country on the Left Coast.
    Best of luck down there.

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  4. I'm scared out of my gourd!

    Good news about that is, I often over-freak where there's no need and under when there's real danger.

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  5. Just saw a great post at The Onion, SiG:

    http://www.theonion.com/article/coast-guard-drags-decoy-boca-raton-middle-ocean-at-56846

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  6. I've recently moved to the kitty-korner of the country from you ... no more hurricanes - nothing to worry about except wildfires and winter.

    Good luck with this one. My thoughts are with you. (Are you sure this isn't a good time to visit Nebraska or some such place?)
    Q

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  7. Here in SW Montana, we are surrounded by huge wildfires, instead. I prefer them to what happened to poor Texas, but I've lived through about ten different hurricanes (including being in the middle of Hurricane Opal in an RV when it passed through Mobile, AL, although the winds that hit us were only 75 mph), and I'd rather have one or two days of the average hurricane than the five or six weeks of choking smoke that has kept us indoors for most of that time.

    Nonetheless, I am indeed glad to be living out here away from the hordes of people in most of the other states I have lived in - including Florida. Good folks in all of them, just too many for my tastes.

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    1. It's like Roseanne Rosanna Danna said, "it's always something." We have a wildfire season, too. It's during the winter when the humidity goes from "bottom of the deep end of the pool" to "normal". Once in 35 years here, the summer thunderstorm machine didn't crank up and we had a bad summer fire season until the fourth of July.

      But we don't have earthquakes or mudslides or avalanches of any flavor. Tornado outbreaks tend to be rare. There are places in town that have flooded during insane rain events, but the reason I picked this place is we rented for a couple of years before buying and we'd drive around after the worst storms and look for the driest places. I suppose a train carrying something poisonous could derail and we'd have to evacuate, but by and large it's pretty easy to live here.

      I've always thought hurricanes are a lazy man's disaster. No need to run to Home Despot and get plywood or batteries or to fill up with bottled water. You can get everything you need in mid-winter. As of this morning, it's looking like I won't need to put up the shutters but that can change.

      Although I'm a bit older and slower every year, we can still get the house ready for a storm in a few hours.

      That story from The Onion about a fake Boca Raton is great. My brother lives in Boca, so I'll have to get that to him.

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  9. When I went to FAU, Boca didn't look anything like that. Many more expensive things there now for hurricanes to munch on...

    FAU was seven years old at the time, and most of the old air base concrete was still there.

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    1. I lived in west Boca until about '82, and my brother still lives there. It didn't look like that when I lived there, either.

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    2. It might not look like that this coming Monday, either!

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