Thursday, October 11, 2018

Hurricane Michael mostly, with a snippet of Hurricane Leslie and Tropical Storm Nadine: October 10,Update A

Oh dear... the Florida panhandle tasted a very different box of cheese today! I haven't seen the full scale of the damage (travel day), but it's gotta be a mess. In case you missed it, he made landfall at around 1.30pm eastern time, just east of Panama City Beach, on Mexico Beach in Florida as a really beautiful storm with a very large and clear eye: 

He was an extremely strong cat 4 storm - actually a border-line cat 4/cat 5 storm with winds of 155mph, central pressure of 919mb (cat 4: 130 - 156mph). And he was the third most intense storm to hit the US - and by intense, I (and everyone who says this) mean the third lowest central pressure of a land-falling hurricane in the US. The only two that were lower are the 1935 Labor Day storm that hit the Keys with a central pressure of 892mb, and Hurricane Camille that hit the northern Gulf in the 1969 with a central pressure of 900mb. Not even Katrina or Andrew had central pressures this low. 

Storm categories are not defined by the wind speed, but by the amount of damage they do, which is why the wind 'brackets' are not equal. A cat 4 is defined as 'Catastrophic damage' which means well-constructed homes have severe damage, including roof loss and wall damage, most trees are uprooted and power lines are brought down (I think I heard over 500,000 people were without power in Florida at the moment), and the area will be uninhabitable for months. And a cat 5 storm is, essentially, 'total annihilation' - complete homes down etc etc. 

So, I guess the little bit of good news is that he wasn't a solid cat 5 and, more importantly, he was a fast moving storm, and continues to be - he is now at 32.1N, 83.8W, heading NE at a pretty brisk 20mph. It was also lucky for Panama City that he made landfall to the east, as the storm surge is on the east side of the eye because the winds push water onto the shore. 

< Cool Data Alert!> You can see the difference between the storm surge at Panama City (from the website) to the west of the eye, where maximum storm surge was 5.62ft above normal: 
And Apalchicola to the east of the eye, where storm surge was 8.26 ft above normal: 
Out of interest (as you all usually are), here are the corresponding wind measurements from Panama City (top) and Apalachicola (bottom): 

64 knots = 74 mph, which is when the sensor in Panama City decided it had had enough. And 54 knots = 62 mph. So, even though the winds were less in Apalchicola, the water was higher simply because it was on the east side of the eye. 

And how do the corresponding pressure measurements look? Panama City - very low: 

Apalachicola - not so low: 

< End Cool Data Alert!>

But he's not gone away quite yet... he is currently over Georgia as very weak cat 1 storm, with winds of 75 mph (cat 1 range: 74-95mph), and is dropping a few buckets of rain as he heads up to South Carolina and then North Carolina, where he will douse the rest of the state! 
There is still a lot of circulation in this one, which you can see in the satellite image:
We'll all see more tomorrow of course, but I'm hoping all of you in that area and in the path are ok! 

Hurricane Leslie and Tropical Storm Nadine
Oh yes, there's a hurricane and a tropical storm in the Atlantic too... one almost forgot. 
Leslie is currently a mid-size cat 1 storm with winds of 80mph, central pressure of 978mb. Nadine is still a Tropical Storm with winds of 65mph, central pressure is estimated to be 997mb.  As they aren't being too much of a bother, and I'm traveling, I'm not going to say too much about them today.

More tomorrow (another travel day though, so it may not be a lot more!). 

Twitter: jyovianstorm
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.

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