Thursday, September 01, 2016

Hurricanes Hermine, Gaston, Lester, and Tropical Storm Madeline: September 1, Update A

I am sitting under the cloudy outer bands of Hermine as I write this quick update on the smorgasbord of storms du jour - they are all pretty much on schedule to do stormy sorts of things. 

Hurricane Hermine - Gulf of Mexico
Not surprisingly, she was upgraded a few hours ago to a hurricane once the hurricane hunter plane data came in. Her winds are currently 75mph, central pressure is 988mb, which makes her a weak cat 1 storm (cat 1 range: 74-95mph). I agree with this given how her circulation (vorticity) looks throughout the troposphere at the moment - and I don't think she will get too much stronger.

She is at 28.5N, 85W, heading NNE at 14mph. It looks like she will make landfall in a few hours: 

You can see her center of circulation in the visible satellite imagery:

And the associated convection in the infrared satellite imagery, which is not very well organized but is dumping a bunch of rain onto Florida. 

She is heading directly towards the Big Bend area. It does look like the strongest winds may skirt the northern Florida coast as she heads in towards Appalachee Bay. As I said yesterday, it's not just the center of the storm but the larger area of convection to watch out for, as well as the storm surge. 

Looking at NOAA's Tidesonline (see yesterday's post for details on what the graphs mean), I see that water levels are 2.5 ft above normal and rising in Appalachicola, St. Petersburg, and Port Manatee; they are currently 3ft above normal in Clearwater; and, Cedar Key is currently around 3.5 ft above normal (it looks like Cedar Key has peaked though).

She is experiencing wind shear, which you can see because the clouds are streaming off to the northeast - as we see in the satellite imagery above because the convection is not very symmetrical around the eye. 

There is some really cool data in the Gulf off the coast that you can look at - amazingly it is being collected in the stormy choppy conditions right under Hurricane Hermine. USF's College of Marine Science/Ocean Circulation Group's COMPS mooring array shows the wind speed at their C12 mooring to be around 20m/s which is about 45mph - and this is at 27.5N, 83.7W, so around 110 miles away from the current center of the storm. 

This data is part of a Coastal Ocean Observing System being developed for the entire US coast, and is super useful in storms and in other situations. Check out the Southeast Coastal Ocean Observing System (twitter @secoora or website information, including high resolution storm surge models and other data for any systems from Florida to North Carolina, and the Gulf of Mexico Coastal Ocean Observing System ( for anything from Texas to Florida.  

Before I leave Florida, there was an explosion of an unmanned SpaceX rocket at Cape Canaveral today (alas), and it was caught on the weather radar! Check it out here (sorry about the super large size... there doesn't seem to be any control over the embedding of tweets!):
Hurricane Gaston - Atlantic
Officially he is now a cat 1 storm with winds of 80mph, central pressure of 984mph (cat 1 range: 74-95mph) and is still heading to the Azores for tomorrow, although his outer bands will be getting there a bit sooner (like right now actually):

I don't think he is a Hurricane anymore - I think he is just a Tropical Storm, and one that is caught up in a front given how he is sort of drifting like a discombobulated Dementor (Harry Potter) instead of moving with purpose like any decent tropical system would. His vorticity (circulation) is almost non-existent in the upper troposphere, although it is still strong in the lower and mid troposphere - which suggests Tropical Storm to me. Still, he has a bunch of convection in him still, so expect rain on the those islands if you are out there! 

Tropical Storm Madeline - Pacific
She is at 16.5N, 157.6W heading W at 13mph and is passing Hawaii. Winds are now 45mph, central pressure is 1004mb. She is barely a Tropical Storm (TS range: 39-73mph) and her convection has continued to deteriorate:

As she is moving away from the islands, this is my last update on Madeline. We have Hurricane Lester close on her heels... 

Hurricane Lester
Hurricane Lester is now officially a very strong cat 2 storm with winds of 110mph, central pressure 968mb (cat 2 range: 96-110 mph). He is at 18.4N, 144.8W, heading W at 13mph (these storms do like to be consistent!). It looks like he will clip the northern edge of Hawaii on Saturday:

He has weakened a bit since yesterday - his upper tropospheric vorticity is weaker. But the wind shear around him has also died down a little, and his convection and symmetry is increasing again, so I think he may be a cat 3 storm again... he is quite good looking:

There is still some wind shear ahead of him, but that is now a day away at least alas. Will be back to talk about this one again tomorrow!

That's it for today. Clouds are getting a little darker here too... clearly it is time to go out and eat! 

Stay safe my friends!!

Ciao (chow! :-)),

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DISCLAIMER: These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.

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