Saturday, September 19, 2020

Hurricane Teddy, Tropical Storms Wilfred, Alpha, and Beta: September 18, Update A

Today is brought to you by the number Three. 

R.I.P. to the truly iconic R.B.G....

(Image credits: Damon Dahlen/Huffpost; Photos: Getty)

She said: "Some of my favorite opinions are dissenting opinions." and "You can disagree without being disagreeable."

This nicely sets the stage for the next thing I bring to you by the number Three. 

The NHC named three storms today. <Very Minor Rant Alert!>Although it is too late and the deed is done, I disagree (without being disagreeable of course) with this silliness because one should definitely not have been named, one is more of a front than a storm, and the third has pretty poor structure for a Tropical Storm. This is not the first time that three storms have been named on the same day, by the way. Back in the 1890's three were identified (pre-naming thought) - and that's in an era without airplanes. Actually, until around the 1940s there weren't planes, let alone satellites, so who knows how many were missed! If we didn't have satellites today, at least 2 of the three today would not have been named either. <End of Very Minor Rant Alert!>

But first, let's look at the only actual important storm out there...

Hurricane Teddy

He is at 24N, 57.4W, heading NW at 13mph. Bermuda is in the clear and well outside the Cone of Uncertainty. Well done, Bermuda! I think this track is pretty good at least until Bermuda because it's so narrow. Beyond that it is still all over the place - there's a good possibility that he'll stay on a more eastward track after Bermuda and barely clip Newfoundland - i.e. staying to the east side of the Cone. But get ready regardless up there! 

As for intensity, winds are 130mph, central pressure is 948mb. This makes him a borderline Cat 4/cat 3 storm (cat 4 range: 130-156mph). I think he's weaker than this - I'd place him on the cat 2/cat 3 border actually - with winds of around 111mph at the most. His convection took a bit of a hit from that dry air I mentioned yesterday, combined with that little bit of wind shear:

You can see that his strong eye clear eye, very classic for a cat 4 or 5 storm, closed up and an area of drier air intruded and has also reduced the convection in his outer bands. That wind shear will continue for another day or so I reckon, and he still has drier air to his west that will continue to get pulled into him:

Ideally, this would knock him down a few pegs, but his circulation is still strong throughout the troposphere, and until that decreases, he can still recover that convection. So, the thing to watch is really the vorticity in the upper levels of the troposphere and see if that decreases tomorrow. 

To show you the circulation of a hurricane, here are the vorticity maps showing the circulation in the lowest section of the troposphere (850mb):

Here's the map from the mid-troposphere (500mb):

And here's the map from the upper troposphere (200mb):

Teddy definitely has the circulation structure of a Hurricane and a fairly strong one at that. 

Tropical Storm Wilfred
They ended up naming that Atlantic Blob with 40% as TS Wilfred today! He has some circulation in the lower half of the troposphere, but it's not well developed as we can see from the vorticity above - the lowest level is still not a stand-alone circular region - it spreads out (the yellow part).

Officially, they estimate him to be at 12.8N, 36W, heading WNW at 18mph. And he should peter out by Monday morning, so a weekend visitor really. 

Winds are 40mph, central pressure is estimated to be 1008mb. This means he's barely a Tropical Storm (and should not have been named!). His convection is very weak for a Tropical Storm...

I really disagree with naming this one today. But it gets worse...

The non-existent Tropical Storm Alpha
I don't know who was manning the stations today, but they were on a role! This one was really made up in my opinion!!! (Three exclamation marks worth of dissent right there). 

First, she formed off the coast of Portugal... a TROPICAL Storm formed in waters a couple of degrees cooler than 26 deg C, at a latitude that is well outside the tropics. I don't think that's tropical! 

Second, they named this one ~2 hours before she made landfall! Really? And then they stopped the advisories because she fell apart quickly.  

Third, there was no tropical storm structural circulation in the atmosphere at any level! There is, however, a massive low pressure area that is still there, all the way across Spain and into France, and into the Atlantic. Here are the vorticity maps from a few hours ago at the 850mb level (the lowest):

(First, find Portugal) This map shows the only time where there was even remotely a red circular-ish vorticity patch in this lowest level of the troposphere - however even at this time, it was still connected to a much broader area of low pressure that extended from Spain into the Atlantic. On either side of this snapshot, the map looked like this:

And the vorticity was not circular, but rather elongated connected to other patches of high vorticity - low pressure systems. And as for the mid-troposphere, that's even more of a low pressure system, and not a tropical storm:

That is the vorticity map that corresponds to the one when she 'formed'. That is most definitely NOT a Tropical Storm structure!

So that's Alpha as a name that's wasted. And that takes us to the third mistake...

Tropical Storm Beta

This is the one that was TD 22 in the Gulf of Mexico yesterday. It is currently at 25.8N, 92.2W, heading NNE at 12mph. Looks like he may scrape along the Texas coast on Tuesday - this will be another messy, soggy storm so get ready for that if that path really does materialize. 

Again, this one doesn't have the structure of a Tropical Storm as you can see from the vorticity maps above. The vorticity in the lower half of the troposphere is elongated - and in the mid-tropopshere, it actually extends northeastward towards LA/MS/AL/FL and then up to North Carolina - which means it's actually a low pressure front! 

Winds are officially 60mph, central pressure is 996mb, which officially makes this a mid-size Tropical Storm (TS range: 39-74mph). I'm really not convinced of this but as it's relatively close to the coast and this data was from a plane, I'll go with it. However, I don't think they have been measuring in the right locations within the storm given how elongated it is. 

You can see the mess that this is in the infrared satellite imagery: 

There is a lot of convection which is to be expected as this is over very warm 30 deg C water, with the upper 75m plus warmer than 26 deg C. But you can also see different areas of very strong convective outbursts - which is why I'm not sure they have the center in the right place (because it doesn't really have a center). There is a lot of wind shear which we can also see in the satellite imagery as the clouds and rainy weather is being swept up towards the northeast. We'll see if that circulation actually becomes more circular tomorrow but today it's messy. 

And there's one more Blobette in the Atlantic - this is actually the remains of Hurricane Paulette, and is approaching the Azores. So, this would be Paulette if it re-forms. Currently, 40% chance.

That's it for today. What a messy sort of a day indeed - I still can't believe that they named some of these storms today... maybe they are really really tired at the NHC from all that activity last week. Not enough ice cream in their freezers perhaps? 

Toodle pip for now,


p.s. and just as I was posting this on twitter, we had a 4.8 or 4.6 magnitude earthquake here (there are conflicting reports on magnitude) - that's the largest I've ever felt! A lot of shaking and things rattling! 

Twitter:  jyovianstorm

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 local 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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