Wednesday, September 02, 2020

Tropical Storm Nana and Tropical Storm Omar: September 1, Update A

Just in case you missed it, today is the 1st of September and for hurricane season, that means...

Bwaahaahaahaa... so funny, I had to use it twice! ;-) 

Meanwhile, on the hamster wheel we have two named storms today. Deja vu, anyone? 

Tropical Storm Nana

This was TD 16, the blob in the Caribbean yesterday. As I said yesterday, I thought it looked a lot stronger than Tropical Depression 15 and it looks like the NHC came to the same conclusion today, after sending a plane into the system to investigate this morning.

She is now at 17N, 80.9W, heading W at 18mph. I agree with this westward track, and there's a good possibility that she may stay on the southern end of this cone, maybe moving the track south a little. 

She is definitely a Tropical Storm. Officially winds are 60mph, central pressure is 999mb, which makes her a mid-size Tropical Storm (TS range: 39-73mph). There is a lot of convection in this storm:

This is because she is moving over very warm sea surface waters, and it's also quite deep warm water - the upper ~150m is warmer than 26 deg C - so she has plenty to munch on and grow.

The vorticity (circulation) is strong in the lower half of the troposphere, but they haven't updated the latest data so I can't see if there is any in the upper troposphere yet. For now, Tropical Storm she is! I'd say she's stronger than the 60mph winds already, but I agree with the NHC forecast which calls for her to become a cat 1 hurricane in the next 24 hours. There is a (very) little dry air to the west but not much wind shear, so there's no reason for her not to get stronger. Here's a close-up... 

Obviously Honduras and Nicaragua will start to get rain in a few hours.

Tropical Storm Omar

He's in the Atlantic, currently at 35.8N, 70W, heading ENE at 14mph and will stay out in the Atlantic....

Winds are officially 40mph, central pressure is 1003mb, which makes him barely a Tropical Storm. There's some vorticity in the lowest level of the troposphere, but not too much in the mid-levels. There is some convection which you can see just flared up because he's over the Gulf Stream, but there is a lot of wind shear so the convection is all to the east of the center...

I wouldn't actually call this one a Tropical Storm, but its too late now. I think this will be my last update on Omar unless he does something odd tomorrow. 

Ciao for now,


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. 

No comments: