Wednesday, September 09, 2020

Tropical Storm Paulette, Tropical Depression Rene, and the Atlantic Blobette: September 8, Update A

I was away for a few days on my annual trip to Planet (Virtual) DragonCon and re-entry to Planet Earth was a little slow yesterday... but here I am back in the real world. Did I miss anything? ;-) 

Tropical Storm Paulette

Paulette materialized a couple of days ago (I may have been on another planet, but I was still watching) and is now at 19.2N, 45W heading NW at 9mph. 

The greater-than-five-day forecast looks like she's heading to Bermuda... so that is most likely where she won't be going. ;-) I agree with that more westward track in the next day or two because she's moving along the southern edge of a high pressure ridge. 

Winds are officially at 60mph, central pressure is 997mb, which means she's a mid-sized Tropical Storm. I think this is an underestimation of her strength because there is good circulation (vorticity) throughout the troposphere - including the upper levels which indicates she's closer to a hurricane (and may already be one). There is also a lot of convection, as we can see in the satellite imagery...

Her convection is the northern red blob... some of you may have noticed a second red blob just to the southeast of Paulette. Very interesting. Here's a close up over the last ~12 hours:

It's all part of the same system, but really interesting in appearance. Both areas of convection are over separate small patches of warm water where the upper 80 m of water is warmer than 26 deg C, with an area in between in which only the upper 70m or so is warmer than 26 deg C. But that's not enough to explain the separation of the two regions of convection - it also looks like there is a sliver of dry air that is being pulled in between the two from the west and gets wrapped around the northern convective area.  There is some wind shear which is impacting the northern part of the storm - you can see the clouds streaming off to the northeast. It's not clear yet how long that wind shear will be around, so it may not have much of an impact.

Tropical Depression Rene

Meanwhile, to the east of Paulette is Rene. He is currently a Tropical Depression with winds of 35mph, central pressure 1004mb. He was a Tropical Storm earlier today and yesterday, but officially a very weak one. His winds officially got to a maximum of 40mph before weakening, which barely means he should have been named as the TS range is 39-73mph. However, I think they have also underestimated him - he has some really good vorticity (circulation) throughout the troposphere which means he is a fully-fledged Tropical Storm. His convection took a little bit of a nose-dive as he passed directly over the Cape Verde Islands and over some cooler water, but he's back in full swing now:

He's at 17N, 29.3 W, heading WNW at 16mph and doesn't look like he's aiming for anything other than islands in the eastern North Atlantic....

Atlantic Blobette

And there's another blobette in the Atlantic because sometimes 2 just isn't enough. This one is at around 30N, 71W - there is some vorticity in the lowest levels of the troposphere, but nothing at the mid-levels yet, so definitely just a blobette. Not much convection either, but worth just keeping an eye on. They give her a 30% chance of development in the next 48 hours.

More tomorrow! I'm still intergalactic-jet-lagged so time for a nap. 
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. 

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