Tuesday, July 28, 2020

Tropical Storm Douglas and the Atlantic Blob: July 27, Update A

It's Monday, grab a glass of wine (which is not contingent upon it being a Monday of course ;-)) and have a seat.

Atlantic Blob
This blob's conversations with the Saharan Air Layer continue... his chances of developing in the next 48 hours have gone down another notch to 70%. He is trying to develop, as we can see with the bits of convection we see in the satellite imagery: 

Although he is over surface warm water with temperatures of 27 deg and he's about to move over warmer waters of 28 deg C (with the upper 75-100m warmer than 26 deg C), I'm not sure how much he will be able to get his act together because the atmosphere is working against him. First, it looks like he'll be having a few days of conversation with the dry dusty Saharan Air Layer (probably catching up on everything that's been going on in 2020 - could take a while!):

And second, wind shear will increase as he moves north and west. 

According to the NHC, he is currently somewhere around 13N, 48.5W and moving WNW at 15-20 mph. However, this location is very much a guess because the circulation is over such a broad area. There is some low level circulation in the lower half of the troposphere, but we can see from the lower tropospheric vorticity map that it is not very well developed at all and is spread out over a very large area indeed. 

The NHC think he will be bringing a few drops of rain and a bit of a breeze to the islands - the Leeward Islands on Wednesday, then on to the VIs and Puerto Rico on Wednesday night and into Thursday. Best to be ready if you are there, but he won't be too much of a storm unless that dust magically vanishes (I'm not going to do any vacuuming until the weekend, so it won't be vanishing from my house any time soon! ;-)). 

Tropical Storm Douglas
As for our friend who visited Hawaii. He's had a few pineapple-themed umbrella drinks and is now drunkenly staggering off into the sunset (well, heading west at 17mph anyway): 

He's currently at 22.9N, 163.3W and has now weakened to a strong Tropical Storm with winds of 70mph, central pressure 993mb (TS range: 39-74mph). There is no longer any vorticity in the highest level of the troposphere, just at the lowest-to-mid-levels, which means he's definitely a Tropical Storm and not a Hurricane. The wind shear is really taking it's toll because we can see the center in the satellite imagery, and what's left of the convection is all to the north: 

He may be a weaker TS than they say at this point, but he's pretty much going to wind down and fizzle out in a couple of days. I think this will be my last update on Douglas. 

By the way, did you realize that...
Hahaha... (thanks to hubby for pointing this one out to me). :-) 

And with that gem, I'll bid you adieu for today. 

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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