Monday, November 16, 2020

Hurricane Iota: November 15, Update A

Ice cream in bowl so I'll jump right in (to the update, not the bowl... although... hmm... ;-)). 

Iota is now officially a strong cat 2 hurricane with winds of 105mph, central pressure 960mb (cat 2 range: 96-110mph) and will soon be a cat 3. There is no wind shear so we see a really beautifully structured storm with good outflow in all quadrants of the system... 

The eye has been really clear and well developed for the past hour at least and I actually think this has already reached cat 3 status with winds close to 115mph. You can also see that coastal areas of Nicaragua and a small part of Honduras are already getting some heavy rain in the outer bands. It's expected to be mid-size cat 4 storm as it approaches the coast (the same intensity as Hurricane Eta when it made landfall on Nov 3). 

It is at 13.3N, 80.2W, heading W at a decent 10mph. The one major difference between this and Hurricane Eta as it approached Nicaragua a couple of weeks ago is that this one is moving at a reasonable pace, whereas Eta was a really slow moving storm when it was just off the coast. 

Landfall is expected to be overnight tomorrow (Mon/Tues). This is a pretty hilly area, so as with Eta (and Hurricane Mitch all those years ago) we can expect landslides unfortunately. 

As I mentioned, there is absolutely no wind shear at the moment and it doesn't look like there will be any before landfall. The sea surface is 28-30 deg C between here and landfall, with the upper ~100m warmer than 26 deg C, so there is plenty for it to use to grow. There is a bit of dry air but only in the lowest sections of the storm so I'm not sure it's going to make a huge dent - which means that the only thing that is going to stop this one from getting stronger is the interaction with land. 

It has a really good structure throughout the atmosphere, which we can see from the satellite imagery above, but also in the vorticity maps, which shows that the circulation is really strong in all levels of the troposphere. Here's the vorticity map from the lowest level (850mb) - you can clearly see the storm... 

Here's the map in the mid-troposphere at 500mb: 

And here it is in the upper troposphere, at 200mb: 

I read that evacuations started a couple of days ago so I hope that will help to mitigate the damage! Wishing everyone in that part of the world a safe few days. 

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: