Thursday, October 06, 2016

Hurricane Matthew and Tropical Storm Nicole: October 5, Update A

And the sage of Hurricane Monster Matthew continues... 

The Aftermath Part 1: Haiti, Dominican Republic, and Cuba
The first reports are now coming out of Hispaniola and Cuba. As expected, Haiti is a disaster because Hurricane Matthew hit as a cat 4 storm. The last cat 4 to hit Haiti was in 1969 - Hurricane Flora (which killed 8,000).  It is estimated that over 3,200 homes have been destroyed and about 350,000 people need aid in Haiti. Add to this the possibility of disease, including cholera. This is the worst humanitarian crisis since the 2010 earthquake for Haiti. The death toll is not yet known - the last I heard was 22 in Haiti, plus four in the Dominican Republic.  

Cuba was better off - he went across the relatively sparsely populated eastern tip, destroyed dozens of homes, damaged hundreds, but they did manage to evacuate 380,000 people before he stopped by. 

Hurricane Monster Matthew: Intensity
He is now slowly crossing the Bahamas and is at 23.7N, 76.7W, heading NW at 10mph. 

Fortunately he did decrease in intensity as he left Cuba, and has officially been a cat 3  with winds of 115mph (cat 3 range: 111-129mph), central pressure 954mb. I actually think he was a solid cat 2 (cat 2 range: 96-110mph) earlier today because his eye was not well developed and his upper level vorticity (circulation) had weakened slightly. However, as expected, this is changing as he has been moving away from the land mass of Cuba and over warm water, and in the last few hours the eye has re-developed:
I think he is now a strong cat 3 again. If his eye goes over any of the islands, then he will decrease slightly in intensity again - and there is a possibility that his eye will pass over Nassau or Andros (the largest island in the chain). Not too good for the Bahamas.

As I said yesterday, once he crosses the Bahamas, he has got room to intensify a little more because he has to cross the Gulf Stream, with its very deep warm waters. There is some wind shear over Florida, but it is not enough to really put any marks on him. 

It does look like at least a cat 3 will impact Florida. And also, everyone in Florida - even on the west coast, should be ready in case you get some of the stronger outer bands.

Track
Things got interesting with the track today! My phone has been beeping all evening with you guys sending me the latest spaghetti models, which look a little different than the forecasts you are used to seeing...
... oops, wrong spaghetti models (a Russian guy, Sergey Pakhomov, made these! ;-) This is what you are fluttering over... 


I can see why the models think something like this is going to happen, but it really is too soon to say if Florida will get hit twice by Matthew! (Although I have to say that it isn't beyond the realms of possibility.) The models are not even sure what will happen in 3 days, let alone 7-10 days!! Here is the official 5-day track as of today: 

In looking at the data I have (which is not much because we don't have a lot of data over the oceans really... after all, why would we need that?!?), there is a high pressure ridge building up in front of him and crossing over northern Florida/Georgia/South Carolina. It has slowly been building over the past couple of days. There are two things a storm will do in this situation, depending on how far it is from the ridge. It will either slow down, because it is like going uphill, or it will shift to the west to try and get around it (which is why I said yesterday that everyone in Florida should be prepared, just in case). 

Today it looks like the High pressure is also building up over central Florida, so he really cannot move too far forward until that dissipates, and we should see a slow down in forward speed - which we have in the last few hours as he went from 12mph to 10mph. As he continues to slow down, this changes everything... which is why there is so much uncertainty in the forecast track beyond day 3.  

The question is, how much will he slow down and where and for how long. We'll see tomorrow how much he slows, but the worse case for the Bahamas is obviously if he stalls over them. 

I'll could try and explain the loopiness of the model tracks in words, but you may require a drink or two (or I may) to get it clear! It's a little complicated out there because of the high pressure building up, but also because Tropical Storm Nicole is a big low pressure area in the middle of the Atlantic. The best thing to do is stay focussed on the 1-2 day track, which the NHC are generally pretty good at anyway. Beyond that, the forecasting skills aren't up to snuff, especially with a ridge building up out there.

By the way, this isn't the first time that a storm has done a loop-de-loop. Last year, Hurricane Ida did a little loop. In 2012, Patty took a spin. In 2010, Julia tried to do a loop before petering out. In 2004, Hurricane Jeanne did a loop in the Atlantic before hitting Florida and so on.

Tropical Storm Nicole
As I said, she's part of the complication for Matthew's track. She is a strong Tropical Storm, close to being a Hurricane with winds officially at 70 mph, central pressure 995mb (cat 1 range: 74-95mph). She is at 26N, 64.1W, and heading NW at 9mph. 

She does have a really strong circulation signal in the lower half of the troposphere. Here it is at 500mb, which is about mid-way up:

You can see the nice 'round' shapes indicating a good storm structure and vorticity/circulation for both Hurricane Matthew and Tropical Storm Nicole in this mid-tropospheric map. Now looking at the upper troposphere (200mb): 

The signal for Hurricane Matthew is still a stand-alone round shape - this is what a hurricane should have. Nicole, on the other hand, is under an elongated area of red that stretches to the south - this is actually a trough (or front), so although the vorticity is high, it is not the same structure as a hurricane. At the moment, I would agree that she is a strong Tropical Storm. I would not classify Nicole as a hurricane because she doesn't have the correct structure.

She does have some convection, but again, not quite a hurricane... 


Because she is stuck under that high pressure, it doesn't look like she is forecast to go very far very fast... Bermuda, you have a bit of time methinks to get ready, assuming she survives for that long.

Finally, to figure out storm categories... the classic storm category photo I showed in this blog last year is doing the rounds again, and quite rightly so! Thanks to everyone who thought of sharing it with me! :-) It makes me chuckle every time I see it, and it is, indeed, one of my favourites, so here it is again for those who missed it... 

Ok, back to being serious... I'll do my best to mind-meld with the storm tomorrow and steer him away from Florida, but I should warn you not to hold your breath on the success of this effort. Evacuate if your local emergency managers are urging you to do so!!

Above all, STAY SAFE out there!! 
More tomorrow,
J. 

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm
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DISCLAIMER: 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 the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.

2 comments:

HandyGeek said...

Ice cream and wine supplies are all topped up. :D

HandyGeek said...

Ice cream & wine acquired. Bring it. :D