Saturday, October 13, 2018

Hurricane Michael wrap-up and Hurricane Leslie: October 12, Update A

It was another travel day yesterday, so catching up today...

As the clean-up begins in the panhandle, I saw this helicopter footage from WXChasing of the devastation that Michael caused:
This looks more like a weak-to-mid cat 5 level of destruction to me - complete houses, block after block, flattened. Unfortunately, the current toll in human lives is 17, and it sounds like a lot more may be expected. I'm pretty sure we won't be seeing another Hurricane Michael as this name will be retired. 

And where is he now? Just like brave Sir Robin, bravely taking to his feet, he beat a very brave retreat (Monty Python) and is currently in the northern Atlantic - he's that swirling mass to the north and right side of this view of the world: 

He's probably heading to the UK to stock up on jaffa cakes, not realizing that they don't need another batch of dodgy weather as they just had a storm with 70mph winds hit them yesterday/today. 

I don't know why they didn't just go ahead and call this a cat 5 with winds that high - maybe because no-one, not even the NHC, expected it? (including me, sadly!) And definitely not with enough lead time to warn people? This is a real world example of the need for realtime data from within the storm:

On the morning of October 7th, 3 days before landfall, he was forecast to turn and head somewhere in the northern Gulf (which he did - so not too bad on the track forecast), reaching maximum winds of 75-80mph - i.e. barely a cat 1 by October 10th (day of landfall). On the afternoon of October 7th, they flew the first plane into the system and based upon the real data they collected, they revised the forecast winds from 80mph to 100mph - going from a cat 1 to a cat 2 storm at landfall. There was one (just one) model (HRWF) that then, with real data, forecast a cat 4 at landfall at this time, but it was discounted because of other conditions and no other model was showing this (probably because they hadn't ingested the data yet). 

October 8, two days before landfall, after another plane went in and measured the actual data in the storm, the wind speed was increased to 110mph at landfall - essentially a borderline cat 2/3 storm. By that afternoon, with more and more data coming in from the storm and the model forecasts improving because of that data, the estimate at landfall was increased to 120mph - a cat 3 storm. 

Continuing on this, by the end of October 9th, his forecast for the 10th was 130mph at landfall, which is a cat 3 storm, but borderline cat 4 storm.

On October 10th, within 10 hours of landfall, they finally shifted him up to a cat 4 storm with winds of 145mph. Still not 155mph. Finally, at 10.30am on the 10th, just 3 hours before landfall, a plane flew into the system and found winds of 150mph. 

I really think this one was a cat 5 at landfall, but it also goes to show how critical that data is from within a storm! 

This is my last post on Michael. As for the other storms, Tropical Storm Nadine has wilted, so not much on her. 

However we still have the never-ending Hurricane Leslie out there - day 19 and she's still out there. She's currently got 80mph winds, central pressure of 976mb, which makes her a relatively weak cat 1 storm (cat 1 range: 73-95mph). She's at 34.7N, 20.7W, heading ENE at a very brisk 36mph. She's aiming to taste the port in Portugal (John S!):
And is expected to make landfall as a weak cat 1 storm tomorrow. I don't think she will be quite that strong, although she will be windy and bring a lot of surf with her. Her satellite imagery is showing her weakening already over the last few hours:
And she only has good circulation in the lower half of the troposphere now, which indicates that she is a strong Tropical Storm. 

She'll have made landfall by the time I get back to this, so I think this will be my last post on Leslie too. I think it's time to have some ice cream now.

The next names, should we have any more, are Oscar, Patty, and Rafael. 

Toodle pip until then!

p.s. congratulations to Princess Eugenie on her wedding. 

Twitter: jyovianstorm
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.

Thursday, October 11, 2018

Hurricane Michael mostly, with a snippet of Hurricane Leslie and Tropical Storm Nadine: October 10,Update A

Oh dear... the Florida panhandle tasted a very different box of cheese today! I haven't seen the full scale of the damage (travel day), but it's gotta be a mess. In case you missed it, he made landfall at around 1.30pm eastern time, just east of Panama City Beach, on Mexico Beach in Florida as a really beautiful storm with a very large and clear eye: 

He was an extremely strong cat 4 storm - actually a border-line cat 4/cat 5 storm with winds of 155mph, central pressure of 919mb (cat 4: 130 - 156mph). And he was the third most intense storm to hit the US - and by intense, I (and everyone who says this) mean the third lowest central pressure of a land-falling hurricane in the US. The only two that were lower are the 1935 Labor Day storm that hit the Keys with a central pressure of 892mb, and Hurricane Camille that hit the northern Gulf in the 1969 with a central pressure of 900mb. Not even Katrina or Andrew had central pressures this low. 

Storm categories are not defined by the wind speed, but by the amount of damage they do, which is why the wind 'brackets' are not equal. A cat 4 is defined as 'Catastrophic damage' which means well-constructed homes have severe damage, including roof loss and wall damage, most trees are uprooted and power lines are brought down (I think I heard over 500,000 people were without power in Florida at the moment), and the area will be uninhabitable for months. And a cat 5 storm is, essentially, 'total annihilation' - complete homes down etc etc. 

So, I guess the little bit of good news is that he wasn't a solid cat 5 and, more importantly, he was a fast moving storm, and continues to be - he is now at 32.1N, 83.8W, heading NE at a pretty brisk 20mph. It was also lucky for Panama City that he made landfall to the east, as the storm surge is on the east side of the eye because the winds push water onto the shore. 

< Cool Data Alert!> You can see the difference between the storm surge at Panama City (from the website) to the west of the eye, where maximum storm surge was 5.62ft above normal: 
And Apalchicola to the east of the eye, where storm surge was 8.26 ft above normal: 
Out of interest (as you all usually are), here are the corresponding wind measurements from Panama City (top) and Apalachicola (bottom): 

64 knots = 74 mph, which is when the sensor in Panama City decided it had had enough. And 54 knots = 62 mph. So, even though the winds were less in Apalchicola, the water was higher simply because it was on the east side of the eye. 

And how do the corresponding pressure measurements look? Panama City - very low: 

Apalachicola - not so low: 

< End Cool Data Alert!>

But he's not gone away quite yet... he is currently over Georgia as very weak cat 1 storm, with winds of 75 mph (cat 1 range: 74-95mph), and is dropping a few buckets of rain as he heads up to South Carolina and then North Carolina, where he will douse the rest of the state! 
There is still a lot of circulation in this one, which you can see in the satellite image:
We'll all see more tomorrow of course, but I'm hoping all of you in that area and in the path are ok! 

Hurricane Leslie and Tropical Storm Nadine
Oh yes, there's a hurricane and a tropical storm in the Atlantic too... one almost forgot. 
Leslie is currently a mid-size cat 1 storm with winds of 80mph, central pressure of 978mb. Nadine is still a Tropical Storm with winds of 65mph, central pressure is estimated to be 997mb.  As they aren't being too much of a bother, and I'm traveling, I'm not going to say too much about them today.

More tomorrow (another travel day though, so it may not be a lot more!). 

Twitter: jyovianstorm
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.

Wednesday, October 10, 2018

Hurricanes Michael and Leslie, and Tropical Storm Nadine: October 9, Update A

Well double double, toil and trouble! 

We'll jump right in with Monster Michael in the Gulf of Mexico today, shall we?

Hurricane Michael
He is currently at 27.1N, 86.5W, heading N at 12mph. His wind speed is now up to 125mph, central pressure is 947mb. This makes him a strong cat 3 storm (cat 3 range: 111-130mph), so that wind shear didn't have too much of an impact and it looks like it is not as strong as it was yesterday. Combined with the warm sea surface waters (plus the upper ~50m is warmer than 26.5 deg C), this means that he can easily topple over into being a cat 4 storm (he's close enough now) and this is in agreement with the  updated intensity from the NHC. The eye has been pretty solid today and both the circulation throughout the troposphere, as well as the convection is very strong: 

It looks like the outer bands of rain have already reached the Florida coast and will soon be in Alabama and Mississippi too. There will be a small dampening down as he gets closer to land, but given the size of this storm, the rain will have saturated the ground ahead of him so I don't think he'll diminish before landfall. 

I've had a lot of queries from people along the west coast of Florida - you guys should be ok, other than the storm surge and a bit of rain. He's far away enough. It's the northern coast that is going to be the issue. 

I agree with the NHC on the forecast track as we are now less than a day from landfall. It looks like the Panama City area is the approximate area of landfall - the first storm of the season, Alberto, also made landfall in that part of Florida. 
Water levels (from at Apalachicola are almost 3 ft above normal: 
Along the west Florida coast, they are generally around 2-2.5 ft above normal, and to the west of the storm, in Mississippi and Louisiana, they are continuing to rise and are over 3 ft in some places. 

For those on the northern Gulf Coast, I know you have been watching this one carefully and will be ready. Please listen to your local emergency managers though, as they have the best information. And remember, run from the water, hide from the wind - meaning if you are in a storm surge area (or near a river that floods), get out if you can. Otherwise, hunker down in an inside room. The really strong convection brings tornadoes with it. Stay safe and good luck!!

Hurricane Leslie
They upgraded her back to a cat 1 hurricane with winds of 75mph, central pressure of 981mb, which makes sense to me from what I saw yesterday, given her circulation (vorticity). She still doesn't have as much convection, but I agree with the cat 1:
She is currently at 29.5N, 42.6W, heading SSE at 9mph. The track takes her towards Europe. Yes John S.... to the general Portugal area, but it doesn't look like she'll quite get that far so enjoy the surf!: 

Tropical Storm Nadine
The NHC upgraded this blobette from yesterday to TS Nadine. I approve. Winds are currently 45mph, central pressure is 1003mb. She is at 11.6N, 31W, heading NW at 8mph. Although they have her as a weak TS (TS range: 39-73mph), I think she is a bit stronger than that. Her convection is quite good, but more importantly, her circulation is now very good in the lower half of the troposphere. 

XPRIZE News featuring Moi (and the talented Drs. Chris K. and David M. and our rockstar teams)!
With all of these storms, I barely have time to tell you about the news today - we announced the location of the final round of testing for the Grand Prize of the Shell Ocean Discovery XPRIZE. Here's the lovely new video we released today to showcase the Finalists Teams:

And a BBC article "Seafloor mapping XPRIZE final will be in the Mediterranean, off Greece" (

And an IFLScience article "Location Revealed for the $7m XPRIZE Competition to Map the Ocean Floor next Month" (

Stay safe out there!! 

And as it's been a busy day today, I'll say ciao for now,

Twitter: jyovianstorm
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.

Tuesday, October 09, 2018

Hurricane Michael, Tropical Storm Leslie, and the Atlantic Blobette: October 8, Update A

Sorry my peeps - I was busy with that silly old work thingy so I missed the Tropical Storm Captain Kirk (who turned out to be a dinky thing anyway) Star Trek jokes! But never fear, there is still some silliness ahead as we still have a toot of Tropical Storm Leslie left and, of course, Hurricane Michael. 

Hurricane Michael
He really started up in the Caribbean a few days ago, but yesterday made his move from blob to Tropical Storm, and is now officially a cat 1 storm in the Gulf of Mexico. Winds are 90mph, which makes him a strong cat 1 (cat 1 range: 73-95mph), central pressure is 970mb. He is currently at 23.2N, 85.3W, heading N at 12mph. 

Currently landfall is projected to be in about 1.5 days, somewhere between the Florida big bend to around Pensacola - a mere distance of around 200 miles of potential landfall:
But he's currently about 200 miles across, so even though landfall location is currently quite large, it looks like you may all get some rain. 

At the moment I think he's right around the 95mph wind range, a cat 1/cat 2 border storm. He has just about developed an eye which indicates winds of around 90mph. We can see this in the satellite imagery:
This satellite image shows the cloud top temperatures - the red areas are very tall clouds, which means a lot of heavy convection - not just rain, but thunder and lighting. As you get out from a storm to the blues, those clouds are lower down in the troposphere and come with a light drizzle. But that area of heavy convection is getting larger, so this big fella is definitely growing, which suggests to me that he's now a little stronger than 90mph.

The circulation (vorticity) is very strong throughout the troposphere - including the higher levels - which means he has a solid structure which would allow him to continue to grow. 

He is currently over 28-29 deg C water - nice and toasty warm and enough to keep him going. But, one thing that won't help him to grow is position of the Loop Current, which is a current of deep warm water that extends into the Gulf of Mexico from the Caribbean through the Yucatan Strait, and then 'loops' back around and out of the Straits of Florida. The Loop Current fluctuates - sometimes it extends into the Gulf, and at other times it is really small and close to western Cuba. At the moment the Loop Current is in the latter state - not extending too far north into the Gulf (from what I can see).  If it had been, he would definitely be a bigger storm and grow a lot faster. 

The other thing that will keep him a little in check is the wind shear, which looks like it will grow as he gets farther north into the Gulf. 

Overall, I think he will grow slowly and I expect to see a strong cat 2 storm tomorrow. 

As he moves northward, west Florida will see some storm surge. If you want to check the water levels near you, look at tidesandcurrents here: (see this post on instructions on how). Currently, water levels are just over 0.5 ft above normal at Key West, which is closest to the storm, so not too bad. (Ignore the date that appears in the box on the top right when you click on a station - I think someone forgot to change the Sept to October. When you look at the plot (toggle the plot button on the bottom left), the date is correct.)

Tropical Storm Leslie
She's been twirling and swirling in the Atlantic for days and days and days and days (16 days so far). I figured I'd let her be as she wasn't bothering anyone in particular (and you'd be well bored of me by now...!), but while I'm here, I may as well say a couple of words. It would be rude of me not to. 

She is at 32.9N, 44.6W, heading SE at 14mph. Winds are officially 65mph, central pressure is estimated to be 983mb. This makes her a mid-to-strong Tropical Storm (39-73mph). 

She's doesn't have a lot of convection and is definitely under some wind shear as you can see from the satellite imagery:
But yet she persists... because she has a pretty solid structure. There is good circulation in all levels of the troposphere (much like Michael), and if it wasn't for her lack of convection, she would be a hurricane as well I think. 

Atlantic Blobette
There's another blobette way out there in the Atlantic, at around 28W, 10N. I think this one is already a Tropical Storm because there is good circulation in the lower half of the troposphere, and may even be a strong one at that. There is a lot of convection in this baby. The next named storm will be Nadine. 

That's it for today but I'll be back tomorrow. Time for a glass of wine with a hint of cheese. :-) 


p.s. Happy 91st birthday to my Dad! :-)

Twitter: jyovianstorm
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.