Hurricane Ophelia: October 13, Update A

Friends, Romans, countrymen, lend me your ears. Has it only been two days when last we met? O wonderful, wonderful, and most wonderful wonderful! In honour of Ophelia, a tropical topical quiz for you lies herein - how many Shakespeare quotes can you catch in this post? J

And so, once more unto the breach, dear friends, once more! It's time to talk hurricanes. Ophelia has achieved the glass of fashion in the storm world, and is now a fully-fledged little Tempest in the form of yet another cat 2 storm.

Since yesterday we find though she be but little, she is fierce. She has 100mph winds, and a central pressure of 971mb, which makes her a weak to mid-size cat 2 storm (cat 2 range: 96-110mph). She’s at 32.3N, 31.8W, heading ENE at 13mph. She has had a more-or-less pretty consistent eye over the last two days, which does indicate at least 90 mph winds, but there are more things in heaven and earth and because she is over cool water (cooler than 26.5 deg C) there isn’t as much convection as we would expect with such a storm:

However, all that glisters is not gold and I don’t think she is quite a cat 2 storm because there is very little vorticity (circulation) in the upper troposphere. Why, it appears no other thing to me than a foul and pestilent congregation of vapours. Here’s the vorticity map from the mid-level (500mb) where you can clearly see a lovely signal:

And the upper level (200mb), which has a very slight circulation at that level:

She is still on track to pass close to/just south of the Azores tomorrow on her way to Ireland and the royal throne of kings, this sceptred isle, Britain on Monday:

But once you get there, I think, Ophelia, Scotland hath foisons to fill up your will, and you won’t be much more than a weak tropical storm when you leave, if that.

There is some wind shear between Ophelia and Ireland, and of course the water is chilly, so she may not even actually be a hurricane by the time she gets there, but it will still definitely be a 'bit' on the windy side. For those of you in the Azores/Ireland/Scotland/Wales, and even this blessed plot, this earth, this realm, this England, do not compare Ophelia to a summer's day. You may be saying a plague upon this howling! They are louder than the weather or our office.

Now, where shall we three meet again in thunder, lightning, or in rain? When the hurlyburly 's done, when the battle 's lost and won. Oh, ok, I’ll try and be back at least once before then! ;-)

Answers on the quotes in the next post! How many did you get? 

J. 

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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. 

Hurricane Ophelia: October 11, Update A

To write or not to write - that is the question. I thought I’d try and take a few days off and not talk about Ophelia because she’s hanging out in the Atlantic and not bothering anyone in particular, but someone clearly missed that memo and decided to upgrade her to a Hurricane today and send her towards some islands… so here I am. Wine and cheese is armed and ready for some slurping and munching. (Speaking of wine… aaagh… California Fires!! Aaagh!! Stay safe out there!)

Hurricane Ophelia is officially barely a cat 1 storm with winds of 75mph (cat 1 range: 74-95mph), central pressure is 990mb. She is at 30.0N, 36.1W, and heading gently eastward at 3mph.

She has slowly developed over the last few days and her convection now looks quite good – there is clearly an eye:

This suggests that her wind speed is actually closer to 90mph, so I would place her as a mid-to-strong cat 1 storm. The reason I wouldn’t put her any higher than that is because the circulation (vorticity) is not quite well developed in the upper troposphere – she is under an elongated low pressure area (a trough) and it doesn’t look like the structure of a really well-developed storm yet.

Wind shear is quite weak which will allow her to develop. But as she continues to wander eastward, she will move over cooler water where the sea surface is actually cooler than 26.5 deg C, so the convection won’t be very strong and I don’t think she’ll get to be much more than a cat 1 storm.

She is following the northern edge of a high-pressure system and I agree with the official forecast that she will head generally east and then northeastward, arriving in the Azores around Saturday:

And then she’s heading to Scandinavia (of course she is... where else would she go? ;-)), bumping into Ireland and the UK area on her way there next week. It'll be a typical Autumn week over yonder - blustery and rainy. Maybe you can get Monday off work? Practice your Shakespeare or something?

And with that... parting is such sweet sorrow that I shall say goodnight till it be morrow. ;-)

J. 

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Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm
-------------------------------
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. 

Hurricane Nate: October 6, Update A

Of course Nate would show up when I’m super busy! Typical. I have been watching him when I can, but between travel, celebrating birthdays (Happy year birthday Ben! J), and not having good internet access it’s been a bit tricky. Anyway, I have some ice cream and so off we go…

Hurricane Nate (as he became just a short while ago) is officially a very weak cat 1 storm with winds of 75mph, central pressure 988mb (cat 1 range: 74-95mph). This upgrade came about because a plane flew into the center and has estimated the winds to be this strong. I would say he is stronger than that. He definitely has a lot of very strong convection, which you can see in this infrared satellite imagery:

He has really grown in the last few hours - the red/gray area are very strong thunderstorms! Also, the circulation (vorticity) signal is really good throughout the troposphere – even at the 200mb level (the upper troposphere), which indicates a hurricane:  

I would estimate him to be a mid-sized cat 1 with winds of around 85mph – he doesn’t really have an eye yet, so not quite at 90mph yet. But I think there is a possibility that he will be a cat 2 at landfall if he develops an eye in the next few hours. 

He is currently at 22.4N, 86.3W, heading NNW at 22mph. Alas, his track is taking him to the central northern Gulf – the general New Orleans to Mobile (AL) area with landfall in 24 hours:

The convection is strong because he is over the Loop Current, which is part of the Gulf Stream system of currents that have very warm water that is quite deep. He is currently over water that is 28-30 deg C and the upper ~100 meters is warmer than 26.5 deg C. There isn’t much to inhibit his development until he gets to around a latitude of 26-27 deg N, when the water is slightly cooler and there is an area of some wind shear. So I would expect some more intensification until then at least, and after that he is getting close to landfall and will be inhibited from growing by the interaction there as well.  

The big thing to watch for is the storm surge - this is not going to be pretty. Nate is pushing the water onto the coast to the east and northeast of his center – which means the entire west coast of Florida and the northeastern Gulf. And because of the Mississippi delta, he will also be pushing water into Lake Borgne and Lake Pontchartrain. The levels are already rising and along the west coast of Florida and the northeastern Gulf they are over 1 ft above normal in most places, with some in Louisiana showing 2ft above normal levels.

I know it’s not been that long in time, but it’s been a jolly long time in terms of posts (what a busy few weeks!), so… <Technical Alert!> To look at storm surge, go to NOAA's Tidesonline: https://tidesonline.nos.noaa.gov/geographic.html, click on station you want on the left side bar, or scroll down to the states and pick the state you want and then the station in that state. Here’s the current data from New Canal Station on Lake Pontchartrain:

The top graph shows the water level. In this graph, the red line is the actual observed sea level, the blue line is what the predicted water level would be because of the tides, and the green line is the difference between the two. The height of the green line gives you the storm surge level (~2 ft at the moment). The graph below that is wind speed and direction. Below that is air pressure (which you can see is still dropping), and below that is air and sea surface temperature. <End Technical Alert!>

Tomorrow is another super-packed day so I may have to resort to tweets only but I'll try and get a short something out. 

Good luck and stay safe out there my friends!

Ciao,

J. 

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Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm
-------------------------------
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.