Saturday, May 26, 2018

Subtropical Tropical Storm Alberto: May 26, Update A


Typical timing - a storm over the weekend and a long weekend in the US to boot. You didn't have picnic or outdoor BBQ plans in Florida did you?
Just like yesterday, and as expected for today, Subtropical Storm Alberto is still very weak and quite disorganized. He is currently centered at around 22.8N, 85.2 W and is heading N now at 13mph, which is a better pace for any self-respecting storm. His central pressure is 999mb and his winds are still border-line Tropical Storm/Tropical Depression at 40mph (TS range: 39-73mph).  
If you squint and have a bit of imagination, you can just about pretend there is a center of circulation in the satellite image above - it's in the southern Gulf of Mexico. It's not as obvious as yesterday though. 
Given how disorganized he is, and that the circulation in the middle of the troposphere (oh happy day! it's the first <Science Alert!> of the season! ;-)) is not well formed, I'm not sure I would even call him a Subtropical Storm at the moment. The convection, which is still being swept off to the east due to wind shear, is because he is still over some warm water, which is also quite deep - the upper ~125m of the water column is warmer than 26 deg C. There is also some dry air coming in still, which is also inhibiting his development.
<Science Alert!> The Troposphere: Our atmosphere is divided into layers - like a delicious layer-cake (that goes very nicely with a cup of tea). In each layer, the air temperature either increases with height or decreases with height. The troposphere is the name of one of these layers - it is the layer closest to the earth and it is the layer that we live and breathe in. This lowest layer of our atmosphere extends up from the earth (ground zero) to about 15-16km above our heads in the equatorial regions, and to about 8km in the polar regions of the planet. All of our 'weather' essentially occurs in the troposphere. The troposphere is defined by decreasing air temperature with increasing height - the higher you go, the colder it gets. You would know this if you climbed a mountain or the easier (and more often used) option is to just look at pictures of mountains and see the snow at the top (known as the 'Flat Florida Option'). ;-) The top of the troposphere is called the tropopause. Strong tropical storms have clouds that reach as high as the tropopause - and in some cases, if they are very strong, they can push into the next layer up - into the stratosphere. The stratosphere is defined by air temperature increasing with height. The ozone hole is in the stratosphere. The top of the stratospheric layer is around 50km and is marked by the stratopause. The layer above that is the mesosphere, where the air temperature decreases with height again... and so on until we get to space where there are no yummy layer-cakes to be found. :-) <End Science Alert!> 
His track is more-or-less the same as yesterday - heading to the northern Gulf coast:
I can see why the track is like this - he is heading towards a low pressure area that is slowly moving across the southern states. Given the speed of the forward motion of Alberto and this low, it is definitely possible that he will make landfall in the Florida panhandle/Apalachicola area.
Got to go and recycle some wine bottles (have to make room for the new season supply!) and buy ice cream in preparation for hurricane season (in California). ;-) I'll be back later with an update, and some thoughts to wrap up the 2017 season... (just in time).  
Ciao,
J.
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DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my storm blog). 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.
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Subtropical Storm Alberto: May 25, Update A

Hello my friends! Did ya miss me? And more importantly, are you ready? Yeah... me neither! But no time for sleeping in... or hibernating at all apparently this year. I guess Mother Nature thought it would be a hoot to start a wee bit early. Can someone take her off the caffeine please? ;-)

As some of you noticed, for the first time in over 10 years, I didn't quite manage to wrap up the 2017 season with my traditional end-of-season post; a consequence of the hurricanes that hit Puerto Rico meant I got caught up in a crazy world tour (in 2.5 months, I flew over 72,000 miles and travelled about 1,500 by road/rail/ship) (more about why in this BBC article). But we'll have a proper catch-up over a nice cup of tea later. For now we have that pesky little Subtropical Storm Alberto hanging out off the Yucatan Peninsula causing a bit of a ruckus.

Officially he's at 19.4N, 85.7W, heading E at a relatively sedate 5mph. He is pretty weak at the moment - barely a storm actually - with winds of 40mph (TS range: 39-73mph) and a central pressure of 1006mb. He is disorganized as you can see in this colour satellite imagery (which goes from light and colourful in the daytime to black and white at nighttime):
This is from the National Hurricane Center (NHC) website. Deary me, it looks like they made a lot of changes on their site since last year and, at first glance, some are for the worse because some useful graphics and satellite imagery features have been removed. Grrr (shaking my head). I'll have to do some digging to see if I can find what we really need, but in the meantime, this satellite imagery will have to do. It does illustrate how poorly organized he is - you can clearly see the center of circulation which is just east of the Yucatan peninsula, but most of the convection (rain storms) are even further east and north east - closer to Cuba. This is because he is under some wind shear which is pushing that convection to the east.

The current track has him going generally north as a Tropical Storm, making landfall somewhere on the northern Gulf coast:
I would agree with this general track and the computer models at the moment because there isn't any good pressure data available and he is quite weak.

For his intensity, he is weak because there is wind shear and also some dry air being pulled into the system. The reason he has any real convection at all is because he is currently sitting over an area of the ocean where the sea surface temperatures are warm, and the warm water is deep (this is part of the Loop Current system - which I'm sure I'll talk about later in the season). But the good news is that as he moves into the Gulf, although the sea surface temperatures are warm, the warm water is not as deep - the Loop Current does not extend as far into the Gulf at the moment as it has in previous years. Also, it looks like the wind shear will continue for a while as he moves north, so although he may intensify a little as he moves north, at the moment I would agree with the NHC that he remains a Tropical Storm.

I'll be back tomorrow with more on STS Alberto and also maybe a wrap up to 2017 and a proper start to 2018... after all, I'm wide-awake now. :-)

Toodle pip,
J.

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DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my storm blog). 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.
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Tuesday, October 17, 2017

Post-Topical Storm Ophelia: October 17, Update A

Ophelia, reached Ireland as a post-tropical storm (no longer a hurricane) and brought some wet and windy weather to Ireland and the British Isles, but she did take a good hit at Ireland and Northern Ireland, with three dead, and 245,000 without power today – their worst storm for 50 years.

Here’s a satellite image from Met Eireann from yesterday, showing her over Scotland:
In the UK (primarily Scotland and northern England) there are also some downed trees, traffic lights and such things that strong winds bring. But generally, this is pretty much the tail end of Ophelia. There’s just a bit of the system left over northern Scotland and then she goes off to northern parts.

Exactly 30 years ago almost to the day, those of us in the UK at the time may remember the 'Great Storm of 1987' (which definitely does sound more dramatic that 'Storm Ophelia')… a post-hurricane that hit southern England (overnight on the 15-16 October, 1997). In addition to the damage and deaths that caused (13), the most famous thing about the Great Storm of ‘87 is that the night before, TV weather reporter, Michael Fish, said we would not be hit by a hurricane. Oopsies. I must say, weather forecasting has definitely improved!

That’s it for Ophelia. If there is another one, he will be Philippe… ooh la la. I’ll be back then. Time for a cuppa tea and a lovely early-season Mince Pie. :-) 

Toodle pip,
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. 

Saturday, October 14, 2017

Hurricane Ophelia: October 14, Update A

Ooh, I see a few Shakespeare fans out there! Jolly good. In this topsy-turvy year, a bit o’culture and art is a nice change, isn’t it? J

Hurricane Ophelia was upgraded to a cat 3 storm today, and currently has winds of 115mph, central pressure of 960mb. This makes her a relatively weak cat 3 storm (cat 3 winds: 111-130mph):
There is a little circulation (vorticity) in the upper troposphere, which means she is a hurricane because her structure is good throughout this part of the atmosphere. And she's definitely still a cat 2 with that good eye. But the vorticity isn't as strong as we see with a cat 3 storm. She is moving over cold water – the surface water is less than 26 deg C – not great there either for a storm. Normally, I would say she is a cat 2 storm, but I can see why they increased the category based on wind speed. The reason is that she finally merged with a front which was working its way across the Atlantic, which added its own energy and forward motion to the storm, so the winds are higher. Otherwise, she should not be more than a cat 2 at the most. Here are a few stills to show the front (the long curvy line of blue and yellow clouds north of Ophelia) moving across to the east and south and meeting up with Ophelia earlier today (I wasn’t able to get a moving satellite image- and oopsie on the layout too! :-)):

 
She is currently at 35.9N, 23.7W, heading NE at 28mph. This incredibly fast forward speed is another indication that she is actually caught up and is moving along with a low-pressure front. She is passing just south of the Azores at the moment, still forecast to head to Emerald Isle and then bonnie Scotland…
Over the last couple of days she has been forecast to be a hurricane more-or-less all the way to Ireland, but I see that today the NHC have downgraded that to a Tropical Storm by the time she gets to Ireland. There is some wind shear ahead of her so this is reasonable.  An autumn front on its own in Ireland and the UK would bring a blustery, rainy day. A front plus the energy from a tropical storm means gale force winds and a rainy day. Here’s the forecast from the Met Office, which pretty much sums it up:

Sunday:
Wet and windy in western Scotland, rain spreading into parts of southern Scotland and northern England later. Elsewhere, will be warm, dry with some sunny spells and easing winds.
Monday to Wednesday:
Windy with severe gales in the west on Monday. Breezy, warm and bright in the east. Strong winds in the north Tuesday, settled and cooler further south. Unsettled on Wednesday.

Pretty much a normal wintery storm over in these parts. 

I’m traveling tomorrow, so I won’t be checking in on progress - unless I run into a weather delay. J But I’ll be flying over Ophelia and will tell her to turn it down a notch! I’m currently in the UK and will be heading to the US, personally evacuating some vital Jaffa Cakes, Jelly Babies, Prawn Cocktail crisps, and Pickled Onion Monster Munch. It was a hastily planned visit because I was actually supposed to be in Puerto Rico... and next week I am supposed to be in Sonoma County, CA, and after that er, hmm... maybe I should just stay put for a while…?

Anyway, enough of that silly storm stuff! Here’s what you have really been waiting for… the Answers from the Shakespeare quiz:
1. Friends, Romans, countrymen, lend me your ears. From Julius Caesar. (No, he’s not asking for people to do a Van Gogh and literally lend him their ears!)
2. …when last we met… From er… that well-known Shakespearean piece that I remember well, called er… Star Wars. Umm, ok, that was a deliberate red herring. Although don't you think Darth Vadar was based upon Romeo?
3…. O wonderful, wonderful, and most wonderful wonderful! From As You Like It. (Shakespeare accidentally hit copy and paste too often – easily done when the keyboard is sensitive)
4. … And so, once more unto the breach, dear friends, once more! From Henry V. (I use this one quite often in daily conversation – especially when I’m talking to myself)
5. …glass of fashion… From Hamlet (the glass of fashion means a mirror of comportment or mirror of form… not to be confused with Harry Potter’s Mirror of Eirised)
6. Tempest From The Tempest (ok, this was more of a title than a quote… I won’t hold it against you if you didn’t count this one)
7. …though she be but little, she is fierce. From A Midsummer Night’s Dream. (Sounds just like me)
8. …more things in heaven and earth. From Hamlet. (with Ophelia around, how could I not have Hamlet in this list?)
9. …all that glisters is not gold… From The Merchant of Venice (sometimes contorted to all the glistens is not gold – I think)
10. …
it appears no other thing to me than a foul and pestilent congregation of vapours. From Hamlet (more about humans than storms, but it works oh so well… I admit I was rubbing my hands in glee at this one)
11. … royal throne of kings, this sceptred isle. From Richard II. (luckily Shakespeare wrote a few words about the British isles).
12. … Scotland hath foisons to fill up your will. From Macbeth (meaning that Scotland has enough treasures to satisfy you… very apropos for this storm methinks)
13. …this blessed plot, this earth, this realm, this England. From Richard II (pretty much continued from the quote above)
14. …do not compare Ophelia to a summer's day. From Sonnet 18 (with a slight modification of course… the actual line is Shall I compare thee to a summer’s day?)
15. You may be saying a plague upon this howling! They are louder than the weather or our office. From The Tempest. (of course!)
16. …where shall we three meet again in thunder, lightning, or in rain? When the hurlyburly 's done, when the battle 's lost and won. From Macbeth (that Scottish play!)

If you remove the red herring, the title, and the split Richard II quote, then we have 13. Otherwise, I’d say 14. J

Back when I can! Stay safe my peeps on this side of the Atlantic... keep the smarties safe for me! :-) 
Ciao,
J. 


--> 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.