Hurricane Bertha: August 4, Update A

I'm going to jump right in today...

The NHC upgraded TS Bertha to Hurricane Bertha this morning. I think they overestimated her intensity and although she is still officially a hurricane, I have to say, I don't think she's been one for most of the day and certainly doesn't look like one now...

Currently her wind speed is 75mph, so she's barely a cat 1 (cat 1 range: 74-95mph). Central pressure is 1001mb. Although it looked like she was going to hang out in conditions that would allow her to grow a bit, she moved rather quickly over colder water! So although the wind shear is low and she's in an area where there is moisture in the atmosphere, we see the importance of the ocean at play... the sea surface temperature is around 27-28 deg C but there is hardly any warm water with depth; water warmer than 26 deg C is only in the upper ~25m. This would account for her scraggy appearance and structure.

She is apparently centered at 31.3N, 73.1W heading NNE 20mph. I really think she's a Tropical Storm and barely got to hurricane strength today. Of course she will continue to deteriorate as she moves north.

<Science Alert!> Although satellite images are one piece of the information puzzle, the biggest clue about what sort of storm we have is in the circulation (or vorticity as this is supposed to be all sciency stuff ;-)) and what that looks like at different levels of the troposphere - this gives us a glimpse into the structure of the storm. A tropical storm will have a well-defined circular "splodge" (yes, you can expect only the most highly technical jargon to be used here! ;-)) on a map of vorticity. The stronger the storm, the more cohesive the "splodge" at all levels of the troposphere.

Luckily for you, I have a Tale of Three Storms to show you this! :-) 'Hurricane Bertha' in the Atlantic, and both Hurricane Iselle and Tropical Storm Julio in the E. Pacific. Earlier today I grabbed the vorticity maps for the Atlantic and E. Pacific. At that time, Bertha was a cat 1 storm officially with winds of 80mph, Iselle was a cat 4 and had winds of 140mph (she is still a cat 4, but with winds of 135mph, still heading to Hawaii) and Julio was just a baby with winds of 45mph (he now has winds of 60mph, and is also heading in the Hawaii direction!).

We can see the how good the structure of these storms are throughout the troposphere by looking at the circulation/vorticity maps for four levels of the troposphere.

The lowest level, pretty darn tootin' close to the surface of the planet (850mb)...
Atlantic (Bertha, the really dark red splodge just to the right of the Bahamas):

E. Pacific (Iselle is the red 'splodge' on the left - actually, the center is white which indicates that the vorticity is really really strong - and Julio is the one on the right):

A bit higher (o.k., 700mb if you want to be all technical ;-))...
Atlantic (Bertha, the  dark red splodge next to the Bahamas):

E. Pacific (Iselle is the red/white 'splodge' in the center and Julio is the red one on the right):

The middle bit of the troposphere (500mb)...
Atlantic (Bertha, the not-so-dark-red-as-the-lower-levels-of-the-troposphere splodge next to the Bahamas, which indicates that although there is some vorticity, it is weakening as you get higher into the troposphere):

E. Pacific (Iselle is the dark red 'splodge' in the center and Julio is the one on the right):

And the upper troposphere (250mb)...
Atlantic (Bertha... no longer a splodge next to the Bahamas! which indicates no vorticity in the upper troposphere):

E. Pacific (Iselle is the round red 'splodge' in the center and Julio is no longer red splodge on the right):

For a hurricane, we always see a 'splodge' at all levels of the troposphere and they always line up on the same spot. The darker red the splodge is at the 200mb level, the stronger the storm. For a Tropical Storm, the vorticity generally stops somewhere in the middle troposphere (around 500mb), so both TS Julio and 'Hurricane' Bertha were really Tropical Storms, whereas Hurricane Iselle is most definitely a strong hurricane!

And thus endeth a Tale of Three Storms. :-) Let me know if you have any questions! :-) (All of these vorticity maps are from the University of Wisconsin... I'll show you how to get to them tomorrow). <End Science Alert!>

Before I zip off, I ought to mention this historic day... 100 years ago today (4th August, 1914) Britain and hence the Commonwealth jumped into The Great War, also known as World War I... or the largest family squabble in history (and you thought 'Dynasty' was bad?). Amazing times with many courageous stories!

Toodle pip!
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.
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Tropical Storm Bertha: August 3, Update A

A lovely Sunday with tea and Jaffa cakes and classic Dr. Who (the first one with the third Doctor, John Pertwee, is really good by the way :-)).

Meanwhile, over in the Atlantic things have also been moving along as suspected... Tropical Storm Bertha is still a Tropical Storm but has, indeed, intensified and now has winds of 65mph (1007mb central pressure). To re-cap from yesterday, this is because she's moved away from land (including the soggy Bahamas), wind shear has decreased (although there is still some), she's moved out of the dry and dusty SAL, and sea surface temperatures are now 28-30 deg C with waters warmer than 26 deg C.

She is not very organized at the moment but it looks like she will get stronger because all those conditions remain the same for the next day or so (wind shear will weaken a bit) and she'll probably be a weak hurricane tomorrow, which is in agreement with the NHC.

She is currently at 24.9N, 73.2W heading NNW at 17mph. The track looks more-or-less ok and she'll stay away from the US and Bermuda, possibly clipping Canada as a weaker storm in a few days:

So that's the Atlantic. Meanwhile, in the Pacific we have a few interesting things going on... the best looking of which is Hurricane Iselle, heading for a vacation in Hawaii on Thursday/Friday. She currently is a borderline cat 2/cat 3 (cat 2 range: 96-110mph, cat 3: 111-129mph) storm with winds of 110mph:

And in the West Pacific, Typhoon Halong is supposedly a border-line cat3/cat 4 storm because it has winds of 130mph, and is therefore stronger than Iselle. Although it is bigger, it does not have a very well-formed eye at the moment so I suspect it may be a bit weaker than a cat 4! (maybe a cat 2):

Not to be outdone by Iselle, Typhoon Halong is going for a vacation to Japan on Thursday/Friday. Japan really does not need more rain this week... I heard some parts had about 40 inches this weekend!

This large difference in the intensity of the storms (relative to their look) is because agencies from different countries issue the forecasts for storms in different parts of the world. Because they don't have enough data (or even the same sort of data) from inside these storms when they are over the ocean, it's pretty tricky for them to figure out their intensity (not for me, obviously, but I use magic ;-)  and I've been doing this for yonks!).

There are a few other blobs and blobettes in the Pacific, but that's all for now folks!

Until tomorrow,
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.
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Tropical Storm Bertha: August 2, Update A

Itsy bitsy Bertha is barely a Tropical Storm. She could be downgraded to Blobette Bertha and hardly anyone would notice, but officially the NHC have kept her as a Tropical Storm with winds of 45mph, central pressure at 1010mb as a precautionary measure. They said they couldn't find a center of circulation (or closed circulation actually)... and neither can I - can you?:

(Sorry about the satellite video loop - can't be helped!)

She does have a bit of convection though, with maybe the odd thunderstorm or two (shown as dark orange patches), as you can see in this infrared satellite image:

I received an on-the-ground report from our intrepid reporter, Tom, in St. Thomas:

"Short update from St. Thomas...first drop of rain at 6:41am with expectations of 6" by days end. Newly cleaned empty cistern awaiting the incoming...gusty wind but nothing like St. Croix to our south must be getting. Cats are in their hurricane beds behind hurricane shutters dreaming of gold fish and swooping birds...Bertha is a breeze!"

Bertha is currently officially centered at 18.9N, 69.1W, heading WNW at 22mph. This is somewhat speculative because, as I said, no-one actually knows the center. She is weak for three reasons:
1. She is interacting with the Dominican Republic, Puerto Rico etc. as shown in the satellite images, and this interaction will weaken her a bit more.
2. She is also in that area of dry, dusty Saharan Air Layer that I showed you yesterday.
3. There is quite a bit'o'wind shear.

The convection is because the water is rather warm - sea surface temperatures are 28-30 deg C, and the upper 100-125 m is warmer than 26 deg C.

Her future intensity depends on how much she weakens as she crosses out of the Caribbean. It is possible that she will begin to strengthen again as some of those inhibiting factors go away... you can see that she is almost out of the dry SAL layer and is moving towards a low-pressure area which has already got convective activity (over the Bahamas) in this IR satellite image:

Wind shear also looks like it will weaken once she is in the Atlantic, and the water temperatures are as warm as those in the Caribbean. All things that will allow her to intensify. The track keeps her away from the US, but it looks like she will roll over the Bahamas (who are already getting a coat of water).

I'll be back with more on Itsy Bitsy Bertha tomorrow!

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.
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Tropical Storm Bertha: August 1, Update A

I had a terribly busy week doing important things like painting my nails and drinking glasses of wine, but finally I have a moment to write!

I saw that the NHC upgraded a blobette to TS Bertha yesterday. I remember the last Bertha, 6 years ago... Big Beautiful Bertha. This Bertha is definitely not so big or beautiful at the moment. She's a dinky little thing with winds of 50mph (central pressure is 1007mb) and not much circulation or convection...

She is now in the Northeastern Caribbean, having crossed the Lesser Antilles earlier today, and is heading towards Puerto Rico. She is currently moving WNW at 24 mph (scampering along) and is currently at 15.2N, 61.9W (ish). The track forecast looks good to me.

The convection is to the north and east of the center, as you can see, so it looks like you guys in the VIs might finally get a spot of rain. Good news, hey? Just bring the cats indoors... apparently some of them don't like water. ;-)

Although sea surface temperatures are a rather warm 28-29 deg C, with warm waters in the upper 100-125m, I don't think she will intensify much in the next couple of days because there is some nice wind shear and she is still moving in oodles of dry and dusty air (known as the Saharan Air Layer) which you can see in this image as the lovely orange 'stuff' (technical term ;-)):

<Really Obvious Jargon Alert!> Saharan Air Layer (SAL): This is dry dusty air blowing off northern Africa (the Sahara Desert to be precise, in case the name didn’t give that away ;-)) and usually inhibits storm development. <End Really Obvious Jargon Alert!>

Once she moves away from the SAL and away from the Puerto Rico 'landmass' area, then she may intensify a bit more. Although I'm estimating this will take a couple of days, she is moving quite fast so we may see some intensification later tomorrow/early Sunday.

Good luck out there! More tomorrow.

Toodle pip!
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.
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Tropical Depression 2: July 23, Update A

I thought it was about time to jot down a bon mot or two on the latest blobette. :-)

I have been watching the mini-blobette (officially known as TD2) as she left Africa and zoomed across the Atlantic. She has been struggling, and at the moment there is very little circulation in the lower half of the troposphere and the convection has just decreased:

She is currently centered at 13.9N, 53.2W and is moving WNW at a very rapid 20mph. This blobette really doesn't have much to it, so it's pretty tricky to see where the center is actually and this location is as good as any other.

She is heading to the Lesser Antilles, and the folks there should be getting ready for it by making sure they have enough fixings for their umbrella drinks. It should be a lovely breezy day, maybe a little overcast with a drop or two of rain.

The forecast is for this system to dissipate any moment now and just be a low pressure trough by the time it moves over the Lesser Antilles. There are a couple of reasons for this. First, the wind shear is not very high, but high enough to hinder this blobette from getting the curling iron out. And second, the blobette is running into a bit of dry air:

(I don't know what they did to the colours of the normal water vapor map because these are horrible). The dry air as that dull dirty icky yellow shaded stuff.

However, so far she has been moving over relatively cold water (sea surface temperatures of less than 26.5 deg C - the temperature needed to sustain a storm). She's about to enter an area where the water temperatures are warmer than 26.5 deg C, with the upper ~100m being warmer than 26 deg C. This should sustain the convection at least and there is a chance she'll have more than one or two drops of rain as she crosses the Lesser Antilles.

I do agree with the NHC that she is too weak to amount to much, but I am still going to keep an eye on her. I'll be back with more if she does strengthen, otherwise I will spend the time watching really old black and white episodes of Dr. Who. :-)

Cheerio for now!
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.
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July 4: Hurricane Arthur, Update A

Happy Independence Day America! A historic day indeed! In honour of today I won't mention that apple pie was an English dish from at least the 1380s or that baseball was played in England in at least the 1740s. Instead, because I'm a nice person (grin), here's a completely different fun fact for you: In 1776 some of the founding fathers (and mothers) of America were as old as Millennials are today (Millennials were born between the early 1980s and 2000)! Details here.

'Hurricane' King Arthur (he's not really one anymore as you will see) is officially at 41.2N, 68.7W, moving  to the NE at a whopping 31mph! This is too fast for a tropical storm and is the first indication that he is no longer a tropical storm, but is an extratropical system and has merged with a low pressure front.

His winds are 75mph, central pressure is officially still 976mb. Although 75mph winds means he is officially a weak cat 1 storm, but I agree with the NHC today because they have actually already said that he isn't a hurricane and have explained that they are being generous with this estimate of winds speed for now. When a storm merges with an extratropical front and has such a fast forward motion, one would expect high winds, even if it isn't a tropical storm/hurricane any more.

The satellite images clearly show how Arthur's appearance has changed over the last few hours:

 

The hint of an eye he had has vanished, his structure and circulation has also pretty much disappeared, and there is much less convection. I expect they will downgrade him tomorrow, so this is my last entry on 'King Arthur of the Nights of the Round Storms'.

I'll be back when we have another one out there. I hope everyone had a safe and fun day! :-)

Toodle pip!
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.
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July 3: Hurricane Arthur, Update A

I think I'll launch right into the thick of things today...

Hurricane Arthur just made landfall between Beaufort, NC and Cape Lookout. Officially as a cat 2 storm with winds of 100mph.

Intensity:
Hurricane Arthur's official wind speed is 100mph, which makes him a weak-to-mid level category 2 hurricane (cat 2 range: 96-110mph). Central pressure is 976mb. I *almost* agree with this! I think he was this strong earlier today, but now he has started to deteriorate. It looks like he maxed out as a weak cat 2 storm a few hours ago, with winds in the 96-100 mph range, but is now a cat 1 again (cat 1 range: 73-95mph). But I'm glad that at least the NHC did finally call him a hurricane by this morning and then upped the intensity to catch up with the real world! Phew. No rant today!

You can see why I think he is deteriorating in the visible and infrared (IR) satellite images. Here is the latest visible satellite image:

 

You can clearly see a solid eye, which indicates winds of at least 85-90mph. But as he is interacting with land, the convection is decreasing. From yesterday's <Technical Alert!> you can more easily see what is happening with the convection from the infrared (IR) satellite images. Here's one I saved about 9 hours ago:

There was very strong convection in Arthur then - lots of thunderstorms and possible tornadoes as well as an eye. All signs that he was a robust cat 1/weak cat 2 earlier today. Now here is the latest IR image:

 

A marked difference! Dry air as well as his interaction with land has taken a bit of a toll. There is still some heavy convection, but it has greatly diminished in structure (not so 'solid' any more), which indicates dry air in the system.

He is definitely still a cat 1 storm, but I doubt very much that when he made landfall he was a cat 2 with 100mph winds! The NOAA station at Cape Lookout (the closest station to the eye) has so far recorded maximum sustained winds of about 77mph (sustained winds are the defining number to find in defining a storm, not gusts) as the eye-wall passed overhead, as you can see here (the eye passing over it is why the winds suddenly dropped):

(Wind speed is recorded in knots, and 1 knot = 1.15mph)

The circulation structure (vorticity) in the troposphere also shows the earlier increase in strength today and weakening now, again suggesting a stronger cat 1/weak cat 2 storm some hours ago, but now it is back to where it was yesterday evening... a cat 1 storm.

Track:
His center is at 34.7N, 76.6W and he is heading NNE at brisk 18mph. He passed to the southeast of Wilmington, NC earlier today and just made landfall north of Beaufort, NC as he continues to on his way up the US East Coast. It looks like the track shifted slightly to the west since yesterday, but definitely remained in the cone of tracks. Not much to add on the track front.

One of the impacts from this storm is, of course, the storm surge!  It had reached a maximum of about 1.5 ft above normal in Wilmington, but it is now just under normal. This is because the eye has passed and water is being pushed offshore by the winds instead of onshore. Whereas the water level at Beaufort has just peaked at about 2ft above normal (as the eye went by) and is now decreasing as the winds have turned and are pushing water offshore.

<Technical Alert!> To look at the storm surge, I use NOAA’s National Ocean Service website, Tides Online, which is an excellent site: http://tidesonline.nos.noaa.gov/geographic.html. Click on the state you are interested in, and then the location within that state. For example, here is the data from Beaufort:

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.  The graph below that is wind speed (which you can see was increasing) and direction. Below that is air pressure (which you can see dropping), and below that is air and sea surface temperature. <End Technical Alert!>

So far the reports I have from North Carolina (Wilmington) are that things are ok. Good luck out there! Stay safe if you are in the stormy area.

Everyone else... Happy July 4th!

Ciao for now,
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.
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July 2: Tropical Storm Arthur, Update A

Tropical Storm King Arthur of the Nights of the Round Storms is officially at 30.6N, 79.1W, heading N at 8mph. And officially, his winds are now 70mph and central pressure is 988mb.

Winds of 70mph makes him a very strong Tropical Storm (TS range: 39 - 73mph)/borderline cat 1 hurricane. I think he is already a hurricane and has been since yesterday, but at least he continues to remain a little hurricane for now (although he is getting stronger). My reasons for knowing that he is a little hurricane (other than just using The Force) are:

1. Since yesterday he has shown signs of trying to develop an eye. An eye will form with winds of 85-90mph and higher (cat 1 range: 74 - 95mph). The fact that it is not there all the time suggests that he is a weak cat 1. You can see it trying to form in this latest visible satellite imagery:

2.  The circulation (vorticity) throughout the troposphere is now stronger than it was yesterday, including in the upper levels (see yesterday's <Science Alert!> about tropospheres), which is a clear signal that he is a hurricane and is actually getting a bit stronger.

3. The dry air and a bit of wind shear is keeping him in check, so he is not a strong hurricane. Although he looks like he has an eye that is surrounded by clouds in the visible image, the clouds are not evenly spread around the storm, as you can see in this infrared satellite imagery:

This shows that there is pretty decent convection all the way around the eye that you and I can see... but that the NHC can't!! Actually... <Minor Rant Alert!> I can't believe the NHC haven't upgraded him!! He's approaching a mid-size cat 1 with winds in the 80-90mph range, not a 'Tropical Storm' with 70mph winds!! How is this storm not a hurricane?? Grrrr. <End Minor Rant Alert!>

<Technical Alert!> Satellite Imagery: I mainly use three sorts of satellite images: visible, water vapour, and infrared. The visible one is obvious… it is what you would see if you took a black and white photo. Best used during daylight hours of course! The water vapor image is also pretty obvious…it shows how much water vapor there is in the atmosphere. Brown areas are dry (think of parched deserts) and any other colour indicates some amount of water vapor. The infrared satellite image is the most interesting though because not only does it show where the storm is, but it also gives us an indication of how strong it is and what sort of weather we have. The colours represent how high the clouds reach into the atmosphere because they are based on the temperature at the top of the cloud (which is what the satellite sees). It gets colder the higher you get in the troposphere (as I mentioned yesterday), so we can tell from cloud top temperature how deep the clouds are and therefore how strong the convection is! The red colours are very big high clouds with the coldest temperatures (other than a dark gray), and blues and whites are lower, warmer clouds. The redder the cloud colour, the more active the convection. My general rule of thumb (having seen these images and lived under them at the same time) is that blue and yellow areas are mostly clouds, with some rain in the yellow areas. But as you get to the orange and red, you get thunderstorms and possible tornadoes (especially in the red/dark gray areas). <End Technical Alert!>

So, it looks like some extremely strong convective activity on the east side of that thing we shall call an 'eye', and some rather strong convective activity on the west side.

Track: I see they have moved the track slightly to the west, bringing it to North Carolina tomorrow night and on Friday, pretty close to the South Carolina border...

so, umm... Wilmington, are you ready? (Gee, I hope no-one just moved there to start a new job or anything... Got those bottle of wine ready? How about the ice cream?) The track may change a little - maybe move slightly further west - but overall it looks reasonable to me. If any of my on-the-ground reporters have photos or reports (I recall some plant damage photos from Wilmington a few years ago), let me know!

At the moment it looks like he will be a cat 1 by the time he gets there because of the dry air and wind shear. The thing to watch out for is if the eye forms and stays fully developed - that's an indication that he's a strong cat 1 and slowly approaching cat 2 intensity.

More tomorrow. Good luck with the preparations out there.
Over here, it is ice-cream o-clock!
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.
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July 1: Tropical Storm Arthur, Update A

I just managed to get onto the interwebs after a long day of travel and meetings and eating of cheeses...

... and while I was busy doing all that, it looks like Tropical Storm Arthur was busy getting stronger. Currently the official winds are at 60mph, but I think this may be a bit too low. It looks like TS Arthur has good circulation in all levels of the troposphere (ooh... I feel a <Science Alert!>  coming on! ;-)), which is the signal we would only see in a hurricane! I think at some point today he may have reached borderline TS/cat 1 winds (around 75mph)... but there is so much dry air around that convection has not really taken hold, which stopped him from growing much beyond that and he may actually be weakening now as a result.You can see that Arthur been 'lanced-a-lot' by dry air (tee hee hee) in this infrared satellite image movie:

<Science Alert!> The troposphere. Our atmosphere is divided into layers – like a trifle or seven-layer dip or lasagna (depending on what country you are from). A characteristic of each layer is that the air temperature either increases with height or decreases with height. The troposphere is one of these layers. It is the lowest section of our atmosphere and extends up from the earth to about 15-16km in the equatorial regions, and to about 8km in the polar regions of the planet. All our 'weather' essentially occurs in the troposphere. It is defined by decreasing air temperature with increasing height. You would know this if you climbed a mountain or you could just use the much easier 'Florida option', which is to look at pictures of mountains and see the snow at the top. J The top of the troposphere is called the tropopause. Strong tropical storms have clouds that reach as high as the tropopause - and in a few very strong cases, they can extend even higher into the next layer up. The layer of the atmosphere above the troposphere is called the stratosphere, which is defined by air temperature increasing with height. The ozone hole is in the stratosphere. <End Science Alert!>

Weak storms have circulation in the lower sections of the troposphere, but hurricanes have circulation throughout the troposphere - and this is what we are seeing with Tropical Storm Arthur.

Officially winds are 60mph, central pressure 1001mb, and he is at 28.0N, 79.1W, heading Northward at a slow 4mph. Given the clear eye, the location is almost spot on (I'd say 28.1N, 79.1W) and he is moving NNW.

Here is the visible satellite movie for Tropical Storm Arthur, just because.

More Tales of Arthur, The Round Storm tomorrow.
Night night!
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.
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June 30: Tropical Depression One, Update A

Here we go! The first Tropical Depression of the Atlantic has been named as Tropical Depression One! (surprise! ;-)) (meanwhile in the Eastern Pacific we're on Tropical Storms number 4 (Douglas) and 5 (Elida)).

Officially he has winds of 35mph, central pressure 1009 mb. In case you are wondering, a Tropical Depression (TD) is a system with closed circular motion (as you see in the "movie" below) and maximum winds of 38mph. I really think he became a TD much earlier in the day today ... here's what he looked like at around 4pm EST:

So I'm glad the NHC finally upgraded him to TD 1 in the 11pm EST advisory!

Like the circulation, the convection has slowly improved during the day too, mostly because of the ocean. He is over warm water, with sea surface temperatures over 29 deg C, and he is interacting with the Gulf Stream which is a current that  runs along the eastern edge of Florida (and the southeastern US) and has warm water over a large depth; the upper ~50-75m of the water column are warmer than 26 deg C. The atmosphere (which has a moderate amount of wind shear and dry air) and his proximity to land have been keeping him in check. This 'battle' between the ocean, atmosphere and land has been going on all day... but it looks like the ocean is slowly winning because the convection is slowly increasing, as you can see in the infrared satellite image:

Actually, with this heavy convection over his center of circulation, I think he is already a Tropical Storm!

His center is officially at 27.6N, 79.1W and he is moving South-Westward incredibly slowly at 2mph. I think he may be a bit to the east of this location, but I agree with the snails pace movement - he must be really enjoying those 'umbrella' drinks in the Bahamas! ;-) The forecast track has him turning to the west (towards Florida) and then eventually north, skirting the Florida and Georgia coastline over the next couple of days:

I think this is a very likely path and as the NHC were quite good at the 1-2 day track forecasts last season I have little reason to doubt this. It is tricky to tell whether he will actually reach the Florida coast but whether or not he does, he will bring rain and possible coastal flooding to parts of eastern Florida. And because he is moving so slowly this may cause a few hiccups so get the wellies out and put the ponies in a barn!

He is going over the Gulf Stream, which usually means intensification, so although officially the Tuesday and Wednesday forecast calls for a maximum wind speed of 50-60mph, I wouldn't be too surprised if he turns out to be a bit stronger (aka Tropical Storm 'Count Arthur Strong' - a very zany British show! :-)). As I mentioned earlier, the dry air and wind shear will inhibit him somewhat so we'll have to see how that battle plays out.

Travel day tomorrow but I will try and hop onto a computer (not literally of course - that would look quite silly and also damage the computer ;-)) and send an update!

Toodle pip!
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.
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June 29: Atlantic Blob,Update A

Just a quick update for now because this Atlantic blob is not quite cooked… it is relaxing near the Bahamas, sipping pina coladas, as one does. ;-)

The circulation has slowly been improving over the last day or so as it moved southward from the South Carolina coast. It is now centered just slightly north of Grand Bahama. It has struggled to become a fully-fledged storm (first one would be Arthur) because dry air around the blob has inhibited a lot of convection forming near the center, as you can see:

The sea surface temperature is about 29 deg C., with the upper 75-100m above 26 deg C. This is definitely warm enough to help the storm to develop (storms need sea surface temperatures of 26.5 deg C to develop) and it has helped to produce a few buckets of rain over parts of Florida (as I’m sure you may have noticed if you are there), to the west of the center of circulation.

Officially the forecast is for it to move to the south and west, and then loop back to the north and east, which should take it into southern Florida in the next few days – but because it is quite poorly formed at the moment, this may not happen. Given the dry air and proximity to land, I am not certain that it will develop into a fully-fledged tropical storm (the current official forecast is for a Tropical Depression in the next 2 days), but even if it does, it will mostly be a rainmaker (with some interesting thunderstormy sort of weather).

I’ll definitely be back tomorrow. We may have a Tropical Depression by then… or even a very weak Tropical Storm King Arthur! ;-)

Ciao!
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.
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June 19: Are female hurricanes really deadlier than male hurricanes?

What's in a name? That which we call a rose by any other name would smell as sweet. – Shakespeare, circa 1590s.

Earlier this month a study came out of Illinois and Arizona, two states well-known for being hit by hurricanes (!), about how female-named hurricanes cause more deaths than male-named hurricanes because people just aren’t as afraid of women as they are of men (you can find the actual article here). The study was conducted by a team from these assorted expert backgrounds: business affairs (including marketing), psychology, women and gender in global perspectives, and statistics. I'm sure everyone is an expert in their arena, but obviously this is not a serious scientific meteorological study!

The data is available on the link to the publication above, so I downloaded it and had a little playtime with numbers (woo hoo! :-)). Here are just a few reasons why I think this study is a bit iffy.

1. GENDER OR STRENGTH?
The naming of storms started in 1950. From 1950-1952, storms were given names from the World War II spelling alphabet (Able, Baker, Charlie, Dog, Easy etc.), so they weren’t male or female names. From 1953-1978, hurricanes were ONLY given female names. Male storm names were not used until 1979, after which they were used alternately with female names.

The study used storm names from 1950-2012. For a fair study, storms should only be included from 1979 onwards.

Also, the authors decided to allocate genders to the non-gender alphabet names from 1950-1952, so, for example, they classify ‘Easy’ as a female name (hmm… interesting choice. Freud would have a field day!). Here are their number of storms per category from 1950-2012 and, using the same dataset, the numbers from 1979-2012:

	1950-2012	1979-2012
Cat 1 (F/M)	22/14	10/13
Cat 2 (F/M)	15/6	8/6
Cat 3 (F/M)	21/7	9/5
Cat 4 (F/M)	3/2	0/2
Cat 5 (F/M)	1/1	0/1

                                (F = female, M = male)

Outlier storms such as Katrina and Gilbert are not in the data, so kudos to the authors for not including those.

In my study of using only storms from 1979 onwards, we see no cat 4 or 5 female name storms – those big scary ones that people really pay attention to. The average intensity of female storms from 1950-2012 was 2.12 compared to 1.96 from 1979-2012. The average intensity of male storms from 1950-2012 was category 2 compared to 2.11 from 1979-2012. So from 1979-2012, on average, the weaker and less damaging storms happened to be the female named storms.

Generally, people are more cavalier about weaker storms compared to stronger storms, regardless of name. Which would you evacuate for, a cat 1 or a cat 4? This study could really be about how more people die in weaker storms than stronger storms, because they don’t feel as threatened by the intensity. We can put gender aside.

2. CAUSE OF DEATH?
Although they did remove outliers like Katrina (1,833 deaths) and Gilbert (433 deaths), what we don’t know is how the deaths occurred. Were they because people took the storm seriously and died during evacuation? For example, the day before Hurricane Rita made landfall in 2005, 23 people were evacuated from a nursing home, but died because their bus caught fire!

3. STATISTICS ARE GREAT!
Correlation should not be confused with causation! Although a flashy title, this study does not prove that “Female hurricanes are deadlier than male hurricanes”. If that’s the case, then here are a few more amazing facts (Note: I have not personally checked the data, but full credit for source is given below)…

• Did you know that the number of people who drowned by falling into a swimming-pool could be decreased if only Nicholas Cage stopped appearing in films?

• Think there is a need for more Civil Engineering doctorates in the US? Well obviously Americans need to eat more mozzarella cheese to make that happen!

And if it’s more Computer Science doctorates in the US that you are after, then you really need to head on down to your local video game arcade:

• Here’s a useful one: the per capita consumption of cheese (hmm… cheese :-)) correlates with the number of people who died by becoming tangled in their bedsheets…

but the number of people who died by becoming tangled in their bedsheets is correlated with revenue generated at ski facilities…

 … so obviously, if ski lodges are having a bad season (no snow, avalanche, summertime etc), then they should increase their cheese-based meals, thus by-passing the bedsheet/deaths thing entirely and saving everyone a lot of bother!

• And, finally, the real reason why honey producing bee colonies have decreased over the past few years is not because of changes to their environment, but because of the increase in the number of juvenile arrests for possession of marijuana. I guess you can only have honey or marijuana, not both.

These graphs and correlations are just a small selection from the hilarious Spurious Correlations website (check it out as there are more!! :-)). Thanks to Tyler Vigen, who put it together!

So, in conclusion, the real take-home message is that all scientists should have someone from their Dept. of Marketing as a co-author… the media attention, apparently, is amazing!

Oh, and by the way, if you come across a Hurricane Jyotika, be afraid. Be very afraid. Run for the hills. Or even better, run to Illinois or Arizona.

For those of you in in Florida and on the east coast… I’m watching that blob and may be back tomorrow…

Over and out (for now!),
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.
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June 5: Gulf of Mexico Blob, Update A

Well that didn't take too long, did it? What happened to my quiet season? Huh. Oh, I forgot to say in my season opening remarks that even though the forecast is for a below-average number of storms this year, it only takes one. The biggest example is, of course, Hurricane Andrew which was the first named storm of the 1992 hurricane season (a season with only 6 named storms, of which 4 were hurricanes) and hit S. Florida and Miami as a cat 5 on the 24th of August! So be prepared and get your supplies in order! My usual supplies list... batteries and flashlight, two tubs of ice cream (different flavours to avoid boredom), twelve bottles of wine (mostly red – no point getting too many white if there is no fridge to cool it in!), first-aid kit, some ice cream cones (optional), canned food, batteries for the camera/video/radio, a non-electronic wine bottle opener, smart phone to tweet from, a non-electronic can opener, sunscreen, good books to read, insect repellant, hand-held fan, cheese, bags of PG Tips in a ziploc bag etc. ;-)

So officially there is a small blob (technical jargon for 'a bunch of clouds loitering with intent' ;-)) in the southwest Gulf of Mexico, very near to the Bay of Campeche (but mostly over Mexico).

Although the National Hurricane Center has been slowly upgrading the likelihood of this blob developing into a storm over the past couple of days, it really doesn't look like much to me. The circulation is pretty poor and is connected to a front, and it doesn't have too much rain as you can see in this infra-red satellite movie (ooh...a movie!! quick, get the popcorn! ;-)):

What you actually see here are the remains of Tropical Storm Boris that merged with a low pressure front that's been hanging out down there in the Gulf for days. Whoa! Where did Tropical Storm Boris come from, you ask? No, I have not had one too many glasses of wine thank you very much (too early in the season for that! ;-)). Although there's not been much in the Atlantic so far, the Eastern Pacific Hurricane season (which started on May 15th) has been a bit busy with cat 5 Hurricane Amanda last week (that fizzled in the Pacific) and Tropical Storm Boris this week. TS Boris ran into the southwest coast of Mexico yesterday, bringing a bunch 'o' rain to Mexico and Guatemala. That's the story of Boris.

Our Gulf of Mexico blob is interacting with Mexico too much to develop into anything at the moment, but there is a small (very small) possibility that it will develop into something (first name is Arthur) if it moves away from land ... so something I'll definitely keep an eye on!

<Science Alert!> It's not too surprising if storms do pop up in the Gulf this early in the season, but the good news is that they would be dinky little things that generally bring much needed rain and not too much wind. Here is a figure that I made a few years ago that shows the track of all storms from 1851 to 2005, divided into the month they formed/existed (graph credit: MOI!).

You can see that in the early and latter parts of the season we have storms that develop in the western Atlantic/Gulf of Mexico/Caribbean region. But because they are so close to land and early in the season things are still warming up, they don’t usually have time to develop. During the peak months it’s another story! Storms develop in the eastern Atlantic and have lots of space and time (but no TARDIS, thankfully!) to get nice and strong before getting to land. This figure also shows why we have a ‘hurricane season’. 97% of all storms form between June 1 and Nov 30, with 78% forming during the peak months of Aug-Sept-Oct (stats from Landsea’s 1993 paper). But you can see that every so often we do get storms that develop outside of the season (including January!). Not common, but not impossible! <End Science Alert!>

I'll be back tomorrow if that Gulf Blob makes any dodgy moves, otherwise I'll be back later. 

Ciao for now!
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.
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June 1: Start of the 2014 Atlantic Hurricane Season

Welcome back my friends! The sun is shining, the birds are tweeting, and ‘Tis the start of ye grande Atlantic Hurricane Season of Two-Thousand and Fourteen (I just watched ‘Lincoln’). I hope you all had a very pleasant and relaxing off-season and are back for some science and some fun.

My off-season was SUPER DUPER busy… in case you haven’t heard, I moved to Los Angeles, California, and am now living a glamorous Hollywood life! ;-)

My entries this year will be peppered with phrases like “oopsie, another earthquake”, “hmm, that fire is awfully close”, “I had a very nice chat with Keanu today”, “traffic was a breeze, it only took me 2 hours to drive 15 miles”, and of course, “is that an alien? Oh, no, it’s just someone with botox”.

Before I get into what a super cool science geek like me (!!) is doing out here in the land of movie-making magic, let’s have a quick chit chat about hurricanes (as one does occasionally). This is shaping up to be a quiet season, partly because the temperatures in the Atlantic are cooler and partly because the atmospheric pressure fields have shifted because there is an El Nino in swing (not to be confused with a swinging el nino). The predictions are mostly below-normal to near-normal. Here are some of the official predictions:

Tropical Storm Risk (prediction date: 27 May): 12 (+/-4) named storms, 5 (+/-3) hurricanes, 2 (+/- 2) major hurricanes.

Colorado State University/Gray-Klotzbach (prediction date: 10 April): 9 named storms, 3 hurricanes, 1 major hurricanes.

UK Met Office (prediction date: 16 May): 10 (+/-3) named storms, 6 (+/-3) hurricanes.

NOAA (prediction date: 22 May): 8-13 named storms, 3-6 hurricanes, 1-2 major hurricanes.

The average season (based on all storms from 1950-2013) has 11 named storms, with 6 hurricanes, and 3 major hurricanes (category 3 or higher).

If you are reading my amazingly fabulous and award-breaking opening remarks for the first time (and even if you aren’t), here are my top ten background notes about this blog so you know what you are getting into for the season (you can always watch reality TV if you prefer, or, for even more entertainment, I’ve found sitting in LA rush-hour traffic can be a barrel of laughs):

1. These updates are about fun, forecasting, and education... and tropical storms (and whatever else pops into my head that may, with some imagination, fit those three words). It is just what I think.

2. I have a British sense of humoUr... you have been warned.

3. This is my hobby - sometimes you'll get one update a day, sometime four. If you are really lucky, you won't get any. If you wish to pay me to write, let me know and I'll send out updates as frequently as you like.

4. I hope you like Monty Python, Eddie Izzard, and The IT Crowd. And other funny stuff.

5. If you have any questions (preferably about tropical storms), please do not hesitate to ask. I will be happy to make up the answers for you. I can also cut and paste from previous entries (it’s a talent, I know) so if I say something or use some "scientific jargon" (ooh ahh, how thrilling), please ask me about it.

6. I often write tongue-in-cheek, which sometimes hurts my cheek but what can you do? Gentle sarcasm, irony, and puns are all acceptable forms of communication. Unfortunately they don't always translate in writing so please don't be offended - like Planet Earth, I'm "Mostly Harmless" (Douglas Adams). Have a piece of chocolate or a drink instead.

7. I'm sure every cloud in the Atlantic is exciting to some but, unless I'm bored, I'll usually write about those that I think have a chance of developing.

8. Despite what you may have heard, I am not always right. But then neither is anyone else. Forecasting is complicated. Sometimes the crystal ball gets smudges and you are all out of Windex to clean it and the store is closed. So PLEASE pay attention to the National Hurricane Center, National Weather Service and your Emergency Managers - especially when a storm is looming because they have the most up-to-date information!!

9. If you are reading this via email, I highly recommend switching to the website (http://jyotikastorms.blogspot.com). It’s much prettier. And I am working towards transitioning to the website only format anyway… as a part of my top-secret grand plan to take over the world (bwa haa haa - evil laughter in case you were wondering).

10. I confess, I am a twit. I am on twitter (@jyovianstorm). Twitter is cool. Just like bow-ties are (still) cool. (Dr. Who).  

Now you know what’s what, the last question for the day is: why on earth would I move from Florida, a land of tropical storms, to California, a land of earthquakes? Two reasons. First (and I have to put this first for the sake of peace and harmony ;-)), so my hubby and I can live in the same place (a novel concept, I know!). Second, I got a groovy new job with an organization that deals with the future!! Perfect for a sci-fi aficionado! :-) I now work at the XPRIZE Foundation (xprize.org) (woo hoo)! XPRIZE designs and operates Global Prize Competitions that result in new technologies to tackle the Grand Challenges of our time – from space ships to real Tricorders^* (Star Trek)! My piece is to help run an international competition to develop accurate and cheap ocean acidification sensing technologies.  

(^*If you don’t know what a Tricorder is… sigh. Sigh AND much shaking of my head. It’s a hand-held device (currently seen in Star Trek) that allows someone to make an accurate medical diagnosis of a number of ailments. Look it up! And if you want a chance to win an actual real Star Trek Tricorder signed by the five Star Trek captains, check out the Tricorder Federation: http://www.tricorderfederation.org/).

I’m sure I’ll be talking about future technologies and what nots throughout the season too. But now it’s time to skidaddle… I’ll be back when we have the next storm! (Er… unless I do actually meet Keanu Reeves, in which case there will be a dedicated Keanu update!)

Ciao for now!

J.

p.s. webpage count at start of season (mostly for my own edification): 72, 350-ish

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.
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