Wednesday, June 27, 2012

Tropical Depression Debby: June 27, Update A

Debby has been crossing the Gulf Stream today, which means she’s had some lovely warm water underneath. Although her circulation improved a little, it looks like the other factors I mentioned yesterday took their toll (dry air and all that jazz – see yesterday’s entry if you really want to know). The NHC issued their last advisory on Debby at 5pm, when she was at 29.5N, 78.3W moving eastward at 13mph. At that time they said she was ‘post-tropical’ <cough> extratropical <cough>, as indicated by the vorticity (circulation) which was like a low pressure front rather than a circular tropical storm. Her convection never really picked up, as you can see in the latest IR satellite image:

They have her spinning off into the northeast in the Atlantic as a weak storm over the next few days.

This is my last update, so I’m Done with Debby! (no not you, my friend, Debbie ;-)).

I know there’s a teensy weensy yellow polka-dot blob out there in the Atlantic.  It’s somewhere around 11N and 40W. It has a little convection and a little circulation, but nothing much to talk about yet. I’ll keep an eye on it but I’m hoping for a nice couple of days off as I have some work and partying to get done. ;-) The next storm would be Ernesto.

Ciao for now kids!
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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Tuesday, June 26, 2012

Tropical Depression Debby: June 26, Update B

I think most of you must know by now, Debby made landfall this afternoon about 35 miles north of Cedar Key, near Steinhatchee, as a very weak Tropical Storm. Down here in St. Petersburg we felt the disturbance in the Force as the bay suddenly calmed down. Here's a visible satellite image that shows her elongated eye just as it touched land:

Tropical Depression Debby now officially has winds of 35mph with a central pressure of 997mb. She’s at around 29.5N, 83.1W, moving ENE at 6mph. There is still a bit of convection in this little storm, as you can see in the latest IR satellite image:

However it is all to the northeast, towards Jacksonville, which shows that there is a lot of wind shear.  There isn’t too much circulation left in Debby. What there is seems to be part of a low pressure front instead of a tropical system.

The NHC forecast thinking is that she will cross Florida tomorrow as a Tropical Depression, and emerge into the Atlantic tomorrow afternoon. She will then reform into a Tropical Storm by Thursday afternoon and head out to sea. This is certainly possible because she will be crossing the Gulf Stream off the east coast of Florida, in the Atlantic. This is an area of warm deep water so it will definitely help her to intensify. However, she is moving quite quickly, there is considerable wind shear, her circulation is not really tropical anymore but rather part of a low pressure front, and there is still dry air to her west so it is a little difficult to tell how strong she will get. I think the general track is reasonable too, although there is a chance she will head more northeastward than the current center of cone is showing.

Storm surge on the west coast of Florida has decreased, with water levels now a mere (ha!) 2 ft above normal in St. Pete and less than that at Cedar Key. However, on the northeast coast of Florida the water levels are on the rise because the winds are pushing water on-shore. Both Mayport and Fernandina Beach at around 2ft above normal and increasing.

That’s it on Debby for today. No howling! Wow… ahh, so that’s what it used to sound like. ;-) More tomorrow when we should see Debby exit (Florida), stage right.

Jeff D. in St. Petersburg kindly sent me the scoop on getting on my Soapbox - The term originates from the days when speakers would elevate themselves by standing on a wooden crate originally used for shipment of soap or other dry goods from a manufacturer to a retail store. Between this and soap operas, the soap industry certainly cleaned up the marketing opportunities back then! (pun intended) ;-). (Thanks Jeff).

I saw about 20 Georgia Power trucks in St. Petersburg today, which reminds me… thanks to all the power peoples (local and from other states), the emergency peoples (of all flavours), and all other helpful peoples who go around getting things back to normal after these storms! Good job. I shall have a glass of something or the other in your honour (it’s the polite thing to do). And don’t worry about the leaves, I can get some of those. ;-)

When I tweet that I’ve posted this entry, it will be my 1001st tweet (I also passed my 500th blog post sometime during this storm)! I’m sure Shakespeare is looking on with great envy. ;-)

Stay safe out there & 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 Debby: June 26, Update A

Ok, ok, I know. *I* might be enjoying this fine British weather (although it could be a little cooler), but you guys are fed-up with it and you want your sunshine and calm air back. So, as a favour to you all, I have spent the last few hours on the seawall here with all the fans going and I think we’ve managed to bring landfall forward to tomorrow morning (Weds) at the latest! ;-)

At the moment Dawdling Debby looks like she’s moving to the Northeast at a faster clip. The NHC in their last advisory (1.5 hours ago) had her moving eastward at 3mph, but I think that’s a little slow and with the wrong heading. Officially she’s at 28.9N, 84.2W, but from the satellite images I’m looking at, she’s at 29.01N, 83.99W. It may not seem like a huge difference, but it is when you are this close to shore.  She’s heading to the Big Bend area of Florida, near/just north of Cedar Key. The current official center of cone track has her making landfall on Cedar Key as a tropical storm at 8am Wednesday.

As she gets closer to land, her winds are going to be a little stronger of course. But she is also weakening. The circulation in the lower half of the troposphere is transitioning from being tropical to more of a low pressure front, so I expect she’ll be a Tropical Depression by the end of today.  The NHC currently have her winds at 40mph and a central pressure of 993mb, based on aircraft and other observations.

Here is the latest IR image of Debby:

The convection is way off to the northeast and you can clearly see the remains of the eye, just offshore.

<Science Alert!> On Sunday, when the forecast track was still heading west to north Texas, Karen M. from St. Petersburg sent me a question: “with so many models pointing toward the big bend region, and what seems to be fewer models pointing toward TX (it's a little hard to tell on the scale of the model map I'm looking at), why isn't the predicted track further north, or even eastward.  Do they think the high pressure will have that great an effect?  Do they trust one model more than others?”.

This is a really interesting question. They do use many different models, and some they think are better than others. But some models are also run many times, each time with a slightly different set of atmospheric or oceanic conditions (called <jargon alert> initial conditions <end jargon alert>). The output from these variations on a model form part of an ensemble of model runs of that particular model. With this storm some ensemble runs from one of their most trusted models was showing landfall to the west, and some ensemble runs were showing landfall to the east. However, other models (not ensemble) were also showing landfall to the west. The reason for the divergence was because they were not sure how strong the storm would be… so the forecast track in this case depended on their ability to forecast the intensity. And the reason why the intensity was important is because if Debby was stronger, the pressure fields higher up in the atmosphere would have played a bigger role in how she moved (which is the high pressure part of Karen’s question). However, she turned out to be weaker than they were expecting, so the model runs that had a weaker system turned out to be closer to the track. <end Science alert> Gosh, I hope everyone followed that… if not, please let me know and I’ll see what I can do.

<begin soapbox alert> ;-) The underlying tale to take away from this is that in order to improve the track forecast, we NEED to know the intensity! And in order to improve the intensity forecast we need to know the track because (for example) whether she is over land or deep warm water will impact her intensity. The two cannot really be divided when it comes to the research and prediction of storms. <end soapboax alert> J (hmmm… why is it called a soapbox? I can’t imagine I’d be much more imposing and commanding of your attention if I stood on a 1 inch soap box, not to mention the technical difficulties of balancing on something that small without crushing it…).

That’s all for now. More later!
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 Debby: June 25, Update B

T.S. Debby is still heading in a northeastward direction and has moved a little since the last update. She is now at 29.2N, 85.1W, just about 35 miles south of Apalachicola in Florida. She has slowed down again from her earlier speedy 3mph to 2mph (steady now, we wouldn’t want to rush anything). Her winds are still 45mph with a central pressure of 992mb, so she’s still a weak TS (range: 39-73mph).

Track: The center of cone shifted slightly to the north from her earlier track, and into the Big Bend area north of Cedar Key. This is reasonable. Landfall has now been shifted forward to Wednesday evening, which is also quite reasonable in my (sometimes) humble opinion. ;-)

Intensity: I don’t know what you guys in the Panhandle/north Florida and southern Georgia were doing this afternoon, but I expect it involved lots of raincoats and wellington boots. These areas had some strong convection north of the center which is weakening now (Rob H. in Atlanta: you asked for rain… did you get any?) – IR satellite image:

Also I see that the circulation is starting to decrease! Hurray! (Although the wind is still howling here. Along with the creaking roof beams it sounds like I’m in some cheesy b/w horror movie.) There is no circulation in the upper troposphere, and the circulation (vorticity) in the lower half of the troposphere has also decreased slightly. This is because the wind shear has increased. I mentioned the other factors inhibiting her development earlier: she is so very close to land; there is dry air in the system; and, there isn’t too much deep warm water under her. I agree with the NHC that she is a weak Tropical Storm.

Storm surge has increased since yesterday along west Florida because water has been pushed onto the coast all day today. The surge above normal tide in St. Petersburg is now just over 3ft, so at high tide this afternoon the water level was almost 5ft. Here is a photo of the road to my work just after high tide:

The water level at Cedar Key is now 4ft above normal, so with high tide earlier this afternoon the water level was over 6 ft. Water levels were higher than usual in southwest Florida too. Fort Myers, for example, had water levels of about 3ft above normal earlier today. Meanwhile, on the other side of the storm the water is now being pushed away from the coast so at Panama City the water level has dropped from 1.5 ft above normal to 1 ft above, and is still decreasing.

Attached is another photo of flooding from Steve M., taken at Coffee Pot Bayou in St. Petersburg from yesterday (thanks Steve!):

Apart from the tornadoes, this really was a water event!

She is now so close to landfall (and yet so far!). Tomorrow I’ll try and figure out what is next for Dillydallying Debby. J Hmm… I don’t think I had any ice cream today. Is it too late to have some as a bedtime snack I wonder? ;-)

Night folks!
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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Monday, June 25, 2012

Tropical Storm Debby: June 25, Update A

As a classic bear once sang…

“Oh the wind is lashing lustily
And the trees are thrashing thrustily
And the leaves are rustling gustily
So it's rather safe to say
That it seems that it may turn out to be
It feels that it will undoubtedly
It looks like a rather blustery day, today
It sounds that it may turn out to be
Feels that it will undoubtedly
Looks like a rather blustery day today”

That pretty much sums up things in my neck of the 100 Acre woods.

TS Debby is still out there, but as expected today she’s more wind than rain (compared to yesterday).  There will still be thundery/showery weather over parts of Florida, but at least it’s not completely covered. There are also clouds over Georgia, the Carolinas, the Bahamas, Cuba and the Yucatan associated with Debby as you can see in this IR satellite image:

If the environmental conditions had been conducive, she could have been much worse!

The latest advisory (about 2 hours ago) had her at 28.6N, 85.2W, moving NE at 3mph. Her central pressure was 995mb, with winds of 45mph making her a weak Tropical Storm (range: 39-73mph).

Track: They have shifted the ‘cone’ (circle) to the east, so it now extends just south of Tampa Bay. I agree with this. The central line has landfall as a Tropical Storm near Cedar Key on Thursday morning. I would accept this as part of the ‘cone’ I had in my head which focused on the “Big Bend area or possibly even farther south” (nothing personal Big Bend people!) – the northern end of my cone would include the Apalachicola region (nothing personal Apalachicola people!). I am thinking that landfall may be on Wednesday, not Thursday. The sooner the better really because she’ll just keep on blowing and picking up moisture and dumping it on everyone until she gets to land. It will make for many bad hair days. In fact, I’d suggest that you shouldn’t even bother with a hair-drier and ‘product’… just go for the windswept bedraggled look and say it’s ‘in’ these days.

Intensity: At this stage it seems unlikely that she will strengthen too much. She may a little, but there is still a lot of dry air to the west, she is still interacting with land, and she continues to swirl away from the Loop Current. Wind shear has died down, but I think it won’t do much other than allow her structure/circulation to improve (so she’ll remain windy). If she’s moved enough by tomorrow, I’ll start looking at what will happen to her beyond Florida.

So… I’m having computer problems and need to sign off now so it can be diagnosed by the computer doctor. J (Obviously I work too hard! ;-)). However, remember you can always check out the blog website for updates because I can post to that from anywhere. Must run. Hope to be back later!

Toodles,
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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Sunday, June 24, 2012

Tropical Storm Debby: June 24, Update D

Final update of the day! Tropical Storm Debby is still hanging out in the Gulf at 28.3N, 85.9W and she is stationary (for a change). Wind speed is still 60mph although the central pressure has dropped slightly to 991mb (from a plane). There has not been much change in her track which still takes her almost due north into the Panhandle, near Apalachicola, with landfall on Friday. I think she still has a chance to move farther east, with landfall in the Big Bend region or possibly even farther south, however it is difficult to assess her track while she is stuck because the pressure fields around her can change while she stays in her little ‘dip’. The circulation is still very strong in the lower half of the troposphere, with a signal in the upper levels which is something we see with very strong Tropical Storms or weak category 1 hurricanes so I expect we will continue to get windy weather and coastal flooding.

In the latest infrared satellite image we see that the convection has diminished even further:

There is still dry air to her west that is now in the storm. Interestingly, although the center is still on the Gulf side of Florida, parts of the storm are now over the Florida Current/Gulf Stream on the east side of Florida. This is a continuation of the Loop Current and has deep warm water and over this area there is strong convection (the red patch). However, I think the west coast of Florida will have a little easier day tomorrow. Parts of the Bahamas may get some sploshes of rain. Before I forget, I have to say mea culpa!! In my first entry today, I had accidentally switched my  ‘warms’ and ‘colds’ in the science alert when I talked about the troposphere (it actually gets colder with height) and the infrared satellite image (the red areas are the deepest convection and have the coldest cloud tops). I have already corrected this on my website blog, but thought I’d better fess up and hope I didn’t confuse anyone any more than I usually do! Obviously I wasn’t awake and it was pre-ice cream. ;-)

Once again, thank you so much to everyone who sent in comments, photos, videos etc. I tweeted them or shared them on facebook them. One of the photos I wanted to follow up on was from Molly M. in Shore Acres. In my last update she showed a car drive along a flooded road. Here is the same location a couple of hours later:

At least it was still being used as a thoroughfare!

With that I’m going to call it a day. It is still windy here in north St. Petersburg, but not much rain. I hope everyone is ok and safe!
More tomorrow.
Ciao,
J.

p.s. I’d also like to thank my cat for not getting alarmed by the howling wind and for helping to analyze the data today:

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 Debby: June 24, Update C

The 5pm update from the NHC has shifted her track to the east so the center of cone is now directly heading into the Florida Panhandle with landfall on Weds. afternoon.  They have removed the warnings for Louisiana. The ‘cone’ takes her anywhere from Alabama to the Big Bend/Cedar Key area of Florida. I think we are more on target with this. If she is heading to the western side of this range, we’ll see her turn to the north and then northwest in the next few hours, so that’s something to look out for today.

She is at 28.4N, 85.8W and still more-or-less stuck, crawling NE at 3mph. She must have had one too many martini’s yesterday! Winds are 60mph, with a central pressure of 993mb.

Her convection is currently taking a hit from many sides. Not only is she already interacting with land (as everyone in Florida can attest to!), but she is no longer over the Loop Current and there is still a little bit of shear. I mentioned these earlier today. But there is another factor that will help us a bit: the western Gulf has some dry air that she is pulling in, which is why the really strong thunderstorms are diminishing (or will be soon). You can see this in the latest infrared satellite image:
Compare this to the one I sent out earlier and you’ll see a huge reduction in the really cold cloud tops (the red areas). This means that the parts of the storm that are currently producing tornados will decrease, as will the really heavy rain over the next day or so. They won’t completely vanish, but it shouldn’t be as it was today. We’ve had a lot of rain over the past 24 hours – almost a foot in some places in Pinellas County.

However the wind shear has definitely decreased and with that her circulation has improved in all levels of the troposphere. If she had more convection, she would be a category 1. This means that even though the convection won’t be as ferocious, it will still be windy tomorrow and on Tuesday at least. There are two problems with this. First, because she is not moving very quickly, water from the Gulf will continue to be pushed on-shore along some parts of the coast. Water moves (along with the winds) in an anti-clockwise direction around a low pressure like Debby. Her center is north of Tampa Bay, so the water will be blowing into Tampa Bay. On the other hand, water will be blowing away from the coast on the northwestern edge of her circulation. This will mean that the coastal flooding will continue. Currently the surge is 2.5 ft above the normal tide in the St. Petersburg area, and 3ft above the normal tide in Apalachicola. We are at high tide in many places now though, so actual water levels are much higher. The second problem is that as her wind field strengthens and expands, she will be pulling in moisture from a larger part of the Gulf. This may result in more convective activity– she is already pulling thunderstorms from the Yucatan area into the northeastern Gulf and across Florida.. So… depending on how long she stays in the Gulf, she may actually become a hurricane before all is said and done.

A lot of reports of damage from downed trees, tornados and high water are coming in. Thanks to all the intrepid reporters on the ground who are sending me videos and photos! I am going to try and put a couple of videos from Steve M. from St. Petersburg on my blog (jyotikastorms.blogspot.com). One was at Pinellas Point just after noon today:
video


The dock that is in that video was destroyed four hours later. He also sent me a video from Coffee Pot Bayou in St. Petersburg at 5.40pm, which shows a lot of flooding:

video


From Shore Acres in St. Petersburg, Molly M. sent this photo of a car driving through some of the street flooding:

Also here is a photo of a downed tree branch from Dawn M. in St. Pete (luckily it missed her house):

It is now just windy where I am. The rain has lightened up and the sky is brighter. It’s wine-o-clock! Yay! I’ll attach more photos in the next update.

Stay safe out there!
More later,
J.

p.s. I’m sick of ice cream. For today anyway. ;-)

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 Debby: June 24, Update B

The NHC shifted Debby’s track away from Texas and extended the Tropical Storm warning and watches eastward and down to the northern end of Tampa Bay in their 11am advisory. This is definitely more plausible as far as the track goes. Currently they are showing landfall in Louisiana on Wednesday afternoon/evening. There is a good possibility that this will shift even farther to the east, and I wouldn’t be surprised if landfall was in the Florida panhandle or Big Bend area as late as Tuesday or Weds.
She is currently at 28N, 86.2W, crawling northeastward at 6mph. Her winds are still at 60mph, with a central pressure of 994mb. The convection is still to the north and the east. It does look like it has eased up a little since this morning – a consequence of her interactions with land and that she is no longer over the Loop Current:
However the circulation in the upper levels of the troposphere has improved as wind shear is slowly decreasing so there is a very good possibility that she’ll be a strong Tropical Storm or a cat 1 hurricane.

I received lots of weather reports! From Richard S. in New Orleans from Saturday night: breezy, but still pretty warm and humid. No rain.  From Karen M. in north Pinellas: dumped rain gauge with 2.75in water. From Molly M. in Shore Acres in St. Pete: even though low tide, flooding starting. High tide still 6.5 hours away. From Tim F. on Madeira Beach: Howling winds. Horizontal rain mid-morning. From Jackie D: wind whipping across Boca Ciega Bay. From Cindy W. in Tierra Verde: water levels 2+ feet above normal.
And from me: first power blip already happened. Glad I had ice cream for breakfast. Might have some more for lunch. J The wind and rain have picked up a lot at the northern end of St. Petersburg and I just turned the light on because it is darker outside than it was this morning. Here is a short video taken from my place - windy palm trees, a bit of rain. The usual stuff.
video

I’ll be back later, power dependent. It’s lunchtime…. ;-)
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 Debby: June 24, Update A

It was a dark and stormy night. Then I woke up and it was a not-quite-so-dark-but-not-very-bright and stormy morning. I have had a lovely morning cup of tea, and for breakfast I will have ice cream. As I told my husband when I did this yesterday, it is the only logical thing to do to prepare for a storm... what if the power goes out? ;-)

Tropical Storm Debby is behaving pretty much as I expected. She is currently at 27.5N, 87W, which means she has slowly been moving northeastward because yesterday she was at 87.5W. The NHC have extended their tropical storm warnings east and into the Florida panhandle. They have also shifted their cone to the north, so although the center is still heading to Texas for landfall on Friday, it is now northern Texas. Currently they say she is moving northward at 3mph. It’s difficult to tell if she’s moving northward at that speed from the satellite images. I don’t think we’ll see her move too far from her current location today though because there is still high pressure to her north. There is a small window and so I think if anything, she’ll scoot a little more to the northeast (towards the FL panhandle) but I’m not sure she’ll actually make landfall, so those of us in Florida and along the northeastern Gulf can expect at least another day of this sort of weather.

The NHC have also increased her wind speed to 60mph, which makes her a mid-to-strong Tropical Storm (TS range: 39-73mph). This seems reasonable to me. I expect the winds to get stronger today. The circulation in the lower half of the troposphere continues to be very strong. There is still some wind shear impacting her, so the circulation in the upper reaches of the troposphere is not quite strong enough for her to be a hurricane yet. (If you are just joining and want to know about the troposphere, scroll down to the <Science Alert> in this post: http://jyotikastorms.blogspot.com/2012/05/subtropical-storm-beryl-may-26-update.html).

Even though wind shear will decrease, I am not sure she will get to hurricane strength actually, and if she does, she will be a weak hurricane. There are a couple of reasons for this. First, although the water temperatures are warm at the surface at 28-29 deg C, she has moved away from the Loop Current, which at the moment extends to the same approximate latitude as Tampa Bay. The Loop Current is the region of very warm water in the upper 125m of the Gulf. At 27.5 deg N, it looks like the upper 50m of the water are warmer than 26.5 deg C. The other thing working against her now is that she is interacting with land.

Her convection is really strong, but still mostly on the east and north sides of the center. Here is an Infrared satellite image of Debby:

I like to look at the IR image because I can get an idea not only of where the convection is, but how strong it is. <Science Alert> In the troposphere the air gets colder the higher up you go. What the infrared satellite image shows is the temperature of the tops of the clouds, with red being the coldest, and blue and white being the warmest. The higher the cloud tops, the colder they will be. But also, high clouds tops are those big deep clouds that you see with very strong thunderstorms. Generally, red areas indicate very severe thunderstorms, with possible tornadoes etc. (the IR image shows dark gray sometimes in the middle of the red, which indicates even more severe weather). Orange areas indicate some thunderstorms and heavy rain. Yellow areas indicate rain. Blue are thick clouds, white are wispier clouds. To look at the IR image for yourself, go here: http://www.ssd.noaa.gov/goes/east/gmex/flash-avn.html for the video and here http://www.ssd.noaa.gov/goes/east/gmex/avn-l.jpg for a still image like the one I attached. <End of Science Alert>

Storm surge: In St. Pete the observations are now showing about 2 ft above normal tides. Apalachicola, FL, in the Panhandle is about 2.5 ft. Elsewhere across the northern Gulf the surge is still between 1-2 feet.

As I said, it’s been raining and windy here in St. Pete all night and it looks like we are about to get some stronger weather. If you want to send me weather reports or pics from wherever you are, please do. I’ll include them in the next update.

More later! Time for ice cream... I mean breakfast. ;-)
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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Saturday, June 23, 2012

Tropical Storm Debby: June 23, Update B

As I thought, the NHC upgraded the Gulf blobette to Tropical Storm Debby at 5pm after getting data back from the plane that went to investigate. I’m not sure I would have waited for plane data (although it is very useful to have) to upgrade her. Also, my earlier estimate of her center (when they still had her at 90% chance of forming) was pretty much on target and she is currently at 26.3N, 87.5W. Officially the wind speed is 50mph, which makes her a mid-level Tropical Storm (TS range: 39-70mph). Her central pressure is 998mb.

At 5pm (EST) the NHC said she was moving N at 6mph, but given that my estimate of her center was made this morning and that’s where she still was this evening, I wasn’t convinced. However, since the 8pm (EST) advisory they changed that and she now continues to officially be ‘stationary’, which gets a gold star and two thumbs up from me. She’s just relaxing there in the middle of the Gulf on a Saturday evening, enjoying the view and having a martini I expect. ;-)

The reason she is stationary is because she is surrounded by higher pressure. You can imagine her as a ball. If you put the ball on a hill, it will move and roll downhill. But if you put the ball in a dip, then it gets stuck and can’t move in any direction. The ‘hills’ in the atmosphere are areas of high pressure, and the ‘dips’ and ‘valleys’ are low pressure. Unlike on solid earth, these pressure areas are continuously changing which is why a storm is almost always moving. I’ll get into overall storm movement some other time, but that’s how to envision what is going on around a stationary storm. Forecasting the track of a stationary storm is trickier than usual because while it is stuck in the dip, the pressure fields and general atmospheric conditions around it carry on changing. So although currently the forecast track has TS Debby moving northwards tomorrow, and then turning towards the west and making landfall in Texas sometime on Friday, I am not certain of this track at all. The current center of cone would take her to the Corpus Christi area of Texas (o.k., I have to say it… at least Debby’s not heading towards Dallas!! Ahem. ;-)). However, I think there is still a chance she could head somewhere along the northern Gulf or even the Florida Big Bend area – i.e. anywhere from Florida to Texas. Tomorrow I’ll be looking for this northward movement that is forecast as opposed to a northeast movement. I would still tell everyone from Florida (central-western side) to Texas to keep an eye on this one. Regardless, the severe weather is currently on the east side of the storm, which means Florida folks should have their raincoats handy when they go for their Sunday sunbathing at the beach (and don’t bother taking a sunshade) ;-). (And if you are in Georgia, Alabama, or Mississippi, you can expect a few clouds too).

Her circulation in the lower half of the troposphere is very strong now, and there is a very small signal in the upper troposphere. If it wasn’t for the wind shear (which has kept all her convection to the east of the center), I think she’d be stronger than 50mph, and would even have been closer to the 65-70mph range. I expect her to intensify tomorrow to a strong TS or weak cat 1 because the wind shear looks like it is decreasing. The convection is also improving with bigger thunderstorms forming off the coast of Florida - you can see this as the red areas in this satellite image:

If you are concerned about storm surge, you can have a look at Tides Online (see the directions on what to do in this post: http://jyotikastorms.blogspot.com/2012/05/subtropical-storm-beryl-may-27-update.html). At the moment most places along west Florida to Texas are showing about 1-1.5 ft above normal tides.

I think that’s it for today. More discussions about the delightful Debby tomorrow!
Toodles!
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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Gulf of Mexico Blobette: June 23, Update A

What a lovely Saturday. No sun, just clouds. Looks just like a wonderful British summer day. ;-)

Our Gulf blobette should actually, at the very least, be a Tropical Depression because some of the buoy winds in the eastern Gulf show winds of 22-31mph sustained winds (TD: 17mph-38mph winds), and I’m sure they are stronger closer to the center.  It may already be Tropical Storm Debby.  A plane is scheduled to go into the system this afternoon to ‘investigate’, so I expect the NHC to change this from a 90% chance of developing in the next 48 hours (really, 90%? Just call a spade a spade already), to a TD or TS in their 5pm advisory.

Circulation has strengthened now in the lower half of the troposphere and it has a very clear center of circulation, which I estimate to be around 87.5-88W, 26N. There is also a lot of convection that spans the entire eastern length of the Gulf, from the Yucatan to the Florida Panhandle. However, the convection is mostly to the east of the center because there is still some wind shear which is keeping it in check.

It doesn’t seemed to have moved much in the last few hours which makes figuring out a track still a bit tricky. Anyway, I’ll be back later with an update on what should be TS Debby!

Anyone want a cup of tea? J
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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Gulf of Mexico blobette and the last word on TS Chris: June 22, Update A

It’s Friday evening and I’m hanging out with some friends (they are now talking about ‘our’ colours… hey, I’m a glamorous scientist, I have to know my colours! J). I’m having a glass of wine (ok, this might be my second or third). This seems like a good time to start writing. ;-)

Tropical Storm Chris

He took a rapid nose-dive from being a ‘hurricane’ (haha, still laughing at that one) to being non-existent… about 24 hours I think. Anyway, the NHC have stopped saying anything about him, and I will happily do so as well. I have to say though that I am very disappointed in TS Chris. I know so many Chris’s in person that I was all set to make fun of…er I mean to compliment… oh well. I can wait for six years (which will be the next time we see a storm named Chris).

(Now the conversation has turned to people dressed as princesses running in a marathon. It’s not my fault… I’m just writing).

Gulf of Mexico Blobette

Ok, so this one might be a little more of a problem for some in the Gulf region. During the day the circulation improved a lot for this blobette. It is still very close to the Yucatan peninsula so it is interacting with land which is preventing it from fully developing at the moment, however I see circulation in all levels of the troposphere now. If this persists once it has left the influence of land and moved into the Gulf, I think that this will be a hurricane (cat 1) – maybe as early as tomorrow. There are two more atmospheric factors that will allow this blobette to develop are that the wind shear is not very strong in the Gulf, and it is weakening, and there is plenty of moisture in the surrounding atmosphere.

This blobette has a lot of thunderstorms and rain because it is also partly over the very warm waters of the Yucatan Strait, where water temperatures are 28-29 deg C, with waters as warm as 26.5 deg C in the upper 100-125m. <Science Alert> This deep warm water is important for a storm to intensify because as it churns up the surface water, the water that replaces it is still warm, so the storm continues to have yummy warm water to feed it and put moisture into the atmosphere. <End Science Alert> So two oceanic factor that will allow the storm to develop are the warm 28-30 deg C waters of the Gulf of Mexico, and that these warm waters are very deep because the blobette is right over the Loop Current. <Science Alert> (Oooh… two science alerts in one entry! The excitement is unbearable! ;-)). The Loop Current is part of an ocean current system that flows from the Caribbean into the Gulf of Mexico through the Yucatan Strait, and then out of the Gulf of Mexico through the Straits of Florida, and up the east coast of the US. How far it extends into the Gulf of Mexico varies from year to year and month to month. At the moment, it’s northernmost extent looks like it is around the same latitude as Tampa Bay (in Florida). As this current flows around Florida, it changes name to become the Florida Current. Then as it flows up the east coast, it changes name again and is known as the Gulf Stream. It leaves the US east coast around North Carolina and flows across the north Atlantic to the UK. This current system is well known because it has the deepest warm waters, and is very fast flowing. The deep warm waters mean that tropical storms that pass over any part of this current system have a jolly good chance of becoming stronger. <end Science Alert>

The track this blobette will take is a little tricky to see at the moment. There is a bit of high pressure to the north, which means that it will move slowly as it crosses the Gulf. This isn’t very groovy because in turn, that means that it has time to get stronger. But because it is slow moving, it also makes it difficult to figure out where the blobette will go. Depending on how fast it moves over the next 2-3 days, I estimate landfall to be next Thurs/Fri, but it could be anywhere from Texas to Florida. Hopefully I’ll have a better idea tomorrow, but it needs to moves away from the Yucatan. Everyone in the Gulf should keep an eye on it.

That’s it for today. Hey, it’s Saturday tomorrow. You know what that means? Yes, I can write more than one update…. Lucky you! ;-)

(My friends are now talking about ‘goo’. Apparently this is something you eat while you are out running. Not just running to catch the bus, but running marathons and things. I’m not sure I’d want to eat goo under any circumstances, but luckily I’m pretty certain I won’t be running any marathons so the pressure is off for now. Goodness me, the things one learns!).

Ciao,
J.

p.s. oh, it’s called ‘Gu’ not ‘goo’… hmm, doesn’t sound any more palatable though.

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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Thursday, June 21, 2012

Tropical Storm Chris and Gulf of Mexico Blobette: June 21, Update A

Sorry for the radio silence yesterday. I was traveling back to Florida from California and didn’t think anyone wanted to read the twaddle I’d probably write when I got home at 3am. Apparently things go a bit wonky when I try and sneak away. I still can’t believe they think Chris is a Tropical Storm! You know all that glitters is not gold (first known use circa 12th century, first known use pertaining to Tropical Storms circa June 21, 2012). A phrase that applies more commonly to pyrite which is appropriately known as <ahem> fool’s gold, and now methinks it could be applied to a fool’s hurricane (you heard it here first! ;-) ). But before I get into my ‘rant-o-the-day’…

Tropical Storm Chris
He is currently at 42.4N, 42.9W, moving NNE at 14mph. His central pressure is estimated to be 990mb, with estimated maximum sustained winds of 70mph (TS range: 39-73mph), which supposedly makes him almost a hurricane. Water temperatures are even cooler and are now around 19 - 20 deg C (66 – 68 deg F). There is some circulation (vorticity) in the very very lowest level of the troposphere. There is also some vorticity higher up, but it is all connected to that extratropical low pressure area. There are NO (that’s a big ZERO) thunderstorms in this system, with very little rain. Don’t you find that remarkable for something that’s almost as strong as a hurricane? (shhh… don’t tell anyone, but that’s because it is not tropical… shhh).

<start rant-o-the-day>
Earlier today they had upgraded him to a Hurricane… oooh, aaah, the first hurricane of the Atlantic season. Huh. I think not. He hardly had any convection to speak of. Next thing you know, there’ll be hurricanes developing in the Great Lakes! Wouldn’t that be funny?

So… All that glitters is not gold or Fool’s Hurricane:
Here is a visible satellite image of Tropical Storm Chris as he looks now:

You can see the spiral bands (clouds only, not much rain) and what looks like it could be an eye. For comparison, I’ve also attached a satellite image of the “Hurroncane” (courtesy of NOAA) that developed in 1996 over… <drumroll please>… Lake Huron!

Many thanks to my second Cool Chris Contributor of the series, Chris M., for sending me info on the Hurroncane! From these images, they both look like tropical storms, don’t they? The Hurroncane even had a low pressure of 993mb, tropical storm force winds, and enough rain to cause some flooding. Everything about this Hurroncane and its development (other than the location) was similar to today’s ‘Tropical Storm Chris’ and yet <gasp> it wasn’t a named hurricane! Why? Because it wasn’t a hurricane (from the NHC page today: “Tropical Cyclone: A warm-core non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and a closed surface wind circulation about a well-defined center.”).These storms didn’t originate over tropical or subtropical waters. The convection in both these storms is very shallow... even the NHC acknowledge that Chris is shallow (no point hiding it Chris, I know it’s all about the looks, hair, make-up, clothes and accessories dahling ;-)). If you want the gory details on the Hurroncane, they are at the bottom of this page: http://www.crh.noaa.gov/dtx/stories/dtxcane.php.

‘Tis too late now to change this, but this storm shouldn’t be named and it shouldn’t be in the archives! What an imposter! <end rant-o-the-day>

That’s all on T.S. Chris for now (oh, other than a quick clarification to my last update: strictly speaking, the Tropics are between 23.5 N and 23.5 S, and the subtropics are between 30N and 30S. J I’ll get into that some other time. However I may (may) complain less about Tropical Storms that develop between 30 N and 30 S).

Gulf of Mexico Blobette
Hmm… at the moment it is a little tricky to figure out whether this will develop into a Tropical Storm or just remain in a blobette as it moves northwardish across the Gulf over the next few days. (If you are just joining me, Blobettes are a mass of clouds and thunderstorms that may develop into something with a name. Usually a she-name. Blobs are the same but develop into he-name storms. Usually.)

The NHC have given this a 70% chance of developing into a named tropical storm over the next 48 hours. This is a very possible scenario. There is a little bit of circulation in the lower half of the troposphere. Nothing that looks like a tropical system yet, just an area of low pressure, but I wouldn’t be too surprised to see it develop further. It is producing a lot of rain because the water temperature is 27-28 deg C, with water warmer than 26.5 deg C in the upper 100m. I will have a proper look tomorrow, but I can tell you now that the computer models are all over the place – some have it developing, others not. Some have it going into Texas, others into Louisiana, and yet others into Florida. We all agree that the next name would be Debby. J

That’s it for now. More tomorrow! Let me know if you have any questions. If ‘42’ doesn’t work, ’ll make up something as an answer for ya. ;-)

Tally ho!
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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Tuesday, June 19, 2012

Tropical Storm Chris: June 19, Update A

Sigh. In ye olde golden days of yore, they wouldn’t have named this one. I can see why they called this a Tropical Storm, but I am not convinced it actually is one, so I personally wouldn’t give it a name. I’ve been watching this system for the past few days, and although it has some circulation (not particularly tropical in nature), there is very little rain in this system. The NHC named it Chris in their 5pm advisory today. He ‘formed’ at 39.3N, 57.7W, and is moving East at 8mph. Estimated minimum pressure is 1005mb, with estimated winds at 45mph (TS range: 39-73mph).

Here are my top ten reasons why this one doesn’t really qualify:

1. The last time I looked, the tropics were between 30N and 30S. The NHS officially says that: “THE NON-TROPICAL LOW PRESSURE AREA LOCATED WELL SOUTHEAST OF THE CANADIAN MARITIMES HAS ACQUIRED TROPICAL CHARACTERISTICS.” At almost 40 deg N? In the middle of the Atlantic?

2. The water temperature is 22-23 deg C… that is 71-74 deg F. Does that sound like balmy, warm tropical water temperatures to you? (no need to answer if you are from Canada) Tropical Storms need 26 deg C or warmer to develop. They are ‘Tropical’. Look it up in the dictionary. 71-74 deg C is the sort of water I’d get into to cool off after sitting in a boiling jaccuzzi for half an hour as a form of hot water/cold water/but-its-good-for-you-so-quit-complaining sort of thing.

3. There is no warm water underneath. It just gets colder. Even the fish probably wear wet suits.

4. If this was a Tropical Storm, the vorticity (circulation) signal I see in this system would be the same as if it were a Cat 3 or 4. This storm is not that strong... there are other things going on afoot (and aloft) – see comment 5 below.

5. The NHC say this will be absorbed by a larger extratropical low pressure area in 3-4 days… see comment 4 above. It already is part of that system.

6. Relative to the storm, the vertical wind shear is strong in this area.

7. We do have rotating storms that develop in the extratropics. We normally just call them storms or low pressure systems. They can have strong winds. Some of them even have buckets of rain. Amongst other places, they like to visit Scotland quite frequently. Along with the other tens of people who like to visit Scotland quite frequently.

8. See point 9.

9. See point 8.

10. Ok, yeah, I ran out of things to rant about.

Definitely not convinced about TS Chris. Harrumph.

Speaking of Chris, my friend Chris K. tweeted from a conference today about viruses in the ocean (how do you like that for a segueway? ;-))… apparently there are “10 million viruses per drop of seawater. So when swim you swallow more viruses than people in the US”. (the good kind of viruses of course). And on that delicious note, time for something to drink.

That’s it 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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Friday, June 01, 2012

June 1: Start of the 2012 Atlantic Hurricane Season

What!?! It’s the start of the hurricane season? Really? How did that happen? Why didn’t anyone tell me! Why didn’t anyone tell Mother Nature?

Well… a grand Welcome to the official start of the 2012 Atlantic Hurricane Season. I won’t play the ‘guess how many storms we’ll have this season’ game, but I will tell you that I’m positively convinced, with 100% certainty, that there will be at least two named Tropical Storms. ;-)

It is too soon to say how active this season will be (I know a few people are a tad concerned) and having two pre-June storms isn’t a good indicator at all. The reason we have an official ‘hurricane season’ from June 1 to November 30 is because that’s when we get about 97% of the storms, with around 78% occurring during the peak season from August-October (from Landsea’s 1993 paper). Here is a figure I made a few years ago that showed the track of all the storms from 1851 to 2005 (graph credit: ME):

You  can see there are quite a few in May. You can also clearly see that in the early and later parts of the season the storms develop in the western Atlantic/Gulf of Mexico/Caribbean region, and during the peak months they develop in the eastern Atlantic. So to have two storms in May that formed in the western Atlantic just means that they are in the elite 3% (the other 97% may be protesting somewhere ... ;-)). Anyway, I like these dinky little storms. They bring much needed rain and they don’t cause too much damage (generally speaking). They are, indeed, agathokakological (hee hee… June 1… already dusting off the fun words – are you all ready? ;-)).

Now on with my amazingly fabulous opening remarks. J Here are a few background notes so you know what you are getting into (and remember, you can always watch reality TV if you prefer):

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, 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. Over the years (and even over the past couple of weeks), I've talked about a lot of things already, but I can cut and paste from previous entries as well as the next person so if I say something or use some "scientific jargon" (ooh ahh, how thrilling), please 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. If you are reading this via email, are sick of me cluttering up your in-boxes, and would prefer to get it via the web go here... http://jyotikastorms.blogspot.com (and send me an email telling me to remove you).

9. 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!!

10. I admit it. I am a twit. I am sometimes on twitter (@jyovianstorm). (I’m also sometimes on tumblr… but that’s mostly pretty pictures of the UK and stuff, so if you want to day-dream, find me there.)

Before I run off (to see an opera this evening J) – Part 1: Being British and all, I have to congratulate Her Majesty, Queen Elizabeth II, for reaching her Diamond Jubilee. Only 4 more years I think, and she’ll be the longest reigning British monarch (Queen Victoria currently holds that title). I shall have a Gin and Tonic to celebrate.

Before I run off (to see an opera this evening J) – Part 2: I have to tell you what I did today! The West Central Florida American Meteorological Society Chapter arranged a wonderful field trip… I went to see the hurricane hunter planes at NOAA’s Aircraft Operations Center in Tampa. Thanks much to the folks at NOAA’s AOC for their time and tour. It was great and I’ll be mentioning things from this visit at random moments during the season.

That’s all I have for the opening speech… and we’re off to the races! (which, coincidentally, is how The Queen is beginning her Jubilee celebrations this weekend).

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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