Ana, Bill,--and Claudette?

By: Dr. Jeff Masters , 1:52 PM GMT on August 16, 2009

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After one of the slowest starts to hurricane season in the past twenty years, the hurricane season of 2009 has exploded with activity over the past 48 hours. This morning, Tropical Depression Four joined Ana and Bill in the Atlantic, and appears poised to become Tropical Storm Claudette later today. Indeed, this may already be Claudette, as morning's QuickSCAT pass showed top winds of 45 mph. NEXRAD radar animations out of Tallahassee, FL, show a small but well-organized tropical cyclone with plenty of heavy thunderstorm activity, and improving low-level spiral banding. Satellite loops show an area of intense thunderstorms with cold cloud tops expanding near the storm's center.


Figure 1. Current long-range radar out of Tallahassee, FL.

It's pretty amazing (and a little unnerving) how quickly this storm sprang up. TD 4 developed literally overnight, and has the potential to be a strong tropical storm by the time it makes landfall tonight along the Florida Peninsula. TD 4 reminds me of 2007's Hurricane Humberto, which became a hurricane just 24 hours after first appearing as a tropical depression. I don't think TD 4 has time to reach hurricane strength, since wind shear as diagnosed by the SHIPS model was moderate, 10 - 15 knots, but it does have time to strengthen into a 50 - 60 mph tropical storm before landfall. Given that the storm is so small, storm surge flooding should not exceed 3 -5 feet, and will not be the major hazard from TD 4; inland flooding from heavy rain of 3 - 6 inches is likely to be the main threat from the storm.

Tropical Storm Ana continues to struggle
Tropical Storm Ana continues to struggle. Dry air continues to plague the storm, thanks to the large area of Saharan air the storm is embedded in. Ana's heavy thunderstorms are limited to just one small spot near the center. Wind shear appears to have lessened some, though, since yesterday. Thunderstorms were not able to form at all near the center yesterday, since strong wind shear tends to blow a storm's heavy thunderstorms to one side of the storm, exposing the low-level center to view. With heavy thunderstorms building near the center this morning, shear appears to be less of a problem for the storm. Top winds seen by this morning's QuikSCAT pass were about 35 mph. The outer rain showers from Ana should appear on radar out of Martinique today.

Shear is low (5 - 10 knots), and is forecast to remain low for the next two days. SSTs are warm, 28°C, and will warm further over the next two days. However, there is so much dry air around Ana that significant strengthening appears unlikely. Nearly all of the models predict Ana will dissipate sometime in the next three days, though the HWRF and GFDL predict that this will happen because Ana will move over the rugged terrain of Hispaniola. Ana is likely not strong enough to survive an encounter with the big island that the Dominican Republic and Haiti share. At this time, it does not appear that Ana will be moist enough to cause a major flooding disaster on Hispaniola.


Figure 2. Water vapor image from this morning showing the large area of dry, Saharan air surrounding Ana, and lying to the northwest of Tropical Storm Bill. Image credit: NOAA/SSD

Tropical Storm Bill gathers strength
Tropical Storm Bill is gathering strength in the middle Atlantic Ocean, and appears poised to become a powerful Cape Verdes-type hurricane later this week. QuikSCAT data from this morning shows a large circulation with top winds of 35 - 40 mph. Water vapor imagery (Figure 2) shows that there is some dry air to the northwest of Bill, and this dry air is being drawn into Bill's center, slowing intensification. It will likely take another day before Bill can moisten the atmosphere enough to ward off the dry air, and allow more significant intensification.

Wind shear is low, 5 - 10 knots, and is forecast to be in the low to moderate range, 5 - 15 knots, for the next five days. Sea Surface Temperatures are about 27.5°C, and will remain in the 27.5 - 28°C range the next four days, then warm substantially as the storm nears the Lesser Antilles Islands. The combination of low wind shear and sufficiently warm SSTs should allow Bill to intensify steadily to hurricane strength by Wednesday.

The big news is that our most reliable computer model from last year--the ECMWF model--appears to have made the right call yesterday, forecasting that a major trough of low pressure would develop along the U.S. East Coast, turning Bill more to the north. All of the other models--with the notable exception of the UKMET model--have now jumped on the ECMWF bandwagon, forecasting that Bill will pass well north of the Lesser Antilles Islands. The UKMET has Bill hitting the islands, but is being discounted since it is an outlier. It currently appears that the trough approaching the U.S. East Coast will be strong enough to recurve Bill before it reaches the U.S., though it is too early to be confident of this. Several of the longer range models show Bill passing near Bermuda or Nova Scotia, Canada.

I'll have an update later today.

Jeff Masters

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Quoting StormW:
Good afternoon,

Hot off the press!

Thanks!

SPECIAL TROPICAL UPDATE AUG 16, 2009 ISSUED 4:25 P.M. EDT


Of all the so called mets on this site..StormW is the man..when he talks I listen
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Quoting jipmg:


I think the GFS? Is showing its going to break through the trough though.. and it was an early model release, the rest may change soon.. the speed is just too great imo


We will find out!
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Quoting CaneWarning:


Some of our experts include people such as Drak, 456, StormW, WeatherStudent and Category5HitsNY

Weatherstudent is not an expert.
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Quoting JAC737:
Serialteq -- it hurts when an acorn hits you in the head at 30 mph


I would believe so!
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Quoting P451:


Because there is a chance in some people's opinions that it might not get pulled north. They're not convinced and they're seeing something to tell them not to trust a model more than a couple days out on the system.

Since it has the potential to be a major hurricane, if it were to miss the trough or beat it to the coast, someone is going to have a very bad day.

I think that's the general feeling that arises when someone simply says it's a fish storm and discounts it's existence.

The models want it to be and personally I think they're fairly trustworthy with their forecast but it's not an absolute - and if it's not - it's not going to be a good day next Saturday or so.

Remember Bill was to suppose to be Ana a few days ago?Then transverse through hurricane channel ,then be a major hurricane in the gulf.Or Hurricane Ike,how the models screwed up on that one.Dont put much stock in them till the storm is 200 miles from landfall..
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Quoting Michfan:


Looking like between PCB and Destin atm.


As I said earlier, probably the Freeport/Red Bay area in Walton county. Ike - got your slicker handy?
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Quoting TexasHurricane:
wow! I take it that Bill really speed up. Is that good or bad?

Bill- 75mph winds
movement- WNW- 23mph



nop it will be has follow

at 5pm update


winds 65mph mb 994mbs
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2018. SaoFeng
the NHC said there was a less than 30% chance... so it was improbable. They did not say it wouldnt form. And this makes up for when they say greater than 50% and it does form. This is why they give probabilities, it shows what the chances are... not a definitive YES or NO
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2017. jipmg
Quoting hurristat:
I just figured out what TWC means.


epic fail LOL
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Quoting TexasHurricane:
I guess since we are on the ant subject. My dogs bowl outside would have tons of ants in it if she didn't eat it quick enough, now I don't seem to have that problem. Hmmmmm
i dont have any pets and we keep a clean yard.
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2015. drj27
now twc is saying pcola lol wow how are they still on tv
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Ike, you might get on the East side of this one
Claudette wants to come ashore further west. Pensacola to Mobile is within reason.
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I just figured out what TWC means.
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Quoting WeatherStudent:


Ike, it really hurted my feelings profoundly to find out this morning that not only did you decide to ignore me, but you also decided to send the blog admin a memo asking him to ban me from Weather UnderGround indefinitely, yet again, that is. WOW, I thought that we were the best of cyber buddies on here, Ike. Geeze, what happened? But, whatever, that's quite alright, because as the following reassuring old saying would go in Spanish. ''Uno recoje lo que uno siembra''. :(


IKE would never do that to you because you are best buds! Where did you hear this???
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do models still forecast development behind bill from that african wave???
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2008. jipmg
Quoting CaneWarning:


That's true, but at the same time, it is likely this will curve away. This is about the second day I've seen models curving it before Florida.


I think the GFS? Is showing its going to break through the trough though.. and it was an early model release, the rest may change soon.. the speed is just too great imo
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Quoting mossyhead:
that should not be a new feeling. sometimes no matter what you do, someone will get irritated.


ok
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Quoting OhioCanes1667:


Why is that funny?


It's not funny, it's a travesty...

LOL and ROFLMAO and "hilarious" are terms also used to mock.

My dissatisfaction with our National Weather Service (and some others in the business) is so pronounced right now that I cannot describe it.

As a nation (and hemisphere), we count on these guys to get it as right as possible.

They got caught eating donuts and reading the paper on the crapper when they needed to be paying more attention.

Okay...so they missed it with the 8...but they continually missed it through the day. That just plain stinks.
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2003. java162
Quoting jdjnola:


I think so. With his size, he can finally do a better job of creating his own environment. Kinda scary though.



bill looks like a hurricane already!!! they gonna upgrade it the next advisary
Member Since: July 24, 2009 Posts: 0 Comments: 301
wow! I take it that Bill really speed up. Is that good or bad?

Bill- 75mph winds
movement- WNW- 23mph
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Claud. has had a definite WNW movement for most of the day. If this keeps up it may even hit al, miss., or LA


Link
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Quoting jipmg:


how do you know?


Dvorak estimates aren't high enough.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Quoting extreme236:


Well we can't be certain its going to be a fish. Notice how the models shifted in one day, they could easily shift back if the trend changes. TWC pointed out two possible scenarios that were very valid. Being pull out to sea, or breaking the trough and continuing. I dont know whats going to happen.


That's true, but at the same time, it is likely this will curve away. This is about the second day I've seen models curving it before Florida.
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Large ant mounds in unusual spots precede incoming tropical cyclones. It's been (un)scientifically proven from reports here over the last 5 years.
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1997. palmpt
I am really amazed at how senstive folks are.let's stay on topic for goodness sake.
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Quoting Tazmanian:
why do i have a feeling that am get a personal attack from some one
that should not be a new feeling. sometimes no matter what you do, someone will get irritated.
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1995. Skyepony (Mod)
The way Claudette just jumped near west there...hhhmmm.
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1994. Michfan
Quoting GBguy88:
Alright, so what do you guys think? Panama City or further west? Seems to me Claudette would have to make a pretty sharp northward turn to move over Panama City.


Looking like between PCB and Destin atm.
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1993. jipmg
Quoting Tazmanian:



bill wont be 75mph at 5pm it will olny be 65mph with a 994mb


how do you know?
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Bill looks poised for a rapid intensification phase.
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Quoting PensacolaDoug:



Then you were not paying very close attention.


What?
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Quoting CaneWarning:


Haha no I don't! It needs to be repeated sometimes.


Well we can't be certain its going to be a fish. Notice how the models shifted in one day, they could easily shift back if the trend changes. TWC pointed out two possible scenarios that were very valid. Being pull out to sea, or breaking the trough and continuing. I dont know whats going to happen.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1988. GBguy88
Alright, so what do you guys think? Panama City or further west? Seems to me Claudette would have to make a pretty sharp northward turn to move over Panama City.
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Quoting CaneWarning:


They did start talking about it. They gave it a code yellow. In my opinion, the NHC was right on track with this one.



Then you were not paying very close attention.
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Quoting jipmg:


Bill- 75mph winds
movement- WNW- 23mph

Ana- 30mph
movement- W 25mph

Claoudete- 60mph
movement - NW 12mph

my prediction =O



bill wont be 75mph at 5pm it will olny be 65mph with a 994mb
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I guess since we are on the ant subject. My dogs bowl outside would have tons of ants in it if she didn't eat it quick enough, now I don't seem to have that problem. Hmmmmm
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Quoting IKE:


System is 100 miles east of you.

I remember when Opal hit. I left Defuniak and went to Sneads,Fl. They had winds of about 30 mph.

I went to Dothan,AL. when Dennis hit. They had 30-35 mph winds.

Both those locations were east of the center. You're west of Claudette.


Yup..like I mentioned..I'd rather be close on the west side than a good ways-even 150 miles sometimes-on the east side
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1983. jdjnola
Quoting P451:
Bill did a good job cutting off that entraining of the dry air. Can he remain isolated from it despite pushing right into it?



I think so. With his size, he can finally do a better job of creating his own environment. Kinda scary though.
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1982. mkmand
Quoting Michfan:
Can i have some of what your smoking?

Look at the 19:45z image

It is showing a formation of a tight eye at 40w
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Quoting JAC737:
Serialteq -- it hurts when an acorn hits you in the head at 30 mph


ACORN hit you in the head??? I haven't heard about them since the election!
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Quoting Skyepony:


Nearly rapped in convection now.. radar



ok
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1979. GatorWX
Quoting fldude99:
Its amazing how Claudette gets the amount of attention on this blog..here in Pcola its like a non event without even the little update box on the tv. About to pick a friend up at the airport..no flight delay or any mention on the airline's website. When something bad is about to happen in the way of a storm..its way different than this


It does because of the very small amount of time it took to develop. May not beat Humberto's record because it's running out of time, but still, will be nearly a record. It's amazing, these tiny storms that is.
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Quoting mossyhead:
i live a few miles west of ike in north walton county in nw fla and i had a problem with ants in the last week.
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1977. jipmg
Quoting hurristat:
Okay, quick contest.

What do you think the position, movement, wind speed and pressure of all three storms are going to be at the 5pm update. Whoever's the closest gets kudos.


Bill- 75mph winds
movement- WNW- 23mph

Ana- 30mph
movement- W 25mph

Claoudete- 60mph
movement - NW 12mph

my prediction =O
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Claudette's COC almost due south of Panama City now and still a good distance from shore. Mobile, you may not be out of the woods just yet. Claudette continues her slow speed, moving WNW at the present time. Check out the latest radar loop.

Link
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Quoting jipmg:


see what I mean, you say the same thing every 5 mins


Haha no I don't! It needs to be repeated sometimes.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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