Tropical Depression Six arrives

By: Dr. Jeff Masters , 5:14 PM GMT on August 22, 2010

Share this Blog
4
+

Tropical Storm Tropical Depression Six is here, but it will not be a threat to land for at least the next five days. Tropical Depression Six is a classic "Cape Verdes"-type storm common during the peak part of hurricane season. Cape Verdes-type storms are so named because they form from tropical waves that come off the coast of Africa and pass near the Cape Verdes Islands just west of Africa. Cape Verdes hurricanes are the largest and most dangerous types of hurricane in the Atlantic, since they spend a long time over water have and have of opportunity to reach full maturity. Tropical Depression Six has a ways to go before it becomes a hurricane, as the storm is embedded in a strong easterly flow of wind courtesy of the African Monsoon that is generating a moderately high 15 - 20 knots of wind shear. There is also a tropical disturbance to the northeast of TD 6 that is sucking away some moisture and is interfering with the storm's circulation. Sea Surface Temperatures (SSTs) are a warm 28°C, and the storm is embedded in a moist environment, so wind shear is the primary inhibiting factor for development. The strong east winds imparting the shear are keeping any heavy thunderstorms from developing on the east side of the center of circulation, which is exposed to view in satellite imagery (Figure 1.)


Figure 1. Afternoon satellite image of Tropical Depression Six.

Forecast for Tropical Depression Six
A ridge of high pressure will force Tropical Depression Six to the west-northwest for the next five days, and the system should increase its forward speed from its current 10 mph to 15 mph by Monday night. A powerful trough of low pressure over the mid-Atlantic Ocean will begin to pull Tropical Depression Six more to the northwest late this week, and the storm should pass well to the northeast of the Lesser Antilles Islands. It remains to be seen, however, it this trough will be strong enough to fully recurve Tropical Depression Six out to sea. The GFS predicts that Tropical Depression Six may pass close to Bermuda about eight days from now, and it is also possible that Tropical Depression Six could eventually hit the U.S. East Coast 9 - 15 days from now. However, we have no skill in making these sort of ultra-long range forecasts, and the long-range fate of TD 6 is uncertain.

Elsewhere in the tropics
The ECMWF and NOGAPS models are predicting formation of a tropical depression off the coast of Africa 3 - 4 days from now.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 382 - 332

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog Index

Quoting btwntx08:
lol admin did already


Yep. :/ I'm keeping a straight face. Didn't know Youtube videos could mess up the blog like that. Well, now I know. :(

BTW to all of the users, Eddy and I are very bored on the Tropics Talk, located right in the box "add a new comment." We're getting lonely! :(
Member Since: Posts: Comments:
Quoting F4PHANTOM:
Couldn't agree more with you on that. People don't talk on cell phones they text.


...and that (texting, E-mail, Blogs, etc...) in turn is all leading to a radical shift in our language. It is de-evolving into something less precise, less able to convey details.

You should see some of the documents that come across my desk; Sheeeesh what %$*@!!!

But please don't get me started on that. Now back to your regularly scheduled weather. Has anyone else noticed that GOM blob besides me?
Member Since: Posts: Comments:
Quoting SFlKatCane5:


What are you talking about? Bermuda is made out of concrete.

Yeh there will be some damage mostly glass and trees.


And the people who stay????
Member Since: Posts: Comments:
Quoting nrtiwlnvragn:


I'll wait untill there is actually a storm that strong and then compare. The GFDL and GFDN have a resolution of 5km, the HWRF 9km and the new ECMWF is 16km. Don't know if I could say the GFDL, GFDN and HWRF accurately predict central pressure.
I understand, and I'm leaning towards this, just reporting what I've read. A 16km resolution is a little too broad for an accurate depiction.
Member Since: Posts: Comments:
Quoting plywoodstatenative:
What is the range on the unmanned plane that NOAA has in its arsenal of weather recon?
it flys at 50000 and would depart from CA
Member Since: Posts: Comments:
Quoting Clearwater1:


Man what a racket! Thanks for the clarification. Hope I/we don't have to worry about this year, at least.
Remember, All policied written in a state have to be approved by that state. ie; the state makes the guildlines that the companies follow. If you do not like your policy talk to the man you elected.
Member Since: Posts: Comments:
Quoting SouthDadeFish:
I've read that the ECMWF now has the resolution to accurately depict a storm's minimum central pressure. If it says 932 mb then it means 932 mb. Source here.


I'll wait untill there is actually a storm that strong and then compare. The GFDL and GFDN have a resolution of 5km, the HWRF 9km and the new ECMWF is 16km. Don't know if I could say the GFDL, GFDN and HWRF accurately predict central pressure.
Member Since: September 23, 2005 Posts: 14 Comments: 10839
372. Vero1
Quoting Patrap:


NASA GRIP Global Hawk



Patrap ~~ Just checked the tracking site for GRIP and they don't have anything in the air today.
Member Since: July 21, 2008 Posts: 4 Comments: 2233
ecm is way off according to 11 nhc discussion. it will start to turn west near 25 long.
Member Since: Posts: Comments:
370. xcool
Tazmanian anyway,
Member Since: Posts: Comments:
Quoting xcool:
Snowlover123 .PLZ STOP .THANKS



he did your the one that needs too stop makeing the commets about it
Member Since: Posts: Comments:
367. xcool
Snowlover123 .PLZ STOP .THANKS
Member Since: Posts: Comments:


NASA GRIP Global Hawk

Member Since: Posts: Comments:
TS next advisory I presume, especially now that convection has fired over the COC.
Member Since: Posts: Comments:
Quoting SouthDadeFish:
I've read that the ECMWF now has the resolution to accurately depict a storm's minimum central pressure. If it says 932 mb then it means 932 mb. Source here.


Ah ok, that's extremely reassuring.. If it didn't have that resolution and predicted the same thing, if the run came true we'd have to all get our erasers out and erase Bermuda off our maps.
Member Since: Posts: Comments:
Quoting CosmicEvents:
That's a good point. I recently checked on the exact way this works, in Florida anyway.
.
.
I found that in most(if not all) policies, if ANY part of the state is under a hurricane warning...this automatically kicks in the hurricane deductible clause for EVERYONE in the state. In other words, if KEY WEST is under a hurricane warning, and DESTIN gets hit with a different cyclone that's only a tropical storm, even if no weather occurs in KEY WEST...the hurricane deductible is in effect for DESTIN on account of a hurricane warning being in effect on some part of the state when the damage occurs.
.
.
The bottom line is that once the hurricane warning goes up for any inch of the state, everyone's hurricane deductible kicks in.


Man what a racket! Thanks for the clarification. Hope I/we don't have to worry about this year, at least.
Member Since: Posts: Comments:
it look like TD6 is now moving west on RBG was at 13.1/2N 34.8W
Member Since: June 13, 2009 Posts: 2 Comments: 10852
Quoting will45:
347. Snowlover123 3:19 PM EDT on August 22, 2010


if you keep on i hope you enjoy the 24hrs



you too the word right out of me LOL
Member Since: Posts: Comments:
Quoting F4PHANTOM:
Your using it now!


Well that's the one example I was hinting at. But, you may rest assured there are many more crutches out there.
When that crutch replaces a previous means of performing a task we eventually loose that ability. Please notice the better Mets analyze all information available, and only reference the models as a secondary tool.

Be wary of becoming too reliant on new technology in any form. I know people who go into depression if they misplace their cellphones.
Member Since: Posts: Comments:
poor Bermuda
Member Since: Posts: Comments:
347. Snowlover123 3:19 PM EDT on August 22, 2010


if you keep on i hope you enjoy the 24hrs
Member Since: Posts: Comments:
What is the range on the unmanned plane that NOAA has in its arsenal of weather recon?
Member Since: Posts: Comments:
I've read that the ECMWF now has the resolution to accurately depict a storm's minimum central pressure. If it says 932 mb then it means 932 mb. Source here.
Member Since: Posts: Comments:
Quoting Cotillion:


I'm not sure if the Euro does the same.

I know if the GFS did it, it'd basically be the Apocalyptocane.

---

932mb typically is a moderate Cat 4, 140-145mph ish territory.

(Of course, there's never a certain translation of pressure to wind, just a rough estimate. Felix was about that and was a strong Cat 5; however, he also had a strong B/A high which increased the gradient).


Hmm maybe you're right, I'm not sure now that the ECMWF does that as well. And plus being as big as this system is and looks like it's gonna be, it may only have Cat3 winds. But since it's so far north and surrounded by highs on both side, that may increase gradient. Ugh. I think I'm overthinking things here lol.
Member Since: Posts: Comments:
Quoting philliesrock:
The HWRF insists on making a left turn near the end of its forecast period.
The GFS has it gettin close to Bermudi....Link
Member Since: Posts: Comments:
Quoting HurricaneSwirl:


Except global models show pressures that are always much too high in tropical cyclones.

943 would probably be around 920 in real life? Maybe 915. Ask Miami, he's pretty good at estimating that lol.


I'm not sure if the Euro does the same.

I know if the GFS did it, it'd basically be the Apocalyptocane.

---

932mb typically is a moderate Cat 4, 140-145mph ish territory.

(Of course, there's never a certain translation of pressure to wind, just a rough estimate. Felix was about that and was a strong Cat 5; however, he also had a strong B/A high which increased the gradient).
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting reedzone:
Models are now coming into agreement on a strong ridge building over 06L as it misses the first recurvature. What happens beyond there is uncertain.


And which models are you referring to? Thanks
Member Since: Posts: Comments:
TD6 is too far away to rule out a US strike! Models or no models!
Member Since: June 13, 2009 Posts: 0 Comments: 6728
look at 11am discussion, it wont be near,what that model shows....
Member Since: Posts: Comments:
Quoting philliesrock:
Wow, the ECMWF destroys Bermuda.


Hey phillies been a while since we have talked.
Member Since: Posts: Comments:
338. xcool
322. Snowlover123
REMOVE IT
Member Since: Posts: Comments:
336. IKE
Quoting weatherman12345:
till too early to tell if it stays ona more westerly path during the next couple of days and misses both recurves with the ridges in place than the entire east coast has to worry about td6. it could very well go out to sea or threaten burmuda though... still to early to tell.


Listen to weatherguy03's take on it...Link
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting IKE:
240 hour ECMWF shows a 932mb cane and nothing else through Sept. 1st....



WOW! And that far north too.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting Cotillion:
943mb.. high Cat3/low Cat 4 type area.


Except global models show pressures that are always much too high in tropical cyclones.

943 would probably be around 920 in real life? Maybe 915. Ask Miami, he's pretty good at estimating that lol.
Member Since: Posts: Comments:

Viewing: 382 - 332

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.