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TD 11, TD 10, and African waves

By: Dr. Jeff Masters, 5:41 PM GMT on August 22, 2005

Tropical Depression 11
TD 11 will be the 4th tropical cyclone to hit the east coast of Mexico this year, and the 3rd weak system to affect the extreme southern Bay of Campeche. It looks almost exactly like Tropical Storm Gert of July. TD 11 will probably intensify enough be called Tropical Storm Jose before landfall tonight, but will be quickly forgotten.

The Hurricane Hunters will investigate the system at 5pm EDT, and one might wonder why NHC bothers with the expense of sending a plane out to an obviously low-threat storm with only a few hours to live. The answer is that these storms are full of surprises, and it is NHC's policy to have an airplane in a storm anytime one threatens land just in case sudden strengthening happens.

Remains of TD 10
The remains of TD 10 are still hanging around the Bahamas-Cuba-Hispanolia area, but continue to look disorganized. Expect this activity to continue moving west at 10 mph with no development over the next two days.

East Coast frontal boundary
Some development is possible off the East Coast later this week near the Carolinas at the trailing edge of a cold front that moved off the coast yesterday. This kind of development is common this time of year.

African waves
The large tropical wave that moved off the coast of Africa Friday night continues to spin and track west-northwest, and is now about 400 miles west of the Cape Verde Islands. The convection associated with this wave has not increased at all the past few days. If the wave does develop, it will probably recurve in the center of the ocean and not affect any land.

I've been calling attention the past few days to the GFS model's prediction of increased hurricane activity over the mid-Atlantic beginning late this week. This morning's GFS model run is now backing off from that prediction, and only shows one instead of three tropical cyclones in the Atlantic on August 31 (the one cyclone is the current wave 400 miles east of the Cape Verde Islands, which the GFS forecasts to recurve north of the Azores Islands). The GFS does show that the ITCZ will be very active, with many stong tropical waves pushing off of the coast of Africa. A new tropical wave is pushing off of the coast of Africa today, but it is too early too see if this wave has potential to develop.

The level of tropical activity we are seeing this week is typical of what one sees during the peak of an average hurricane season (hurricane season peaks on about September 10). It will be interesting to see if the GFS's earlier prediction of much-above average activity by next week will come back with newer runs of the model.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

You know, with all of the "activity" we've had this year, only 2 actual hurricanes have threatened land. Granted Dennis set the record for the strongest July hurricane, only to later broken by Emily, but everything else has been of tropical storm force.

So either: A) this is going to be a busy season, but the worst hits having already come
or B) someone is going to have a BIG problem in the next month.

The water is just too warm out there in the Gulf and the Carribean. Its like a puddle of gasoline in your driveway - its not hurting anyone until someone lites a match.

Does anyone else find it ironic that Tropcial Storm Jose (if it even gets named) will hit Mexico, and not anywhere in the US?

Just curious.


By the next afternoon (17 August), reconnaissance aircraft reached Hurricane Camille about 2:00 p.m. CDT, 100 miles south of the Mississippi coast. Historic conditions now existed in the tightly knotted vortex of Camille. The aircraft had measured a barometric pressure of 905 mb (26.73). This was one of the lowest barometric pressure readings ever measured by aircraft up to that time. Only two supertyphoons in the Pacific - Ida in 1958 (873 mb/25.90), and Marge in 1951(895 mb/26.20), had a lower barometric pressure been measured (JTWC 1976). Sustained winds had now increased to an incredible 190 mph. Camille was now estimated to make landfall along the Mississippi coast around midnight on the 17th.

the recon aircraft was 100 miles away and look at the sustained wind speed it was very nasty i was there and know a little about the storm
Hiya :)
Does the Td-10 clone that is hanging near us in The Bahamas even moving ??? It looks like it set up shop and is having a few drinks off of Hispaniola :) Also, The track is supposed to be west; yet Accuweather is still saying that it will split in two and part with go NW. Anyone else heard that ?
mybahamas- what is interesting is that several models are now developing big things out of the former TD 10...albeit after it reaches Florida. The NOGAPS and CMC explode a storm just off southwest Florida and move it WNW across the Gulf. The Euro and GFS also indicate the same feature, as does the UKMET. Given the water temps in the Gulf, should be interesting to see how this evolves...
What about the front off of the carolina coast? What are the chances of this developing and where would it go?
Cane...do you have the links for these models? If it's so why do you suppose that Dr. Jeff hasn't brought this to our attention?
Valence: I find the bigger coincidence in that so far the 4-letter named storms were storms that formed very close to land, and landed within a day. Bret, Gert, and now (possibly) Jose. Makes you wonder what Nate, Rita, and Stan will do.

All in the Bay of Campeche too! Didn't notice that one there ...
I'm not sure why Jeff hasn't mentioned it. I don't have my hopes up too high yet but it's been indicated for several model runs now and with each run the interest should grow.

IMO, the front off the Carolina coast is very unpredictable. It could spin up a wave of low pressure that is more baroclinic in nature, or more tropical....either way I don't know that it matters much considering it will soon be heading NE over the open Atlantic.
Heads up. NHC is saying that the surface trough (formerly TD 10), near Hispanola and the Turks n Caicos is starting to show signs of an LLC.
Someone please post links to the models. Amateurs like myself can't find models pertaining to unnamed storms. Thanks!

What's the history of depressions forming off the coast of the southern US?

LLC=low level convection? Limited Liabilty Corp.?
Low level center, lol.
alright, here come the links:

GFS and NAM (NAM is essentially useless w/ tropical systems IMO): http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/index_carib.shtml

EURO=ECMWF (click on that picture w/ 3 maps...then choose your region + height):

NOGAPS (very good on track IMO, especially once storm has formed...):

CMC (which I find to be quite good at picking up on early trends), GFDL, UKMET, and some others:
Try thisLink
or this:http://www.independentwx.com/tropical.html
rxse...see my last post.
Why will it be moving NE and out to sea? The Carolina front that is. What will cause this motion?
The upper level westerlies...it's sort of self-induced considering it would be forming ON the front.
What are the chances of the African Wave developing into TD 12?
eh, it might but its future is still dismal. The dust is all through it and I doubt it will ever be able to shake that, and it will be heading northwest into cooler waters according to most model data ATT. I think the one behind it might be a little more promising...
Thanks 'Cane & Shera! Bookmarked them. My wife hates this time of the year as I'm perpetually stormtracking and ignoring the family. All the friends come to me though for my "forecast." :D

Thanks again,

Hiya :)
I keep seeing tracks sending "td-10 clone" across Cuba's coast to Gulf. Accuweather is still saying that they think it will split in twain and part would affect NW Bahamas and probably South to Central Florida. Anyone else thinks this?
OH YES BIG EXPLOSION OFF OF AFRICA ON THE SECOND WAVE..THIS IS LIKELY TO BE A DEPRESSION ALREADY...........this is my katrina by tomorrow night and growing rapidly as she heads for the caribbean sea.....this is impressive when you are not working with any dust in the system....
everyones going to remember that name i predict a cat 5 in the next 7 days from katrina...........pay very close attention winward and leeward islands.....this gal will mean business......