TD 2 nearly dead; African disturbance 90L gathering strength
Tropical Depression Two is near death, but is still worth watching. The dry, Saharan air to the north and west of the depression, combined with moderately high levels of wind shear of 15 - 20 knots, have almost completely destroyed all of TD 2's heavy thunderstorms. Satellite loops of the storm show a well-formed circulation, but almost no heavy thunderstorm activity.
Wind shear over TD 2 is expected to remain in the modereate range, 10 - 20 knots, over the next five days. Sea Surface Temperatures (SSTs) are 27°C, but will warm to 28°C three days from now. There is plenty of dry, stable air from the Saharan Air Layer (SAL) to to TD 2's north and west that will continue to cause the storm problems. The relatively cool SSTs and dry air mean that TD 2 will not be able to intensify quickly, and some of the models indicate the TD 2 may get destroyed in the next day or two. However, several models still predict TD 2 will become a tropical storm. The HWRF model predicts TD 2 will become a hurricane five days from now, but this seems unlikely given the dry air and relatively high wind shear affecting the storm.
Figure 1. Tropical Depression Two (left side of image) and tropical wave 90L (right side of image).
African tropical wave 90L
A strong tropical wave with a large circulation and plenty of heavy thunderstorm activity is a few hundred miles south of the Cape Verdes Islands, off the coast of Africa. NHC dubbed this disturbance 90L this morning. This morning's QuikSCAT pass shows that 90L has a very large circulation, and top winds of about 30 mph. Satellite imagery from the European METEOSAT satellite show that the heavy thunderstorms associated with 90L are in two major bands, to the north and to the south of the center. There is no heavy thunderstorm activity near the center yet, and this would have to happen before 90L can be named Tropical Depression Three. Water vapor imagery shows that since 90L is forming several hundred miles south of the dry air of the Saharan Air Layer (SAL), the storm should not be affected by dry air and dust as much as Tropical Depression Two has been. Wind shear is about 20 knots over 90L, and is forecast to remain in the moderate range, 10 - 20 knots, over the next five days. Sea Surface Temperatures are about 28°C, and will remain in the 27 - 28°C range the next five days, which are high enough above the 26°C threshold for tropical cyclone formation to allow some slow development to occur. The GFS and ECMWF models continue to predict the development of this wave, though they are now less aggressive about intensifying it than they were in earlier runs. The consensus among the reliable HWRF, GFDL, GFS, and ECMWF models is to bring 90L to point near or just north of the northernmost Lesser Antilles Islands 6 - 8 days from now. The storm could be at hurricane strength by then, as forecast by the SHIPS intensity model.
I'll have an update Friday morning.
Jeff Masters
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and remember, the margin of error on all these 10 days GFS runs is thousands of miles...
Historical climatology supports this thing heading to the SE US, with that strong Atlantic ridge and the 1st named storm so late in an El Nino season. Coincidences I hope. And I hope I don't start to worry until I have something to worry about.
Once convection gets going in the COC we can expect a TD by Saturday.
Exactly. The larger a storm is the harder it is to intensify rapidly.
You have it about 4 times larger than the NHC. From the vital statistics record:
NHC 90L INVEST 20090813 1200 116N 0225W 280 036 1009 1012 0222 13 111 -999 -999 -999 -999 M -999 -999 -999 -999 -9 -99N -999W -999 -999 -999 -999
222 km is the estimated radius of outermost closed isobar, so diameter = 444 km, ~275 miles.
Any storm could do this. So what. You can't have any idea that a storm is going to do this until it forms, and then gets within 5 days of land. Even then, the error is +/- 300 miles.
A sane retort is always a Breath of fresh air.
Each storm has it's own set of properties, dynamics,etc...and it will have it's own name. Let's not start causing panic where it is not needed :)
*steps off soapbox*
Also the larger the storm the more it can fight off wind shear and dry air, kinda makes it own environment.
193. AllBoardedUp 11:33 AM EDT on August 13, 2009
...Before you call me a troll I have been on this site for since 2004, I just don't comment very often.
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I'm impressed, especially since the site didn't exist until 2005!
Though ADT shows it, the visible is clear as day with that.
If it can't build on top of the COC, it ain't going anywhere fast.
It was really underground when he joined.
Too bad its incorrect. Read above.
It shows a modest anti-cyclone building aloft...much smaller than a couple days ago...which is one of the reasons the GFS doesn't forecast quite the intensification.
If this massive storm gets going...I think the anti-cyclone might end up being more like the runs from a few days ago, but I guess we'll see
90L reminds me of either Floyd or Dean.
Uh... no... as far as I know it is A Satellite dedicated to a particular system.
-and Andrew was very small in size in comparison. This is 3000 miles away so you can name any hurricane ya want at this point..
If TD2 was a car, the cambelt may not have gone, but it only has a 4 cylinder right now and the head gasket's blown.
we may see a similar story (different injuries of course) if we have people imitate what they see posted. DO NOT try riding out a storm for the sake of youtube or peoples entertainment. your not smart enough, it will not end well
lmao
Charlie,in 04 showed many that a Storm dosent listen to the Forecasters.
They have no Ears.
Everyone thought He was going to Tampa,But Right turn Charley did a Lil turn and went in at Punta Gorda and caught MANY by Surprise.
As I always state,never turn your back to a Storm when its south of one,as the threat is always there till its past.
Be prepared as we lean into the meat of the season.
Ignore rumor,and follow the NHC track and Discussions for the most updated info as well.
Relax. You'll all get what you want in the coming weeks.
Just be careful. When it comes to the Carolinas, Florida, or any number of places on the Gulf Coast...it may not seem near as exciting!
How do you view the update regarding possible GOM ramifications?
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