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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many of the models are now showing a strong mid to upper level trough over the SEUS in that time frame which could potentially steer what is 90L away from the Eastern seaboard depending on the timing of the trough some models predict the trough could come in soon enough to turn 90l out to sea....Happy?
as I said we go to bed knowing TD2 is a remnant low we wake up and at 5am newly re-born TD2
456,any decent rain yesterday?
I'm getting too much rain in my area,When the itcz settles over in August its not nice.
I dont mind a tropical storm, but I dont want another David, Hugo or Georges. No way!
yes, it rained heavy all last night. Was very refreshing since nights here can be warm.
Visible
Thank you for being a voice of reason, Savannah!
What's even more interesting about this area is how it appears to have a low shear environment and possible an upper high, allowing ventilation (outflow) in all directions. I have a feeling this will dissipate overnight, but you never know this time of year.
On a sidenote.
Reducing Greenhouse gas emissions in the first place, would help to prevent such super forces.
For example, more Co2 emission means hotter oceans.
Now, i agree it's out of human control.
Jean wasnt any fun either no light or water for 5 days
yep, that year was full of 'casters, especially with Karen and Dean.
CMC was actually showing both storms nearing hurricane strength and merging in the CATL a few days ago (which I and pretty much everybody else on here made fun of), they're probably too far apart and since they're heading in roughly the same direction at about the same speed any interaction would be at most minimal.
http://www.smh.com.au/world/typhoon-victims-tell-the-president-to-get-moving-20090813-ejwn.html
I'm not positive but I'm pretty sure they'd both have to get quite a bit stronger before that could even become a possibility and even then I'm not sure they're close enough to eachother. but don't quote me on that:P
Oh so i redeemed myself? lol
Its not as rare as you might think and in theory could affect any two cyclones or anticyclones and is far more likely to be a regular occurence that just goes mostly unnoticed except in extreme cases.
No! Though to be honest we are quite overdue from receiving the full brunt of a Cat 5. It's been what... nearly 70 years? Statistically we are about to be hit by one soon. I am honestly ready for that one with the sole exception I live 1 mile away from the beach =P
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