Two African waves, 92L and 93L, worth watching
An African wave is near 13°N 35°W, about 700 miles west-southwest of the Cape Verde Islands. This system, (Invest 92L), is moving west to west-northwest at 10 - 15 mph, and has the potential to develop into a tropical depression or tropical storm before arriving near the northern Lesser Antilles Islands early next week. Recent visible satellite loops show that 92L has less heavy thunderstorm activity near where it is trying to develop its circulation center than yesterday. Water vapor satellite loops that a large area of dry air lies just to the west of 92L, but the atmosphere in the immediate vicinity of 92L is moist. Even so, the decline of heavy thunderstorm activity since yesterday implies that dry air is probably working its way into 92L. The SHIPS model and University of Wisconsin CIMSS wind shear analysis are showing moderate wind shear of 10 - 15 knots affecting 92L. Sea surface temperatures are 26.5° - 27°C, which is very close to the 26.5°C threshold usually needed to support a tropical storm.
Figure 1. Morning satellite photo of Invest 92L and Invest 93L.
Forecast for 92L
Low to moderate wind shear of 5 - 15 knots is predicted along 92L's path over the coming three days, which should allow the storm to organize, assuming it can shut out any incursions of dry air that might intrude. The latest 00Z and 06Z model runs of the four best models for predicting tropical storm formation (GFS, ECMWF, NOGAPS, and UKMET) show weak development or no development of 92L, and NHC gave 92L a 30% chance of developing into a tropical depression by Saturday morning in their 8am outlook. A steady west to west-northwest motion for 92L is predicted by all of the models, which would put the storm in the vicinity of the northern Lesser Antilles Islands by Sunday. On Saturday and Sunday, 92L is expected to enter a region where an upper-level low pressure system will bring high wind shear of 20 knots to the storm, which should slow development. This upper-level low is also expected to turn 92L more to the northwest, so the storm is likely to pass north of the Lesser Antilles, though may pass close enough to give heavy rains to the northernmost islands. It is too early to know if 92L will recurve out to sea and potentially threaten Bermuda, or continue to the northwest towards the U.S. East Coast.
93L
An African wave that emerged off the coast of Africa is near 10°N 22°W, a few hundred miles south of the Cape Verde Islands. This system, (Invest 93L), is also moving west at 10 - 15 mph, and has the potential to develop into a tropical depression or tropical storm before arriving near the northern Lesser Antilles Islands near the middle of next week. Recent visible satellite loops show that 93L has a decent amount of heavy thunderstorms, but this activity is not well organized. There is not much spin associated with 93L yet. 93L is fairly well-protected from dry air to its north and west. The SHIPS model and University of Wisconsin CIMSS wind shear analysis are showing moderate wind shear of 10 - 20 knots affecting 93L. Sea surface temperatures are 27.5°C, which is one degree above the 26.5°C threshold usually needed to support a tropical storm.
Forecast for 93L
Moderate wind shear below 20 knots is predicted along 93L's path over the coming five days, which should allow the storm to steadily organize. 93L is about 600 miles east of 92L, which is close enough that the two systems may interfere with each others' organization. The latest 00Z and 06Z model runs of the four best models for predicting tropical storm formation (GFS, ECMWF, NOGAPS, and UKMET), have only one model, the GFS, that is indicating significant development of 93L. This model brings 93L near the northern Lesser Antilles Islands by Wednesday. NHC gave 93L a 20% chance of developing into a tropical depression by Saturday morning in their 8am outlook. Due to moister air, the potential for less wind shear, and a more southerly track, 93L is probably a greater threat to the Lesser Antilles than 92L.
Jeff Masters
Reader Comments
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Not to say it could not happen, but that is the longest, straightest upper jet segment I have seen (or remember anyway). Especially for August. 100 knot jetstreak. Nary a dip or a turn from out in the NW Pacific almost all the way across North America. This probably would quickly take the kink out of any east coast/western ATL troughing. Looks a little hokey.
93L's strong outflow can be seen in the closed isohype over FL and the Bahamas.
18Z 200mb @ 264 hrs
click to enlarge
It's turbo'd up all by itself :P
When I used to use boards once they went up, they were up for the season. Maybe take off 1 or 2 to let some light in the house.
The current pattern, as long as the ridge stays over Texas, tends to prevent things from getting into the Gulf of Mexico from the east, as the ridge blocks them, plus the weakness along the eastern seaboard likes to grab the storms and take them north before reaching the GOM. I wouldn't worry too much with 92L and 93L, but something developing farther west and getting into the western Caribbean would be more of a potential concern for the gulf. We may get some of those later this season.
One thing I can do is open up all the tabs for the images and then click through all the tabs. That's the quick and easy way to get the animation. Only problem is I can't share it
The ensemble mean of the same run for the same time makes a little more sense, though of course probably more smoothed out than it would be in reality due to the averaging of the members.
You should get it. You can run it alongside Windows and boot into either of them from a list at startup. Linux is what the cool guys use ;)
Don't think my parents would be willing to pay for something I already have and neither am I lol.
And if it is free, does it take much computer knowledge/awareness to install and operate and all that jazz? I'm not all that computer savvy.
Well IMO (in my opinion) 92L looks like trash right now...but if they were to go into Fujiwhara interaction, they would rotate counter-clockwise about each other....that would mean a more west track for 92L are a more NW track for 93L....
Thanks for the info.
To everyone else, who may not have been aware about what Levi and I are talking about:
There is great (~15 minute) satellite imagery over Africa available here. Only problem is it is a link to thousands of individual images, and it isn't an animation. There are a few ways around this, one way is to make the animation for yourself and another is to make a script. Problem with the first solution is it takes forever, and the problem with the second is you have to know what you are doing to make a script.
Another solution is to open up FireFox (idk if it works in other browsers, only checked Chrome and FF) and go to the link. Open up all the images you want in a new tab. Then hit the tab button on your keyboard once. You can now scroll through the images with your arrow key, effectively creating an animation. You get to control the speed and direction (forward/backward) of the loop. Only problem is you can't share it with other people.
Linux is free, but it is not for the faint hearted.
Rob from RainmanWeather.Com will have another giveaway. Whats happening in the Tropics, and more. .
We will be talking Tropics and our Weather 101 segment!
The Barometer Bob Show is on now. You can watch the show via my blog also.
A Mac is the best. No viruses, no problems with the blog, no crashes. It's a great fit :)
I sure hope not I was in Charleston that night in September 1989, NEVER want to go through it again!!
Easier to use Link
Where else have you been stationed?
NO
Roll he mouse wheel over the tab bar, more than likely that will cycle the tabs.
93L is un-argumentatively better organized than Invest 92L at this time.
lol.
You have to get out more if you want to see the heavy weather. ;-) I do move around a lot: born in California; Iowa; Missouri; Alabama; back to California; Wyoming; Montana; back to Wyoming; Minnesota; Florida; Texas; Ohio; back to Florida; Colorado; back to Florida, back to California; back to Florida; back to California; and, now, back to Florida. Whew... ;-)
All of the above and more with Linux :P
I'm a weather widow...
take a breath !!!
It is free. There are multitudes of distributions, some requiring more advanced knowledge than others. Rob is right that it is not for the faint of heart, but the most popular distribution, Ubuntu, is very user-friendly and is basically the "Windows" of linux. It is aimed at beginners and requires little hands-on maintenance. For the most part, it takes care of itself, though you can still run into problems, just like Windows.
it's legit. Happy birthday, JFV. Maybe you'll win the giveaway tonite.
Wubi would be a fit, it sounds like.
I was going with the no one cares theme.
no he hasn't yet. will be soon.
Linux can be a real pain though sometimes. I manage our Linux network in my department, and some really strange problems crop up all the time that take days to fix.
Must be using Dead Rat or S*cksy.
well...I figure every human deserves to hear happy birthday.
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