Unusually well-organized 92L disturbance may become a tropical depression

By: Dr. Jeff Masters , 2:14 PM GMT on June 14, 2010

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Invest 92L, a remarkably well-developed African tropical wave for so early in the season, is midway between Africa and the Lesser Antilles Islands. Infrared satellite loops show a modest area of heavy thunderstorms along the north side of 92L's center of circulation, and the storm's heavy thunderstorms activity appears to be slowly increasing in intensity and areal coverage. Upper-level outflow is apparent to the west and north of 92L, and the outflow has been gradually improving this morning. Visible satellite loops do not show much in the way of low-level spiral bands, and my current take from the satellite imagery is that 92L is slowly organizing, and will not become a tropical depression any earlier than 11pm EDT tonight (Monday.) A 4:27 am EDT pass from the WINDSAT satellite saw a partially closed circulation at the surface (open on the south side), with top surface winds of 25 - 30 mph north of the center.


Figure 1. Morning satellite image of Invest 92L (left side of image) and a vigorous new tropical wave that has moved off the coast of Africa (right side.) None of models develop the new tropical wave, but it bears watching.

Sea surface temperatures
Climatology argues against development of 92L, since only one named storm has ever formed between Africa and the Lesser Antilles Islands in the month of June--Tropical Storm Ana of 1979 (Figure 2). However, sea surface temperatures (SSTs) underneath 92L are an extremely high 28°C, and will increase to 29°C by Thursday. In fact, with summer not even here, and three more months of heating remaining until we reach peak SSTs in the Atlantic, ocean temperatures across the entire Caribbean and waters between Africa and the Lesser Antilles are about the same as they were during the peak week for water temperatures in 2009 (mid-September.)

Dry air not a problem for 92L until Wednesday
The disturbance doesn't have to worry about dry air today or Tuesday--Total Precipitable Water (TPW) loops show a very moist plume of air accompanies 92L, and water vapor satellite loops show that the center of 92L is at least 200 - 300 miles from any substantial areas of dry air. As 92L continues to push northwest, though, the SHIPS model is predicting that relative humidity at middle levels of the atmosphere will fall from the current value of about 70%, to 60% on Wednesday. This dry air may begin to cause problems for 92L on Wednesday, especially since wind shear will be increasing at the same time. Tropical cyclones are more vulnerable to dry air when there is substantial wind shear, since the strong winds causing the shear are able to inject the dry air deep into the core of the storm.

Madden-Julian Oscillation
The 60-day cycle of enhanced thunderstorm activity called the Madden-Julian Oscillation is currently favoring upward motion over eastern tropical Atlantic, and this enhanced upward motion helps create stronger updrafts and higher chances of tropical cyclone development.


Figure 2. Tropical Storm Ana of 1979 was the only June named storm on record to form between Africa and the Lesser Antilles Islands.

Wind shear
A major issue for 92L, like it is for most June disturbances, is wind shear. The subtropical jet stream has a branch flowing through the Caribbean and tropical Atlantic north of 10° N that is bringing 20 - 40 knots of wind shear to the region. Our disturbance was located near 10°N, 40°W at 8am EDT this morning, a few hundred miles south of this band of high shear, and is currently only experiencing 5 - 10 knots of shear. This low amount of shear should allow for some steady development of 92L over the next two days as it tracks west-northwest or northwest at 15 mph. The latest run of the SHIPS model is predicting the shear will rise to 20 knots on Wednesday, which may start to cause problems for 92L.

The forecast for 92L
The National Hurricane Center is giving 92L a high (60% chance) of developing into a tropical depression by Wednesday morning, which is a reasonable forecast. The odds of development have increased since yesterday, as the storm has moved considerably to the northwest, away from the Equator. Now it can leverage the Earth's spin to a much greater degree to help get it get spinning. It is quite unusual for a tropical depression to form south of 8°N latitude.

I expect that 92L's best chance to become a tropical depression will come on Tuesday, and the storm could strengthen enough by Wednesday to be named Tropical Storm Alex. The farther south 92L stays, the better chance it has at survival. With the system's steady west-northwest movement this week, 92L will probably begin encountering hostile wind shear in excess of 20 knots by Wednesday, which should interfere with continued development. Several of our reliable models do develop 92L into a tropical storm with 40 - 55 mph winds, but all of the models foresee weakening by Thursday or Friday as 92L approaches the Lesser Antilles Islands and encounters high shear and dry air. I doubt 92L will be anything stronger than a 45 mph tropical storm when it moves through the northern Lesser Antilles Islands on Friday and Saturday, and it would be no surprise if wind shear has destroyed the storm by then. However, as usual, surprises can happen, and the GFS and the SHIPS model (which is based upon the GFS) do indicate that more modest levels of wind shear in the 15 - 20 mph range late this week may allow 92L to stay stronger than I'm expecting. Residents of the islands--particularly the northern Lesser Antilles--should follow the progress of 92L closely, and anticipate heavy rains and high winds moving through the islands as early as Thursday night.

Oil spill wind forecast
There is little change to the oil spill wind forecast for the coming two weeks. Light winds of 5 - 10 knots mostly out of the south or southeast will blow in the northern Gulf of Mexico all week, according to the latest marine forecast from NOAA. These winds will keep oil near the coast of Louisiana, Alabama, Mississippi, and the extreme western Florida Panhandle, according to the latest trajectory forecasts from NOAA and the State of Louisiana. The long range 8 - 16 day forecast from the GFS model indicates a typical summertime light wind regime, with winds mostly blowing out of the south or southeast. This wind regime will likely keep oil close to the coastal areas that have already seen oil impacts over the past two weeks.

Jeff Masters

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which way is that moisture going in the BOC?
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2539. KEEPEROFTHEGATE (Mod)
EMPTY SPACE COMPLETED
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2538. JLPR2
convection is actually over the center but...
were are the exciting red blobs of convection? XD
are we in a downward MJO pulse? Or has 92L simply become allergic to such convection?

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Seven earthquakes in 10 minutes, Southern California (Ocatillo)

MAP 4.1 2010/06/15 04:36:06 32.681 -115.918 0.0 SOUTHERN CALIFORNIA
MAP 4.1 2010/06/15 04:35:47 32.696 -115.965 8.7 SOUTHERN CALIFORNIA
MAP 3.4 2010/06/15 04:34:26 32.696 -115.955 0.0 SOUTHERN CALIFORNIA
MAP 3.2 2010/06/15 04:33:04 32.568 -116.553 10.7 BAJA CALIFORNIA, MEXICO
MAP 3.2 2010/06/15 04:32:57 33.153 -116.250 27.5 SOUTHERN CALIFORNIA
MAP 3.6 2010/06/15 04:31:54 32.715 -115.947 0.1 SOUTHERN CALIFORNIA
MAP 3.9 2010/06/15 04:29:55 32.733 -115.973 2.9 SOUTHERN CALIFORNIA
MAP 5.7 2010/06/15 04:26:58 32.698 -115.924 6.9 SOUTHERN CALIFORNIA
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Good Lord... Can't we all just all get along and sing KUMBAYA?
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Quoting Hurricanes101:
those of you who quoted him, may get banned too

"
yeah if you quoted, modify it asap. We dont want you going down for his stupidity.
Member Since: August 27, 2008 Posts: 0 Comments: 1497
Wow I can't believe what just happened with altesticstorm10 it is like he was a featured and respected blogger on here. It's almost like he's bipolar, I know somewhere in that guys head he has regretted what he has done & if he has heart he will come on here and apologize... that is if he hasn't been banned yet. He fooled us all. I have for all the yrs I have lurked on this blog never seen such uncharacteristic behavior, I get mad and pissed off sometimes, but this can't be tolerated here!
Member Since: August 31, 2009 Posts: 0 Comments: 5628
those of you who quoted him, may get banned too

Member Since: March 10, 2010 Posts: 1 Comments: 7726
ding dong the witch is dead ...
Member Since: August 27, 2008 Posts: 0 Comments: 1497
2528. Levi32
He's gone....good to know admins are on watch even at this hour.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Quoting RitaEvac:
My worst fear is a couple of majors coming in gulf and tearing everything up and washing oil along entire gulf coast, platforms/rigs destroyed, gas prices sky rocket, and then a 9.0 quake in LA within the same period. Serious consequences to this country.


Well we just got a preliminary 5.7 quake in SoCal near the border w/ Mexico.
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2526. xcool
altesticstorm10:
poof poof & poof
Member Since: September 26, 2009 Posts: 2 Comments: 15675
2525. Levi32
Quoting WindDamage:
levi is teh convection growing with 92l right now, is it expected?


Not growing anymore. We'll see what it looks like in the morning, but it is not too healthy right now.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
one that went suicide on the blog
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Just flag the comments, don't respond or quote them, and move on.
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biggest detriment to 92L is that upper trough .... check out WV imagery ... cloud tops that in a healthy system would be headed east are moving due west and right into the COC ... Until/If that ceases 92L will not be doing much of anything more than struggling to survive.
Member Since: August 27, 2008 Posts: 0 Comments: 1497
Quoting nocaneindy:


My thinking has been, since the start of 92l, that it was going to travel farther south than some of the models showed. I had been seeing the ivcn?(maybe icvn?) as the most reliable on track, still I thought maybe a little more south still.
Just to use as a reference for lat/ long, and in that mindset only, I think 92L will take a track in between 2007's Felix and Dean. But I'm only willing to commit to that till 65-70W. After that, I'm more than willing to admit that I lack a sound enough knowledge of long term predictions to hazard a guess.

Here is the map showing Felix and Dean's respective paths.


Here is the steering I am currently looking at.


That map you posted and the weakening to 1012 got me thinking that just maybe I'm correct.
If you can tell me why I'm right or wrong, I'd appreciate any feedback, from anyone. I'm trying to really apply myself to the track of systems, more so than the strength.


Why are the storm names all messed up??
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Think I heard a gun shot few houses down, reportedly someone was upset with a blog and couldnt take it no more
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Thank you windamge.I am sorry if I seemed a lil aggrivated,but it was really upsetting to listen to that stuff.This afterall is a weatherblog not a boxing match.LOL!!!!!!!!!!!
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Quoting Drakoen:


Seems you have spoken to late
Yes I did wow what did I miss on that one????

Taco :o)
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oh wow .... nice knowin' yah
Member Since: August 27, 2008 Posts: 0 Comments: 1497
2512. will45
Quoting KEEPEROFTHEGATE:
altesticstorm10 YOU SHALL BE REPLACED WITH EMPTY SPACE JUST LIKE WHATS IN YOUR HEAD


would have been nice if he had visited your blog then we would have an ip address
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May be wrong, but it appears that deep convection now completely covers the circulation of Invest 92L. Its doing much better tonight than last night for sure. Basing that upon Shortwave IR imagery.
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Quoting Levi32:


That's because it was not unlike a west Pacific monsoonal depression, which are usually large systems. 92L lost convection and size because it became fully separated from the ITCZ, and thus lost the benefit of its convergence. Cooler SSTs and a weak upper trough to the south punching in dry air and cutting off outflow have also contributed to the loss of convection today.

Systems embedded in the ITCZ or monsoon trough, especially in the Indian Ocean and western Pacific, are generally large and broad because the ITCZ/monsoon trough is a perpetual boundary of converging winds, and it is very hard to get a small, tight circulation within that boundary.

Oh man you really know your stuff, I really appreciate it. Thanks :) I'll save that just in case someone asks me about it.
Member Since: August 31, 2009 Posts: 0 Comments: 5628
I'm out for the night... hopefully... things will be clearer in the morning.




AOI

AOI

AOI

AOI
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2505. Levi32
Quoting nocaneindy:


My thinking has been, since the start of 92l, that it was going to travel farther south than some of the models showed. I had been seeing the ivcn?(maybe icvn?) as the most reliable on track, still I thought maybe a little more south still.
Just to use as a reference for lat/ long, and in that mindset only, I think 92L will take a track in between 2007's Felix and Dean. But I'm only willing to commit to that till 65-70W. After that, I'm more than willing to admit that I lack a sound enough knowledge of long term predictions to hazard a guess.

Here is the map showing Felix and Dean's respective paths.


Here is the steering I am currently looking at.


That map you posted and the weakening to 1012 got me thinking that just maybe I'm correct.
If you can tell me why I'm right or wrong, I'd appreciate any feedback, from anyone. I'm trying to really apply myself to the track of systems, more so than the strength.


Well in my opinion 92L won't track that far south, because while your points are valid for surface steering, 92L appears to have been following the mid-level steering, as it is a fairly deep system despite its high surface pressure. Looking at mid-level steering, there is still a pronounced weakness in the ridge between 40W and 60W, which is why 92L has been moving northwesterly today. The ridge will be building back stronger over the next couple days, turning 92L back towards a more westerly direction, which we may already be starting to see tonight. The most likely crossing point into the Caribbean will be over the leewards, followed by a movement near PR and Hispaniola.

Member Since: November 24, 2005 Posts: 635 Comments: 26647
2504. KEEPEROFTHEGATE (Mod)
altesticstorm10 YOU SHALL BE REPLACED WITH EMPTY SPACE JUST LIKE WHATS IN YOUR HEAD
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2503. 7544
do we really need that quote
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Wow... blog suicides have reached an epidemic rate. reminds me of the Foxconn suicides...

Has 92L really gotten people that worked up?
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2501. Drakoen
Quoting taco2me61:
ok I'm out for the night and I want everyone to play "Nice"....


Seems you have spoken to late
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Quoting altesticstorm10:


That's it...You've pushed my buttons...











Have a very fucking good 2010 Atlantic hurricane season, hope all of the n00bs here get fucked up the ass!


NOTE: I do respect several users: StormW, Drakoen, Levi, Weather456, extremewwe, extreme236, sporteguy03, patrap, moonlightcowboy, jphurricane2006, StormJunkie...everyone else who isn't an antagonist like the user I quoted...and all the women.

The rest of you TROLLS, can eat shit and DIE!!!!!!!!!!!!!!!!!!!!!!
OH my goodness please refrain from all the vulgarity.I am a christian lady who would much like to be respected on here please.I mean no offense but I do enjoy being on here listening to all.But i dont like the vulgarity you have expressed.
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2499. will45
altesticstorm10 should be banned for life
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Quoting reedzone:


Well it's like my argument with scottsvb last night. I put out a few forecast that were wrong, but were based on patterns and trends. He called me a wishcaster. I don't respect METs like him, he almost made me not go into the field after what he pulled with me on the Flhurricane site 3 years ago after I predicted Humberto to reach at 65 mph. the most, while other forecasts had a 45-50 mph. at landfall. He called me a wishcasting noob and other names I can't share. That's not how a MET should be to people who are learning, like me. We all aren't right with our forecasts, but try to put out the best of them to let the people know what COULD happen. This is why we have percents.

*I go overboard, but in the end I learn from my mistakes and move on and let Mother Nature surprise us.*


Reed, I would like to see that posting of me calling you anything more than a wishcaster or noob. Noob @ what? Your making up lies and it makes you look bad.

Problem is, you just make wild predictions of everything thats a cloud in the Atlantic has a good chance of becoming a TD or Storm. Also just cause you guess and something comes true, you cant say "Told ya so" eventually 1 wave will be a TD or TS or even a HUR. Point is, if we went by your forecasts, the average season would have 80 TD, 50 being TS and 25 of them being Hurricanes. Even JV makes more sense @ times.

Dont get upset when I tell ya why something wont form and you dont listen..and when it doesnt form, you get upset and start posting comments.
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2496. xcool
altesticstorm10 poof lmao
Member Since: September 26, 2009 Posts: 2 Comments: 15675
Man I have lived in Tampa all my life and can't recall ever having a heat wave like this I mean near 100 degree temperatures on the weekend with today expected to be 96. Can I get a break in the form of rain. Right now call me a wishcaster but I will take a storm over this oppressive heat any day of my life...jeez.
Member Since: August 31, 2009 Posts: 0 Comments: 5628
Quoting Drakoen:


Why do I get the feeling that would be very awkward.


Cause it would be :P

What would happen? You guys sitting around talking about the effects of the MJO?
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ok I'm out for the night and I want everyone to play "Nice"....
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The framework is in place. All 92L needs now is some meat on them bones.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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