Two African waves worth mentioning

By: Dr. Jeff Masters , 3:51 PM GMT on July 18, 2009

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There are two African tropical waves worth mentioning today, though neither looks particularly threatening. A tropical wave near 12N 45W, about 1200 miles east of the Lesser Antilles Islands (97 L), is moving west at 15 - 20 mph. This wave is now surrounded by an area of very dry air from the Sahara Desert. The dry air has disrupted most of the wave's heavy thunderstorm activity, and will continue to make it difficult for this system to develop over the next 2 - 3 days. Wind shear is a modest 10 knots over the disturbance, and should remain in the moderate 10 - 15 knot range over the next 2 - 3 days. Thereafter, shear is expected to rise to 20 - 30 knots. This morning's QuikSCAT pass showed no evidence of a surface circulation, and only a modest wind shift associated with 97L. The National Hurricane Center is giving this system a low (less than 30% chance) of developing into a tropical depression in the next 48 hours.

A second tropical wave now approaching the northern Lesser Antilles Islands is under 30 knots of wind shear, and has little prospect of development due to the high shear. However, the wave will bring heavy rain to the islands over the next two days.

None of the computer models are forecasting tropical storm development over the next seven days, and I don't expect either of the two African waves mentioned today to develop over at least the next three days.


Figure 1. Current satellite image of African wave 97L, 1200 miles east of the Lesser Antilles Islands.

I'll have an update Sunday afternoon.
Jeff Masters

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2250. WxLogic
Quoting all4hurricanes:

what about north of the carribean cause thats where this thing is supposed to be heading

heres an eerily similar Ana from 79


Would be funny if it has the same fate...
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Quoting Weather456:
There was an Anna in this very same location



Do the Windward Islands have their own weather service that broadcasts on tropical systems about to effect them just wondering if there was any news on the invest in that region.
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Hopefully 97l can develop enough with 5kt shear and even if shear is strong gets through the shear zone and has enough to get into the gulf.Gulf has low shear right now,and blazin temps.
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Quoting weatherwatcher12:

Shear in the Caribbean is decreasing as the TUTT moves out

will it move out fast enough?

heres an eerily similar Ana from 79
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Quoting Weather456:
There was an Anna in this very same location



30 years ago.. i wonder if this storm will follow the same fate. if it forms getting shredded by the trough and dying in the east caribbean. possible.
Member Since: July 7, 2008 Posts: 2 Comments: 3237
wait wait wait lol

you cant start another poll while one is still going on, it just confuses people lol

why not wait until after the 2pm update to do that poll?
I think we should give some credit to the Reed man on here.. He never gave up on it and now everyone is talking about a possible td in the making..

Actually everyone deserves credit on here, I love hearing everyones opinions and predictions. I have learned alot from being on this blog.

BTW: Tampaspin is still looking for the shear of his lol
Member Since: May 18, 2009 Posts: 0 Comments: 474
2243. Drakoen
97L at it's current latitude cannot escape the Upper level trough. The trough needs to move northward.
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I do believe we have LLC or one is forming

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These cold tops will stay,no shear =5kt will not kill them.So this is def a storm in the making.
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97L should be headed towards the south bahama's area,and next weekend could be a interesting one for south FL!!!!,IMO
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Quoting all4hurricanes:
Ok to answer both polls i say red circle and TD tomorrow


Not that much dry air and low shear for at least the next day but then shear steadily increases especially is this moves north so i think a td might form but probably not Ana

Shear in the Caribbean is decreasing as the TUTT moves out
Member Since: May 16, 2009 Posts: 1 Comments: 1231
"Ana" by this time tomorrow? Could be at the rate its spinning up now but, storms that are not very organized before getting to the eastern Carrib don't usually develope until they get to western Carrib. Eastern Carrib is usually kind of a "dead zone" for developement.
But it sure is looking impressive right now.
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I don't like the looks of those tracks. A Charlie type tracking.
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Quoting Drakoen:


Yes. It is either going to send 97L through the shredder or provide a poleward outflow channel.


interesting. so if it lifts out then 97L gets extra help, but if it stays then it gives 97L extra uhhmm, not help? seems like a hit or miss situation.
Member Since: July 7, 2008 Posts: 2 Comments: 3237
2235. aquak9
what was the question again?

If ANYONE wanted to learn about primary cyclogenesis, now's the day to lurk and LEARN. Good posters, good comments backed up with graphics, decent textbook situation, and respectable bloggers.

I got MY inverted V, so I'm happy.
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I think our 97L is looking quite good right now. Anything is possible.
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If this thing goes into the gulf with low shear,watch out.The gulf temps are really warm and haven't been touched.
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I was interested in what HaboobRsweet would say on 97L I did not see any posts from him but curious what he thinks.
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Ok to answer both polls i say red circle and TD tomorrow


Not that much dry air and low shear for at least the next day but then shear steadily increases especially is this moves north so i think a td might form but probably not Ana
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Quoting Weather456:
There was an Anna in this very same location



1969. Yup.
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These models take it into my area:



Member Since: May 16, 2009 Posts: 1 Comments: 1231
2228. Drakoen
Quoting HurricaneSwirl:


do you think the trough is that important in the possible formation of 97L?


Yes. It is either going to send 97L through the shredder or provide a poleward outflow channel.
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Quoting TampaMishy:
Isn't it kind of early to be predicting where 97L is heading?


Yes other then West currently heading towards the Windward Islands in a day or so.
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2226. WAHA
I will be back later. gonna show someone a video I made.
There was an Anna in this very same location

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F:strait to TS status w/out td status first.



Probably w/be based on quickscat and sat presentation and should be named in the next 48hrs,IMO
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Nice, 97 is getting it together. SAL is much less now, and conditions at the moment are quite good for it's development. 97 is getting organized nicely. I'll vote B in the poll now for 97, although with NHC logic it may be a C type deal. I'm not sure about the long term future of 97, though. If it does head north, it could end up weakening greatly, or fizzle.
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Quoting Drakoen:
That upper level trough is either going to make or break 97L.


do you think the trough is that important in the possible formation of 97L?
Member Since: July 7, 2008 Posts: 2 Comments: 3237
2221. Drakoen
I can't see Brennan saying the convection remains disorganized at this hour.
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hurfin ???? I am just giving my thoughts....
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Quoting WAHA:

B and E

sorry only one
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2218. WAHA
Quoting HURRICANECAT5:
Invest 97L is looki better by the minute. I had a feeling this would happen once it reach 50W. We may have a TD in the making.

no kidding.
2217. pottery
SAL is pretty non-existant in the Trop Atl right now.
Visibility in Trinidad 11 miles.
Temp 90 F
Humidity 47%
pressure 1015
wind ENE 11 mph

Not much to say about that..

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2216. JRRP
Quoting wunderkidcayman:
ok vote
A it becomes a td at the 8:00pm update
B it becomes a td tomorrow updates
C it becomes a td tuesday
D it dosen't become anything but the invest that it is now
E it becomes ts ana in any of the above dates

D
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AOI

AOI

AOI

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2214. Drakoen
That upper level trough is either going to make or break 97L.
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I think we've got a good system going. Good contributions, all. Thanks.

I'll be back when Acorn stops polling! LOL.
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2212. hurfins
Quoting claimsadjuster:


I vote "E"
Quoting wunderkidcayman:
ok vote
A it becomes a td at the 8:00pm update
B it becomes a td tomorrow updates
C it becomes a td tuesday
D it dosen't become anything but the invest that it is now
E it becomes ts ana in any of the above dates
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Invest 97L is looki better by the minute. I had a feeling this would happen once it reach 50W. We may have a TD in the making.
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2210. WAHA
Quoting wunderkidcayman:
ok vote
A it becomes a td at the 8:00pm update
B it becomes a td tomorrow updates
C it becomes a td tuesday
D it dosen't become anything but the invest that it is now
E it becomes ts ana in any of the above dates

B and E
2209. Drakoen
15:15z imagery shows some deepening convection so we will see what happens...
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B again :)
Member Since: August 2, 2006 Posts: 0 Comments: 1240
2207. JRRP
Quoting HurricaneSwirl:


its honestly too early to tell for a TD. remember it can die just as quickly as it organized right now. but if this trend keeps on going then B.

true
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Quoting wunderkidcayman:
ok vote
A it becomes a td at the 8:00pm update
B it becomes a td tomorrow updates
C it becomes a td tuesday
D it dosen't become anything but the invest that it is now
E it becomes ts ana in any of the above dates

If it continues like this B
Member Since: May 16, 2009 Posts: 1 Comments: 1231
2205. WAHA
Quoting robie1conobie:
for as smart as some of you are with weather; I am going out on a limb to say there are not too many spelling bee champs in here!

It's called lolspeak. We all can spell, it's just we need a faster way of communicating.
Quoting wunderkidcayman:
ok vote
A it becomes a td at the 8:00pm update
B it becomes a td tomorrow updates
C it becomes a td tuesday
D it dosen't become anything but the invest that it is now
E it becomes ts ana in any of the above dates


its honestly too early to tell for a TD. remember it can die just as quickly as it organized right now. but if this trend keeps on going then B.
Member Since: July 7, 2008 Posts: 2 Comments: 3237
2203. Drakoen
Quoting WxLogic:


Ohh so after looking up some credentials you then decide now... hehe.


I already went with B before I considered that LOL!
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Quoting robie1conobie:
for as smart as some of you are with weather; I am going out on a limb to say there are not too many spelling bee champs in here!


Luckily this isnt a grammar blog. Plus some here english isnt their first language.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting wunderkidcayman:
ok vote
A it becomes a td at the 8:00pm update
B it becomes a td tomorrow updates
C it becomes a td tuesday
D it dosen't become anything but the invest that it is now
E it becomes ts ana in any of the above dates


B
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Quoting wunderkidcayman:
ok vote
A it becomes a td at the 8:00pm update
B it becomes a td tomorrow updates
C it becomes a td tuesday
D it dosen't become anything but the invest that it is now
E it becomes ts ana in any of the above dates


I vote "E"
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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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