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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1400. JLPR
Quoting TampaSpin:


Thank you for being observant...its not tearing it apart yet....just enough to cause some uplift.....but, in 6-12hrs...its poof as i have been stating...why do you all think NHC took the invest away......


no prob xD normally this small systems need perfect conditions to develop as opposed to large systems so if that ULL moves a little bit more to the south to cause some decent shear 97L might be done for
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Well I am impressed, 97L is holding it's own and DMAX is helping it go through. If organization continues, they should re-tag it by the a.m.
Member Since: July 1, 2008 Posts: 13 Comments: 7429
maybe it's deja vu all over again...but ...Is that a little action I'm seeing off the mythical "Carolina coast"?
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Long time no see. Another quite night in the tropics, I see. Well, I won't write a story of my last 3 months, but I have a blog on it if you'd like to see. I'm in the Navy now, so my time to track the tropics will be limited, but I still hope to get on and do so when I can. As for 97, I haven't seen much on it, but it doesn't seem like a player to me. I still need to get some info, though.
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1396. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #29
TROPICAL STORM MOLAVE (T0609)
12:00 PM JST July 19 2009
============================================

Subject: Category One Typhoon Overland Southern China

At 3:00 AM UTC, Tropical Storm Molave (992 hPa) located at 23.0N 111.8E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The storm is reported as moving west at 15 knots.

Dvorak Intensity:

Gale Force Winds
================
160 NM from the center

Forecast and Intensity
=======================
24 HRS: 25.1N 106.0E - Tropical Depression
Member Since: May 24, 2006 Posts: 52 Comments: 46518
1395. beell
Drak is too quick-yes Homeless, the axis or "centerline" of the ridge.

The other is the 1014mb line of constant pressure.
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Anyone still out there? LOL
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Not that either of us need any help press, but you know what assuming does!
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1392. Skylink
where off the florida coast?
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http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8shr.html

Shear is moving north as expected and will continue to weaken. I sense no shear in the future of the remnants of 97L which is still regenerating and blowing up some deep convection on the north and south.
Member Since: July 1, 2008 Posts: 13 Comments: 7429
SJ...Shall I assume that, as you have time to screw around on the blog, you have fixed my compUter?
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Quoting Drakoen:


The zigzag line is the ridge axis.


Ok. Thank you very much. :)
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Take a look at the low forming off the florida coast. Bet it becomes anna before 97 ever has a chance.
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1387. Drakoen
The Navy is still keeping updates on the system so we will see what happens in the AM.
Member Since: October 28, 2006 Posts: 57 Comments: 30671
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1385. Drakoen
Quoting homelesswanderer:


Evening All.

On that surface map, the top one, can someone tell me what that zigzag line means? And also is the line going through the Yucatan the edge of the Burmuda high? I can never read those right. TIA


The zigzag line is the ridge axis.
Member Since: October 28, 2006 Posts: 57 Comments: 30671
And the microwave scans are three hours old Drak. Can't look any worse now then it did three hours ago.
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Quoting beell:
Valid 12Z Monday


Valid 12Z Monday


Evening All.

On that surface map, the top one, can someone tell me what that zigzag line means? And also is the line going through the Yucatan the edge of the Burmuda high? I can never read those right. TIA
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1382. Nikko
Quoting StormFreakyisher:

I saw both videos and they are really nice.I subscribed to your channel and it is from Jan280.


Thanks, I'll post more... I have always my camera, ready to shoot some severe weather!
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1381. Drakoen
Interesting microwave images on the system. There still is a chance it may become better organized.
Member Since: October 28, 2006 Posts: 57 Comments: 30671
It is a pretty small system TS...And the shear is not as far south as the apparent center.
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Ah by tomorrow maybe there won't be much...night all.
Member Since: May 16, 2009 Posts: 0 Comments: 684
Quoting StormJunkie:
Down the road that ULL low might be problem TS, but right now it is not. Depends a lot on track...But like last night, the shear is fairly light for the time being.









Oh i agree shear is only about 15kts.....now but it will increase alot in 6-18hrs..
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Quoting StormJunkie:
Down the road that ULL low might be problem TS, but right now it is not. Depends a lot on track...But like last night, the shear is fairly light for the time being.









yea I agree SJ, not seeing the so called shear, but whatever its his opinion

Quoting Nikko:
Another severe thunderstorm in Florida tonight... looks like it is going to continue for the next 3-4 days...

Here is the movie I've made while I was driving through this very strong thunderstorm

Link

Thunderstorms in the Caribbean can be very impressive (and dangerous)

Driving into it is quite a challenge : 20 MPH or you are in trouble!

I saw both videos and they are really nice.I subscribed to your channel and it is from Jan280.
Member Since: May 16, 2009 Posts: 0 Comments: 684
why do you all think NHC took the invest away

I was guessing it was because the low dissipated?
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1374. JRRP
Link
Member Since: August 16, 2007 Posts: 0 Comments: 6209
Down the road that ULL low might be problem TS, but right now it is not. Depends a lot on track...But like last night, the shear is fairly light for the time being.







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anyway nothing really big going to change tonight, so I am going to take a break from the site

night all, see you tomorrow
1371. Nikko
Quoting hunkerdown:
By the way, you need to get gas.


Haha, you are right...
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Quoting Nikko:
Another severe thunderstorm in Florida tonight... looks like it is going to continue for the next 3-4 days...

Here is the movie I've made while I was driving through this very strong thunderstorm

Link

Thunderstorms in the Caribbean can be very impressive (and dangerous)

Driving into it is quite a challenge : 20 MPH or you are in trouble!


SE Texas here. Wish we could get some good storms..
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Quoting TampaSpin:


Thank you for being observant...its not tearing it apart yet....just enough to cause some uplift.....but, in 6-12hrs...its poof as i have been stating...why do you all think NHC took the invest away......


ah so he is observant because he agrees with you and what the rest of us arent cuz we disagree with you?

Classic LOL

1368. beell
Valid 12Z Monday


Valid 12Z Monday
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Quoting Nikko:
Another severe thunderstorm in Florida tonight... looks like it is going to continue for the next 3-4 days...

Here is the movie I've made while I was driving through this very strong thunderstorm

Link

Thunderstorms in the Caribbean can be very impressive (and dangerous)

Driving into it is quite a challenge : 20 MPH or you are in trouble!
By the way, you need to get gas.
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actually that ULL is forecasted to keep a good distance from ex 97L and help ventilate it, not shear it

but whatever, I think I am going to bed
Blog Update
Reflector site which includes Weather456, daily update.


AOI

AOI

AOI

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Quoting JLPR:


I see your point
but is it enough shear to tear it apart?
the Dvorak loop at the NHC also shows it impacting the NE of ex 97L


Thank you for being observant...its not tearing it apart yet....just enough to cause some uplift.....but, in 6-12hrs...its poof as i have been stating...why do you all think NHC took the invest away......
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Quoting TampaSpin:


That stalled front has a better chance than 97L has......it could get very interesting in a couple of days in the GOM or just off the Atlantic Seaboard...


Thanks i was thinking the same. but wanted to see what you thought.
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1362. Nikko
Another severe thunderstorm in Florida tonight... looks like it is going to continue for the next 3-4 days...

Here is the movie I've made while I was driving through this very strong thunderstorm

Link

Thunderstorms in the Caribbean can be very impressive (and dangerous)

Driving into it is quite a challenge : 20 MPH or you are in trouble!
Member Since: Posts: Comments:
Quoting LPStormspotter:


Hey TS. Do you think the front in the GOM will do anything?


That stalled front has a better chance than 97L has......it could get very interesting in a couple of days in the GOM or just off the Atlantic Seaboard...
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97L really has no chance.....the ULL located at 23N will cause even more Shear....Watch....Look at the loop i just posted...
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Quoting BurnedAfterPosting:


SAL all gone, interesting

Just what I was thinking.
Member Since: May 16, 2009 Posts: 1 Comments: 1231
Quoting StormFreakyisher:
Whoa!How did all three of them get banned?


They were spamming the blog with unnecessary posts....
Quoting hunkerdown:
Please, not again...this is how last night ended. No matter how much proof is shown, he sees shear and hes sticling to it.


yea I know, I am done lol
Quoting TampaSpin:


Hi Neighbor.....nothing to worry about 97L Yet .......maybe if it makes it into the Caribbean ......we should start looking...if it goes north at all its Poof....South it might have a chance...


Hey TS. Do you think the front in the GOM will do anything?
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1355. JLPR
Quoting TampaSpin:
Look at this loop......it is very clear that out of the Shear has increased over 97L out of the NW.....LOOK!

Gang i don't just make things up....LOL!


I see your point
but is it enough shear to tear it apart?
the Dvorak loop at the NHC also shows it impacting the NE of ex 97L
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Quoting weatherwatcher12:


SAL all gone, interesting
Convection is increasing with Ex 97L, but it's lost it's cyclonic turning....
Whoa!How did all three of them get banned?
Member Since: May 16, 2009 Posts: 0 Comments: 684
Quoting BurnedAfterPosting:


Again I disagree, I dont see shear causing that convection. The shear caused all of the convection with the wave at 60W, but not with this system.

Please, not again...this is how last night ended. No matter how much proof is shown, he sees shear and hes sticling to it.
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Member Since: May 16, 2009 Posts: 1 Comments: 1231

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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.