Little change to TD 7; 93L may develop off the coast of Africa

By: Dr. Jeff Masters , 1:57 PM GMT on August 10, 2012

Share this Blog
27
+

Tropical Depression Seven continues westward across the central tropical Atlantic with little change in appearance. Looking remarkably like the tropical depression that became Tropical Storm Ernesto last week, TD 7 has a limited region of heavy thunderstorms, as seen on satellite loops. A large amount of dry air to the west and north is visible on water vapor satellite loops, and this dry air is interfering with TD 7's heavy thunderstorms. Wind shear is a light 5 - 10 knots, which is favorable for intensification. Ocean temperatures are 26.5°C, which is a bit on the cool side, but these temperatures are 0.5° warmer than on Thursday. Winds at the Middle Atlantic buoy 41041 peaked at 29 mph, gusting to 38 mph, at 1:50 am EDT this Friday morning, when the center of TD 7 passed about 40 miles to the south. TD 7 will pass about 60 miles south of buoy 41040 near midnight tonight. The first hurricane hunter mission into TD 7 is scheduled for Saturday morning.


Figure 1. Morning satellite image of TD 7.

Forecast for TD 7
TD 7 formed about 400 miles east-northeast of where Ernesto became a tropical depression, as seen on our wundermap. Atmospheric and oceanic conditions are currently quite similar to what Ernesto experienced, and I expect TD 7 will struggle with dry air like Ernesto did. The SHIPS model predicts that shear will remain light through tonight, then rise to the moderate range on Saturday, when the storm will encounter upper-level southwesterly winds associated with a trough of low pressure. However, ocean temperatures will warm to 28°C, which may partially counteract the increase in shear, as far as maintaining a favorable environment for development. Dry air and shear may be significant enough to destroy TD 7 on Sunday, as predicted by the GFS and ECMWF models. These models tried to kill off Ernesto in a similar situation last week, so I am inclined to believe TD 7 will survive for the coming five days, but struggle. The official NHC forecast of a 45 mph tropical storm moving through the Lesser Antilles Islands Saturday night and Sunday is a reasonable one.


Figure 2. Morning satellite image of Invest 93L.

93L
A strong tropical wave in the far Eastern Atlantic that emerged off the coast of Africa Thursday night was designated Invest 93L by NHC. In their 8 am Tropical Weather Outlook, NHC gave 93L a 50% chance of becoming a tropical depression by Sunday morning. Satellite loops show a pronounced spin to the atmosphere at mid levels, but little in the way of heavy thunderstorm activity. The latest Saharan Air Layer Analysis from the University of Wisconsin shows that while the atmosphere immediately surrounding the disturbance is moist, there is a large area of dry air from the Sahara to the west and north. This dry air will be a significant impediment to development during the coming week. The ECMWF model shows some weak development of 93L over the coming week, and predicts a general west-northwesterly track. The storm may be something Bermuda needs to be concerned about in eight or so days.

I'll have a new post this afternoon.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 324 - 274

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15Blog Index

Quoting Grothar:
The GFS. I am trying to get it to come around to my way of thinking but it is stubborn.




Bet you posted Ernesto's Caribbean Cruise model to see who was paying attention. :p
Quoting hydrus:
Amazing how quickly that convection gets going with only part of the circulation over water.
Well, darn. 1000am cdt last advisory discussion on Ernesto..
...THE REMNANTS OF ERNESTO ARE EXPECTED TO MOVE OFF MEXICO INTO THE
EASTERN PACIFIC WITH THE POTENTIAL TO BECOME A TROPICAL CYCLONE. IF
THIS IS THE CASE...IT WILL ACQUIRE A NEW DEPRESSION NUMBER...OR A
NEW NAME IF IT BECOMES A TROPICAL STORM.

THIS IS THE LAST ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON
ERNESTO.


FORECAST POSITIONS AND MAX WINDS

INIT 10/1500Z 18.0N 99.2W 20 KT 25 MPH
12H 11/0000Z...DISSIPATED

$$
FORECASTER AVILA

(T-6)
Member Since: Posts: Comments:
Quoting FtMyersgal:


Heh, thanks for that link bappit. since it was inconclusive I'm gonna try it anyway. Been using Amdro but I'd rather use something that isn't a chemical. We use too much of that kinda stuff on our planet


it works..I have done it plenty of times..maybe the study was done on Yankee fire ants..
Member Since: Posts: Comments:
anyway I am going for a break but before I do I just want to say this if Ernesto can develop and become a TS and a Hurricane in a little bit worse conditions than TD7 then TD 7 sure hell can so let us sit back and watch well except those who are in the windward islands they need to keep close eye and once those watches and warning are issued then start prepairing or even prepare before the watches and warnings
Member Since: Posts: Comments:
Quoting mcluvincane:


Not just td7, it's the entire tropics. Not much happening this year. I honestly thought this would be a good year to track some descent cylcones. Not gonna happen


Don't throw in the towel just yet! I did the same thing after Tropical Storm Edouard (2008) and look what happened.
Member Since: Posts: Comments:
Joe B. is not at all high on TD7. However, he does have one eye on the blob in the Western Caribbean. He also is saying the same thing as Levi about the impacts of El Niño on the rest of the season.
Member Since: June 12, 2011 Posts: 0 Comments: 934
maybe for a while but once the MJO returns to the atlantic basin, logically activity should pick up. then again....who knows. this has been an active strange season so far.
Member Since: Posts: Comments:
Quoting mcluvincane:


Not just td7, it's the entire tropics. Not much happening this year. I honestly thought this would be a good year to track some descent cylcones. Not gonna happen


A repeat of 2009, activity-wise?
Member Since: Posts: Comments:
Quoting bappit:

No evidence that grits works. Here is one study.

"Because no colony was eliminated by either treatment, no statistical analysis was conducted on these data.

Results of this no-choice, laboratory study do not support use of instant grits or Malt-O-Meal as an effective treatment for eliminating colonies of the red imported fire ant."


Heh, thanks for that link bappit. since it was inconclusive I'm gonna try it anyway. Been using Amdro but I'd rather use something that isn't a chemical. We use too much of that kinda stuff on our planet
Member Since: Posts: Comments:
What are the chances that Ernesto will redevelop in the Pacific?
Member Since: Posts: Comments:
Member Since: Posts: Comments:
I've been listening to this guy for years. It is a nice link.




Link



Member Since: July 17, 2009 Posts: 69 Comments: 25369
Quoting CaribBoy:


What a shame TD7 is lol....


Not just td7, it's the entire tropics. Not much happening this year. I honestly thought this would be a good year to track some descent cylcones. Not gonna happen
Member Since: Posts: Comments:
TD 7 RGB Loop

Member Since: July 3, 2005 Posts: 421 Comments: 127559
Quoting 7544:
something trying to form by andros island again maybe a small spin there
This has been the "hot spot" of the basin since May... things that are just as Grothar said moving blobs are constantly trying to get above themselves and spin up in that area... I have a bad feeling about anything with real organization hitting that spot...

Quoting LargoFl:
..oh boy..looks like a wet and interesting weekend ahead for florida huh
Among other places...
Member Since: Posts: Comments:
Quoting PalmBeachWeather:
There are so many intrusive animals and insects here in sout Florida now..Fire ants, Iguanas, Peacock bass, Oscars, Cuban lizards, Africanized bees, Now freekin' Pythons......
I saw some wierd looking bird in the Publix parking lot last week... Looked kinda like a Mynah bird
Member Since: October 3, 2008 Posts: 0 Comments: 5821
What's the ECMWF looking like for the 7th tropical depression of the 2012 Atlantic Hurricane Season?
Member Since: Posts: Comments:
Quoting Relix:
No CaribBoy, that same steering layer you posted should alredy tell you why TD7 isn't coming up to the Leewards. There's also no possible way for it to slow down. It will die a slow painful death as it reaches the Caribbean. I am not even sure it will get named


What a shame TD7 is lol....
Member Since: Posts: Comments:
Quoting Grothar:
The GFS. I am trying to get it to come around to my way of thinking but it is stubborn.






Wow, really moving models, Gro!
Member Since: Posts: Comments:
Quoting GeoffreyWPB:


So Jeff, what do you think?
Member Since: July 17, 2009 Posts: 69 Comments: 25369
Quoting PalmBeachWeather:
I so much wanted to hear Levi's blog today. He forgot to put the mike close to him... My laptop has sucky speakers.... Any suggestions to make it louder?


try plugging in head sets. my speakers stink as well and it helped.
Member Since: September 30, 2008 Posts: 0 Comments: 108
Member Since: July 17, 2009 Posts: 69 Comments: 25369
Quoting Grothar:


She was only called that once.


And never more. Well, maybe in the 80's novels...
Member Since: Posts: Comments:
Member Since: Posts: Comments:
298. Relix
No CaribBoy, that same steering layer you posted should alredy tell you why TD7 isn't coming up to the Leewards. There's also no possible way for it to slow down. It will die a slow painful death as it reaches the Caribbean. I am not even sure it will get named
Member Since: Posts: Comments:
Quoting tennisgirl08:
Saw an image that storms that have formed near TD 7s position (since 1851) have gone either straight through MX or curved northward into FL.

Still looking for the image again so I can post it.

Member Since: Posts: Comments:
Quoting Grothar:
I wouldn't be surprised if Ernesto becomes a Cat 3.

Amazing how quickly that convection gets going with only part of the circulation over water.
Member Since: Posts: Comments:
Quoting Msdrown:
l

Alright really my last ant comment. Ants actually are good for the soil especially hard packed clays . They very rarely attack/destroy plants or roots. They dig/sow the soil making it looser which is actually better for any plant roots. The bugs of any kind don't stand a chance. Hence we humans are on there agitation list when disturbed. Really the last one.
There are so many intrusive animals and insects here in sout Florida now..Fire ants, Iguanas, Peacock bass, Oscars, Cuban lizards, Africanized bees, Now freekin' Pythons......
Member Since: October 3, 2008 Posts: 0 Comments: 5821
Quoting FtMyersgal:


Heh nc.. do you use uncooked grits? Instant grits of the long cook? Inquiring minds what to know, plus I'm allergic to fire ants and we are getting some on our property also

No evidence that grits works. Here is one study.

"Because no colony was eliminated by either treatment, no statistical analysis was conducted on these data.

Results of this no-choice, laboratory study do not support use of instant grits or Malt-O-Meal as an effective treatment for eliminating colonies of the red imported fire ant."
Member Since: Posts: Comments:
293. wxmod
Arctic Sea ice anomaly is increasing rapidly now and will probably surpass 2007s record low ice cover next week.
Member Since: Posts: Comments:
Quoting PalmBeachWeather:
I thought that was for Jiggers


It also works for ants
Member Since: Posts: Comments:
Quoting jascott1967:
Here's a little known fact (Cliff Clavin style):

Messina Hof Vineyards near College Station, Texas used to and may still use fire ants instead of pesticides to kill off any insects that would otherwise feast off the grapes and vines.
l

Alright really my last ant comment. Ants actually are good for the soil especially hard packed clays . They very rarely attack/destroy plants or roots. They dig/sow the soil making it looser which is actually better for any plant roots. The bugs of any kind don't stand a chance. Hence we humans are on there agitation list when disturbed. Really the last one.
Member Since: Posts: Comments:
Quoting wunderkidcayman:

nah not at all

...INTERESTS IN THE WINDWARD AND LEEWARD ISLANDS SHOULD MONITOR THE PROGRESS THIS SYSTEM



Time will tell. Don't be too much confident....
Member Since: Posts: Comments:
Quoting CaicosRetiredSailor:


XErnesto



The green almost looks like a Phantom of the Opera mask.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
According to the gfs and ecmwf, the tropics are going to come to a complete hault.
Member Since: Posts: Comments:
Check the Box FRONTS and MSLP

Gulf Of Mexico - Rainbow Loop
Member Since: July 3, 2005 Posts: 421 Comments: 127559
Quoting 7544:
the nhc talked about a watch for the LEEWARD ISLANDS are they tring to tell us that td7 could be going further north hmmmm

nah not at all

...INTERESTS IN THE WINDWARD AND LEEWARD ISLANDS SHOULD MONITOR THE PROGRESS THIS SYSTEM...


INTERESTS IN THE WINDWARD AND LEEWARD ISLANDS SHOULD MONITOR THE
PROGRESS OF THE DEPRESSION SINCE TROPICAL STORM WATCHES OR WARNINGS
COULD BE REQUIRED AT ANY TIME

Member Since: Posts: Comments:
Quoting 7544:
the nhc talked about a watch for the LEEWARD ISLANDS are they tring to tell us that td7 could be going further north hmmmm


Probably.
Member Since: Posts: Comments:
Quoting hurricanealley:


No. Thank you, Nyota


She was only called that once.
Member Since: July 17, 2009 Posts: 69 Comments: 25369
Caribbean - Rainbow Loop
Member Since: July 3, 2005 Posts: 421 Comments: 127559
Here is the example of hurricane jose in 1999

Below is the forecast from discussion #1 (oct 17th):
INITIAL 17/2100Z 10.0N 51.5W 30 KTS
12HR VT 18/0600Z 10.0N 53.2W 35 KTS
24HR VT 18/1800Z 10.5N 55.3W 45 KTS
36HR VT 19/0600Z 11.0N 57.5W 55 KTS
48HR VT 19/1800Z 12.0N 60.0W 65 KTS
72HR VT 20/1800Z 14.5N 63.5W 75 KTS

Now, see the forecast from advisory #11 (oct 20th):
INITIAL 20/0900Z 16.7N 60.7W 80 KTS
12HR VT 20/1800Z 17.6N 62.0W 90 KTS
24HR VT 21/0600Z 18.8N 63.8W 95 KTS
36HR VT 21/1800Z 20.0N 65.3W 100 KTS
48HR VT 22/0600Z 21.5N 66.5W 100 KTS
72HR VT 23/0600Z 25.5N 68.5W 100 KTS

Things can change between 55 and 60W!!!
Member Since: Posts: Comments:
Saw an image that storms that have formed near TD 7s position (since 1851) have gone either straight through MX or curved northward into FL.

Still looking for the image again so I can post it.

Member Since: Posts: Comments:
Quoting FtMyersgal:


Heh nc.. do you use uncooked grits? Instant grits of the long cook? Inquiring minds what to know, plus I'm allergic to fire ants and we are getting some on our property also


If I'm not mistaken Lime powder will help to. My hubby also uses this ant killer stuff it looks like saw dust, know when he puts it on a mound u can go back in about 30 min and they are gone. I don't know why but in the last couple of weeks they have been mounding up in my yard and coming in the house and it's not because of a bunch of rain, same thing at our shop. Kinda strange.

sheri
Member Since: Posts: Comments:


XErnesto
Member Since: Posts: Comments:
Quoting GOLSUTIGERS:


Clear nail polish on them and they will stop itching.
I thought that was for Jiggers
Member Since: October 3, 2008 Posts: 0 Comments: 5821
12z Early Cycle NHC model tracks
Invest93

Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)




Dynamic Models (More sophisticated models)




Early Model Wind Forecasts

Member Since: July 3, 2005 Posts: 421 Comments: 127559
Quoting Grothar:
I wouldn't be surprised if Ernesto becomes a Cat 3.


I think I've heard that for over a week now... :P
Member Since: Posts: Comments:
Quoting PalmBeachWeather:
Any home remedies to put on the ant bites?


Clear nail polish on them and they will stop itching.
Member Since: Posts: Comments:
Afternoon all. Currently overcast here with light showers / wind...



Not sure if this is from the ULL that was hanging about in the area or from the Twave which I thought had moved west towards the Keys....



This of Ernesto is also pretty interesting...
Member Since: Posts: Comments:

Viewing: 324 - 274

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.