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

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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

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I don't know much about the ants, but it is the birds I watch. Before an approaching storm, birds will fly higher and in circles. They will repeat the pattern frequently. One can almost tell the direction the storm will approach by watching the birds leaving. Before Andrew, most birds left and headed straight North. This indicated the storm move move East to West. I knew Wilma would be much worse than forecast, because the birds flew in in NW motion and were gone the day before.
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Quoting jeffs713:

Try something else for the fire ants. I rotate between Ortho, Spectracide, and Bayer Advanced. 3 different active ingredients. Treating them with the same thing each time is kinda like treating an infection with penicillin each time. Eventually, it will grow resistant.


throw some grits on those fire ants..I guarantee you wont be bother by them anymore..they eat them and explode..I just didnt want to bother mine since they arent at my doorstep or trying to get in my house..
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CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W...
TROPICAL WAVE ACROSS THE NW CARIBBEAN FROM CENTRAL CUBA TO HONDURAS
WILL MOVE W OF THE AREA SAT. SCATTERED MODERATE TO STRONG CONVECTION
IS WITHIN 150 NM E OF THE WAVE.


Yep a "mess" alright!
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BULLETIN
TROPICAL DEPRESSION SEVEN ADVISORY NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012
1100 AM AST FRI AUG 10 2012

...TROPICAL DEPRESSION MOVING FASTER TO THE WEST...INTERESTS IN THE
WINDWARD AND LEEWARD ISLANDS SHOULD MONITOR THE PROGRESS THIS
SYSTEM...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...13.7N 49.5W
ABOUT 775 MI...1245 KM E OF THE WINDWARD ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 23 MPH...37 KM/H
MINIMUM CENTRAL PRESSURE...1009 MB...29.80 INCHES
Member Since: August 6, 2011 Posts: 4 Comments: 38436
Quoting Skyepony:
Looks like Ernesto's damage to the oil industry was nothing more than a delay. Energy stocks fade as Hurricane threat eases..


I've got fire ants trying to get in the house today too.


Oil never did make much of a move in the face of Ernesto. It's down 53 cents today, but still above $93. If we do get a Gulf storm, you can look for $100 oil in a heartbeat.
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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?
Member Since: October 3, 2008 Posts: 0 Comments: 5862
Quoting jeffs713:

And drive them next door into your neighbor's yard. I coordinate with all of my neighbors when I put fire ant killer down. Unfortunately, one of my neighbors is lazy, so they don't put the fire ant killer down... and they get all of the mounds.


Thats exactly how it works. I live on the corner of two streets. I put this stuff down with a drop spreader every 2-4 months depending on the time of year. I even put it down along both sides of the road so they don't migrate my way. I never get ants except after total floods that removes the grain and the ant mats float in. I in S MS has had the same rain you have because it has been training from the NW and W for almost a week. I'm over due right now for the treatment and still no ants. Heck with your neighbors.
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Quoting catman306:
I posted this at the bottom of the last thread, I'm reposting in hopes that more eyes see it.

A tremendous lightning storm rolled through my area yesterday afternoon (NE Georgia). The lightning bolts were unbelievably powerful, with crackling thunder and ground shaking. Megabolts, I think they’re called. At least 50 of the super bolts and many more of the more usual type. That got me thinking:

I’ve read that 10,000 lightning bolts per second flash worldwide and can be perceived by some weather satellites.

Does anyone keep track of Coulombs per second that are released with those bolts? That would or could be another measure of how the atmosphere is getting more energy with the increased water vapor (four percent.)

Expert opinion would be appreciated.
..we here by tampa had that kind of storm a few days ago, over 1000 lightning bolts in one hour whew
Member Since: August 6, 2011 Posts: 4 Comments: 38436
Quoting Grothar:


I know, these bloggers are throwing around the word blob without understanding the full science behind it. I declared 93L a blog 4 hours before they named it.

I declared TD 7 a blog 7 hours before they named it.

The correct terminology for what it off of Florida and in the Caribbean is called a "mess".


A big LOL for that one...and a gold star...
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Quoting Grothar:


One of the greatest achievements of mankind and I consider one of the Wonders of the New World. It changed the way the world traded and contributed to the US as a world wide exporter.

Dr. Mudd, who was one of the co-conspirators convicted for the assassination of Lincoln, was sent from prison to help with the Yellow Fever outbreak. He was later commended for his work. Estimates of over 6,000 people died in the construction. Something we take for granted came at a high price by the sacrifice of others.


Fascinating!
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New Blog Update with Video!!
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I posted this at the bottom of the last thread, I'm reposting in hopes that more eyes see it.

A tremendous lightning storm rolled through my area yesterday afternoon (NE Georgia). The lightning bolts were unbelievably powerful, with crackling thunder and ground shaking. Megabolts, I think they’re called. At least 50 of the super bolts and many more of the more usual type. That got me thinking:

I’ve read that 10,000 lightning bolts per second flash worldwide and can be perceived by some weather satellites.

Does anyone keep track of Coulombs per second that are released with those bolts? That would or could be another measure of how the atmosphere is getting more energy with the increased water vapor (four percent.)

Expert opinion would be appreciated.
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Yes there are the nicest blob is N.E. of Nicaragua/Honduras border. Could be topic of today. Lookout wonderkidcayman it's drifting north.
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Quoting hurricanealley:


Enlighten this young lad (Post #115) with your experience digging the Panama canal.


One of the greatest achievements of mankind and I consider one of the Wonders of the New World. It changed the way the world traded and contributed to the US as a world wide exporter.

Dr. Mudd, who was one of the co-conspirators convicted for the assassination of Lincoln, was sent from prison to help with the Yellow Fever outbreak. He was later commended for his work. Estimates of over 6,000 people died in the construction. Something we take for granted came at a high price by the sacrifice of others.
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Member Since: August 6, 2011 Posts: 4 Comments: 38436
Quoting Skyepony:
Looks like Ernesto's damage to the oil industry was nothing more than a delay. Energy stocks fade as Hurricane threat eases..


I've got fire ants trying to get in the house today too.

Fire ants are all over my front porch.
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Quoting Grothar:


What do you people want now? I was taking a nap!
I think they want an American History lesson from a source that was there when it happened.....You know, for accuracy sake :)
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Quoting washingtonian115:
Here's a joke I thought I tell to you all..Warning it's really bad..


When the continent of north America first formed what did the Atlantic and Gulf tell Florida?..

Watch out we got you surrounded!!.(Get it you know like what a police officer tells a suspect...)
You were right wash........really bad
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Member Since: August 6, 2011 Posts: 4 Comments: 38436
203. Skyepony (Mod)
Looks like Ernesto's damage to the oil industry was nothing more than a delay. Energy stocks fade as Hurricane threat eases..


I've got fire ants trying to get in the house today too.
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Quoting sar2401:


That's weird part. It's been extremely dry here, and the fire ants have been eating OrthoMax like it's lunch. I've treated the yard three times since spring and they still keep coming. It think it has something to do with that end of the world thing that's supposed to happen in December. I think we'll all die from fire ant attacks. :)

Try something else for the fire ants. I rotate between Ortho, Spectracide, and Bayer Advanced. 3 different active ingredients. Treating them with the same thing each time is kinda like treating an infection with penicillin each time. Eventually, it will grow resistant.
Member Since: August 3, 2008 Posts: 16 Comments: 5881
201. VR46L
Quoting washingtonian115:
Nice blob in the caribbean.If it persist then we may need to watch it.All though shear is high in the caribbean and Gulf right now.

If T.D 7 can continue to blow up convection around it's center Gordon may come later today.


I see a few nice blobs in the area



but the one south of Jamaica has me interested a little more, very little dry air ...

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..................................OMG NYC is going to get blasted..just look at that radar
Member Since: August 6, 2011 Posts: 4 Comments: 38436
Quoting PensacolaDoug:
Caribe wave flaring today! Hey Gro! Does it rate "blob" status yet?


I know, these bloggers are throwing around the word blob without understanding the full science behind it. I declared 93L a blog 4 hours before they named it.

I declared TD 7 a blog 7 hours before they named it.

The correct terminology for what it off of Florida and in the Caribbean is called a "mess".
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Quoting LargoFl:


And hopefully that doesn't interrupts tonight's Dolphins game.
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Quoting Msdrown:


If you have alot of rain they mound up especially if you have high water tables. OthorMax once a quarter will keep them from even being there in the first place.


That's weird part. It's been extremely dry here, and the fire ants have been eating OrthoMax like it's lunch. I've treated the yard three times since spring and they still keep coming. It think it has something to do with that end of the world thing that's supposed to happen in December. I think we'll all die from fire ant attacks. :)
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Member Since: August 6, 2011 Posts: 4 Comments: 38436
Quoting Grothar:


What do you people want now? I was taking a nap!


Who dares to wake the almighty Grothar
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Quoting Levi32:


I put an annotation on the video mentioning the audio problem and apologizing. Supposedly everyone should be able to see that message. Lately it's one thing or another that I forget before turning the recorder on that has been giving audio issues.


It only gets worse with age, Levi. At least you can still find your recorder.
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193. Skyepony (Mod)
Ernesto has killed two fishermen. Looks like many stayed to protect possessions, roofs have been lost. Lot of rain. 2000 navy set up to move in & help after. Largest oil port & a few others in the area are closed. Article here.
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Quoting AussieStorm:

GFS has it back to a T-wave before it reaches the islands

Goodnight.


GN, Aussie. I keep forgetting it's winter down there. No need for electric blankets here. :)
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Oh lol, the ant problem has already been mentioned on here.
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190. JLPR2
Quoting GeoffreyWPB:
TD 7...



I'm not sure how, but I think TD 7's LLC looks stronger than yesterday.
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Quoting Msdrown:


If you have alot of rain they mound up especially if you have high water tables. OthorMax once a quarter will keep them from even being there in the first place.

And drive them next door into your neighbor's yard. I coordinate with all of my neighbors when I put fire ant killer down. Unfortunately, one of my neighbors is lazy, so they don't put the fire ant killer down... and they get all of the mounds.
Member Since: August 3, 2008 Posts: 16 Comments: 5881
I don't know if it means anything, but the ants around here are ridiculous. It's been very wet this year, just like 1999.

More things I've found related to that year.
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Link
Lighting Density Map for the Northeast US for the Past 60 Minutes
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how boring
Member Since: July 12, 2010 Posts: 0 Comments: 1130
Quoting Grothar:


What do you people want now? I was taking a nap!


Enlighten this young lad (Post #115) with your experience digging the Panama canal.
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Quoting JasonRE:
I come here to follow the weather because it's the most informative site I know of.

I'm located in Lafayette LA and so far this year has been a bust. Don't get me wrong, I don't like damage to anyone's home, property, but I am fascinated with storms. It's so interesting to watch them develop.

Does anyone see a storm hitting the Gulf this year? I see this TD-7 is heading pretty much where Ernesto hit but could it make any turn Northerly at all before it hits land? Haven't had any real activity since 09 here.

Anything can happen.
Member Since: August 3, 2008 Posts: 16 Comments: 5881
Quoting sar2401:
On the ant model front, we've had a huge increase in new fire ant mounds over the past 10 days here in central Alabama. I have no idea if there's a correlation with tropical storms but, not only are there more mounds, the little suckers really bite faster and sting more than usual. They are riled up about something.


If you have alot of rain they mound up especially if you have high water tables. OthorMax once a quarter will keep them from even being there in the first place.
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Quoting Grothar:


What do you people want now? I was taking a nap!

rhut rho...you awakened the Grothar...
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Quoting Grothar:


What do you people want now? I was taking a nap!


Kind of early for a nap, Gro, even for us old guys. :) Now you've made me sleepy.
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Quoting JasonRE:
I come here to follow the weather because it's the most informative site I know of.

I'm located in Lafayette LA and so far this year has been a bust. Don't get me wrong, I don't like damage to anyone's home, property, but I am fascinated with storms. It's so interesting to watch them develop.

Does anyone see a storm hitting the Gulf this year? I see this TD-7 is heading pretty much where Ernesto hit but could it make any turn Northerly at all before it hits land? Haven't had any real activity since 09 here.


Your are the second person who recently said that this season has been a bust. Don't know what you mean by that. We have had 2 tropical storms bust the drought in Florida and southern Georgia. That alone makes this season good. What we need now is a really good soaker in Texas and find a way to get the rains into Oklahoma.
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Quoting sar2401:


You are correct. I was using a typical thunderstorm as a model rather than a tropical storm, which probably did more to confuse than help. Low level circulation in thunderstorms is typically disrupted when it crosses a large lake and sucks in cooler water. Obviously, that's not the case with a tropical storm over the ocean. Since the remnants of Ernesto are over land, it seemed like a better analogy for the storm in question.

That really depends on the time of day, time of year, size of storm in relation to the body of water, and how fast the storm is moving.

For example, I see storms cross Lake Pontchartrain all the time without so much as a hiccup. I've also seen storms start over a lake (like Lake Conroe, near me), then die over land.

There are so many extraneous variables involved with the situation that you describe that it is basically impossible to test the hypothesis with any confidence.
Member Since: August 3, 2008 Posts: 16 Comments: 5881
Quoting Coastalgramps:
The Fireants are going nutz in my yard this week. Maybe they know something we don't know. Or it could be all the rain we have had lately.



Ortho max with drop spreader every quater=no ants.
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Quoting sar2401:


Is it just me or does TD7 already look more like a tropical wave than a TD?

GFS has it back to a T-wave before it reaches the islands

Goodnight.
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Quoting LargoFl:
..I could be wrong but I think its a cold front moving across the US


There is a front far to our north but it should be kicking off convection in north AL, not in SE AL. It looks to me like there's a low just south of Pensacola that's not being picked up by any models that's responsible but it's been out there for three days.
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Quoting hurricanealley:


Get Grothar on here now!


What do you people want now? I was taking a nap!
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Quoting AussieStorm:


Here is all of August 2005. Not many comments for each blog.


Thanks for the link, Aussie. Very interesting reading!

Lindy
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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.