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Three tropical depressions may form by Wedneday in the Atlantic

By: Dr. Jeff Masters, 7:03 PM GMT on September 24, 2007

Satellite imagery this morning shows that a new surface circulation has developed in the Gulf of Mexico near 23N 93W, about 350 miles southeast of Brownsville, Texas. This new circulation has been labeled 94L by NHC this morning. Heavy thunderstorm activity has begun forming near the center of circulation, and this system has the potential to become a tropical depression by Tuesday. Wind shear is about 15-20 knots over the disturbance, and is expected to remain 15 knots or below for the next three days. The disturbance is headed west-northwest at less than 10 mph, and should bring heavy rains to northern Mexico--and possibly southern Texas--by Wednesday. However, most of the computer models show that 94L may stall before it reaches the coast, then loop erratically in the Gulf for several days. A Hurricane Hunter flight is scheduled to investigate 94L Tuesday afternoon.

Figure 1. Today's lineup of tropical systems to watch.

Lesser Antilles disturbance 97L getting more organized
A tropical wave (97L) is just north of Barbados in the Lesser Antilles Islands. This wave has developed a closed circulation centered over the southern Lesser Antilles Islands, as seen on the 9:10 am EDT pass from the ASCAT satellite. This is confirmed by wind observations from Barbados this afternoon, where the winds have turned to westerly and increased to 20 mph. The latest Satellite imagery shows a marked increase in heavy thunderstorm activity in the past few hours, and a tropical depression could form by Tuesday. The wave is under about 10 knots of wind shear. The shear is forecast to slowly rise to 20 knots by Thursday, which may slow intensification. The future evolution of the storm depends on how close it comes to the mountainous island of Hispaniola. Most of the models predict 97L will pass over the island on Wednesday or Thursday, which would greatly disrupt the storm. None of the models predict 97L will grow stronger than a 55 mph tropical storm for the next four days. There is a band of very high wind shear predicted to lie just north of Hispaniola all of this week, and 97L could well encounter this band of high wind shear Thursday, which would weaken the storm. In any case, this system represents a threat to the Dominican Republic, Haiti, Puerto Rico, and the northern Lesser Antilles Islands, and residents may experience tropical storm conditions as early as Wednesday afternoon. The Hurricane Hunters are on call to investigate 97L Tuesday afternoon, if necessary. This afternoon's flight was canceled.

Links to follow for 97L
Martinique radar
Barbados weather
Dominica weather
Guadaloupe weather
Martinique weather
St. Lucia weather

Figure 2. Microwave image from 11:28 am EDT today showing low-level spiral bands starting to form around 96L. Image credit: Navy/NRL.

Atlantic disturbance 96L midway between Africa and the Lesser Antilles nearing tropical depression strength
A tropical wave (96L) near 9N 33W, midway between Africa and the Lesser Antilles Islands, is moving west-northwest at 10-15 mph. This wave has gotten much more organized this afternoon, as seen in the latest satellite loops. The circulation associated with the wave is unusually large. The storm has been slow to organize, since it is so large and so far south. At the storm's current latitude--9 degrees north of the Equator--it cannot leverage the earth's spin very much to help spin up the huge circulation it has. However, the storm will probably be a tropical depression by Tuesday morning. Low-level spiral bands have already formed, as seen in recent microwave satellite images (Figure 2). This morning's 7:29 am EDT ASCAT pass showed a better defined circular wind pattern with top winds of 25-30 mph. The wave is under about 10 knots of wind shear. The shear forecast is problematic, with some of the models expecting high wind shear later this week, and others keeping the wind shear low. I expect 96L will become at least a weak tropical storm by Wednesday, then we'll have to see how the upper level winds evolve. The storm is expected to gradually work its way north as it crosses the Atlantic, and appears likely to pass north of the Lesser Antilles Islands next week. The last few runs of the GFS model show 96L eventually recurving out to sea next week.

Tropical Storm Jerry
Tropical Depression Jerry is only worth mentioning since it increases our storm totals for the year to ten. Jerry will be gone tonight, absorbed by an extratropical low pressure system.

Hurricane Rita anniversary
Today marks the second anniversary of Hurricane Rita's landfall in Southwest Louisiana. Wunderblogger Mike Theiss has written a blog and posted his usual amazing photos documenting his experience with Hurricane Rita. One of the more remarkable features of the account is his encounter with hundreds of exhausted birds in the eye of Rita. The unfortunate birds got trapped in the eye for days, unable to escape.

I'll have an update Tuesday morning.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Posted By: jphurricane2006 at 8:58 AM AST on September 25, 2007.
456 your blatent nonchalance surprises me this morning

really why watch the tropics at all after you are so sure Karen is a fish and 97L is dead

oh well I guess there is NOTHING to watch at all now, everyone can leave I guess

I'm joking this morning JP...just feel like to...I know tropics are unpredictable. I'm just letting lose some extra time before i eat my crow.lol
Whic direction is the SE FL disturbance moving? I only seen one loop on it, didn't really interest me too much due to proximity to land and the sudden-ness of it.
2004. Patrap
Oh..dat one...,LOL
Sad thing is Floridian, one of these times, it's going to be right. I usually make myself look at it for that reason.
97L is no more it lost it spin to it the last time i look its now this a blob and no more
Ditto - but it has spun up everything from dust-devil size on up this year. Makes it tough to believe anything until you see the actual conditions develop...
2009. Bonedog
LOL lady met on CNN just said Karen is a fish storm :D Never heard a TV met before say fish storm.
2010. NEwxguy
SW,I couldn't help noticing that little spin off the southwest coast of Florida,interesting.
2012. Nashda
Posted By: AnnularHurricane at 9:03 AM AST on September 25, 2007.

I propose a deal that I, Andrew Hansen of Dallas, Texas, will ultimately become this site's WunderSlave and total slave to this site and everyone within it if Karen does not make landfall. I guarantee that Karen will NOT be a fish storm, I swear it on my e-life.

This I'm going to SAVE!!!!!!! Not bad having a wunderslave. For how long will you be a slave??
In southeast fl Thunderstorms dont come off the water constantly. this is very unusual. Storms come off the land. Ive lived here on and off since 1981 and it has always been that way. Unless something is brewing. Last time I remember it doing this was b4 Irene in 99
here is what the nhc said about it


I'm leaning awway from karen being a fish storm 4 the moment.
Thats what they said about humberto.
houston am 740 weather lady, called Karen a fish storm too for first time ever, it only afftects the fish she said, as noone in radio studio knew what she was talking about. so the word fishstorm has gotten out
all the models in agreement Karen will be a fish correct?

I'm with you on 94L developing. Looks like the shear is relaxing...finally...and the storms are firing up around the center...which I believe has reformed under the blow up of convection. If this trend continues we could have not just TD#13 later...we could have our next named storm as well.
coming together: Karen will have us LovedStoned

Circulation is lowering. The low clouds have changed direction from Ne to more Se. It is at least mid level i'd guess. It may well be robbing 94 under our noses.
I think recon is on stand by for 94L but if we continue to see the organization with it that is happening now I believe they will have to send a HH out.
2032. Bonedog
yup "fish" storm has gotten out. Local news channel (WCBS) just said it too.

This has got to be the first time I have ever heard that phrase by ANY met on TV.
94 is not getting robbed...have you looked at the satellites lately of 94L???
Stormw whats up with Karen will she be a fish feeder
Dont trust 94L...this one seems to be a beautiful liar

I was Praying for rain last week here!

Ok Ok that's enough, you da man, lol, stop it.

8+ inches of rain over the past week in Palm Beach Gardens. Ponds are starting to reach their banks.
Definately some spin seen here if you speed it up. It will be interesting to see what the NHC 2p update will say.

2039. A4Guy
Posted By: Tazmanian at 12:47 PM GMT on September 25, 2007.

at this time you can put all mode runs and the nhc track out the window all ways look at the XTRP it shows you where the storm is going and look where its going it has it pointing at PR right now

Taz - the XTRP (Extrapolated direction) only assumes the path the storm would take ABSENT any steering currents. It is simply showing the track based on current motion - it says nothing about any future projection.
Up in gardens how often do you see rain like this coming off the ocean?
2041. Bonedog
for folks asking about recon...

A. 25/1600Z
C. 25/1345Z
D. 22.0N 94.0W
E. 25/1530Z TO 25/1930Z
F. SFC TO 10,000 FT
2042. NEwxguy
I forget,what is the next name on the storm list
Guys im only here for a few min. I personally dont see Karen taking that sharp of a turn....
2046. Bonedog
I think StormW has it about nailed. mid level maybe subtropical.
can some one tell me how mean storms we have seen in SEP and can we rule out may be one or two more storms?
2050. NEwxguy
Thanks guys
If it weren't fot the competing Fl low 94 would be a cat 1 now
La Nina years are usually late strong hurricane season makers
2054. Bonedog
Taz I believe its 4 for the sept average. I am trying to find the link to where I have seen a breakdown for the averages for each month
Good Morning. Ivansurv reminded us of IVAN & poster Georges98 evokes that one. Here's the archive track Georges '98 (funny, as I worked USAR in the Keys, my My memory was of a TS there, but it shows Cat 2)
AnnularHurricane has been posting some valid observations about his "eyewitness weather" (I look out the window & I witness the weather. True, I say, those tropical looking clouds & showers moving onshore (nothing there yet)
SE FL do mean something - If you're standing in the road & cars are whizzing by, you might want to start watching for trucks. NOT doomcasting, please, just joining you all in remaining among the most informed thanks to this blog. 94l is still doing it's job - moving the heat form where it is to where it needs to go.
2056. CJ5

I see 96L got bumped up to Karen. I also see all of the models are in agreement with a sharp N turn around 50w. I do see weakness in the high but that turn is pretty agressive. It obviously is the prevailing thought though.

97L looks a little ragged, similary to Ingrid at this location. The models agree more to a WNW movement with this one. I am not sure its going to be able to overcome the shear. This one has a tough road to hoe.

94L looks about the same, just keeping everyone guessing. If it could get into the N gulf it may cause some problems but it doesn't appear right now that is going to happen.

An interesting aside, GFS develops two disturbances behind Karen. The next few weeks may be the busiest part of the season.
All us Floridians need...another STD! lol
Anybody notice how wide the cone is 4 karen?
Because it is getting later in the season we might see a system or two pulse up in the afternoon and down in the night. I guess part of the reason is the lower air tempertures. Further analisis by someone who knows what they are bloggin about.
Good morning everyone, I live in So FL, is that blob in the SE Bahamas anything I need to be concerned with? It look omnious on Satellite.
2061. Bonedog
found it..

we are now up to 6 name storms for SEP
94L failed to maintain any significant thunderstorm activity overnight and is having a difficult time overcoming shear and dry air to the west. I think if 94L would have become a depression, it would have happened overnight. Unless it can maintain what little activity is associated with it now for the next 24 hours or so, I do not give it much chance of becoming anything more than a rain maker for northern Mexico.

96L- TS Karen obviously

97L- better organized and now closed circ but pretty far north around N L Antilles
and possibly headed to PR

94L- still struggling, COC is too far west to build much right now

98L could be wave behind TS BUT there's a small closed circ in between 97L and TS that is still puffing along. It looks to be too close to TS Karen but we'll see.
You can see it in 456's pic (nice pic).
i take that back 5 name storms and one TD
97L will be upgraded today IMO. The closed surface circ that I couldn't ind yesterday is evident on vis sat today (fairly far north from previous plots points).

I respect your opinion but going to have to disagree with you on 94L. The fact that it has kept its identity through the shear it has been encountering says a lot. In fact, it is building storms this morning as we speak and is still fighting off some shear. Once that shear relaxes 94L will not only become a depression but will be named as well. Just my take on it...
All I was getting at is 94 will wait until out low moves out of the way. With it remaining weaker it's not getting steered much. I did not intend to doomcast sfl. LIke I said b4-StormW wasprobably spot on subtropical/mid level. watch the sat loops and 94 is been feeding the fl low the whole time. Thats probably savecasting not doomcasting
94L looks ok on this end wind shear is olny 3 to 10kt where 94L is if 94L had any higher wind shear with it it would not be looking this goos at this time

2070. Bonedog
wow 7 storms in september witha few days and some disturbances to go.

I'd say thats above average

well we can now say that SEP is now has the most subtropical storms and STD we evere seen LOL
Notice how the moisture from 94 is flowing S.E?
Should the people in florida have any concerns on the blob in the bahamas? The CMC model shows a storm hitting FL could that be it?
2074. help4u
It seems all the storms that develop this time of year way out in the atlantic [2000 miles]or so,have hardly any chance of effecting the US. .Shear,dry air,troughs,ull,tutt,a system may have a 1%chance of making it thru.What is left of it.That is the way it has set up this year.Other years may be different.
To give you some idea of how HUGE Karen is, the center of the TropicalStorm was here when it was named.
Click on the third rectangular button from the bottom, and you'll see the coast of SouthAmerica on the bottom left and Mindelo on SaoVicente of the CapeVerdeIslands near the top left.
Click on the second rectangular button from the bottom and you'll see it's about halfway between Cayenne,FrenchGuiana and Praia,CapeVerdeIslands.
The distance between Cayenne and Mindelo is 2027miles/3262kilometres.
And Karen's influence spans that distance.
Once either 94 or "I95" gets enough strength one will push the other out of the way
Looks like 97L is getting some deep convection.. Also trying to become the smallest storm in history. lol
2078. Bonedog
aspectre that would explain why its taking so long to develope. Sucha large circulation takes alot of time to wind itself up. Good news for all.
It's not only CMC, the GFS and GFDL also show a low forming off the S FL coast. I'm not sure howto read the strength. Does anyone have any further info or "real" predictions?
94L seems to be stationary, Right?
Sometimes storms of Karen's magnitude become large enough and strong enough to push the other large scale steering influences. Like Ioke last year.
Is 97L upgraded yet? TIA...
It's possible, OUSHAWN. I just do not see any organization with it. We'll see what happens during the day...

I'm off to the job. Back later on.
"Sucha large circulation takes alot of time to wind itself up. Good news for all."

Not necessarily. Slower development makes recurving less likely
Another sign that the shear is decreasing around 94L is that for the first time you can see storms starting to fire up on the western side of its rotation...which has not been happening until now. Let's see if this continues...
Morning all. Just watched TWC and they say we really have nothing out there that will affect the US. Is this correct or just wish casting. ??
2091. IKE
06Z GFDL has Karen as a fishie and the system behind it developing and becoming a fish storm too....

2092. IKE
Posted By: cattlebaroness at 8:54 AM CDT on September 25, 2007.
Morning all. Just watched TWC and they say we really have nothing out there that will affect the US. Is this correct or just wish casting. ??

They could be right...for now.
2093. Bonedog
Ivan I was talking more along the lines of intesity not landfalls. But you are correct slower developers have a chance to miss things which wouldn't be good :( I should have clarified, I appologize.

I will say though that the strong front that is in the Nations midsection is a very powerful one which should be a big influence by the weekend for the coastline of the US
TWC won't say a word until a red cone touches land somewhere
97L is under high shear with more N track. But you can see some slight anticyclonic flow in southern portion
2097. help4u
Correct,none of these areas will effect the US.Coditions are highly unfavorable.
2098. CJ5
Posted By: cattlebaroness at 1:54 PM GMT on September 25, 2007.
Morning all. Just watched TWC and they say we really have nothing out there that will affect the US. Is this correct or just wish casting. ??

It is fairly accurate. Karen is expected to turn out to sea, though this could change.

97L is not expected to develop into anything major but it is forecast to move towards SFL. This to could change.

94L is expected to move W/WNW into MX but I think it is possible for something else to happen.

So, bottom line if everything goes as planned right at this moment they would be correct. If things change the could be wrong.
You mean at wilma's strongest point in the carrib. when it was basically a big tornado
2101. Bonedog
no not Wilma I was refering to the big storms taking a while to get their act together. Once they do though some do spin up to monsters.
Like I said last nite, Dr. lyons was somewhat random in his description of steering currents.
2104. IKE
Annular....this from the 5 am EDST discussion on Karen....

" After that...the large-scale models agree on the
development of a mid/upper-level trough to the northeast of the
Lesser Antilles...which would turn Karen northwestward or
So recon will be in the gulf (94L)at noon?

any bets on a TD or not?
To give you some idea of how HUGE Karen is, the center of the TropicalStorm was here when it was named.
Click on the third rectangular button from the bottom, and you'll see the coast of SouthAmerica on the bottom left and Mindelo on SaoVicente of the CapeVerdeIslands near the top left.
Click on the second rectangular button from the bottom and you'll see it's about halfway between Cayenne,FrenchGuiana and Praia,CapeVerdeIslands.
The distance between Cayenne and Mindelo is 2027miles/3262kilometres.
And Karen's influence spans that distance.
2108. Bonedog
just looked at the Dorvak.

Karen droped another mb in just 30 min

2007SEP25 121500 2.5 1005.0
2007SEP25 124500 2.6 1004.0
Posted By: Ivansvrivr at 1:56 PM GMT on September 25, 2007.

TWC won't say a word until a red cone touches land somewhere

But TWC is "the hurricane authority". hahaha!
2110. IKE
Posted By: AnnularHurricane at 9:03 AM CDT on September 25, 2007.
Keyword...models. I'm with Taz, the models are basically rubbish at this point, look how far South this is

Rubbish? Because they don't agree with what you want Karen to do?
I agree 100% my handle says enough. Ivan was no 2 mile wide storm. Small ones fluctuate much more rapidly. Remember Ioke last yr in the Pacific?
2114. Bonedog
also Karen droped 5mb in 11 1/2hrs I know its nothing spectacular but still something to mention

2007SEP25 024500 2.0 1009.0
2007SEP25 131500 2.6 1004.0
And I have a phd in rocket science:)
The storm off of florida, to me, looks like one that develops from the frontal system that moves off the coast in a few days. It also looks like it might just be carried away with the front. So, it might not be a tropical system at all. Have to watch however, as any frontal system that makes it that far south can easily gain tropical characteristics. It also might be interacting with whatever is left of 97L at that point (hurricane...still an invest? who knows!). But it does look like a possible TD10/Gabrielle type situation.
Posted By: AnnularHurricane at 9:00 AM CDT on September 25, 2007.

TWC deserves to eat 35,000,000,000 crows considering how inaccurate they've been this season.And seasons in the past.Lyons didn't think Dean would develop until it got to about 50W.Karen won't be going out to sea.

Yeah, and Humberto was too close to land to develop much past a minimal tropical storm...LOL....
2119. NEwxguy
bonedog I agree thats a real strong front pushing through the us.Were going to be in the 90's here in new england and 60's by the weekend.
Ivan was a cat 1 in montgomery Al. What's rare is something like Katrina. She was large and bottomed out quickly. Probably mostly because of the loop current.
2121. CJ5
Based on the steering layers, if Karen stays around 10N there is a real possibility it could avoid the sharp N turn and make a more gradual NW turn. If it holds it W movement until 65W then all bets are off on a fish storm.
2122. Bonedog
Karen does have nice banding features and a classic pinwheel structure to her

So far NOAA has named 3 exta-tropical storms and 3 storms that reached tropical strength for less than 6 hours. Seems that no one wants egg on their face after saying it would be another devastating year for hurricanes. Next year, when people start ignoring the warnings, NOAA should bear in mind how many time it has cried wolf.
we should put an ankle bracelet on big Jim Cantore so we can see what the Weather Cahnnel is really thinking. If Jim heads South you know its not good....LOL
Morning all :~)

Everything seems to still point to Karen heading out to see. Even the 12 BAMM has shifted further N.

The area int he straights of Fla could be something to watch although it does look like it will have some shear to deal with.
97l or its remnants may interact with system coming off of the coast this weekend and develop into something. gfs model hint at this.
2128. Bonedog
agrred NEwxguy. 87 on thursday and 68 on friday

already started seeing lower 40s at my house cant wait to see what this front brings (rollseyes)
How far south and east does this front get though?
Back to work, see y'all in a little while.

Quick Links
-Easily navigate forecast models, imagery, marine data, wind data, preparedness info, and much more.

There are also some nice model tutorial videos under the learning section on that page.

2132. kap333
What the HEY!!!


Gotta pay attention all the time at this time of year in Florida!
2133. Squid28
Everyone up north is prepping their snowblowers for the upcoming season, meanwhile we are still test runing our generators on the coast.......
2134. SamTeam
The Good Dr. M has spoken....new blog!
This is about as complex as i ever remember the tropics being. And thank goodness everybody here is staying civil. Thank you everybody!
Posted By: AnnularHurricane at 2:08 PM GMT on September 25, 2007.

karen will be a fish storm...and Mahmoud Ahmedinejad will convert to Judaism.

That's the best example of spelling i've seen on this blog. Well done Annular, setting a good example :-) Incidentally, your well reasoned posts are also an example to others.
2137. Bonedog

Day 4 fronts

Day 5 Fronts

Good Morning all. What's going on in the tropics? I have been at home taking care of my 18yr old daughter she was in a bad wreck sunday afternoon, and i haven't been able to look to much. Thanks in Advanced
This year has been strange for Atlantic storms.....
Yeah, I saw that system when I was checking out 94l...Just another blob to watch. It does appear to have some surface low w/it, but we need to see if it persists. UL conditions appear favorable for the time being. However, w/ these fronts starting to plow through, I think we are very near the end of hurricane season for the gulf coast in a couple more weeks.

Over tropical oceans the diurnal temperature range is much less than over land. Also, in the tropics you don't have nearly the decrease in sunlight (equator is always 12 hours day/nigt) during the fall that you do in the midlatitudes.
The little red L over Puerto Rico doesnt seem to be turning north though. Looking at the little green lines (Isobars) it doesnt seem to bring a westerly wind into Fl. The Steering low is way north. that could very easily drive storms westward if they slide a little 2 far underneath.
Don't typical la nina years have fewer and weaker fronts through fall which bottles up cold air up north leading to a florida freeze in Feb?
Morning, CatAdjuster...some interesting stuff going on. Sorry to hear about your daughter...
2145. help4u
Mark Sudduth on hurricane tracker basically said the season was pretty much over.
Morning Catadj, hope daughter gets well soon.
Catadjuster I hope all is well with your daughter
2148. beell
Is the little swirl at 14N 51W also moving W?
I guess at some point 97l and/or 96l could affect the swirl's direction,. Not yet tho imho
HyperText Transfer Protocol

...this shows a slight movement west (or possibly south). Could be just a temporary jog, or the center adjusting under the convection. I still believe the models will shift more to the west, as this huge pile of convection slowly pulls itself together and moves just slightly north of due west. Timing is going to be critical to catch the mid-Atlantic trough (if it does at all) to become a fish!
2150. hcubed
"Posted By: FitzRoy at 5:09 PM CDT on September 24, 2007.

I'd love Taz to publish his ignore list - it must be quite a read lol!"

It's probably everyone that has ever commented on his spelling - which makes me #81.
Any comment on the CMC model have a storm from key west up to tampa out to east back to ga / fla border