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Southeast U.S. development

By: Dr. Jeff Masters, 6:25 PM GMT on July 17, 2006

The tail end of an old cold front over the waters off the Southeast U.S. coast could serve as the focus for some tropical development over the next few days. Some impressive thunderstorms are developing over the waters due east of Georgia, thanks to a narrow area of reduced wind shear of 5-10 knots that has developed here. The GFS computer model is indicating that this reduced shear will remain for the next few days, and the Hurricane Center has scheduled a reconnaissance aircraft to check the system out on Tuesday at 2pm EDT, if needed. The system is over the warm Gulf Stream waters, where sea surface temperatures are very favorable for development, 28-30 C. The system is still pretty disorganized, although the latest visible imagery is hinting at a surface circulation. I believe that the earliest a tropical depression would form is Wednesday.

Steering currents are weak, so it is difficult to tell where this system might go. A strong trough of low pressure is expected to push off the East Coast by Wednesday, so this may turn the disturbance northwards and recurve it out to sea. However, it's quite possible the trough will not be strong enough to grab the disturbance, which will wander about off the Carolina coast for most of the week.

Figure 1. Latest satellite image of the Southeast Coast disturbance.

Figure 2. Preliminary forecast model tracks for the SOutheast Coast disturbance.

A very large area of concentrated thunderstorms is a few hundred miles northeast of Puerto Rico. This is associated with a tropical wave interacting with an upper-level low pressure system. Wind shear is 20 - 30 knots over this area, and no tropical development is expected. We will have to watch this area later in the week as it approaches the East Coast, but it appears now that wind shear will remain too high to allow development.

An extratropical or subtropical low is about 220 miles south-southeast of southwestern Nova Scotia, and is moving northeast away from the U.S. at 20 mph. The storm is over the Gulf Stream where water temperatures are in the upper 70s, which is borderline for a tropical storm. The low has a large area of heavy thunderstorms on the northeast side of the center of circulation, and is undergoing significant wind shear that is exposing the center. This storm is not a threat to develop into a tropical storm, since the waters in front of it are too cool to allow tropical development.

Figure 3. Visible satellite image for 8am EDT July 17 2006, showing the various areas of interest along the East Coast.

A solid-looking tropical wave has just emerged off the coast of Africa, and is headed towards the Cape Verde Islands at 15-20 mph. Water temperatures are marginal for tropical development in this region, wind shear is high, 10-30 knots. I'm not expecting this wave to be a threat, even though the wind shear forecast shows wind shear dropping tomorrow. It's very common this time of year to see impressive looking waves come off the coast of Africa, only to fizzle after spending a day over the water. If the wave is still holding togther by this time tomorrow, I'll take it seriously. But I think we need another two weeks for the waters to warm before these African waves will bear watching.

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

How many storms will hit south Florida..Depends,how many develope,where the Bermuda High is.Move it east and ya get the North Carolina hook.

South Florida May get spared completely or may get slammed..I am betting on this being a light season as far as U.S landfalls
ProgressivePulse...I got that a long while ago! 30 is just way too long a duration for me! LOL.
And by the way I never went through Hurricane Andrew...not any part of it! Randrew is just a nickname I have had for many decades. I have however been through countless other canes and TS's. But I won't brag about it. I'd rather forget it!
Tapping into the ITCZ, May be enhancing convection but the satalite presentation is great.
hurricaneman23 once august and september roll around especially october iam probably going to live next to my pc and my laptop.
I really don't think Dr. Grey is too far off with 17 named storms. 04 had 15 named storms, the first forming at the end of July.
Here are several views of the wave in the Eastern Atlantic...

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ProgressivePulse...I pretty well agree with Gray's outlook. I just hope they get spread out this year and I only have to deal with maybe one or none! I am not able to look further into the future of tropical weather more than about 5 or 6 days. Maybe others here can know about October but I do not.
I can't either, I was just pointing out that others were pointing out that his forcast was outlandish, when it is really not.
Getting my blood pumping 23. Great links
ProgressivePulse...I was making a point for another blogger. Not you personally. Sorry.
Right. Gray's ability to hindcast is based on a huge volume of statistics over many decades. I have seen no one else that is this accurate.
This 5-day Satellite Hovmller diagram gives an interesting time series view of the Tropical Atlantic and Caribbean. It shows the last impressive wave that came off of Africa starting to lose its identity while crossing around 30 W, and the current one coming off of Africa now. It will be informative to check this link daily to watch the progress of the current wave...

It looks like poor little 97L is getting stretched very thin, with very little convection and perhaps an exposed weak surface circulation as conditions for development deteriorate. I feel safe enough now to turn in for the night ;) Goodnight all!
Never had ant's in my new place, till now. 2nd floor, big ones too.
jp - You are right, it is not a forecast at all. It is just a way to show the progress of the wave over time to see how it evolves. Just a different way to look at the progress of the wave without the distractions that can exist in a long-term loop. Not rocket science, I agree, but a nicely organized 5-day time series.

Catch ya later!
Thanks Guygee
Grabbed one off my floor earlier in a napkin and I looked at it and it had a stinger popping out of his arse.
if the african wave doesnt weaken, it will make a strong turn out to sea, am i correct?
Not really hurricane23 the GFS is showing a pretty strong ridge at 48 hours.
U guys see the turning in the GOM?
Pay attention to the progress of the current system traveling up and out of the coast and the next. These 2 systems by the GFS could bring us to our Atlantic Season.
Killed 6 since my last post, time to call the Bug man!
Guys Tropical Storm Daniel is Exploding right now...Looks very impressive on Rainbow imagery,only a matter of time before it becomes a hurricane.
i heard on twc, that if the african wave does not weaken, there is an 80-90% chance of it going out to sea. im just learning here, i really dont know
You are so very right and so are they 23

Posted By: ProgressivePulse at 5:12 AM GMT on July 18, 2006.
Pay attention to the progress of the current system traveling up and out of the coast and the next. These 2 systems by the GFS could bring us to our Atlantic Season.

They are supposed to weaken the high as they sit to it's Northwest, significantly. This wave will probably fall victim to that. But as I stated, this will bring us to our atlantic season if it takes place. Holding to the last week of July guys.

There is a strong ridge to the north of this wave shown by the GFS.
Even with preview lol, as they sit to the high's northeast. Sorry
Here's a guess... Typhoon Vamei formed 85 miles from the equator.
how is the african wave lookin now?
more or less health than at 1030
Iam good....LOL!
I think Hurricane Ivan in 2004 was the strongest storm to be so close.
Well I had been here lurking in the background about ready for bed and checked it one more time and the system in the Atlantic seems to be undergoing a growth spurt. Like it just entered more favorable waters, less shear or something . The lower level clouds are also looking healthy on the IR. Especially considering the time of night.
Still kickin Hurricaneman as of 11:45
I was thinking the same thing Jflorida. Looking for 30W though.
I collect hurricane pics...i just finished a 50 pic album one of my favorite hurricanes last night.Wilma is probably my favorite.
id say katrina jp
wilma also looked almost perfect when it was a cat5
OK How about the best Hurricane Image? Answer, Cozumel through the eye of Wilma, no brainer!
jphurricane2006 Here is your answer take a look at my HURRICANE WILMA photo album.Tell me what u think!
Cozumel was one of the best places to be in that picture.
jphurricane2006 look at my hurricane wilma photo album tell what u think!There's 50 images.
Guys here is my 50 image photo album of hurricane wilma.opinions welcomed.
you went threw the 50 pics already?there's about 4 pages.
hey hurricaneman, where where were u when wilma hit? i was in pembroke pines, i think i got the worst of it
Jacksonville, Florida 29.95 in / 1014.1 hPa (Falling)
Here are a couple of pics from my photo album of hurricane katrina...

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Free Image Hosting at www.ImageShack.us

Free Image Hosting at www.ImageShack.us

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Free Image Hosting at www.ImageShack.us
ok u wants picks of them?
Could that thing at 74w be transitioning to warm core now? Its doing well for this time of night. There supposed to drop down in convective intensity right before. Im wondering if we could see red soon.

Oh and the last Katrina Im a symmetry freak. I like the larger eye though.
Best storm at landfall
Oh ok cool...Hey iam going to bed soon i just looked at the eastern wave one last time and its still holding convection.

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Notice no outflow at all. Self sustained cat 5 through landfall.
Loosing symmetry a bit though 23
Yea jp this is what i had over my house in 1992.

Free Image Hosting at www.ImageShack.us
Can't imagine 23, have a good night all.
Good night all.Iam going to bed also.
Adios JP
any blobs around????LOL
Katrina was New Orleans worst nightmare, it moved almost due west after crossing Florida, hit the loop current and stayed on a westward track, and when it finally turned to the North it was almost at New Orleans longtitude. If Katrina would have kept going on that due West course for even a few more hours, it would have hit just west of the river.....most of New Orleans would have been completely blown down, and then flooded. Half off the French Quarter would have blown down...
Andrew was a direct hit over my house also. It went from 30mph winds to 150mph winds in a matter of minutes. Hard to forget watching your roof rip off your house while you hold a mattress over you. This is my first post here and it looks like a interesting place to read about tropical weather.
That blob in the Carribean looks a whole lot more impressive then the others!
Welcome, Miken! Always good to have members with personal experience.

Really looks like SD 2 or SS Beryl off the east coast, good solid convection firing near the center.
well, expected to wake up this morning to find "frick" (carolina storm) fizzled out.....

instead, i found this!!!

to me.... this is the healthiest i have saw this storm.... seems to be little if any shear, the storm is more "symmetrucal, and tstorms are wrapping around the center......

Dr. Masters siad he believed "that the earliest a tropical depression would form is Wednesday."

well, if this current strengthening trend holds up...... could be today!

based upon the above, i'd say the HH may be a go today!!

motion appears due east........
Ok Tropical blobs, enough of this mickey mouse attempts at formation.
Cease and desist all development immediately or face the consequences.
Caneman has some tricks up his sleeve to deal with these kinds of nuisances.
Atlantic Ocean...
cloudiness with embedded moderate convection between the
northern Leeward Islands and Bermuda are associated with a
tropical wave moving across the eastern Caribbean which is
interacting with an upper low centered near 25n63w. Surface
pressures remain high in the area and tropical cyclone formation
is not expected. A band of showers and thunderstorms primarily
associated with a low pressure area along a frontal zone extends
from the northern Bahamas northeastward over the Atlantic. The
low is located near 31n74w. There are no signs of tropical
development at this time...however...there is a potential for a
tropical depression to form during the next day or two.
well, at least for the moment, looks due east....

none of the models i have seen, show this motion......

if i had to guess..... i'd say east motion, with a turn to the nne, then ne.....

just cant see this this heading back westward.......
StormW - Good Morning! The system seems pretty close to where it was yesterday evening...it looked to have moved slightly east and then stalled, with the area of convection expanding somewhat to the northeast. The convection was at its minimum when I logged off here late last night/early morning, really ragged looking, then started to increase as I watched it before I turned in.

The base of the mid-level trough is to the west of 97L and retrograding towards FL somewhat. I can't see 97L going any farther south unless the ULL to the East comes too close and shears it, which would cause it to dissipate, I believe...so still an area of interest, despite what I thought last night when I loggged off of here...

So all I am saying is "not south", IMHO ;) Will have to wait and see...
thelmores - If pressed to guess, I would guess N or NE too, but wouldn't yet rule out some slow retrogression back W...
On the 20060718 0600 UTC 97L model runs, BAMD, BAMM, A98E and LBAR have come into closer agreement with NE motion. SHIPS and DSHIPS show slower development but still to TS in about 48 hours. Newest GFDL run not out, yet.
Hey, thelmores.

I checked the donuts over South Carolina this morning. There are three of them that all start at the same time, about 6:15 am local. Two are centered on reservoirs and a third is on a river. My theory is that they are caused by water cooling at electrical generation plants. They fire up in the morning as demand starts to increase.
601. WSI
bappit, sent you a message earlier yesterday. The "explosions" are Purple Martins leaving their nests around the area lakes.
bappit - Are there electrical power generation plants located at the centers of those "clutter bursts"? If true, that would seem to be more than just coincidence, if it happens at all three.
durn, should check my mail more often. That is pretty amazing.
Will - Thanks for that explanation, it seems to make sense. Over the Everglade birds often show up during migratory season.
Good Morning: 97L is holding out.....and EATL wave has not only hold together but got mentioned by the NHC..........
Good morning just looking at first visibles and 97L looks a tad bit better organized then yesterday.recon will tell us more.

right now iam seeing a possible LLC elongated to the NW.
hurricane23 - Switched to visible, are you looking at the area NE of the convection?
Sorry, make that "NW" ?
609. WSI
No problem guygee.

If you get a chance, look at that Wiki article on the Purple Martins I linked on my forum. They only live in housing provided by humans. That is pretty interesting.
I just checked the watervapor for 97L. It has very dry air to the West, which matched up very well to where the circulation has thunderstorms and where it doesn't. On the IR Channel 2, it almost looks like a sheared system, with half the circulation exposed, but I think that is all dry air.

OK- my dark horse system of the day: The showers and thunderstorms sinking into the Gulf off Louisiana and Texas this morning.

Shear between 10 and 20 knots, not super-favorable, but not too unfavorable.

Something for Gulf Scotsman to ponder.
Good morning everyone. The EATL wave is looking fairly healthy. It appears as though the model consensus for 97l has it curving out to sea.
hurricane23 - Anyways, on the visible loops I agree, I see some low-level convergence bands NW of the main area of convection curling in cyclonically...
Will do , WSI, I need to get on the road to Orlando today to work, but I am curious about the little purple beasties, so I will definitely check in when I get there. It is very interesting how they apparently take off nearly at the same time, ascending and scattering almost uniformly...I would like to learn more...

Talk to everyone later!
dangit, knew i forgot to do something this morning! the martins! DOH!

guess it could be a power plant or something...... guess i'd have to try to determine a more "exact" location.....

as for the ULL affecting the carolina storm ("frick"), i dont think it will play a major role in track, but certainly could affect intensity.....

terograde back west? can you explain more what could cause this..... i just dont see it..... course havent had my coffee yet! LOL

Three wx factors going against 97L developing further this morning in my opinion:
1) Southwesterly wind shear.
2) EXTREMELY DRY CONTINENTAL AIR entraining into the system from the west.
3) Very dry air approaching the system from the east.
WONT41 KNHC 181221
820 AM EDT TUE JUL 18 2006


820 AM EDT TUE JUL 18 2006


thelmores - Remote possibility, but I see the base of the mid-level trough retrograding, and the ULL is still pushing towards the west...so I don't rule out some retrogression (drift towards the west)for 97L. The models say otherwise...

Catch you later, gotta go!
Hmmm... It looks like three of us posted the disturbance statement at the same time. LOL
good points getreal..... would seem that the ULL coming from the sse may be the end of our carolina storm...... especially if the caroilina continues eastward........

seems its biggest opportunity may be just to stay put, and i dont see that! :)
The long range GFS has shown the eatl wave del. and move wnw and hit se fla and move into the GOM on its last 3 runs. I know this is a long way out and the long range models are not very accurate but if this trend in the model continues it will be somethihng to watch. with the sst in the gulf we dont want something already del. getting into the GOM.

no "sub" or "extra" rhere! LOL
would that ruin some stone tablets???? :D
Posted By: GulfScotsman at 12:44 PM GMT on July 18, 2006.
ponder... hmmmm

ponder ponder ponder..... hmmmm

OK, Gulf, you've pondered long enough, now spit it out if you've got something to say...
Bye-bye on the by and by.
oh shoot all the models have tracks shifted more northeast
the BAMM, BAMD, LBAR, and A98E 8am runs all show a nw component at some point.....


when is the next gfdl?
i dunno when it comes out thelmores....i wonder wehn dr masters ill update his blog?
Morning all
thel, the gfdl was also run at 8, but because it is a much more complex model the data output for it along with the likes of the GFS, Nogaps, CMC, and Ukmet, will not be out until about 2. Just how long it takes teh models to eat all of there data.

I do not see how this does anything but head NE, but that is just from looking at the WV loops. Maybe I am missing something.

See ya'll later. Off to work
some of my keys are sticking sorry
yeah seems to have a NE drift but hopefully i am wrong! ):


Hopefully wrong on the NE drift?

where do ya live,Bermuda?
638. WSI
"I do not see how this does anything but head NE"

Well right now the steering currents are weak. Wouldn't take much of a push west from the BH to change everything.
"I do not see how this does anything but head NE, but that is just from looking at the WV loops. Maybe I am missing something."

i must be missing it too! LOL

Guess the HH should be on station around 3pm..... guess we'll "finally" get some answers! :)
no i live in florida i want it to hit here (just as longf as its not a cat 4 or cat 5 hurricane i can stand anything else) I have been waiting since 2004 for nother hurricane to hit near me
i'm the only floridian that thinks like that (excluding my news crew!)
642. WSI
NAM as of this morning is showing more or less the same solution it was yesterday. A push into NC, then riding up the coast a little.
so c2, a cat 3 heading your way is ok???

LOL....glutton for pinishment! :)
644. PBG00
Where in Fla wre you?
yeah a cat 3 is okay i've gone through it before (Jeanne 04) though I wasn't as prepared as I hadn't restocked my hurricane kit from Frances.....I rode out Frances in a makeshift hut in Palm Bay..till Melbourne police threw me out...i got great footage though
I was anywhere from jacksonville to palm bay....i live in jax
647. WSI
New blog!
dr. jeff has a new blog.....
649. PBG00
Oh..just wondering..Went through Francis and Jeanne too...Even though Francis was weaker it was worse cause it just sat over us for hours and hours
yeah i know i noticed that about frances....it tok jax through a five day ride....even though jeanne had the brunt in jax overnight.....in the morning we woke up to all the roads within 3 blocks of the ocean flooded
seems to me, that some tstorms are trying to form very near the center of our carolina storm ("frick")..... we will have to see if this persists....

this is definitaly a sign of possible intensification.........

Are you one of those reporters that gets a woody over a storm?...out there reporting like you've got danger in the palm of your hand? I'm career Navy. I've seen ugly things all my life. They bring me no pleaure. Three years ago my wife and I purchased what will be our retirement home on the Indian River of Jensen Beach, FL. We've been through 3 hurricanes in the last 2 years. Calling for a complete rebuild of our home, outbuilding, dock and the complete loss of our sailboat that my wife and I spent 4 years refurbishing it to it's origins of 1926. To watch storms...to try to predict them....understand them and be awestruck by them I have no problem and i include myself in this category. To want them to hit land makes me sick.