WunderBlog Archive » Category 6™

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.


By: Dr. Jeff Masters, 10:52 PM GMT on November 23, 2005

This is Tim Roche in for Dr. Masters.
Tropical Storm Delta was classified as a tropical storm as of the 4:00pm EST update from the National Hurricane Center. Delta formed out of a non-tropical low pressure system that has been slowly aquiring tropical characteristics, while drifting eastward over the Atlantic since the middle of last week. Convection wrapped almost all the way around the center earlier today, and a recent Quikscat pass showed several areas with uncontaminated 50kt wind vectors. The system is forecast to drift southward for the next few days then to accelerate northward and lose its tropical characteristics. As Delta becomes extratropical, it will likely strengthen more, with winds possibly reaching hurricane strength. Delta shouldn't effect any landmasses as a tropical storm, and is mostly a threat to nautical interests.

Figure 1. Official NHC 5 day forecast

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

It ain't over till its over, someone should have told SteveG this!
And even then it might not be over, this year!!
Wow! Another storm ... thankfully it appears that it will remain over water. Happy Thanksgiving everyone!
Thanks TIM! Have a good & Tasty turkey!
*sigh* I think the NHC is underestimating Delta, as usual. Look at the size of the windfield, and tell me it won't reach hurricane strength as it tightens up.
This is going to be big trouble for the open Atlantic and possibly the second tropical storm to hit Spain or Portugal.

dcw is absolutely right. When is NHC going to stop their ridiculous underestimations of every disturbance?
it's not over yet....hello and goodbye delta

happy thanksgiving to everyone!

love and light,
sean white
extract from the script of 'Animal House' right after the interfraternity council rules against Delta House

DEAN WORMER: You're not walking out
on this one, mister.
You're finished.
No more Delta!
(Deltas hum the national anthem)
You've bought it this time, buster!
I'm calling your national office!
I'm going to revoke your charter!
(National anthem plays)
If you wise guys try one more thing...
one more, l'll kick you out of this college!
No more fun of any kind!
ROTFLMAO....StSimons, you got that scene playing thru my head now...
Way to go bro!

Tim, thanks for the update.
Thanks Doc :)
It's late November and we've got a tropical storm in the Atlantic and two inches of snow on my deck in Virginia where no snow belongs at this time of year. What's next?
whats up all and doc lol
Hi guys, new here.
MarcD: There's no way it'll make it to Spain/Portugal as a tropical storm (look at the computer models), and the NHC is certainly doing the best it can. I agree it's probably underestimated a bit from our perspective, but they have a lot of information that we can't access.
According to the satellites, the NHC is actually being liberal in their advisories.
They should have named it yesterday, they're so conservative
Hey everyone..just stopped in to wish all a Happy Thanksgiving.:)

In regsards to Delta... Tony (Tornadoty)is right about the Dvorak intensity estimates which are derived from the satellite imagery where the latest "T" numbers were 3.0 which corresponds to 52 mph sustained winds. However, that estimate was taken earlier this afternoon.

Yesterday, it wasn't named nor should it have been in my opinion honestly, because it was a purely cold core low pressure area with the deepest convection well away from the circulation center as is usualy the case with such systems.

Now, the convection is wrapping around the center and it appears Delta will possibly reach hurricane intensity before transitioning back into a cold core extratropical cyclone as it moves north in time.

As always, only time will tell. This is Tropical meteorology which is an inexact science and anything within reason can happen.
hey chaser
Delta now seems to be heading SSE
Hey Jeff:)

I just stopped in as I am just blog hoping to wish everyone a Happy Thanksgiving :)
Hey St.Simons,

Delta was officially moving SSE at the 4 PM EST advisory.

Honestly, based on the latest Infrared satellite loop, I was thinking there is definately more of an eastward component than a few hours ago.
oh ok see ya later then
Heres the latest visible satellite loop...


It looks like the circulation center is now moving more SE or possibly a bit more east of even that trajectory. Its hard to tell because there has been a big blowup of convection on its eastern side during the past couple of hours and this could cause it to wobble more eastward as a result. We will just have to look for consistency in the movement to determine the overall direction of forward motion.

Another point to notice is that there is better outflow on its north and eastern quadrants as well which appears to be an indication of some gradual strengthening.
Its cool Jeff...I have a few minutes, I was just explaining what I was doing.:)

What are your plans for Thanksgiving?
just having some family coming over and you
We are going to the wifes family which is always alot of fun (sarcastic). LOL
Im curious when did you first become fascinated with weather and was it a result of a particular event?
ok..guess I missed you..

I hope you have a great Thanksgiving Jeff and the rest of you who are checking in from time to time.:)
im back oh man i guessed im issed you chaser darn
Happy Thanksgiving All...

Just got back...catching up..also see the more easterly trend w/ Delta..wont go much more than another degree S. Should be quick loop back E and N within 24-36 hrs...might be able to wrap convection completely at that time, briefly away from dry air entraining...depends on shear values.


Tracking a cyclone on Thanksgiving...and possibly beyond.
My prediction in late Sept/early Oct. of 4th letter of Greek alphabet might have been conservative.
Happy Thanksgiving doc. I see what they (NHC) are referring to. Have a look at the 18z GFS animation: Link
whats up doc same to you and whats up sub same to you also
Hi all - Happy Thanksgiving!
Doc, Who would have thought we'd this far in the Greek aphabet as your post suggests.... unless 88888 by changing to KatrinaRitaWilmaZeta did it uncounscuously, and it ain't over till Zeta sings :)
sub, lat & long please??
THE 11 PM AST POSITION...25.3 N... 40.3 W.
wow, I got your link to animate - always thought something was wrong with computer when this graphic was posted, cause it says "animation" but doesn't move. Not computer fault, lack of brain LOL
Wow subtropic...even more amazing, I was just checking out your blog and about to wish you same greeting my friend! Thanks...yeah if it plays out, next week could be another record setter...This season wont quit.
Glad you finally got it to work finn. That's not the first GFS run that showed the system splitting and the western system becoming predominant. I haven't been checking much, but the 12z showed basically the same thing.
I'm a bit lost... got it moving but see like Delta is splitting, is that it? sub, doc? sry, still very ignorant
Just in case there is anyone lurking that couldn't get the animation going, give the page some time to load all the images and then click the FWD button on the far right side of the page to start the animation.
Correct finn. The GFS is one of the models that is suggesting the system will split and redevelope west of the original Delta.
well, that son-of-D looks a lot healthier than Delta ever did!
I have just prooved that you CAN teach an old dog new tricks LMBO ))) this is FUN lol
You want a link to more models finn?
Hey Happy Thanksgiving Finn, Boldman...Zeta might be a stretch, but in one of my late nite musings I half joked to Lefty and SJ on getting to Delta. We're really in (almost) uncharted territory if still talking tropics past Dec 10th.
Well doc, your half joke turned out to be one of the most poignant predictions this year. Congratulations.

Now ... can you give me the winning lottery numbers please?
Finn..... Party hardy.... Link
Hey hey...LOL..if I only really knew, sub.
Just use the "Submit" buttons. Sea level pressure is fine for a developed tropical system.
rats. Oh well. Just thought I'd ask.
That would be great sub :) I have the Dvorac etc page, the 18 gfs, the SSTs, but I dont have the spaghettis Ukmet, GDFL etc. or others that I maybe should have
53. dcw
Hey chaser, if you're listening to the satellites, it should have been named Subtropical Storm Delta yesterday morning, when a couple ST2.5s came in.
Already up finn. Just scroll up to my "Party hardy" comment. That is a collection of global models including the GFS I already posted earlier. The GFDL is there too, but that one, you need to select the system you want to see from the first pulldown menu. Right now, you want the default (invest95l)
55. dcw

Look at the GFS! Link
The GFDL looks different. It is split into two images. The smaller one on the right is just a close-up of what you are seeing in the larger image.
sub, I'm in total awe. They animate with the submit button... I never even saw that button, too much to the rigt of the screen, hidden from view. Thanks a LOT
Anytime finn. I guess I'm out for a bit. Maybe I will catch you all later. If not, once again, Happy Thanksgiving everyone.
That one I figured all by myself sub, lol (the smaller one being a zoom)
Remember finn, Submit gets you to the model. You still need to click the FWD button when you get there to animate..
Disregard that last post. I'm sure you already realized that. Sorry.
Sub, Catch you a little later...have a good one.

Finn, took me awhile to figure out had to scroll waaaaaaay over to find it also! Although in my case, w/ dialup I often just select individual frames to speed up my viewing.
I am just checking back in before I cal it a night to wish any new arivals a "Happy Thanksgiving".

Hey DCW,

you are correct about there being two T 2.5 's from yesterday on the Dvorak scale.

Three inportant factors that precluded it from being clasified a tropical storm at that time.

First, it was a ST 2.5 which means it was a subtopical wind estimate. As it was transitioning into a more tropical system those T numbers dropped to 2.0 not because the system became less intense but rather because it had begun to bring the deeper convection closer to its circulation center. In short the T 2.0 was more representative of its true intensity than the two ST 2.5 estimates from earlier.

Secondly, the Dvorak intensity scale is not the only one that the NHC uses to estimate intensity from satellites. There are a couple of them and they try to find a consensus between all of them to come to a specific conclusion regarding such intensity. This is similar to the track forecasts they make based on a multitude of global models and not focusing on one specifically.

Thirdly, the NHC was looking for what they call persistence over a given time period (usually 6 to 12 hours or so), it would be irresponsible if they were to keep adjusting intensity of a specific storm based upon the various fluctuations that tropical cyclones undergo especially in the formative stages.
yes, thanks. I posted your post on my blog so I can always find it to forwad easily. Say hi to Donkey!
please excuse all my typos as usual when I'm trying to type more quickly in these blogs.:)
That should've been ST 2.5 (not T 2.5) in the third sentence and numerous typos included prior to that and shortly thereafter..:)
Doc, I have a quick DSL, so I'm fine, but my laptop screen a bit small. I'm glad I stayed up, learned from a few post more than a weeks worth lurking. I'll give thanks for that too, over a yummy dinner!
stayed up wayyyy past my bedtime, it's 6.30 am. Now off to wonderland, see you soon - good nigh all!
Finn, enjoy...mealtime should be soon for you, eh...assume your still in Finland. Take care gal...

'canechaser..seems the system should have at least warranted STD status yesterday..although I feel NHC anticipated the transition that's more or less occurred, and waited to see it persevere as well.
Also, hope you and your family have a fine Thanksgiving.
Hey Doc,
I have to admit that I was a little frustrated that it wasn't clasified a Subtropical depression yesterday or even earlier today as both the Dvorak estimates as well as the satellite presentations both warrented that classification in my opinion as you pointed out.

As in my reply to DCW, I also believe it was simply a matter of them waiting for persistence as you also alluded (thanks to DCW I am no longer spelling it "eluded") to.

Thank you and I hope you have wonderful Thanksgiving as well.:)
Delta was not classified as a TS until persistence of convection around the center, and I believe also waiting until convection had banded around more than halfway. It was still transitioning from subtropical yesterday.

Delta will rotate around the inside of the larger low (counter-clockwise).
Yeah, I guess the NHC doesn't want any "fizzlers" this late in one long heckuva season that's racked us all out. My opinion, they still missed TD 28 - not Delta, but the true origin of Gamma, the surface low that rose up from Panama and swept thru Nic/Hon...TD 27 was only an enhancer.

Well enough tropics tonite for me...Good nite all and once again (in NHC type) 11:15 PM CST TROPICAL UPDATE: HAPPY THANKSGIVING ALL!!!
Hey Squeak..just saw your post as I was signing off...agree, that west side is still a bit naked, but could improve tomorrow..we'll see. Happy Thanksgiving. Also to you DCW if you're still here...have a good one pal.
74. dcw
Hey Chaser, I have absolutely no clue on this storm. You appear to, and I'd like to keep amateur advisories going, are you interested?
75. dcw
I was back for a minute, doc :D
Hey all Just wanted to say Happy Thanksgiving

Gobble -gobble~ nearly burnt the sweet potatoes catching up. Suprised to see the 00Z run of the cmc also shift to a two storm senario. At 12Z it hung with the gfdl.
78. dcw
O.M.G. All the models are lining up around Epsilon splitting off and moving towards the U.S.! *sound of gunfire, thud*
oh dcw
Could you guys give me a link to the most recent Z runs. And also, just because the models show it veering toward the U.S., does that mean it will make it all the way or play ir sort of like Delta and meander back north/east? You guys arent supposed to know this, but if you do, let me know, thanks.


Alright, found the links. And you dont have to answer my question, answered it myself. Does look a bit ominous with a few of those runs lining up and showing that split off system going SW towards the hurricane factory area.

Hope everyone has a good thanksgiving. If anyone is on here?
83. OGal
Happy Thanksgiving to you Lobcarl. Eat some of those great Maine lobsters for me. We were in Maine a year ago for the first time. What a neat state.
A happy Thanksgiving to all my American friends (we celebrate ours a month earlier)!

So what about the new storm (Epsilon???!!!!) that is going to split off from or form to the west of Delta? I agree DCW that the initial motion seems to be toward the Americas...
Now folks, even though the models are painting a scary picture, let us remember that this is the end of November, and a front will way more than likely pick up any Epsilon and drive it away from the US.
NHC says the forecast new low will be extratropical in nature.
However, the GFS and NOGAPS disagree and say it'll be warm-core. Not enough data points on the UKMET to see if it's in the middle of transitioning it into cold-core.
Lets hope you are right tornadoty, Ocean heat potential is still rather high on the east coast. GFS seems to have been rather accurate with the past couple storms.
Well, happy thanksgiving everyone. Looks like we could be in for an exciting week or two with Epsilon.


Hi everyone I am new here as well. This has been a long season. I think it was 2001 or 2002 where we had a hurricane in December it was the second latest hurricane ever recorded. I kind of wish there where more Hurricanes in the Eastern Pacific rather then the Alantic. Happy Thanksgiving!
... and a silence fell on Dr. Jeff Master's blog after Stormtop's visit. Is everyone in shock? lol
I think we all thought he was dead after saying he was going to go outside and feel Katrina's fury. (At least I thought he was dead....)
hellooooo STORMTOP - can't wait to hear about the Cat. 6
94. dcw
Well, we can always dream, AySz88.

However, I am also considering using a new classification for my own advisories based on pressure, windfield, and winds.
come on hc, let's try to focus on tropical storms - do you think the storm (Epsilon) predicted to spin off or form west of Delta is likely to pose any threat to the Americas, or will it stay a fish storm?
97. iyou
STORMTOP!! Wow, is that really you?? I've missed you alot. Happy Thanksgiving! Come back soon. It's just like you to leave us hanging!! ;-)
Yo STORMTOP, Happy Thanksgiving and all that jazz...Glad you're still on Planet Earth.
hey iyou, cold enough for you?
100. iyou
hey snowboy - I'll have to wear more than a windbreaker to-day! We've a dusting of snow-but yes, it's cold and windy-how about you?
iyou it is BRISK - a few inches of snow on the ground, more in the air, and an awful wind. Hard to imagine that there's still a tropical storm (soon to be hurricane) still in play, and that another may form within days...
102. iyou
snowboy - I'm going out into it now - the worst part is that first intake of cold air-it's a wake-up for the lungs!............Hurricanes know nothing of calendars.
103. dcw
I think that the possible Epsilon will come close, but remain a fish.
warm and 73 here in South Ga, 'severe clear' and a swift 20-25 mph wind from the SW as a trough approached from the north.
dcw...come close to where?
I wish it would snow here, but Mike hates snow though.
happy thanksgiving guys

account will be terminated in 5 mins. enjoy storm tracking and discussing in the future.
and I still wonder what the deal is with Stormtop, and I miss Steve Gregory's graphics.
that Stormtop is a real tease, eh? popping in to startle us all, and then disappearing again. and good to hear from you atmos, hope to see you next year..

billsfan, the new storm could approach the NE caribbean
Thanks again Snowboy,

You can read my response to snowboys question about my impressions of Delta and a possible splitting of the system in my own blog that I just updated or in my response to snowboy in Leftys blog.

Most importantly, I simply want to wish ALL of you a safe and wonderful, "Thanksgiving" day.

I am going to go now to celebrate all the things I have to be thankful for and certainly don't deserve based upon my own merits. I hope to talk with each of you again soon.:)

thanks, and have a good one hurricanechaser
112. iyou
Apart from the collective chewing rumbling up here from the States, it is conspicuously quiet in the blogs to-day! Happy Thanksgiving to all my American neighbours - you have a great and beautiful country! Enjoy ;-)
you're right, I sense the contented communal celebration too, iyou - note that you should have some snow streamers coming your way over the next little while
snowboy....thanks... too close for my liking..
115. iyou
snowboy, you're right-it's here now-this is the most snow we've had yet-what about where you are?

I'm so glad to see your post! The eye of Katrina went right over my area so I've only had phone service for about a couple of weeks now. I could not use my home computer. Yes, I still have my home. I have five relatives who each lost everything.

I want to express my gratitude to you, especially on this Thanksgiving Day, for taking the time to post your forecasts about Katrina. I'm glad I listened to your predictions early enough to be able to make plans to leave and get to a safe place.

Everyone is being so strong and courageous in the face of tremendous hardship and challenge. The storm has been a great equalizer. It put us all in the same situation. Only a strong character sets some apart now and makes them admired.

I am looking forward to reading your future posts.

Hey all,

Just wanted to say that is is good to see that Stormtop is ok and that we have not heard from him for some time... Now I also see that we may have a split of Delta and head towards US but I think that will be a hard from all of the fronts that come this way, so we will have to wait and see...

I did want to say I hope everybody had a safe and Happy Thanksgiving...

Love All My Weather Buddies

Taco :-)
Steel, it is a relief to see communications coming back up for some affected by Katrina, more and more hurdles everyday are overcome. I am sorry to hear about your relatives, but I am sure they are in good hands with you and they have a whole country behind them. It Put a smile on my face to see you and stormtop post, things are coming together.
Please do not mention NE Caribbean too loudly.

That splitting is pretty darn scary . . .
Delta's looking pretty perky tonight
NHC is taking more crediance to the split as of 10pm advisory.
Not much, but it went from extrotropical to an unsure.
Yeah Baha I agree, Bahama's have been through too much.
yeah progressive, they're hedging now with this quote from 10 pm discussion:

Little hope is that the latest GFS shows #2 stalling, like tornadoty stated earlier, chances are it will get picked up and out of the area (fish storm).
We now see persitance in the split, now we need to see persitance in the track, which is not there!
Nor will it be till it happens, then it is highly complicated due to the patterns this time of year, almost anyones guess.
it is November, but think of how far west TD27/Gamma made it before fizzling out (it started out well east of the Windward Islands)
this quote says it all:
Yeah but this system is much farther north and in a much more hostile enviornment. If it were to track west it would be faced with crazy wind shears. GFS at 12Z dissipated the system around Puerto Rico.
12Z says stall for all, exept for the nogaps. Will change tomorrow and the next and the Next. Have to see at 3 days, will it happen?
true we're far out in the land of speculation - first need to see what happens with Delta and if new storm (Epsilon?) spins of or forms...
then (3 days from now) see what conditions are 5 days out

in the meantime, you have to hand it to Delta, it's a plucky little November storm (padding the record books with no risk to land, which is good)
133. dcw
Ph33r the w0rd split.
thanks guys for the input..please keep it coming.....because we will not get much down here in So Fla....
what d'ya mean, billsfan?
snowboy....South Florida relies on tourism...so if ANYTHING is coming this way, it will be squashed by the media.....some of us are relying on the knowledge and expertise here...we live here....we care
wow billsfan had never considered that possibility - that is not good at all. providing access to the best possible information should be the goal of the media as far as I'm concerned
Whats the difference in the outcome if it stalls or not?
is it still a cold core system or has it turned to a warm core system yet does anybody know
Hey everyone,

I have just updated my blog not too long ago. Here is my perspective concerning the talk of Epsilon forming from a split of Delta and heading in the general direction of the U.S. I also go into my assessments of Delta as well as my thoughts about any further development this season in my blog.

What about Epsilon?

I mentioned yesterday that Delta could split into two seperate and distinct low pressure areas (as a couple of models suggested)with the new Low moving more toward the west. Although this possibility can't be ruled out, it's fairly unlikely and would be a very rare occurance if it were to happen. Therefore, it is far more likely that a new Low will develop to its west as a seperate entity and this process could very well be taking place as we speak. The atmospheric pressures are falling to Deltas west and this could be the beginnings of the formation of our new Low. If so, this developing Low could take the energy away from Delta and basically absorb that weakening system. The latest computer models all develop a Low to Deltas west and move it in a general west to NW motion. However, this is not a sure thing till the new Low were to actually materialize. If it does do so as I anticipate, it is highly unlikely at most that this system could be a major threat to the U.S. coastline. As is typical for this time of year, there is far more atmospheric activity across the United States moving generally from west to east through the mid latitudes. As a result, the troughs that move through the U.S. and off the U.S. East Coast are much more amplified (stronger)and should keep any system that does form from getting too close to the U.S. Until such a Low forms to Deltas west, its all just speculation at this point as to its eventual strength or future track.

I hope you all had a wonderful Thanksgiving and I look forward to talking with you again soon.
Hello everyone,,,,,,,,,,hope everybody had a great Thanksgivng Day!.....Good to see you HURRICANE CHASER, glad to hear everything is going well.......Good to see your weather forecasts on here. Please continue the good work....... and PLEASE STOP acknowledging anything derogatory on here!!!!!! These people need vindication. They are lacking somewhere and have to attack you to make themselves feel good. Just ignore them as I do. You have to understand what this forum is. Just a simple weather chat room with lots of lurkers who like to come on here and read our opinions. A lot more than you know. For their benefit ignore the few underachievers and have fun! Thats what this blog is about,discussing the weather and having fun..............As far as the tropical season.....nothing but Delta out playing with the fishes......boring.......and good to here from the ole STORMTOP.........WHATS KICKING BUDDY..........HOPE YOUR DOING WELL.............See ya
143. Alec
weatherboyfsu!!!!!!It's been a great thanksgiving, for im thankful everyday!!!LOL
I'm going back to the future LOL!
145. Alec

I think Epsilon will form on November 30th, thats just a guess LOL!
147. Alec
heyRich we can have a blog scavenger hunt!!!!this is totally awesome!!!!!!people will wonder whats going on!!!!
The last storm will be Zeta and it will last into next year!
I can really buy into this Canary Island landfall idea right now........ROFLOL!!!!
150. Alec
i think Michael and the rest of the gang got lost!!LOL or maybe they'll find us soon.......a new time capsule soon..............
LOL Alec brilliant!!! Hey, we could unearth all of the blogs from last year and put them at the top of the list and that'll really confuse people LOL!!!!
I killed the dead blog.
Got lost? LOL

I followed the link; even without it, all I have to do is click on the link under last comment in the blog directory.
155. Alec
The Emily blog!!!

next place....see ya...
156. Alec
WE probably need to get out of here. Dont need to mess up this blog.
wtf?? Who did this? pretty funny
159. Alec
see you there
160. Alec
hahahaha.....LOL cajunkid we're on a time capsule...sit back and ENJOY the ride!!!!LOL