Surface low of 1010 mbs with east atlantic wave near 10.5n

[cycloneye]

From 2:05 discussion:

THE TROPICAL ATLANTIC...
A
LOW IS STARTING TO DEVELOP ON THE EASTERN MOST TROPICAL WAVE
NEAR 11N27W. IN THE UPPER LEVELS...A RARE CYCLONIC CIRCULATION
IS NOTED NEAR 8N28W. CYCLONIC FLOW IS FROM THE EQUATOR TO 14N
BETWEEN 20W-40W.

That rare cyclonic circulation is not common to see down there 8n in the upper levels and that may be the confusion from the models about initial positions for the low.

[Derek Ortt]

8N is where I placed the center today for the NOAA-HRD map discussion. Got an ODT value of about 3.8, which is totally unrepresentative. If the center is farther north, well then things may be different. Still dont look for development before wednesday, but it still has a good chance to ebcome frances.

However, we will be saying "Here fishy fishy!" by Saturday

[cycloneye]

It looks more clear now that convection is developing near that surface low forming at 11n.

[MWatkins]

The 1KM visible images from NRL suggest there may be more than one vorticity center embedded in the broader circulation. We should see slow...steady improvement in intensity and organization in the coming days.

One other thing...this system was progged by the GFS and UKMET to start developing today...however...it was progged to develop 300NM further to the east than it's current position.

As it is...though...the UKMET model still does not give this system a chance to get past 50W...and the GFS is even less "optimistic" taking the system north further east than in the previous run and a full 7 degrees to the east than the UKMET.

The medium/extended GFS weakens the 500MB ridge almost identically to the 00Z GFS...however...the evolution of the ridge is a little different therafter...owning to the fact the stronger 500MB low off the US east coast is not nearly as strong as it was in the 0Z run.

I still do not believe a "fish" storm is assured. Of course...if this develops...a northward turn is the more likely scenario...this stuff is all happening in the models around day 5....and details about the pattern are starting to change...

However...the GFS believes one of the following systems behind this one will come all the way across in 2-3 weeks.

MW

[cycloneye]

Thanks Mike for that complete anaylisis of the model inputs at this time.The key will be how fast or how slow it will develop to then see if it goes fishing or not.Another key is if the system passes the 15n-50w below that point then the islands may have to deal with it but if it goes north of that 15n-50w then from the islands we can say adios.

[hurricanetrack]

Yes- Mike, I was watching the GFS too and it yanks 96L out to sea but brings what would be "G" rather far to the west. I guess "G" is still over Africa somewhere. Wow, what are the odds that we make it to "G" before the end of the month?

Say it- the "G" storm before September 1. That would be incredible.

[MWatkins]

Thanks Mike for that complete anaylisis of the model inputs at this time.The key will be how fast or how slow it will develop to then see if it goes fishing or not.Another key is if the system passes the 15n-50w below that point then the islands may have to deal with it but if it goes north of that 15n-50w then from the islands we can say adios.

Yep...and this is going to take some getting used to by folks here. We've seen these race across the Atlantic all year...this one will be moving closer to 10/15 knots which will seem like FOREVER to some. By Friday we will know for sure but I'd say if it's moving w to wnw south of 15/50 the islands would stand a pretty good chance of dealing with this system.

MW

[Brent]

Thanks Mike for that complete anaylisis of the model inputs at this time.The key will be how fast or how slow it will develop to then see if it goes fishing or not.Another key is if the system passes the 15n-50w below that point then the islands may have to deal with it but if it goes north of that 15n-50w then from the islands we can say adios.

Yep...and this is going to take some getting used to by folks here. We've seen these race across the Atlantic all year...this one will be moving closer to 10/15 knots which will seem like FOREVER to some. By Friday we will know for sure but I'd say if it's moving w to wnw south of 15/50 the islands would stand a pretty good chance of dealing with this system.

MW

10-15 knots is more normal anyway.

[bigmike]

8N is where I placed the center today for the NOAA-HRD map discussion. Got an ODT value of about 3.8, which is totally unrepresentative. If the center is farther north, well then things may be different. Still dont look for development before wednesday, but it still has a good chance to ebcome frances.

However, we will be saying "Here fishy fishy!" by Saturday

For a non-met major how far south can a storm develop? And how can you tell it'll be a fish?

[MWatkins]

Yes- Mike, I was watching the GFS too and it yanks 96L out to sea but brings what would be "G" rather far to the west. I guess "G" is still over Africa somewhere. Wow, what are the odds that we make it to "G" before the end of the month?

Say it- the "G" storm before September 1. That would be incredible.

If it happens...you'd have to like the chances of getting into the upper range of the NOAA outlook (14/15 named storms). Heck...we'd equal the TOTAL for 1992 by then.

MW

[PurdueWx80]

It's extremely difficult to get a closed circulation within about 5-10 degrees of the equator because the Coriolis force is almost nonexistent.

[Derek Ortt]

Well, Typhoon Vamei formed at 1.5 degres north, though there was a strong monsoon circulation.

This is an almost certain open ocean storm because the global models are in good agreement that there will be a large weakness in the ridge

[HURRICANELONNY]

How come alot of you are calling a wave a fish when it didn't even turn to a depression yet??? If the wave doesn't develop till, let say 40w, then what will be the result. I think some of you are jumping the gun a little early. Especially, when you look at models that have no meaning until it's Frances.

[Renata]

The UKMET develops the system pretty quickly but in real life it has not yet developed to the point that was envisaged. According to UKMET's first run, it should have been a TD by now. The speed at which it develops will have an influence on when it curves.

This evening, showers seem to be developing to northeast of the center of rotation which leads me to believe that shear is reducing and giving it a good chance of development. At the same time, the forward speed has increased. Will it cover much "ground" before developing and being pulled northward as the models forecast?

My belief (strictly gut feeling -- no science here) it will continue westward reaching 40W before it starts serious development.

R.

[cycloneye]

Renata watch the 15/50 lines.If it goes south of that point the islands are going to be in trouble but if it goes north of there we can say goodbye from the islands plain simple.

[Renata]

Good guage Luis

[cycloneye]

Very poor initial plots of UKMET for wave.Already wave axis is close to 30w but they are WAY!!! back at 22 w.

TROPICAL STORM ANALYSED IN THE MODEL AT POSITION : 10.7N 22.8W



VERIFYING TIME POSITION STRENGTH TENDENCY

-------------- -------- -------- --------

12UTC 23.08.2004 10.7N 22.8W WEAK

00UTC 24.08.2004 8.7N 26.6W WEAK LITTLE CHANGE

12UTC 24.08.2004 9.6N 30.8W MODERATE INTENSIFYING RAPIDLY

00UTC 25.08.2004 10.3N 34.1W MODERATE LITTLE CHANGE

12UTC 25.08.2004 11.2N 37.3W MODERATE INTENSIFYING SLIGHTLY

00UTC 26.08.2004 12.2N 40.5W MODERATE LITTLE CHANGE

12UTC 26.08.2004 13.2N 43.4W MODERATE INTENSIFYING SLIGHTLY

00UTC 27.08.2004 14.7N 45.5W MODERATE LITTLE CHANGE

12UTC 27.08.2004 16.0N 47.0W MODERATE WEAKENING SLIGHTLY

00UTC 28.08.2004 17.2N 48.1W MODERATE LITTLE CHANGE

12UTC 28.08.2004 18.7N 49.0W MODERATE LITTLE CHANGE

00UTC 29.08.2004 20.6N 49.1W MODERATE INTENSIFYING SLIGHTLY

12UTC 29.08.2004 22.2N 49.3W MODERATE INTENSIFYING SLIGHTLY

[Derecho]

It's extremely difficult to get a closed circulation within about 5-10 degrees of the equator because the Coriolis force is almost nonexistent.

Ummm....storms form between 5-10 degrees north (and even make it to Typhoon status) in the Pacific and Indian Oceans on an absolutely ROUTINE basis.

And of course Typhoon Vamei was at an unbelievable 1.5N when it hit Singapore (where there actually SHOULDN'T have been enough Coriolis, how it was able to spin up is an interesting and complicated issue...do a web search on Vamei and read some of the papers.)

And Coriolis is EXACTLY the same around the world, at the same latitudes.

THE LACK OF FORMATIONS SOUTH OF 10N IN THE ATLANTIC HAS NOTHING TO DO WITH LACK OF CORIOLIS.

An amazingly difficult myth to kill over the years. The Atlantic is truly the world's "oddball" basin, remember.

The most likely cause is how far north the ITCZ is in the Atlantic during the time periods when shear is low and SSTs favorable in the Cape Verde Region; all tropical systems naturally gain latitude as they develop due to the "Beta" effect; to get something that becomes a TD, TS, or cane South of 10N, you really need the initial disturbance south of 7N....you very rarely see waves in the Atlantic during Aug-Sept south of 8N or so.

[cycloneye]

...TROPICAL WAVES...
TROPICAL WAVE PREVIOUSLY ALONG 27W IS REPOSITIONED A BIT FARTHER
E ALONG 25W/26W S OF 17N MOVING W 10 KT. SATELLITE PICTURES
INDICATE A BROAD 1010 MB LOW HAS FORMED ALONG THE WAVE NEAR
10.5N. TSTM ACTIVITY HAS BEEN INCREASING IN THE PAST FEW HOURS
WITH SOME EVIDENCE OF BANDING FEATURES FORMING. COMPUTER MODELS
CONTINUE TO PINPOINT THIS WAVE AS THE NEXT FEATURE WITH
POTENTIAL FOR TROPICAL CYCLONE DEVELOPMENT. WIDELY SCATTERED
MODERATE FROM 9N-12N BETWEEN 25W-31W.

UPPER DIVERGENCE CONTINUES TO
ENHANCE THE CAPE VERDE WAVE WITH CONSIDERABLY MORE TSTM ACTIVITY
TONIGHT THAN LAST NIGHT AT THIS TIME.



That is from the 8 PM discussion a little more agressive in the wording.

[Derecho]

Well, Typhoon Vamei formed at 1.5 degres north, though there was a strong monsoon circulation.

This is an almost certain open ocean storm because the global models are in good agreement that there will be a large weakness in the ridge

Based on very minimal data......and many of the recurves were likely based on an unrealistically rapid strengthening of the storm.

Plenty of storms which have eventually hit the Carib or US had a variety of sharp recurves during the INVEST and TD periods of the storm.

I'm fairly dubious of accepting model recurves in the Central Atlantic for a disturbance beginning at 8N...if it was 14N, another story.