TD #4 East Atlantic,Comments,Sat Pics,Models Thread #2

[Trugunzn]

u can see some of that SAL is being gulped in, but i dont think it will to much of a prob.

LINK

EDIT: URL changed to hyperlink. -senorpepr

[Trugunzn]

Huge shift west comapring to yesterdats 12z:

LINK

EDIT: URL changed to hyperlink. -senorpepr.

[storms in NC]

A weaker system will tend more westerly, yes in this case. Hard to tell if it would miss the weakness entirely.

Thank you so kindly.I thought that but wanted to make sure. This has been a weird year for the models to pick up on them. was it last year the UK did a good job on the storms?

[storms in NC]

u can see some of that SAL is being gulped in, but i dont think it will to much of a prob.

LINK

EDIT: URL changed to hyperlink. -senorpepr

From the looks of that it might want to drop south and to the west if it want to survive.

[SouthFloridawx]

The 12Z gfs is now joining the other models indicating a weaker system than before through 60 hours.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_060s.gif
12 60 Hours

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_054s.gif
06Z 54 Hours

If the system remains weak low level steering flow would be more effective.

I would say a wnw track for the next 48-72 hours is likely if this remains a weaker system.

[storms in NC]

out of Miami
http://articles.news.aol.com/news/_a/de ... 0000000001

[deltadog03]

We need to learn some lessons here folks. Many of you do know this but, for some who don't lets take a little lesson on models and tropics. I have seen some posts this morning about WOW look at the models...HUGE shift left. Well, you have to understand that the GFS, most popular model, LOVES to recurve everything waaay to quickly most if not all the time. I mean remember this easy trick and you will be better off. A weaker system will ALWAYS track west when its in the middle of the ocean due to the tropical easterlies. The only way they recurve is if the system really gets strong quickly and there is a weakness in the H5 ridge.

[storms in NC]

This is a nice loop from the time it was comeing off till now
http://cimss.ssec.wisc.edu/tropic/real- ... java5.html

[Sanibel]

Obvious SAL weakening now.

[Trugunzn]

almost there:

[beachbum_al]

000
WTNT44 KNHC 221452
TCDAT4
TROPICAL DEPRESSION FOUR DISCUSSION NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042006
1100 AM EDT TUE AUG 22 2006

DVORAK INTENSITY ESTIMATES AT 12Z WERE 30 KT FROM TAFB AND AFWA...
AND 35 KT FROM SAB. SINCE THEN CONVECTION HAS DECAYED SOMEWHAT AND
SO THE ADVISORY INTENSITY WILL REMAIN 30 KT. HIGHER VALUES IN THE
8Z QUIKSCAT PASS ARE BELIEVED TO BE RAIN CONTAMINATED.

THERE IS CLEAR ROTATION IN THE MID-LEVEL CLOUDS THAT COULD BE
REPRESENTATIVE OF THE SURFACE CENTER...BUT THE LOW CLOUD LINES
SUGGEST THE CENTER COULD BE DISPLACED A BIT TO THE SOUTHEAST. THE
QUIKSCAT AMBIGUITIES SLIGHTLY FAVOR A DISPLACED CENTER. SO WITH
SOME UNCERTAINTY...THE INITIAL MOTION IS ESTIMATED TO BE 295/14.
GLOBAL MODEL GUIDANCE IS UNANIMOUS IN SHIFTING THE SUBTROPICAL RIDGE
EASTWARD WITH INCREASED MID- TO UPPER-LEVEL TROUGHING IN THE
CENTRAL ATLANTIC OVER THE NEXT SEVERAL DAYS. THIS SHOULD ALLOW THE
DEPRESSION TO MAINTAIN ITS PRESENT WEST-NORTHWESTWARD HEADING FOR
AT LEAST THE NEXT THREE DAYS. AFTER THAT...THERE SEEM TO BE TWO
PRIMARY OPTIONS. THERE IS GOOD AGREEMENT IN THE GLOBAL MODELS THAT
THE CYCLONE WILL ENCOUNTER INCREASED SOUTHERLY SHEAR. THIS COULD
TURN THE CYCLONE NORTHWARD...IF THE SYSTEM CAN HANG TOGETHER.
ALTERNATIVELY...THE SYSTEM COULD SHEAR OFF AND THE WEAKENED
REMNANTS TURN WESTWARD. THE FORMER SCENARIO IS FAVORED BY THE GFS
AND GFDL...WHILE THE LATTER SCENARIO IS THE CHOICE OF THE UKMET AND
ECMWF MODELS. FOR NOW...I'VE MADE NO CHANGES TO THE PREVIOUS
ADVISORY TRACK...WHICH SPLITS THE DIFFERENCE.

THERE IS A LOT OF STABLE AIR IN THE ENVIRONMENT AHEAD OF THE
DEPRESSION. NEVERTHELESS...BOTH THE SHIPS AND GFDL GUIDANCE
INDICATE STRENGTHENING TO AT LEAST A STRONG TROPICAL STORM. GIVEN
THAT THE DEPRESSION HAS NOT STRENGTHENED YET OVER THE WARMEST
WATERS IT WILL SEE FOR THE NEXT FOUR DAYS...I WONDER IF THE
GUIDANCE IS A LITTLE TOO AGGRESSIVE.


FORECAST POSITIONS AND MAX WINDS

INITIAL 22/1500Z 13.6N 26.1W 30 KT
12HR VT 23/0000Z 14.6N 28.1W 35 KT
24HR VT 23/1200Z 16.1N 30.7W 40 KT
36HR VT 24/0000Z 17.6N 33.4W 45 KT
48HR VT 24/1200Z 19.2N 36.3W 50 KT
72HR VT 25/1200Z 22.0N 42.5W 60 KT
96HR VT 26/1200Z 25.0N 48.0W 65 KT
120HR VT 27/1200Z 28.0N 53.0W 65 KT

$$
FORECASTER FRANKLIN



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[benny]

The GFS is probably way left of previous because it no longer develops the system and moves it more to the west-northwest like a shallow system. Still hard to imagine how it would threaten anything but shipping... and as it sucks in all that stratocumulus/stable air... hard to think it will do too much in general..

[curtadams]

THERE IS CLEAR ROTATION IN THE MID-LEVEL CLOUDS THAT COULD BE
REPRESENTATIVE OF THE SURFACE CENTER...BUT THE LOW CLOUD LINES
SUGGEST THE CENTER COULD BE DISPLACED A BIT TO THE SOUTHEAST. THE
QUIKSCAT AMBIGUITIES SLIGHTLY FAVOR A DISPLACED CENTER. SO WITH
SOME UNCERTAINTY...THE INITIAL MOTION IS ESTIMATED TO BE 295/14. $$
<snip>
FORECASTER FRANKLIN

Given that mid shear is from the S and upper shear from the NE, the LL center *should* be SE-ish of the mid-level center. IMO Franklin nailed it and is being too cautious. Also, seems it's finally turning NW.

[storms in NC]

THIS SHOULD ALLOW THE
DEPRESSION TO MAINTAIN ITS PRESENT WEST-NORTHWESTWARD HEADING FOR
AT LEAST THE NEXT THREE DAYS. AFTER THAT...THERE SEEM TO BE TWO
PRIMARY OPTIONS. THERE IS GOOD AGREEMENT IN THE GLOBAL MODELS THAT
THE CYCLONE WILL ENCOUNTER INCREASED SOUTHERLY SHEAR. THIS COULD
TURN THE CYCLONE NORTHWARD...IF THE SYSTEM CAN HANG TOGETHER.
ALTERNATIVELY...THE SYSTEM COULD SHEAR OFF AND THE WEAKENED
REMNANTS TURN WESTWARD. THE FORMER SCENARIO IS FAVORED BY THE GFS
AND GFDL...WHILE THE LATTER SCENARIO IS THE CHOICE OF THE UKMET AND
ECMWF MODELS. FOR NOW...I'VE MADE NO CHANGES TO THE PREVIOUS
ADVISORY TRACK...WHICH SPLITS THE DIFFERENCE.

[LAwxrgal]

Sheesh... many different scenarios possible with this one. But IMO Franklin is right on the money here. As we've seen in the past, weaker systems get trapped underneath subtropical ridges and continue westward, only to develop when they reach more favorable environments.

But currently my thinking with this system is even if part of its circulation gets cut off the main one, it is too far out in the ocean to do very much. (If I'm wrong, I'll be first in line for a nice helping of crow ) It's most likely to recurve due to the coming weakness in the ridge.

[storms in NC]

I think the UK has a better handle on this. TD4 will be to weak for the weak ridge and will go on a more west movement in a few days. IMO

[gatorcane]

I think the UK has a better handle on this. TD4 will be to weak for the weak ridge and will go on a more west movement in a few days. IMO

I've been saying this all along. Let's see if it happens.

[Thatsmrhurricane]

If and I mean if it stays weak, and or misses the ridge as in the Stewart 8/21/06 11am disco, where does TD4 go and what does it do?

[LAwxrgal]

It's going to recurve eventually... the question is where and when...

[Windtalker1]

It's going to recurve eventually... the question is where and when...

What if the ridge builds back in...they all do not recurve you know.