ATL: TROPICAL DEPRESSION ANA (02L)

[Sanibel]

That westerly shear exposes a much tighter surface spiral today.

That is from the opposite direction of the previous denuding shear.

[Javlin]

What if Ana keeps on in this state till the Islands,weak and W once past the Islands the moisture content is better I think,then development in the so called graveyard might actually occur.We have seen plenty of times LLCs continue devoid of percipitation to find it later but for two or three days as such will be tough.

[Stormsfury]

Not implying in any way we are seeing Andrew's little sister but this is a bit eerie if only a coincidence


8/17/92 TS Andrew winds: 50 mph, 14.2N, 47.1W

8/15/09 TS Ana winds: 40 mph 14.6N, 46.8W


In the days that followed, Andrew would weaken some as he fought shear. And then conditions changed.

I don't think Andrew weakened at all in the shear. Recon still found 70 kt winds at 1,500 feet even when the pressure was 1015mb, which supports an intensity of 50 kt.

Environmental pressures in Andrew were very high. The recon found a lone thunderstorm complex in the midst of Andrew on the verge of becoming a remnant low. However, the circulation aloft was vigorous. The upper trough that was shearing Andrew split with the northern end lifting out to the northeast, and the southern end moved SW into a position favorable and vented the western semicircle of Andrew. A large upper level ridge built in over the Southeast and Mid-Atlantic forcing Andrew westward increasing its forward speed, and providing favorable conditions for rapid intensification.

Immediate disclaimer (I am in no way making claims that Ana will do this): Ana and Andrew BOTH have similarities regarding their own respective lifespans up to this point. Initially, in the inception of both systems, both had to battle easterly shear. Andrew had to fight off westerly shear mid way in. Ana now is fighting westerly shear and some dry air entrainment. Both systems have well defined and quite vigorous circulations.

As to the comments that why now TPC reclassified #2, and then now Ana is this. Ana is a tropical storm, and even if doesn't survive, it has to be called and classified for what it is, or was. That is the TPC's responsibility.

Oh, I forgot to mention the upper trough over the Eastern US is retrograding west a little bit and a subtropical ridge is forecast to build over the Southeast at the surface and aloft (an extension of the Bermuda high).

[Sanibel]

Track through 55W is critical to see if it stays on the southern models tracks


Estimate current heading 272*

[thetruesms]

That westerly shear exposes a much tighter surface spiral today.

That is from the opposite direction of the previous denuding shear.

So what you're saying is, Ana looks a lot better naked now?

But I do agree It's a healthy looking circulation for now, but needs convection to start going up again.

[Evil Jeremy]

Convection nicely blowing up right now: http://www.ssd.noaa.gov/goes/flt/t1/loop-wv.html

[Scorpion]

Good.. needs all the convection it can muster

[clfenwi]

12Z NOGAPS runs it throught the Florida Straits to set this up:



Complete loop

[Blown Away]

Looks like a little WNW wobble in the last frame.
http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

[artist]

thanks senor! Good to see you as always!

[jlauderdal]

Looks like a little WNW wobble in the last frame.
http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

i was waiting for a wobble comment, although every wobble counts in the final track outcome of a track

[Sanibel]

Heads up on possible tropical formation right outside my window here. Disturbance possibly developing over Key West. Remnant energy from Hispaniola wave:

[Tropicswatcher]

Thunderstorms still forming (or are getting blown) to the east of the center of circulation.

[Blown Away]

Can't figure out if Ana is a fighter or a wimp? Is she going to run away from the last bit of convection?

[Tropicswatcher]

Looks like a little WNW wobble in the last frame.
http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

A little north of due west the last couple of frames.

[caribepr]

Can't figure out if Ana is a fighter or a wimp? Is she going to run away from the last bit of convection?

Wimp is good! We go for wimp! And TD3 can follow suit.

[thetruesms]

12Z NOGAPS runs it throught the Florida Straits to set this up:

[img]http://img15.imageshack.us/img15/9660/nogaps2009081512180h.gif[img]

Complete loop

It almost makes you want to think that someone sat down and drew that out rather than it being the output of a numerical model . . . almost.

[clfenwi]

POD is finally out (most immediately relevant part bold-faced):

NOUS42 KNHC 151715
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0115 PM EDT SAT 15 AUGUST 2009
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 16/1100Z TO 17/1100Z AUGUST 2009
TCPOD NUMBER.....09-079
I. ATLANTIC REQUIREMENTS
1. TROPICAL STORM ANA
FLIGHT ONE -- TEAL 70
A. 16/1800Z,17/0000Z
B. AFXXX 0102A ANA
C. 16/1530Z
D. 15.6N 56.3W
E. 16/1700Z TO 17/0000Z
F. SFC TO 10,000 FT
FLIGHT TWO -- TEAL 71
A. 17/0600Z,17/1200Z
B. AFXXX 0202A ANA
C. 17/0330Z
D. 16.7N 60.0W
E. 17/0500Z TO 17/1200Z
F. SFC TO 10,000 FT
2. OUTLOOK FOR SUCCEEDING DAY: CONTINUE 6-HRLY FIXES.
A G-IV SURVEILLANCE MISSION IS PLANNED FOR 18/0000Z
WITH TAKEOFF AT 17/1730Z. A FOLLOW-ON G-IV MISSION
IS POSSIBLE FOR 18/1200Z WITH TAKEOFF AT 18/0530Z.
3. REMARK: NOAA43 AND THE G-IV WILL FLY FOUR SUCCESSIVE
RESEARCH MISSIONS INTO AND AROUND ANA DEPARTING FROM
TBPB AT 15/2000Z, 16/0800Z, 16/2000Z, AND 17/0800Z.
II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.
SEF

[thetruesms]

Thunderstorms still forming (or are getting blown) to the east of the center of circulation.

Looks like they're going up to the east of the center, since it's been exposed all morning

[Frank2]

Breaking news - LLC pops out from under convection:

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

P.S. I stand by my comment of yesterday - perhaps the models should have some sort of "El Nino shear bias" built into them, since shear is such a big factor during El Nino events...