ATL: Ex-Tropical Storm GASTON - Discussion

[Sanibel]

I'd say the structure and convection are good enough for possible development still.

[supercane]

Latest ASCAT pass shows only a tropical wave (albeit with a sharp axis), quite different from yesterday:


Looking at that buoy (42060), hard to say if that's the local effect of a thunderstorm vs a true reflection of the environmental flow. I suspect the former. Plus, there is no significant pressure drop to indicate a developing system.

The upper-level environment seems favorable enough:


Latest microwave:

[Sanibel]

The SCATs are notorious for missing west winds in the Caribbean.


I think people are looking at this backwards. Once it's survived this long it should burst in the favorable west Caribbean.

[5KOVERLIBOR]

>>KWT, Aric Dunn - much thanks to the both of you for your knowledge. Is it in your opinions that we can point to these anomalously low vertical instability profiles as a cornerstone in any explanation for the lack of activity, not only with ex-Gaston, but in the basins as a whole? And if this is the case, is it reasonable to state that until we see these instabilities increase, we cannot reasonably expect "typical" peak-season performance?

I don't think it is at all. I think each of the storms is a product of what's going on at the time. The biggest issue to date, and it's something Bastardi threw out there a few weeks ago that KWT and I had been talking about, is that the generally lower pressure in the NE US and Canada have been doing the work of redistribution of heat. In other words, there hasn't really been a need for the tropics to do the dirty work (at least up until Danielle and Earl came along). We're also in a somewhat strong and increasing La Nina season where there is a greater likelihood of a later season with plenty of weaker, western-biased storms and recurves. I think we total it up at the end of the year and see if things made sense. If not, then we wonder if it was low vertical instability, lack of temperature contrast between the sea surface and upper atmosphere (which was what Dr. Masters started hinting at in mid-August before the season took a turn) or if it was something else or many factors. But I think the initial slow start had to do with low pressure profiles in the northeast. There is no strong signal that that profile is going to change or flip for any length of time as both the ECMWF and GFS are +/- neutral-negative NAO for the forseeable future.

Steve, much thanks for your thoughts. It was Masters' very highlighting of the vert instabilities a month ago (specifically the improvement of the Trop Atlantic profile - which has since again gone below seasonal norms) that prompted me asking about them in a binary sense (they improve --> season does, etc). Rightly or wrongly, in my company's daily monitoring of the tropics, first stop are these instability profiles. Until they improve we just aren't expecting much that resembles "peak season" performance. Of course this doesn't rule out genesis anywhere and everywhere, but it seems in so far as you really can't get warm parcels ripping through the atmosphere, those looking for a good deal of convection are just behind the 8 ball with these anomalously tame instability profiles.

[chrisnnavarre]

Yep'er heading due west...right down the 17N line. Probably stay south of Haiti and maybe even a little south of Jamaica, but right now he looks "CDBR" with that island.

This ones gonna be a ride....

[ColinDelia]

Amazing that there have been approximately 1,500 posts on a system that has never been more than a weak TS - life's very short folks - don't waste valuable time on something that doesn't require this much discussion...

Frank

Cyclogenesis is the most interesting part of meteorology to me. I would rather spend days trying to figure out why a system develops or doesn't develop than to watch a full-blown hurricane go through its ups and downs for a week. Whether a TC actually forms or doesn't I could care less. There will be plenty of enough both in a season.

[Steve]

>>Steve, much thanks for your thoughts. It was Masters' very highlighting of the vert instabilities a month ago (specifically the improvement of the Trop Atlantic profile - which has since again gone below seasonal norms) that prompted me asking about them in a binary sense (they improve --> season does, etc). Rightly or wrongly, in my company's daily monitoring of the tropics, first stop are these instability profiles. Until they improve we just aren't expecting much that resembles "peak season" performance. Of course this doesn't rule out genesis anywhere and everywhere, but it seems in so far as you really can't get warm parcels ripping through the atmosphere, those looking for a good deal of convection are just behind the 8 ball with these anomalously tame instability profiles.

Gotcha. My theory is that it will help to explain some of the earlier sesaon inactivity, but I really think (and I'm a little by myself on this one) if there was one thing to point to, it's the lower than normal pressure in the NE US and Eastern Canada. I think Masters had to put something out there because a chorus of "where the hell is this crazy season?" was infecting the media, message boards, newspapers and everywhere else. It might help explain some of it, but I think he probably should have waited a little longer to address as almost right thereafter, there was a big pulse that brought us the D, E, F & G storms. To sum it up, I think it's part of the argument, but it's not the entire argument. That's just my opinion, but I felt like Masters was kind of fishing for something to appease the people who were railing that all the crazy seasonal predictions weren't coming true. This board is a microcosm of that where you had posters just dying to be 'right' - many of whom haven't been seen since Earl hit the map.

[Vortex]

Should I dare say we have lift off....

[cycloneye]

Should I dare say we have lift off....

Can you elaborate more?

[southerngale]

Amazing that there have been approximately 1,500 posts on a system that has never been more than a weak TS - life's very short folks - don't waste valuable time on something that doesn't require this much discussion...

Frank

Just a curious question from a novice and rare poster ...... but why tell people not to waste valuable time on a topic you appear to be following and posting to regularly ??? Are you saying you are not wasting your time , or that your posts are more valuable then someone else's ??

And who cares how other people spend their time? Everyone just worry about themselves.

And let's try to stay on topic, please.

[Vortex]

was referring to the convective bursting taking place which has been lacking for days..maybe now with a surface circulation Gaston is closing in taking his name back...

[Ivanhater]

Let me squash this right now. If someone wants to post in a certain thread, they have every right.

If you don't like it, go to a different thread.

Anymore thoughts or concerns about the matter can be brought up through PM to S2K staff. This thread is about Gaston. Back on topic.

Edit: beat me to it SG

[southerngale]

Back up to 20%


ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT TUE SEP 7 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM HERMINE...LOCATED INLAND ABOUT 15 MILES SOUTH-SOUTHEAST OF SAN
ANTONIO TEXAS.

1. SHOWERS AND THUNDERSTORMS REMAIN DISORGANIZED IN ASSOCIATION WITH
THE REMNANTS OF GASTON LOCATED ABOUT 120 MILES SOUTHEAST OF PUERTO
RICO. DEVELOPMENT...IF ANY...OF THIS SYSTEM IS EXPECTED TO BE SLOW
TO OCCUR AS IT MOVES WESTWARD NEAR 15 MPH. THERE IS A LOW
CHANCE...20 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
AGAIN DURING THE NEXT 48 HOURS.

2. SHOWER ACTIVITY ASSOCIATED WITH A WEAK AREA OF LOW PRESSURE LOCATED
ABOUT 400 MILES WEST-NORTHWEST OF THE NORTHERNMOST CAPE VERDE
ISLANDS REMAINS MINIMAL. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO
BE UNFAVORABLE FOR DEVELOPMENT DURING THE NEXT COUPLE OF DAYS AS
THE LOW MOVES WESTWARD NEAR 10 MPH. THERE IS A LOW CHANCE...10
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

3. A TROPICAL WAVE APPROACHING THE CAPE VERDE ISLANDS IS PRODUCING A
LARGE AREA OF DISORGANIZED SHOWERS AND THUNDERSTORMS.
DEVELOPMENT...IF ANY...OF THIS SYSTEM IS EXPECTED TO BE SLOW TO
OCCUR AS IT MOVES WESTWARD AT 10 TO 15 MPH DURING THE NEXT COUPLE
OF DAYS. THERE IS A LOW CHANCE...20 PERCENT...OF THIS SYSTEM
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER CANGIALOSI/PASCH
NNNN

[Shuriken]

The whole thing is exploding this morning....apparently Gaston's singular purpose for existence is to make monkeys out of as many NHC odds-makers as possible.

All I hope for is it stays south of Haiti. I will go out on a limb and say it develops within 48 hours(barring land interaction).

If it stays south of Haiti/DR, and develops, you're probably getting a cat-4 in the west-carr. Remember how quickly Gustov intensified?

[CourierPR]

I've been watching this on the RAMSDIS floater and it looks better with every frame. Convection is firing in all quadrants around the apparent center.

[tolakram]

Doesn't look to be anything there, even at the mid levels.

Saved loop:

[Bailey1777]

looking better and seems it will go south of the islands, so next question does it ride all the way into s.america or come up into the gom? any thoughts on steering?

[Frank2]

LOL - now the NHC should have gone the other way (perhaps 30%), but perhaps they read a comment here about waiting for at least one forecast cycle before getting excited over a flare-up, though seriously my guess is that perhaps they've noticed that this circulation has had a diurnal flare-up each early afternoon - only to dissipate later in the day and evening...

P.S. Per the earlier comments about my comment - those here who are unfortunate enough to know me (lol) know that I'm only on this board off and on for few hours each day and then go on to other things...

[Wx_Warrior]

Cat 4 Shuriken?

Gee whiz slow down....Glad Hermine didn't end up going north into Louisiana.

[Ivanhater]