ATL: Ex COLIN - Discussion

[HurrMark]

The SHIPS forecast, in case anyone is curious where it is, is located at

ftp://ftp.tpc.ncep.noaa.gov/atcf/stext/

Scroll all the way down and look for the last instance of the storm header (in this case 10080112AL9110_ships.txt)

It does show increasing shear as it approaches the islands...probably TUTT related. It does have a stretch for the next 72-96 hours of fairly light shear...this does seem to be more convective in nature, but it looks all ITCZ related...not much turning yet. Maybe in 36-48 hours we will something.

[Sanibel]

I don't think that dry air will just go away.


If it flares up again tonight it should say a lot.


CMC shows a classic recurve out into the Atlantic.

[Recurve]

The 6Z GFS has a storm that seems to grow, fall apart, reappear, strengthen, weaken as it moves toward and through the Bahamas.

Just for fun I started my landfall tracking chart: 2,737nm from south florida, at avg. 10 knots, 11.4 days away or landfall on Thurs 12 Aug.
There's a set of Excel functions that use lat/long to calculate distance away, change in position, etc. if anyone needs it I can send it, or search Excel geo function on the web.

[Vortmax1]

I know many will not like what I will say but I am rooting hard for king TUTT to park near us

I'm rooting along with you Luis!
Strong upper troughs seem to be somewhat of a norm in that area this season so chances are pretty good there will be a presence when Colin comes calling.
As we all know, shear forecasts are horribly unreliable. But when there's a TUTT feature in the picture you can expect shear to be a factor.

[jinftl]

As always, Dr. Masters is the voice of reason based on an objective analysis of the current...and forecast...dynamics that 91L could encounter. He is not indicating in any way that the 'dye has been cast' and that someone in the islands is going to get 'pounded', that some area's 'luck has run out' because of what is coming, and that south florida and then the gulf coast are at risk of a major hurricane making landfall.

Here is the latest discussion by Dr Jeff Masters.

Posted by: JeffMasters, 1:51 PM GMT on August 01, 2010

A concentrated area of intense thunderstorms near 9N 36W, midway between Africa and the Lesser Antilles Islands, has become more organized this morning. NHC has labeled this system Invest 91L, and is giving it a 60% chance of developing into a tropical depression by 8am Tuesday. Wind shear is a moderate 10 - 20 knots, sea surface temperatures are at record highs, and the dust and dry air of the Saharan Air Layer (SAL) are far enough to the north of 91L to potentially allow further development. The main negatives for development are the current phase of the Madden-Julian Oscillation, which favors downward motion over the tropical Atlantic, and the fact that 91L is too close to the Equator to take much advantage of the Earth's spin to get spinning. Last night's ASCAT pass of the region did show a large region of westerly winds south of 91L, indicating that a surface circulation is trying to form. Satellite imagery shows that the intensity and areal extent of 91L's heavy thunderstorms is increasing. However, there are no signs of a surface circulation, and low-level spiral bands and upper-level outflow are not apparent yet.

Forecast for 91L
There is strong model support for 91L developing into a tropical depression. The GFS, ECMWF, NOGAPS, and UKMET models all develop 91L into a tropical depression by Tuesday or Wednesday. A west to west-northwest motion is predicted, and residents of the Lesser Antilles Islands should anticipate the possibility of a tropical storm arriving in the islands as early as Thursday. It is possible that 91L would pass northeast of the islands, as predicted by the UKMET model, and it is too early to speculate on which of the islands is at most risk. As the storm approaches the Lesser Antilles late this week, 91L will encounter a strong upper-level low pressure system centered north of Puerto Rico. This upper-level low will likely bring high levels of wind shear to the waters just north of Puerto Rico and Hispaniola. Thus, if 91L stays to the south, in the Caribbean, it is far more likely to attain hurricane status than if it pushes north of the Caribbean. As always, long range forecasts of this sort are speculative, and it is too early to reliably say what the long-term risks of 91L becoming a hurricane are. The latest intensity forecast from the SHIPS model shows 91L peaking in strength four days from now, then weakening as it encounters the high wind shear area north of Puerto Rico.

[cycloneye]

The latest.

[CrazyC83]

I think this might just stay well to the south all along. If that is the case, this could become a dangerous hurricane. Perhaps Felix could be an analog here?

[cycloneye]

I think this might just stay well to the south all along. If that is the case, this could become a dangerous hurricane. Perhaps Felix could be an analog here?

On what base you see it go that way?

[srainhoutx]

The longer this stays buried in the ITCZ and remains slow and weak, the further W option seems likely over the next 48-72 hours IMO.

[ROCK]

The longer this stays buried in the ITCZ and remains slow and weak, the further W option seems likely over the next 48-72 hours IMO.

exactly....I think we and a few pro mets have mentioned that a few pages back in the old thread....I will keep pounding away though....

[cycloneye]

The 12z Best Track was just updated:

Pressure down one millibar.

AL, 91, 2010080112, , BEST, 0, 100N, 363W, 25, 1007, LO

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 010.invest

[Vortmax1]

Based on this 700-850 steering chart a Felix-like track certainly does come to mind:

[Brent]

The 12z Best Track was just updated:

Pressure down one millibar.

AL, 91, 2010080112, , BEST, 0, 100N, 363W, 25, 1007, LO

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 010.invest

Getting there.

[Riptide]

I don't believe in all of this talk about a TUTT from hell in the western Atlantic because I don't believe in shear/upper-level forecasts that are 5+ days out.

Just my two cents...

[hurricaneCW]

I don't think this one will get that strong due to eventual shear, but it's only the beginning. It's certainly gradually organizing and beginning to pull further north and away from the ITCZ. I'm banking on Danielle as being the big cane of the season.

[jinftl]

Huh?

stats on Bonnie:


SUMMARY OF 615 PM EDT...2215 UTC...INFORMATION
--------------------------------------------------
LOCATION...22.9N 75.4W
ABOUT 200 MI...320 KM SE OF NASSAU
ABOUT 415 MI...670 KM ESE OF KEY WEST FLORIDA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/HR
PRESENT MOVEMENT...NW OR 315 DEGREES AT 14 MPH...22 KM/HR
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES

The 12z Best Track was just updated:

Pressure down one millibar.

AL, 91, 2010080112, , BEST, 0, 100N, 363W, 25, 1007, LO

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 010.invest

It's officially stronger than Bonnie.

[Aric Dunn]

well besides its nearly TD ... what i miss in the last 15 hours.. lol

[Vortmax1]

WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1130 AM EDT SUN 01 AUGUST 2010
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 02/1100Z TO 03/1100Z AUGUST 2010
TCPOD NUMBER.....10-063

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK: POSSIBLE NOAA G-IV
SURVEILLANCE MISSION OUT OF TISX AROUND CENTRAL
ATLANTIC SYSTEM FOR 04/0000Z IF IT DEVELOPS.

[Weatherfreak000]

The longer this stays buried in the ITCZ and remains slow and weak, the further W option seems likely over the next 48-72 hours IMO.

exactly....I think we and a few pro mets have mentioned that a few pages back in the old thread....I will keep pounding away though....

The models initially were developing this so quickly they didnt notice the dual wave situation which accompanied with the area's massive size, has made this process slow and painful.



Vorticity on the rise, but I totally agree with ROCK here. No matter where the storm is until the LLC develops you never ever know. Even when the LLC DOESN'T develop that still has massive track ramifications. Visible imagery suggests the organizational trend is continuing. I'm finding a hard time believing we won't see Colin.


Edit: Models are just a game at this point, without the LLC.

[dixiebreeze]

Pressure is dropping, IR Sat. is pretty definitive, the Bonnie TUTT was something of an anomaly, and climatic conditions are almost perfect. IMHO, it will almost be a miracle if Colin doesn't develop --- and most likely by sometime Monday as a TD/TS.