Extratropical Storm Chantal: last CHC advisory issued

[Thunder44]

latest satellite imagery indicates a partially exposed low-level
circulation center with the deep convection occupying the north-
eastern semicircle. At 0600 UTC...SHIPS c60y4 and zcdm6 reported
sustained 32 kt and 31 kt winds respectively. Dvorak intensity
estimates from TAFB were 2.0...and UW-CIMSS automated 3-hr averaged
intensity estimates have been running around 30 kt as well. Based
on the above...the initial intensity will be held conservatively at
30 kt.
The initial motion is estimated at 025/18...a little faster than
earlier. The depression is currently being steered ahead of a
large mid-latitude trough along the U.S. Eastern Seaboard. The
dynamical model guidance is in close agreement with an acceleration
toward the northeast and east-northeast through 3 or 4 days. The
models...however...significantly differ as to whether the cyclone
will become absorbed in the frontal system currently to the
northwest...or remain its own entity. The official track forecast...
albeit a low confidence one...keeps the system separate through 5
days similar to the previous advisory.
The cyclone is still over 26-27c waters...and a small window of
opportunity remains for it to reach tropical storm strength before
transitioning to an extratropical cyclone. FSU phase-space
diagrams derived from global model fields suggest full transition
in about 24 to 36 hours. SHIPS guidance has the extratropical
cyclone strengthening to a powerful 60 kt storm in 3 days. The
official intensity forecast does indicate strengthening but is less
bullish than SHIPS and a bit higher than the previous forecast.

Forecast positions and Max winds

initial 31/0900z 37.8n 64.9w 30 kt
12hr VT 31/1800z 40.4n 62.5w 35 kt
24hr VT 01/0600z 44.5n 57.0w 40 kt...extratropical
36hr VT 01/1800z 49.2n 47.6w 45 kt...extratropical
48hr VT 02/0600z 55.0n 37.0w 45 kt...extratropical
72hr VT 03/0600z 59.0n 28.5w 50 kt...extratropical
96hr VT 04/0600z 61.0n 21.0w 50 kt...extratropical
120hr VT 05/0600z 63.0n 13.5w 45 kt...extratropical

$$
forecaster Mainelli

[HURAKAN]

Convection has been increasing over the past few hours:

[HURAKAN]

Good morning sleeping beauty, it seems your center of circulation is under the convection, that's good.

[punkyg]

I want 99L to be chantel. not you! so wait a while!

[Matt-hurricanewatcher]

This deserves the name a lot more. It is taking off big time in the last hour or so...The center has moved close to the center...In you can see the convection and outflow really starting to explode on this storm. I would not be suprized if it was 45 knots at 8am pst/11am est.

[HURAKAN]

I want 99L to be chantel. not you! so wait a while!

This is like a pregnancy in the 37 week, it cannot wait any longer. 11 AM is probably its best and last shot at Chantal.

[Matt-hurricanewatcher]

If they keep this a TD at 8am, I will sell them a bridge I own in New york city. This is likely 45-50 knots.

http://www.ssd.noaa.gov/goes/flt/t1/vis.jpg

[Chacor]

I think you need to calm down.

[Matt-hurricanewatcher]

Prove otherwise that it is not?

[Chacor]

Here's the 9:44 UTC pass - nothing more than at the very most 35 kt.

http://manati.orbit.nesdis.noaa.gov/ocean_image21/qscat_barbs_atl_11.png

Top of the left-most pass.

[Thunder44]

QS pass at 9:46 UTC shows a couple of 35kt to 45kt barbs just north of the well-defined center:

http://manati.orbit.nesdis.noaa.gov/dat ... MBas19.png

There are alot rain contaminated barbs surrounding that area though.

[Matt-hurricanewatcher]

Wow thunder44 this thing has really became organized since the last quickscat. 45-50 knot wind flag on the northern quad.

[Thunder44]

Here's the 9:44 UTC pass - nothing more than at the very most 35 kt.

http://manati.orbit.nesdis.noaa.gov/ocean_image21/qscat_barbs_atl_11.png

Top of the left-most pass.

This closer look taken at 9:46 UTC:

http://manati.orbit.nesdis.noaa.gov/dat ... MBas86.png

The higher resolution image shows some 50kt+ flags.

[Matt-hurricanewatcher]

I don't mean any hard feelings with any ones. But just point out what the system appears to be doing.

[Chacor]

I don't mean any hard feelings with any ones. But just point out what the system appears to be doing.

I did not appreciate your rather terse PM to me. To quote yourself, "don't like it don't read it". I'm stating my own view that you were going overboard. The NHC are the experts here. You came very close to bashing them in my view, and I asked you to calm down.

The fact that you had to send me the PM probably proves my point that you needed to calm down, which you have since done, and I thank you for that. You're free to think as you do, as am I. We're also free to air our views. But when that borders on bashing a professional agency, I don't accept it.

For what it's worth I think it'll be a minimal TS (35 kt) at the next advisory.

[HURAKAN]

Looks better than ever:

[Thunder44]

From looking at QS ,visible and infrared imagery, I think we likely have a 40kt to 50kt TS. Unfortunately there no ship reports around yet to confirm the intensity.

CI # numbers are at 2.5 as of 10:45 UTC:

http://cimss.ssec.wisc.edu/tropic/adt/odt03L.html

[HURAKAN]

...SPECIAL FEATURES...

TROPICAL DEPRESSION THREE CENTERED NEAR 37.8N 64.9W AT 31/0900
UTC OR 330 NM NORTH OF BERMUDA AND ABOUT 330 NM SOUTHEAST
OF CHATHAM MASSACHUSETTS MOVING NNE 18 KT. ESTIMATED MINIMUM
CENTRAL PRESSURE IS 1007 MB. MAXIMUM SUSTAINED WINDS ARE 30 KT
WITH GUSTS TO 40 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR ADDITIONAL DETAILS.
THE SYSTEM REMAINS IN A SHEARED ENVIRONMENT WITH THE DEEP
CONVECTION CONFINED TO WITHIN 120-150 NM NORTHEAST OF THE
PARTIALLY EXPOSED LOW LEVEL CENTER. ALTHOUGH THE SYSTEM IS
EXPECTED TO REMAIN IN THIS ENVIRONMENT UNTIL IT TRANSITIONS TO
AN EXTRATROPICAL SYSTEM WITHIN 24 HOURS...THERE IS THE POTENTIAL
FOR THE DEPRESSION TO REACH STORM STRENGTH WITHIN THAT TIME.

Are they looking at the same visible images we are looking???

[Chacor]

We'll know the next advisory intensity in a while when the ATCF is updated...

[Aquawind]

Looks like some impressive deep convection this morning.. time is running out as the waters are about to cool quickly..