ATL: CLAUDETTE - Post-Tropical

[cycloneye]

I'm thinking the genesis time will be backed up to 0000Z or 0600Z.

Yes,they will have to revise back to extend it's life.

[wxman57]

Shear is really hitting it now. Winds are likely down. Center is becoming exposed. I think it peaked 2-3 hours ago and will go downhill from here...

[gatorcane]

ECMWF called for development many days in advanced and it did verify

[wxman57]

ECMWF called for development many days in advanced and it did verify

Yep, Saturday morning's ECMWF had a weak low moving off the NE U.S. Coast:

[HURRICANELONNY]

I need to point out the irony that, with this year being compared to 1997 as far as El Nino, that the same list was used that year, and Claudette formed on the same day in roughly the same place.

Claudette was the 4th storm of 1997, however[/quo

How can that be. It's the C storm

[galaxy401]

I need to point out the irony that, with this year being compared to 1997 as far as El Nino, that the same list was used that year, and Claudette formed on the same day in roughly the same place.

Claudette was the 4th storm of 1997, however[/quo

How can that be. It's the C storm

An unnamed Subtropical storm formed in the first days of the season.

[cycloneye]

TROPICAL STORM CLAUDETTE DISCUSSION NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032015
500 PM AST MON JUL 13 2015

Claudette is a sheared tropical cyclone, with the low-level center
exposed to the southwest of the main mass of deep convection. The
current intensity estimate is held at 45 kt, well above the Dvorak
estimates, based on the earlier scatterometer data. The numerical
guidance indicates that the cyclone will be affected by vertical
shear of greater than 30 kt over the next day or so, and this
should prevent significant strengthening. Weakening should
commence tomorrow, and the system will likely become a
post-tropical cyclone in 36 hours or sooner. Both the ECMWF and
GFS global models show the cyclone losing its identity in 48 hours,
so the official forecast shows dissipation at that time.

Claudette is beginning to accelerate and the motion estimate is now
045/15. An additional increase in forward speed is expected as the
storm moves in the flow ahead of a mid-level trough near the Great
Lakes. The official track forecast is similar to the previous one
and on the left side of the guidance envelope. This is in best
agreement with the latest GFS and ECMWF solutions.

FORECAST POSITIONS AND MAX WINDS

INIT 13/2100Z 38.1N 66.9W 45 KT 50 MPH
12H 14/0600Z 39.9N 64.9W 45 KT 50 MPH
24H 14/1800Z 42.6N 62.0W 40 KT 45 MPH
36H 15/0600Z 45.7N 59.5W 35 KT 40 MPH...POST-TROPICAL
48H 15/1800Z...DISSIPATED

$$
Forecaster Pasch

[gatorcane]

still this storm chews up another name. I believe we are above average on number of systems for this point in the season?

[Alyono]

still this storm chews up another name. I believe we are above average on number of systems for this point in the season?

more than 2 storms more than average so far.

of course, by mid July, 1995, we were on the 5th storm. Only had 3 more

[Hammy]

I don't remember who made a mention of it earlier, but we have indeed had the mid-July El Nino east coast storm that was common before 2009's. And the NAM model gets it right yet again, as it was the first one to develop this, and did well with intensity of the last two as well.

[JonathanBelles]

Blog Post: http://jonathanbelles.com/2015/07/13/we ... med-storm/

[cycloneye]

TROPICAL STORM CLAUDETTE DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032015
1100 PM AST MON JUL 13 2015

Claudette has not changed much in strength this evening. The cloud
pattern remains asymmetric with all of the deep convection confined
to the northeast part of the circulation due to about 30 kt
of southwesterly shear. Continued strong shear combined with much
colder water along the expected track should cause Claudette to lose
its tropical characteristics in 24 hours or less. The global
models show the post-tropical low dissipating on Wednesday.

Satellite fixes indicate that the center of the storm is located to
the southeast of the previous track. The latest initial motion
estimate is east-northeastward at 17 kt. A turn to the northeast
or north-northeast is expected to occur on Tuesday, and that general
motion should continue until the storm dissipates. The official
track forecast is adjusted to the right of the previous one and is
in best agreement with the GFS model.

The intensity and wind radii forecasts are based on guidance from
NOAA's Ocean Prediction Center.

FORECAST POSITIONS AND MAX WINDS

INIT 14/0300Z 38.9N 64.9W 45 KT 50 MPH
12H 14/1200Z 40.6N 62.7W 45 KT 50 MPH
24H 15/0000Z 43.2N 59.8W 40 KT 45 MPH...POST-TROPICAL
36H 15/1200Z 46.3N 57.0W 35 KT 40 MPH...POST-TROPICAL
48H 16/0000Z...DISSIPATED

$$
Forecaster Cangialosi

[cycloneye]

TROPICAL STORM CLAUDETTE DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032015
1100 AM AST TUE JUL 14 2015

Claudette's cloud pattern is rapidly becoming less organized. Deep
convection continues to burst northeast of the low-level center,
with the latter becoming increasingly exposed and diffuse this
morning. The cyclone's current structure is symptomatic of deep
layer of southwesterly shear of over 30 kt, as diagnosed by SHIPS
model analyses. Dvorak classifications were T2.0/30 kt and T2.5/35
kt from SAB and TAFB at 1200 UTC, respectively. The initial
intensity is lowered to 35 kt, at the higher end of these estimates
due to the storm's increasing forward speed. Claudette has already
passed the northern wall of the Gulf Stream and will be moving
over sea surface temperatures below 20 deg C soon. Cooler waters, a
much more stable and drier atmosphere, and continued strong
southwesterly shear should contribute to Claudette's weakening.
Global models suggest that extratropical transition should occur in
about 24 hours, with the system opening up into a trough shortly
after that. The official intensity forecast is in excellent
agreement with the multi-model consensus.

The initial motion estimate is 050/18. Prior to dissipation
tomorrow, Claudette's track should turn north-northeastward with
some additional acceleration while it rotates around large
deep-layer cyclone over eastern Canada. The latest track forecast
has changed little from the previous one.


FORECAST POSITIONS AND MAX WINDS

INIT 14/1500Z 41.4N 61.3W 35 KT 40 MPH
12H 15/0000Z 43.6N 59.0W 30 KT 35 MPH
24H 15/1200Z 46.7N 56.8W 30 KT 35 MPH...POST-TROP/EXTRATROP
36H 16/0000Z...DISSIPATED

$$
Forecaster Kimberlain

[cycloneye]

TROPICAL STORM CLAUDETTE DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032015
500 PM AST TUE JUL 14 2015

Recent visible satellite imagery indicates Claudette's circulation
has become shallow and disorganized, with the low-level circulation
completely decoupled from the convection to the east-northeast. An
uncontaminated ASCAT pass at 1430 UTC observed winds of 42 kt in the
southeast quadrant, which indicates that Claudette has maintained
its intensity longer than expected. Assuming some weakening has
occurred since the ASCAT pass, the initial intensity estimate is set
at 40 kt. Further weakening should occur over the next 12 hours as
the system moves over progressively colder SSTs and transitions to
an extratropical cyclone. Global models show the system opening up
into a trough in 24 hours and the official forecast calls for
dissipation by that time.

The initial motion estimate is 050/18 kt. Claudette is forecast to
continue toward the north-northeast while it rotates around a large
deep-layer cyclone over eastern Canada. The official track
forecast is close to the dynamical model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT 14/2100Z 42.5N 59.8W 40 KT 45 MPH
12H 15/0600Z 44.8N 57.6W 35 KT 40 MPH...POST-TROP/EXTRATROP
24H 15/1800Z...DISSIPATED

$$
Forecaster Kimberlain

[cycloneye]

Last advisory.


POST-TROPICAL CYCLONE CLAUDETTE DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032015
1100 PM AST TUE JUL 14 2015

Claudette has lacked organized deep convection for nearly 10 hours
now, and it only consists of a swirl of low-level clouds. The
cyclone is currently over SSTs near 17 C, so it is highly unlikely
that significant thunderstorm activity will return. Therefore,
Claudette is considered a post-tropical cyclone, and this is the
last advisory on this system issued by the National Hurricane
Center.

The post-tropical cyclone is moving quickly northeastward at
about 18 kt, and this general motion is expected to continue until
the cyclone dissipates on Wednesday. The current wind speed is
estimated to be 40 kt based on recent ASCAT data. Environment
Canada's buoy 44141 has been helpful in locating the center and
estimating the minimum pressure.

Additional information on this system can be found in High Seas
Forecasts issued by the National Weather Service, under AWIPS
header NFDHSFAT1, WMO header FZNT01 KWBC, and available on the Web
at http://www.opc.ncep.noaa.gov/shtml/NFDHSFAT1.shtml.

FORECAST POSITIONS AND MAX WINDS

INIT 15/0300Z 43.8N 57.8W 40 KT 45 MPH...POST-TROPICAL
12H 15/1200Z 46.0N 55.5W 35 KT 40 MPH...POST-TROP/EXTRATROP
24H 16/0000Z...DISSIPATED

$$
Forecaster Cangialosi