EPAC: GEORGETTE - Post-Tropical

[Yellow Evan]

CIMSS seems to be siding with SSD in terms of CDO temp.

[RL3AO]

Very impressive round of RI for the storm. Looks like a 110 to 115kt storm.

[1900hurricane]

It's amazing how good a storm can look when it stays south of the pronounced cold wake and generally colder waters.

[Yellow Evan]

----- Current Analysis -----
Date : 25 JUL 2016 Time : 020000 UTC
Lat : 16:16:28 N Lon : 125:57:00 W


CI# /Pressure/ Vmax
5.8 / 953.6mb/109.8kt


Final T# Adj T# Raw T#
5.8 5.9 6.0

Estimated radius of max. wind based on IR : 14 km

Center Temp : +12.2C Cloud Region Temp : -65.3C

Scene Type : EYE

[RL3AO]

John went with 115kt. Now a category 4.

[cycloneye]

HURRICANE GEORGETTE DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082016
800 PM PDT SUN JUL 24 2016

Georgette has been rapidly intensifying. The eye of the hurricane
has become much more distinct in satellite images since the previous
advisory, and the deep convection is fairly symmetric around the
center. The latest Dvorak estimates from TAFB, SAB, and CIMSS at
the University of Wisconsin support raising the initial intensity to
115 kt, making Georgette a category 4 hurricane on the Saffir-
Simpson Hurricane Wind Scale. This is an impressive 50-kt intensity
increase in the past 24 hours. Even though Georgette is a major
hurricane, scatterometer data from a few hours ago indicated that
its wind field is fairly compact.

Georgette has been taking advantage of favorable environmental
conditions of very low shear and sufficiently warm waters of about
27 deg C during its rapid intensification phase. Although the shear
is expected to remain light during the next few days, Georgette is
forecast to track over progressively cooler SSTs and it should cross
the 26 deg C isotherm in about 12 hours. Therefore, some additional
strengthening is possible overnight, but a steady weakening trend
should commence on Monday. Georgette is forecast to become a
post-tropical cyclone in 3 to 4 days when it is expected to be
embedded in a dry air mass and located over SSTs of 22-23 deg C.

The hurricane is moving northwestward at about 10 kt toward a
weakness in the subtropical ridge caused by an upper-level low. This
general heading with a decrease in forward speed is expected during
the next couple of days. After that time, a faster motion toward
the west-northwest and then west is forecast when the weakening
system becomes steered by the low-level trade wind flow. The NHC
track forecast is not too different from the previous one, and lies
close to the multi-model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT 25/0300Z 16.3N 126.1W 115 KT 130 MPH
12H 25/1200Z 17.1N 126.9W 110 KT 125 MPH
24H 26/0000Z 17.8N 127.8W 95 KT 110 MPH
36H 26/1200Z 18.5N 128.5W 80 KT 90 MPH
48H 27/0000Z 19.3N 129.4W 65 KT 75 MPH
72H 28/0000Z 21.3N 132.6W 45 KT 50 MPH
96H 29/0000Z 22.8N 137.5W 30 KT 35 MPH...POST-TROP/REMNT LOW
120H 30/0000Z 23.5N 143.0W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Cangialosi

[Ntxw]

No surprise there, rightfully so.

[hurricanes1234]

Category 4!!?! I did suspect it would become a major but this is really impressive!

[euro6208]

115 knots, does this make her the strongest so far in the EPAC? According to unisys, Blas peaked 5 knots lower.

It's quite small too.

It was fun watching her but just like most EPAC storms they peak and start to weaken out to sea. It's like replay after replay.

[Yellow Evan]

----- Current Analysis -----
Date : 25 JUL 2016 Time : 030000 UTC
Lat : 16:20:59 N Lon : 126:02:52 W


CI# /Pressure/ Vmax
5.9 / 951.4mb/112.4kt


Final T# Adj T# Raw T#
5.9 5.9 5.9

Estimated radius of max. wind based on IR : 15 km

Center Temp : +13.0C Cloud Region Temp : -64.4C

Scene Type : EYE

[1900hurricane]

Blas also peaked at 115 kt.

The latest Coriolis and NOAA-18 passes may be indicating a developing outer eyewall.

[Yellow Evan]

Blas peaked at 120 knts IIRC.

[1900hurricane]

Yeah, the latest F-17 pass certainly confirms the beginning of eyewall replacement.

[1900hurricane]

Blas peaked at 120 knts IIRC.

Yeah, you're right. The 03Z July 6th advisory was 120 kt, even though the working best track (what I looked at initially) only maxed out at 115 kt on the surrounding 00Z and 06Z.

[Alyono]

the globals do not have a handle on the environment at all

Ignore SHIPS/LGE. They failed big time with Darby

Take the 0Z MU. It has a weakening from 965mb to 985mb from 0Z to 6Z. Laughable at best.

The only model that has a grasp on this may be the NAVGEM.

Now, I do not expect this to threaten Hawaii. This should pass north in about a week

[Alyono]

ec initialized this at 994mb...

[cycloneye]

HURRICANE GEORGETTE DISCUSSION NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082016
200 AM PDT MON JUL 25 2016

Georgette is maintaining its organization. The cyclone exhibits an
annular appearance, with a nearly symmetric CDO and essentially no
banding features. A 0245 UTC SSMI/S hints at a possible eyewall
replacement, though it's not clear at what stage it has progressed.
Dvorak satellite classifications are a unanimous T6.0 at 0600 UTC,
and on this basis, the intensity estimate is kept at 115 kt.

The initial motion estimate is 315/09. A low- to mid-level ridge
to the north and east of Georgette would tend to steer it westward
or west-northwestward during the next few days. However, an upper-
low ahead of it should continue to impart a more northwesterly
motion, though at a much reduced forward speed. After 72 hours,
Georgette is forecast to become a much shallower cyclone, at which
time the track should bend toward the west and accelerate in the
low-level flow. The new track forecast is not much different than
the previous one, except that it is slower beyond 72 hours and a
little to the south, in agreement with the consensus track guidance.

The intensity forecast seems straightforward. Georgette's movement
over a colder sea surface and into increasingly drier and more
stable air mass should soon result in weakening. The caveat is that
Georgette's annular structure could allow it to maintain more
strength than forecast in the very short term. By 48 hours,
however, the thermodynamics in the storm's environment should
become hostile, and a more rapid weakening is expected to commence.
The new NHC intensity forecast is somewhat lower than the previous
one and is close to the multi-model consensus, except prior to 48
hours when the storm's annular characteristics have been taken into
account.


FORECAST POSITIONS AND MAX WINDS

INIT 25/0900Z 16.9N 126.8W 115 KT 130 MPH
12H 25/1800Z 17.6N 127.5W 105 KT 120 MPH
24H 26/0600Z 18.2N 128.2W 90 KT 105 MPH
36H 26/1800Z 18.8N 128.9W 75 KT 85 MPH
48H 27/0600Z 19.6N 130.0W 55 KT 65 MPH
72H 28/0600Z 21.4N 133.5W 35 KT 40 MPH...POST-TROPICAL
96H 29/0600Z 22.3N 138.4W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 30/0600Z 22.4N 143.2W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Kimberlain

[cycloneye]

HURRICANE GEORGETTE DISCUSSION NUMBER 16
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082016
800 AM PDT MON JUL 25 2016

Georgette's satellite presentation has begun to degrade. The small
eye has become filled in infrared imagery and the coverage and
symmetry of cold tops in the CDO have decreased. The initial
intensity of 105 kt is based on a blend of the latest Dvorak Final-T
and CI numbers from TAFB and SAB. Quick weakening is expected as
the cyclone will be moving over progressively cooler SSTs and into a
drier and more stable airmass during the forecast period. Georgette
should become a remnant low in about 3 days over SSTs of less than
23C and the remnant low is expected to dissipate in 4 to 5 days.
The new NHC intensity forecast is lower than the previous one but
is still a bit above the latest IVCN consensus aid.

The initial motion estimate is 315/08. Georgette is being pulled
northwestward by an upper-level low centered to its northwest, and
this motion should continue for the next 48 hours or so. After that
time, a shallow Georgette should accelerate westward in the low-
level trade wind flow. The new NHC track forecast is shifted a bit
to the right of the previous one and is close to the latest TVCN
consensus aid.

FORECAST POSITIONS AND MAX WINDS

INIT 25/1500Z 17.5N 127.3W 105 KT 120 MPH
12H 26/0000Z 18.0N 127.8W 95 KT 110 MPH
24H 26/1200Z 18.7N 128.5W 80 KT 90 MPH
36H 27/0000Z 19.4N 129.2W 65 KT 75 MPH
48H 27/1200Z 20.3N 130.6W 50 KT 60 MPH
72H 28/1200Z 21.9N 134.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 29/1200Z 22.5N 139.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 30/1200Z...DISSIPATED

$$
Forecaster Brennan

[hurricanes1234]

Oops :-/

Is this weakening only due to the eyewall replacement cycle or is it a combination of that and the storm entering the less favourable environment they were forecasting?

[cycloneye]

 https://twitter.com/RyanMaue/status/757588132619489280