EPAC: EUGENE - Post-Tropical

[Sciencerocks]

08/0600 UTC 13.1N 112.1W T2.5/2.5 EUGENE -- East Pacific

Still lagging...Based on the banding and central convective structure I'd say 45 knots.

[Sciencerocks]

Keeps looking better and better!

[Sciencerocks]

ZCZC MIATCDEP5 ALL
TTAA00 KNHC DDHHMM

Tropical Storm Eugene Discussion Number 3
NWS National Hurricane Center Miami FL EP052017
300 AM MDT Sat Jul 08 2017

Eugene's convective pattern has continued to improve since the
previous advisory, with a pronounced band of cold-topped convection
now wrapping more than halfway around the center. An ASCAT-A pass
at 0432Z indicated peak winds of 37 kt north of the center, but the
northeastern quadrant was missed where stronger winds could be
occurring. The initial intensity is being maintained at 40 kt for
this advisory based on consensus T2.5/35 estimates from TAFB and
SAB, and a UW-CIMSS ADT estimate of T2.7/39 kt.

The initial motion remains 315/08 kt. There is no significant change
to previous forecast track or reasoning. Eugene is expected to
continue moving around the southwestern periphery of a deep-layer
ridge that extends westward across central and northern Mexico for
the next 36-48 hours, and afterwards move into a weakness that is is
forecast to develop in the ridge well to the west of the Baja
California peninsula. The latest NHC model guidance is tightly
packed about the previous forecast track, so only minor along-track
speed changes were required.

The aforementioned ASCAT pass indicates that the inner-core wind
field of Eugene has become better defined and that the radius of
maximum winds has also contracted down to about 30 n mi. As
mentioned in the previous discussion, this now smaller RMW, in
conjunction with a nearly ideal environment, would typically support
rapid intensification. However, AMSU microwave and new GOES-16 water
vapor imagery indicate that a pronounced tongue of dry air has
penetrated into the southwestern quadrant, temporarily disrupting
the development of inner-core convection. But should the dry air mix
out during the next 12 h or so, then rapid strengthening is still a
distinct possibility before Eugene reaches colder water shortly
after the 36-h period. Beyond that time, the cyclone will be moving
over muh colder SSTs ranging from 21-24 deg C, which should induce
rapid weakening despite the low vertical wind shear conditions that
will exist throughout the forecast period. The new intensity
forecast is similar to the previous advisory, and closely follows
the HCCA consensus model.

FORECAST POSITIONS AND MAX WINDS

INIT 08/0900Z 12.9N 112.1W 40 KT 45 MPH
12H 08/1800Z 13.7N 113.0W 50 KT 60 MPH
24H 09/0600Z 14.9N 114.1W 60 KT 70 MPH
36H 09/1800Z 16.4N 115.2W 70 KT 80 MPH
48H 10/0600Z 17.9N 116.5W 70 KT 80 MPH
72H 11/0600Z 20.5N 119.0W 55 KT 65 MPH
96H 12/0600Z 22.9N 121.2W 40 KT 45 MPH...POST-TROPICAL
120H 13/0600Z 25.1N 123.3W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Stewart

NNNN

[Kingarabian]

CDO has finished forming and the LLC is tucked in nicely. On the verge of spitting out all the dry air. Should bomb out soon.

[cycloneye]

Rapid spike.

08/1200 UTC 13.0N 112.3W T3.5/3.5 EUGENE -- East Pacific

[Yellow Evan]

EP, 05, 2017070812, , BEST, 0, 133N, 1125W, 50, 1000, TS, 34, NEQ, 60, 40, 0, 50, 1012, 180, 20, 0, 0, E, 0, , 0, 0, EUGENE, D, 0, , 0, 0, 0, 0, genesis-num, 008,
EP, 05, 2017070812, , BEST, 0, 133N, 1125W, 50, 1000, TS, 50, NEQ, 20, 0, 0, 20, 1012, 180, 20, 0, 0, E, 0, , 0, 0, EUGENE, D, 0, , 0, 0, 0, 0, genesis-num, 008,

[Ntxw]

Sun is up

[talkon]

000
WTPZ45 KNHC 081432
TCDEP5

Tropical Storm Eugene Discussion Number 4
NWS National Hurricane Center Miami FL EP052017
900 AM MDT Sat Jul 08 2017

Eugene's cloud pattern has improved significantly since yesterday,
and it now consists of a cyclonically-curved convective band
wrapping around the center. The upper-level outflow continues to be
very well established in all quadrants. Based on the average of
intensity estimates of T3.0 and T3.5 on the Dvorak scale from TAFB
and SAB, respectively, and objective numbers from UW-CIMMS, the
winds have been increased to 50 kt in this advisory.

Eugene has the opportunity to gather some strength and become a
hurricane during the next 24 hours or so. However, after that time,
a portion of the circulation will begin to reach cooler waters and
drier air resulting in gradual weakening. By the end of the
forecast period, the cyclone will be over much cooler waters, and
Eugene will probably lose most of its associated convection and
become a remnant low. The intensity forecast is similar to the
previous one.

Eugene is moving toward the northwest or 315 degrees at 8 knots
around the southwestern periphery of a mid-level ridge centered
over the western United States and northern Mexico. A weak
mid-latitude trough will cause an erosion of the ridge, and this
steering pattern will keep Eugene on a general northwest track
during the next 4 to 5 days. The NHC forecast is basically in the
middle of the tightly-packed track guidance. No important changes to
the previous NHC forecast are necessary.


FORECAST POSITIONS AND MAX WINDS

INIT 08/1500Z 13.6N 112.8W 50 KT 60 MPH
12H 09/0000Z 14.5N 113.6W 60 KT 70 MPH
24H 09/1200Z 15.8N 114.7W 70 KT 80 MPH
36H 10/0000Z 17.5N 115.9W 70 KT 80 MPH
48H 10/1200Z 18.9N 117.2W 70 KT 80 MPH
72H 11/1200Z 21.5N 119.5W 55 KT 65 MPH
96H 12/1200Z 23.8N 121.6W 40 KT 45 MPH...POST-TROPICAL
120H 13/1200Z 25.5N 124.0W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Avila

[Ntxw]

[1900hurricane]

Looks to be in the early stages of building a banding type eye.

[hurricanes1234]

Eye see you!

[Sciencerocks]

Chance of Hurricane at 2pm Maybe cat2 by 2am.

[cycloneye]

08/1800 UTC 13.4N 113.0W T4.0/4.0 EUGENE -- East Pacific

[SouthDadeFish]

Looks like it is in the middle of RI. Should continue to strengthen quickly for the next 12-24 hours.

[Kingarabian]

Still hasn't completely exhausted the dry air.

[Kingarabian]

NHC is going with 60kts. But you cannot ignore that eye, and an eye means hurricane.

[cycloneye]

Tropical Storm Eugene Discussion Number 5
NWS National Hurricane Center Miami FL EP052017
300 PM MDT Sat Jul 08 2017

The cloud pattern in visible images looks much better than
the infrared presentation. Eugene appears to be developing a
banding type eye, and the outflow remains fair. Dvorak estimates are
now T3.5 and T4.0, and on this basis, the initial intensity has
been adjusted upward to 60 kt.

Eugene has the opportunity to gather more strength and become a
hurricane tonight. However, beyond 24 hours a portion of the
circulation will begin to move over cooler waters resulting in
gradual weakening. By the end of the forecast period, the cyclone
will be over much cooler waters, and Eugene will probably lose most
of its associated convection and become a remnant low. The intensity
forecast brings the winds a little bit higher than the earlier
forecast, but beyond 24 hours, the forecast is similar to the
previous one.

Eugene is moving toward the northwest or 320 degrees at 7 knots,
steered by the flow around the periphery of a mid-level ridge
centered over the western United States and northern Mexico. A weak
mid-latitude trough will cause an erosion of the ridge, and this
steering pattern will keep Eugene on a general northwest track
during the next 4 to 5 days. The NHC forecast is basically in the
middle of the tightly-packed track guidance, and very close to the
multi-model consensus. No important changes to the previous NHC
forecast track are necessary.


FORECAST POSITIONS AND MAX WINDS

INIT 08/2100Z 13.7N 113.4W 60 KT 70 MPH
12H 09/0600Z 14.7N 114.2W 70 KT 80 MPH
24H 09/1800Z 16.2N 115.5W 80 KT 90 MPH
36H 10/0600Z 17.8N 116.8W 70 KT 80 MPH
48H 10/1800Z 19.5N 118.2W 70 KT 80 MPH
72H 11/1800Z 22.0N 120.5W 50 KT 60 MPH
96H 12/1800Z 23.8N 122.2W 40 KT 45 MPH...POST-TROPICAL
120H 13/1800Z 25.5N 124.5W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Avila

[Kingarabian]

ADT having trouble positioning the eye. Or else we would be seeing a T5.5.

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 08 JUL 2017 Time : 210000 UTC
Lat : 13:38:59 N Lon : 113:02:23 W


CI# /Pressure/ Vmax
3.0 / 998.5mb/ 45.0kt


Final T# Adj T# Raw T#
2.8 3.2 5.4

[Kingarabian]

Working on a CMG/WMG?



The RI continues. 60kts was too low and thus the RI rate will be a lot higher.

[Yellow Evan]

Not a fan of storms that clear eyes around 60-65 knots.