EPAC: MARIE - Post-Tropical

[aspen]

The large convective band on the west side of the storm is warming and more cold convection is firing over the core. It also appears that an eye-like feature is attempting to form.

[Extratropical94]

18Z BT updated to hurricane

EP, 18, 2020093018, , BEST, 0, 142N, 1144W, 65, 988, HU

[aspen]

Forecast peak has been raised to 120 kt with this advisory. At the rate Marie is getting herself together, she could be nearing Cat 4 status tomorrow night, and a Cat 5 is not out of the realm of possibility if the surrounding environment allows her to take full advantage of the 28-29C SSTs. However, the one problem I see is that the current structure with such a large curved outer band could funnel dry air into the core and stall intensification, like how Genevieve was stalled due to dry air intrusion.

[cycloneye]

Hurricane Marie Discussion Number 7
NWS National Hurricane Center Miami FL EP182020
200 PM PDT Wed Sep 30 2020

Marie has continued to become better organized today, with a
well-defined convective band that wraps more than completely around
the cloud system center. This yields a Dvorak intensity estimate of
at least 65 kt, and subjective and objective T-numbers from SAB and
UW-CIMSS respectively also correspond to an intensity of 65 kt.
Therefore, the system is being upgraded to a hurricane, which is the
first for the month of September in this relatively quiet eastern
North Pacific hurricane season. The vertical wind shear has
decreased and is forecast to remain low for the next few days.
This, combined with a moist low- to mid-tropospheric air mass and
warm sea surface temperatures, should lead to an environment that is
very conducive for strengthening. In fact, the SHIPS RI Index shows
a significant probability of rapid intensification over the next 24
hours. Therefore, the official forecast calls for Marie to become a
major hurricane tomorrow with additional strengthening during the
succeeding day. This is close to the predictions from the two
corrected consensus techniques, HCCA and FSSE. By 72 hours, Marie
should have begun passing over progressively cooler waters, so a
steady weakening trend is likely to be underway by that time.

The motion continues just north of due west, or 275/14 kt. The
track forecast reasoning hasn't changed much from the previous
advisories. Over the next few days, the hurricane should be steered
on a westward to west-northwestward course on the south side of a
mid-level subtropical ridge. Right around the end of the forecast
period, Marie should begin to turn more to the right in response to
a weakness in the ridge. The official track forecast is similar to
the previous one and lies between the simple and corrected dynamical
consensus predictions.


FORECAST POSITIONS AND MAX WINDS

INIT 30/2100Z 14.3N 115.1W 65 KT 75 MPH
12H 01/0600Z 14.4N 117.3W 85 KT 100 MPH
24H 01/1800Z 14.8N 120.0W 100 KT 115 MPH
36H 02/0600Z 15.6N 122.5W 115 KT 130 MPH
48H 02/1800Z 16.6N 124.7W 120 KT 140 MPH
60H 03/0600Z 17.7N 126.7W 120 KT 140 MPH
72H 03/1800Z 18.6N 128.4W 100 KT 115 MPH
96H 04/1800Z 20.3N 131.4W 70 KT 80 MPH
120H 05/1800Z 21.8N 134.0W 50 KT 60 MPH

$$
Forecaster Pasch

[aspen]

That western band needs to go for Marie to take off.

[Kingarabian]

Definite warm spot in the CDO. Structure looks great.

[Kingarabian]

AMSR2 pass:


Progressing nicely.

[ElectricStorm]

That western band needs to go for Marie to take off.
https://rammb-data.cira.colostate.edu/tc_realtime/products/storms/2020ep18/amsusr89/2020ep18_amsusr89_202009301720.gif

I've always wondered about those western bands. What exactly do they do that hurts TC's? I know storms like Haiyan have those and can get intense

[aspen]

A massive hot tower just burst and is expanding over the CoC.

[Astromanía]

It looks good

[ElectricStorm]

No change
18E MARIE 201001 0000 14.4N 115.8W EPAC 65 988

[aspen]

Marie is firing massive hot tower after massive hot tower. The latest one is producing <-80C cold dark grey convection, and other smaller towers indicate core building is well underway. Once the eyewall solidifies, Marie is going to go nuclear.

[cycloneye]

Hurricane Marie Discussion Number 8
NWS National Hurricane Center Miami FL EP182020
800 PM PDT Wed Sep 30 2020

Passive microwave satellite data and satellite intensity estimates
indicate that Marie has undergone a brief intensity hiatus since the
previous advisory. Date from the 2055Z AMSR and 2306Z SSMI
microwave passes indicated that the earlier eye feature has eroded
some and opened up on the east side due to dry air entrainment and
modest easterly vertical wind shear of about 10 kt. The initial
intensity is being held at 65 kt based on subjective Dvorak
classifications of T4.0/65 kt from both TAFB and SAB, and UW-CIMSS
objective intensity estimates of T4.1/67 kt and 62 kt from ADT and
SATCON, respectively.

The motion estimate is 280/14 kt. The latest NHC model guidance
remains in excellent agreement through about 96 h on Marie moving
west-northwestward toward a weakness in the subtropical ridge
located to the north of the cyclone. Thereafter, there is
considerable divergence in the guidance with the ECMWF and UKMET
taking Marie more westward, while the GFS, HWRF, and HMON models
take the hurricane northward into a break in the ridge; the latter
scenario is preferred by the various simple and corrected consensus
models. As a result, no significant changes were required to the
previous forecast, and the new forecast track essentially lies down
the model of the tightly packed consensus model envelope.

Although the eyewall has eroded somewhat, the small inner-core wind
field still appears to be intact based on low-level cloud features
seen in 36-37 GHz satellite imagery. Once the narrow dry air
intrusions mix out in about 6 hours or so, rapid intensification
(RI) should resume and continue through 48 hours while the shear
gradually decreases to near zero by then. By 60 hours and continuing
through the remainder of the forecast period, cooler sea-surface
temperatures, along with cold upwelling generated by Marie, should
cause the hurricane to weaken, with rapid weakening likely beginning
by 72 hours when significant southwesterly vertical wind shear kicks
in ahead of a deep-layer trough that will be moving eastward out of
the central Pacific. The new official intensity forecast is
essentially identical to the previous NHC forecast, and lies along
the extreme upper end of the intensity guidance, about midway
between the Navy COAMPS-TC model (CTCI) and the NOAA-HCCA
corrected-consensus model.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0300Z 14.5N 116.5W 65 KT 75 MPH
12H 01/1200Z 14.7N 118.6W 80 KT 90 MPH
24H 02/0000Z 15.3N 121.3W 100 KT 115 MPH
36H 02/1200Z 16.2N 123.6W 115 KT 130 MPH
48H 03/0000Z 17.2N 125.6W 120 KT 140 MPH
60H 03/1200Z 18.2N 127.5W 100 KT 115 MPH
72H 04/0000Z 19.1N 129.1W 85 KT 100 MPH
96H 05/0000Z 20.7N 131.8W 65 KT 75 MPH
120H 06/0000Z 22.6N 134.3W 45 KT 50 MPH

$$
Forecaster Stewart

[Yellow Evan]

Having some dry air issues but at the same time it doesn't look THAT bad on MW. I'd expect serious progress tomorrow.

[Kingarabian]

Continues to progress:

[cycloneye]

Hurricane Marie Discussion Number 9
NWS National Hurricane Center Miami FL EP182020
200 AM PDT Thu Oct 01 2020

Recent microwave data and satellite images indicate that Marie has
become much better organized over the past several hours, with a
nearly completely closed eye noted in a 0451Z AMSU composite
microwave overpass. The initial intensity has been increased to 80
kt, based on a blend of the latest satellite intensity estimates
from TAFB, SAB, and the UW-CIMMS ADT and SATCON.

Marie appears to have resumed its anticipated rapid intensification
(RI), and this RI should continue for the next day or so while the
hurricane remains in an environment of very low vertical wind shear
while over warm waters. After 48 h, the cyclone is forecast to begin
moving over progressively cooler waters, while encountering
increasing vertical wind shear and a drier, more stable atmospheric
environment. These factors should cause Marie to begin weakening by
Saturday. Rapid weakening could occur by late this weekend when the
cyclone is expected to be over waters with SSTs cooler than 26
degrees C while vertical wind shear becomes greater than 25 kt. The
latest NHC intensity forecast is very close to the HFIP corrected
consensus aid HCCA and the DSHP guidance.

The initial motion is 280/15 kt. Marie is forecast to continue
moving westward around a subtropical ridge to its north and
northeast for the next 12 to 24 hours. A gradual turn to the
west-northwest along with a decrease in forward speed is expected to
occur beginning later tonight as the ridge weakens slightly. By late
in the forecast period, a turn to the northwest should occur as
Maria reaches a break in the ridge. The models are generally in
good agreement on this scenario, but vary somewhat in how sharp of a
turn to the right Marie makes later on in the forecast period. The
latest NHC track forecast is little changed from the previous one,
and lies near the various track consensus models.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0900Z 14.8N 118.1W 80 KT 90 MPH
12H 01/1800Z 15.2N 120.2W 100 KT 115 MPH
24H 02/0600Z 16.0N 122.7W 115 KT 130 MPH
36H 02/1800Z 16.9N 125.0W 120 KT 140 MPH
48H 03/0600Z 18.0N 126.9W 120 KT 140 MPH
60H 03/1800Z 19.0N 128.5W 100 KT 115 MPH
72H 04/0600Z 19.8N 130.0W 85 KT 100 MPH
96H 05/0600Z 21.1N 132.8W 65 KT 75 MPH
120H 06/0600Z 23.0N 135.0W 45 KT 50 MPH

$$
Forecaster Latto

[Darvince]

Why hello there suspicious warm spot...

[aspen]

The eye should be clearing out very soon.

[aspen]

12z best track is up to a 90 kt/973 mbar Category 2 hurricane.

[aspen]

Raw T#’s have shot up to 7.4!