CPAC: LINDA - Post-Tropical

[Kingarabian]

It's still pretty dry in the northern quads but because northerly shear has letup just a little (actually looks like shear is from the NW now), the CDO has been able to reform with the core structure embedded properly. To the point where a warm spot is becoming more prevalent.

[Yellow Evan]

The latest Euro runs are keeping this deep somehow over cooler waters in the CPAC.

Yet another example of the ECMWF keeping storms in this basin too deep over 23-24C waters.

[Kingarabian]

The latest Euro runs are keeping this deep somehow over cooler waters in the CPAC.

Yet another example of the ECMWF keeping storms in this basin too deep over 23-24C waters.

We normally see this scenario with the GFS.

[Yellow Evan]

With 36-48 hours left and the gradual structural improvements, Linda certainly could make a run at Category 3/4. Shear is finally subsiding a little and if the GFS is correct will continue to for the next several days. The biggest issue going forward is dry air intrusions that could disrupt the inner core and prevent Linda from getting over the hump. However, I like it’s chances at becoming a major hurricane better than I did yesterday but I’m a little reluctant to go gungho.

[Yellow Evan]

The latest Euro runs are keeping this deep somehow over cooler waters in the CPAC.

Yet another example of the ECMWF keeping storms in this basin too deep over 23-24C waters.

We normally see this scenario with the GFS.

Nah it’s an issue with the ECMWF as well just not as bad.

[Yellow Evan]

CDO expanding at least. I really need to see a good microwave pass to properly gauge its intensity.

[cycloneye]

Hurricane Linda Discussion Number 11
NWS National Hurricane Center Miami FL EP122021
300 PM MDT Thu Aug 12 2021

There hasn't been much change to Linda's structure since this
morning. The hurricane's center is embedded within a small Central
Dense Overcast, and a dimple is evident in visible satellite images
where an eye would be likely to form. For the most part, satellite
intensity estimates have not changed from this morning, and a 1550
UTC ASCAT-A pass showed peak winds in the 55-60 kt range. Given
that instrument's typical undersampling, especially for a small
cyclone, the 65-kt initial intensity still seems appropriate.

Linda is moving toward the west-northwest, or 300/8 kt, to the
south of a mid-tropospheric ridge located over northern Mexico.
This ridge, and a stronger mid-level high developing over the
western United States, are expected to continue driving Linda
toward the west-northwest for the next 2-3 days. By days 4 and 5,
another mid-level high is forecast to develop between Hawaii and
Alaska, and that feature is likely to block Linda's northward
progress, and possibly even cause a south-of-due-west motion by the
end of the forecast period. The track guidance is in good
agreement on this scenario, and the updated NHC track forecast has
been nudged southward mainly on days 4 and 5. It should be noted
that this new forecast is not as far south as several of the track
models, and additional southward adjustments may be required in
subsequent forecasts.

Various shear analyses suggest that the northerly shear affecting
Linda may have decreased slightly, with the magnitude now on the
order of 10-15 kt. SHIPS diagnostics indicate that this level of
shear is likely to continue for another 24 hours or so, and then it
could decrease further and enable some gradual strengthening.
Models generally show Linda's intensity peaking and leveling off in
the 36-60 hour window. After 60 hours, Linda is expected to move
into a less favorable thermodynamic environment, highlighted by
colder sea surface temperatures and drier, more stable air, and
weakening is therefore shown on days 3-5. One important note is
that further southward shifts in the forecast track would keep
Linda over warmer waters and potentially slow the cyclone's
weakening trend.


FORECAST POSITIONS AND MAX WINDS

INIT 12/2100Z 15.3N 108.7W 65 KT 75 MPH
12H 13/0600Z 16.0N 110.3W 70 KT 80 MPH
24H 13/1800Z 17.0N 112.4W 75 KT 85 MPH
36H 14/0600Z 17.9N 114.6W 80 KT 90 MPH
48H 14/1800Z 18.7N 116.8W 80 KT 90 MPH
60H 15/0600Z 19.0N 118.8W 80 KT 90 MPH
72H 15/1800Z 19.0N 120.8W 75 KT 85 MPH
96H 16/1800Z 18.6N 124.5W 65 KT 75 MPH
120H 17/1800Z 18.5N 128.3W 55 KT 65 MPH

$$
Forecaster Berg

[Yellow Evan]

ECMWF has this at 17N 128W at day 5. If it verifies, SST's in the area are 26C. Day 6 is similar. Days 7-10 is where the ECMWF weakens this too slow as SST's drop to 23-25C yet ECMWF keeps this as a full fledged tropical system.

[Kingarabian]

[url]https://i.imgur.com/dqZxYuZ.png[url]

ECMWF has this at 17N 128W at day 5. If it verifies, SST's in the area are 26C. Day 6 is similar. Days 7-10 is where the ECMWF weakens this too slow as SST's drop to 23-25C yet ECMWF keeps this as a full fledged tropical system.

Even the Reynolds SST method which is warmer than others shows cool waters around 20N/140W. Maybe the Euro is incorporating a fast forward speed that limits the affects of cooler waters.

[Kingarabian]

Nevermind, the reason the Euro keeps this a deep system is because it makes this an annular hurricane.

[Kingarabian]

Excluding the WSW dip between 125W/130W the Euro is showing a Lester 2016 type track. However, Lester 2016 had an ample amount of warm SST's.

[Yellow Evan]

:uarrow:

Nevermind, the reason the Euro keeps this a deep system is because it makes this an annular hurricane.
https://i.imgur.com/7XdIbHo.png

From my understanding, an annular hurricane here is unlikely unless the shear direction changes to easterly (which the SHIPS output does not do).

[Yellow Evan]

Excluding the WSW dip between 125W/130W the Euro is showing a Lester 2016 type track. However, Lester 2016 had an ample amount of warm SST's.
https://i.imgur.com/oDcPMzt.png

The issue here ofc is the lack of +PMM SST setup. Would be a sure fire 30+ ACE storm otherwise.

[Kingarabian]

:uarrow:

Nevermind, the reason the Euro keeps this a deep system is because it makes this an annular hurricane.
https://i.imgur.com/7XdIbHo.png

From my understanding, an annular hurricane here is unlikely unless the shear direction changes to easterly (which the SHIPS output does not do).

Seems like the GFS attempts to make it annular at some point:

[Kingarabian]

HWRF also eventually makes it annular:

[Hurricane Mike]

If Linda goes annular, she'll be here atleast another week.

[Kingarabian]

Slowly strengthening its core:

[Yellow Evan]

TXPZ23 KNES 130001
TCSENP

A. 12E (LINDA)

B. 12/2330Z

C. 15.5N

D. 109.1W

E. THREE/GOES-E

F. T4.0/4.0

G. IR/EIR/VIS

H. REMARKS...8/10 BANDING AROUND LLCC YIELDS DT OF 3.5. MET AND PT ARE
4.0 AND FT IS BASED ON MET DUE TO BANDING NOT BEING CLEAR-CUT.

I. ADDL POSITIONS

NIL


...MLEVINE

Why no embedded center pattern?

[Kingarabian]

[Yellow Evan]

Closed eyewall.