EPAC: LOWELL - Post-Tropical

[Yellow Evan]

I've never really seen a storm like Lowell in the EPAC. The second image you posted looks amazing.

[somethingfunny]

I've never really seen a storm like Lowell in the EPAC. The second image you posted looks amazing.

It really is. I want the new page to see it, it's incredible!

[Kingarabian]

Lowell is fricking huge.

[Ntxw]

What season it is to follow the EPAC! Even the run of the mill casual storm gives us some love. Regardless of what happens the rest of the way, this basin this year has made do what the Atlantic has been unable to do for me for the past two years when tracking real systems.

[Yellow Evan]

Lowell is fricking huge.

The convection isn't that huge. It's eye is though.

[Yellow Evan]

On another note, this is the EPAC's 6th hurricane in a row.

2011 didn't even have this.

[somethingfunny]

Lowell is fricking huge.

The convection isn't that huge. It's eye is though.

Lowell's footprint is bigger than Texas, I think it may even give Alaska a run for its' money.

[Yellow Evan]

This has to be one of the largest eyes of all time.

[Yellow Evan]

Why?

EP, 12, 2014082200, , BEST, 0, 207N, 1226W, 60, 984, TS, 34, NEQ, 160, 140, 140, 160, 1008, 375, 60, 0, 0, E, 0, , 0, 0, LOWELL, D,
EP, 12, 2014082200, , BEST, 0, 207N, 1226W, 60, 984, TS, 50, NEQ, 80, 70, 60, 80, 1008, 375, 60, 0, 0, E, 0, , 0, 0, LOWELL, D,

[supercane]

Lower Dvorak from SAB, perhaps?
DATE TIME LAT LON CLASSIFICATION ID NAME
20140822 0000 20.7 122.4 T3.5/4.0 12E LOWELL
20140821 1730 20.2 121.8 T4.0/4.0 12E LOWELL
20140821 1130 19.7 121.8 T4.0/4.0 12E LOWELL
20140821 0600 19.4 121.7 T3.5/3.5 12E LOWELL

BTW, normally everyone likes to trot out the UW-CIMSS ADT, but it's not performing well with Lowell at all, with a T number that wouldn't even qualify it as a tropical storm. (See http://tropic.ssec.wisc.edu/real-time/adt/odt12E.html)

[Yellow Evan]

It's struggling due to the weird structure.

[supercane4867]

ADT is having the wrong scene type with Lowell. It should be "large eye" using EIR pattern and curved band analysis does not apply

[Ptarmigan]

East Pacific hurricanes are rarely large as the basin is smaller than West Pacific and Atlantic. Lowell has to be one of the largest East Pacific hurricanes in some time.

[Ptarmigan]

We all know that these simulated IR satellite graphics are unreliable at best (and usually flat out wrong) but they give us an easy-to-see representation of potential rainfall. Check out how Lowell's moisture plume may affect the United States according to the 12z GFS!

Initialization



Although the track will remain well offshore, the scenario forecast by the NHC is pretty interesting:

Since Lowell is such a large cyclone, it will likely take
longer than average to spin down. The NHC forecast shows Lowell
becoming a post-tropical cyclone with gale-force winds in 3 days and
weakening to a remnant low afterward.

A "naked swirl" with gale-force winds??

I notice the last two forecast model has a massive hurricane.

[Yellow Evan]

We all know that these simulated IR satellite graphics are unreliable at best (and usually flat out wrong) but they give us an easy-to-see representation of potential rainfall. Check out how Lowell's moisture plume may affect the United States according to the 12z GFS!

Initialization



Although the track will remain well offshore, the scenario forecast by the NHC is pretty interesting:

Since Lowell is such a large cyclone, it will likely take
longer than average to spin down. The NHC forecast shows Lowell
becoming a post-tropical cyclone with gale-force winds in 3 days and
weakening to a remnant low afterward.

A "naked swirl" with gale-force winds??

I notice the last two forecast model has a massive hurricane.

That's Invest 92E.

[cycloneye]

TROPICAL STORM LOWELL DISCUSSION NUMBER 17
NWS NATIONAL HURRICANE CENTER MIAMI FL EP122014
800 PM PDT THU AUG 21 2014

Lowell as now weakening as about half of the circulation is over
sea surface temperatures of 26C or colder. While microwave imagery
continues to show a 75 n mi wide eye, the eyewall convection has
warmed and become asymmetric. Satellite intensity estimates are now
55 kt from TAFB and 65 kt from SAB. The initial intensity is
therefore decreased to 60 kt.

The storm is now moving 325/5. The track forecast reasoning remains
unchanged, as Lowell should move a little faster toward the
northwest due to a ridge rebuilding to the east and north of the
cyclone. Late in the period a shallower Lowell should be steered
more toward the west-northwest by the low-level ridge to the north.
There is no significant change to the track guidance since the last
advisory, and the new forecast track lies close to the previous
track and near the center of the guidance envelope.

Lowell is expected to remain in a light shear environment for the
next few days, with the intensity being controlled by decreasing sea
surface temperatures along the forecast track. The new intensity
forecast is an update of the previous forecast and calls for Lowell
to become a remnant low in about 72 hours. It is possible that the
associated convection could dissipate earlier than currently
forecast, with Lowell briefly becoming a gale-force post-tropical
low.

FORECAST POSITIONS AND MAX WINDS

INIT 22/0300Z 20.9N 122.8W 60 KT 70 MPH
12H 22/1200Z 21.7N 123.8W 55 KT 65 MPH
24H 23/0000Z 22.8N 125.3W 50 KT 60 MPH
36H 23/1200Z 23.9N 126.7W 45 KT 50 MPH
48H 24/0000Z 25.0N 128.0W 40 KT 45 MPH
72H 25/0000Z 26.5N 130.5W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 26/0000Z 28.5N 133.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 27/0000Z 30.0N 137.5W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven

[somethingfunny]

Lower Dvorak from SAB, perhaps?

BTW, normally everyone likes to trot out the UW-CIMSS ADT, but it's not performing well with Lowell at all, with a T number that wouldn't even qualify it as a tropical storm. (See http://tropic.ssec.wisc.edu/real-time/adt/odt12E.html)

While I wouldn't be shocked if hypothetical recon confirmed the winds really aren't any higher than 60kt - it could be as low as 55kt or as high as 70 kt in my opinion but this seems like a fine windspeed to estimate - I think a recon mission would find Lowell's pressure way lower than 984mb.

[Kingarabian]

I hope Lowell sticks around until Marie develops its eye.

[Yellow Evan]

Lower Dvorak from SAB, perhaps?

BTW, normally everyone likes to trot out the UW-CIMSS ADT, but it's not performing well with Lowell at all, with a T number that wouldn't even qualify it as a tropical storm. (See http://tropic.ssec.wisc.edu/real-time/adt/odt12E.html)

While I wouldn't be shocked if hypothetical recon confirmed the winds really aren't any higher than 60kt - it could be as low as 55kt or as high as 70 kt in my opinion but this seems like a fine windspeed to estimate - I think a recon mission would find Lowell's pressure way lower than 984mb.

Well, 982mbar is low for a 60 knt TS in the EPAC. In the WPAC, not so much.

[Yellow Evan]

000
WTPZ42 KNHC 220834
TCDEP2

TROPICAL STORM LOWELL DISCUSSION NUMBER 18
NWS NATIONAL HURRICANE CENTER MIAMI FL EP122014
200 AM PDT FRI AUG 22 2014

Lowell continues to exhibit a large ragged eye-like feature in
satellite imagery, however the convection surrounding it has
continued to warm and decrease in coverage overnight. The initial
wind speed has been reduced to 55 kt, which is a blend of the latest
Dvorak T- and current intensity numbers. Lowell will be moving over
progressively cooler waters and into a drier and more stable
environment during the next several days. This should lead to
gradual weakening, and Lowell is expected to become a gale-force
post-tropical cyclone in a couple of days. The cyclone should
continue to spin down after that time.

The latest satellite fixes indicate that Lowell is moving a little
faster toward the northwest or 320/7 kt. The storm should continue
moving northwestward around the western portion of a building
mid-level ridge during the next couple of days. After that
time, the weaker and more shallow post-tropical cyclone is expected
to turn west-northwestward to the south of a low-level ridge. The
updated NHC track forecast is similar to the previous advisory and
near the middle of the guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT 22/0900Z 21.5N 123.4W 55 KT 65 MPH
12H 22/1800Z 22.3N 124.4W 50 KT 60 MPH
24H 23/0600Z 23.5N 125.8W 45 KT 50 MPH
36H 23/1800Z 24.6N 127.2W 40 KT 45 MPH
48H 24/0600Z 25.4N 128.4W 35 KT 40 MPH...POST-TROPICAL
72H 25/0600Z 26.7N 130.5W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 26/0600Z 28.5N 134.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 27/0600Z 30.3N 138.0W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brown