ATL: LESLIE - Post-Tropical - Discussion

[Ubuntwo]

This is kind of a dumb question but what would the NHC do if Leslie became a subtropical cyclone with hurricane force winds?

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Hurricane! Noal 2001 did this.

That's a different case, it purportedly transitioned to tropical as it reached hurricane intensity.
As per NHC:

The subtropical cyclone drifted northward initially, its speed increasing to about
10 kt by late on 4 November. Convection, which had been limited to the northern semicircle,
became more symmetric as it formed a ring around the center with a radius of about 60 n mi. The
system developed a weak mid-level warm core early on 5 November, strengthened and became a
hurricane with 65 kt winds at 1200 UTC that day, about 535 n mi south-southeast of Cape Race

[cycloneye]

Post-Tropical Cyclone Leslie, located over the central Atlantic
Ocean several hundred miles west of the Azores, remains a powerful
non-tropical low with storm-force winds. The associated shower
activity has gradually become better organized around the low's
center since yesterday, and Leslie is expected to again become a
subtropical storm, or possibly a tropical storm, on Friday while it
moves west-southwestward at about 10 mph over the north-central
Atlantic. For more information on this system, see High Seas
Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

[galaxy401]

If a storm has hurricane winds while it's subtropical, I believe they still call it a Subtropical Storm.

[EquusStorm]

Has had far more convection in the last 24 hours than when it was classified (still not fully convinced it was subtropical the whole time it was classified the first time) and yet no upgrade yet. Seems par for the course this year. I assume it'll be reclassified this evening, as convection remains as organized as it was, or better than, the first time.

[NDG]

It is starting to acquire if not already subtropical characteristics, IMO.
Is over SSTs in the mid to upper 70s which is warm enough and as it moves towards warmer waters over the next few days it should acquire more tropical characteristics and should become a full tropical hurricane. It should add some nice ACE numbers to the Atlantic Basin because is going to meander around for so long.

[EquusStorm]

I'd love this to be a good ACE builder, not hurting anyone except for the swells it produces and sitting and spinning gorgeously. Slight trend upward with intensity in the ensembles; this would be interesting to watch.

[EquusStorm]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Fri Sep 28 2018

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical
Storm Kirk, located over the eastern Caribbean Sea.

Post-Tropical Cyclone Leslie is located over the central Atlantic
Ocean about 1000 miles west of the Azores. The associated shower
activity is becoming better organized, and recent satellite wind
data indicates that the circulation has become more characteristic
of a subtropical cyclone. If current trends continue, advisories
will be re-initiated later today or tonight. Regardless of whether
the system becomes a subtropical or tropical cyclone, Leslie should
continue to produce strong winds and high seas over a large portion
of the central Atlantic for the next several days. For more
information on this system, see High Seas Forecasts issued by the
National Weather Service.
* Formation chance through 48 hours...high...near 100 percent.
* Formation chance through 5 days...high...near 100 percent.

[cycloneye]

100%/100%

Post-Tropical Cyclone Leslie is located over the central Atlantic
Ocean about 1000 miles west of the Azores. The associated shower
activity is becoming better organized, and recent satellite wind
data indicates that the circulation has become more characteristic
of a subtropical cyclone. If current trends continue, advisories
will be re-initiated later today or tonight. Regardless of whether
the system becomes a subtropical or tropical cyclone, Leslie should
continue to produce strong winds and high seas over a large portion
of the central Atlantic for the next several days. For more
information on this system, see High Seas Forecasts issued by the
National Weather Service.
* Formation chance through 48 hours...high...near 100 percent.
* Formation chance through 5 days...high...near 100 percent.

[cycloneye]

SubTropical Storm at 5 PM:

AL, 13, 2018092818, , BEST, 0, 363N, 474W, 45, 986, SS

[bg1]

SubTropical Storm at 5 PM:

AL, 13, 2018092818, , BEST, 0, 363N, 474W, 45, 986, SS

Where can I find the best track data?

[cycloneye]

SubTropical Storm at 5 PM:

AL, 13, 2018092818, , BEST, 0, 363N, 474W, 45, 986, SS

Where can I find the best track data?

ftp://ftp.nhc.noaa.gov/atcf/btk/

[cycloneye]

...POST-TROPICAL CYCLONE LESLIE REGAINS SUBTROPICAL STORM STATUS...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...36.1N 48.1W
ABOUT 1170 MI...1880 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 260 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...986 MB...29.12 INCHES

[Kazmit]

That's a big wind field.

[Emmett_Brown]

It sure is! This thing must be a wave generating machine!

[Ubuntwo]

It sure is! This thing must be a wave generating machine!

You'd be right about that.

[Kazmit]

It sure is! This thing must be a wave generating machine!

You'd be right about that.

https://cdn.discordapp.com/attachments/289981599448039425/495339248833265664/wvheight.JPG

Time to dust off the surfboard again.

[galaxy401]

Yeah that is big! That means some of the waves in Nova Scotia and Hispaniola are from Leslie!

[HurricaneRyan]

Hope this can become a fish hurricane then. I want to hit 100 ACE

[Ntxw]

Hope this can become a fish hurricane then. I want to hit 100 ACE

The current NHC forecast through 5 days yields 3-4 units of ACE. So far Leslie has generated about ~1 unit.

[WAcyclone]

CSU predicts Leslie to generate between 10 and 15 ACE: https://tropical.colostate.edu/media/sites/111/2018/09/2018-0927.pdf