Official Discussion issued by the National Hurricane Center

Leslie (AL132018) DATA RELEASED: 10/9/2018 11:00:00 PM UTC

Copy of official data

Hurricane Leslie Discussion Number  55
NWS National Hurricane Center Miami FL       AL132018
1100 PM AST Tue Oct 09 2018

Satellite and microwave data indicate that Leslie has become a
hurricane again, almost exactly a week after it did the first time.
A WindSat pass from earlier today showed the development of an eye
feature, and with the Dvorak estimates from TAFB and SAB at
hurricane strength, the initial wind speed is set to 65 kt.  The
latest GOES-16 proxy visible imagery suggests that a ragged eye has
formed, although the eyewall is open on the southwestern side.

Leslie is atypically intensifying while moving south-southeastward
at 8 kt.  The hurricane should continue to lose latitude for a day
or so then get accelerated east-northeastward by a mid-latitude
trough until Friday.  After that time, there is a ginormous spread
in the model ensembles with Leslie's final destination ranging from
Ireland all the way to missing the trough and turning around to the
southwest due to a building eastern Atlantic subtropical ridge.
Compared to 12 hours ago, more of the ensemble members are showing
Leslie getting left behind, which is also reflected in the latest
deterministic runs as well.  Something tells me that Leslie has at
least one more trick up its sleeve, so the official forecast shows
this trend, but is very low confidence.

With fairly low shear and marginally warm waters for the next day
or two, there is no reason to expect that Leslie won't continue to
intensify.  Model guidance is higher than the last cycle, with the
normally conservative ECMWF and GFS models even suggesting that
Leslie becomes a category 2 hurricane in a couple of days.  Most of
the rest of the guidance is lower than those models, but the
intensity forecast is shaded in the direction of the ECMWF/GFS,
and is higher than the last NHC prediction.  After that time, an
increase in shear and lower SSTs should cause Leslie to weaken. It
is even possible it will become a post-tropical cyclone by day 5,
but I'm not going to show that at this time since I was too
premature last night in this transition.


FORECAST POSITIONS AND MAX WINDS

INIT  10/0300Z 29.5N  42.6W   65 KT  75 MPH
12H  10/1200Z 28.4N  42.3W   70 KT  80 MPH
24H  11/0000Z 28.0N  41.6W   75 KT  85 MPH
36H  11/1200Z 28.6N  39.8W   80 KT  90 MPH
48H  12/0000Z 29.9N  36.4W   80 KT  90 MPH
72H  13/0000Z 32.2N  27.0W   75 KT  85 MPH
96H  14/0000Z 32.0N  21.0W   55 KT  65 MPH
120H  15/0000Z 30.0N  22.0W   40 KT  45 MPH

$$
Forecaster Blake