Official Discussion issued by the National Hurricane Center

Joyce (AL112024) DATA RELEASED: 9/29/2024 3:00:00 PM UTC

Copy of official data

Tropical Storm Joyce Discussion Number   9
NWS National Hurricane Center Miami FL       AL112024
1100 AM AST Sun Sep 29 2024

The center of Joyce is exposed on the southern side of a small
area of deep convection due to continued strong south-southwesterly
vertical wind shear. The most recent scatterometer data from 1230
UTC indicates at least 35 kt winds are within the circulation, and
given the known low bias of the instrument, 40 kt is chosen as the
initial intensity, closest to a blend of the TAFB T- and CI-numbers.

The storm has been moving more slowly this morning, estimated to be
northwestward at about 5 kt.  Joyce should turn northward on Monday
due to a deep-layer trough over the north-central Atlantic.  The
only notable change to some of the guidance this cycle is that they
generally agree Joyce or its remnants will be less vertically deep
by mid-week. This evolution should result in less northward
acceleration as the circulation decays due to persistent shear and
dry air aloft.  Thus, the new NHC forecast is a bit to the left and
slower based on the latest aids.  The intensity guidance remains in
good agreement, and the only slight intensity change from the last
advisory is to show Joyce becoming a remnant low at 48 h.


FORECAST POSITIONS AND MAX WINDS

INIT  29/1500Z 21.6N  48.5W   40 KT  45 MPH
12H  30/0000Z 22.1N  49.2W   35 KT  40 MPH
24H  30/1200Z 22.6N  49.3W   30 KT  35 MPH
36H  01/0000Z 23.3N  49.3W   30 KT  35 MPH
48H  01/1200Z 24.1N  49.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
60H  02/0000Z 25.2N  49.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
72H  02/1200Z...DISSIPATED

$$
Forecaster Blake