Tropical Storm Joyce Discussion Number   5
NWS National Hurricane Center Miami FL       AL112024
1100 AM AST Sat Sep 28 2024

Joyce seems to be experiencing the effects of moderate-to-strong 
vertical wind shear.  After maintaining a decent convective burst 
overnight, southerly wind shear appears to be pulling the 
thunderstorms to the north, partially exposing the low-level 
circulation.  A new burst of convection is now growing near the 
center. Satellite-derived surface wind data measured a few wind 
speeds greater than 40 kt in the northwest quadrant, and the 
initial intensity is held at 45 kt for this advisory.  

The storm continues to move at 305/9 kt.  Joyce is on the south side 
of a narrow and weakening subtropical ridge, and should continue 
generally west-northwestward to northwestward for the next day or 
so.  As a deep-layer trough over the northern Atlantic amplifies and 
breaks the ridge, Joyce should slow and turn more poleward early 
next week.  The official forecast still shows the storm not 
recurving to the north, as it is expected to be a shallow vortex at 
that time, and instead drifts north-northwestward until the system 
dissipates, similar to the previous prediction.

Atmospheric conditions are forecast to remain marginal around Joyce 
in the coming days.  The SHIPS model diagnostics show the deep-layer 
vertical wind shear staying moderate-to-strong, likely forcing dry 
air into Joyce's circulation.  The latest intensity forecast is 
similar to the previous advisory and calls for little change in 
intensity today, followed by steady weakening through early next 
week.  Joyce is still expected to become a remnant low by day 3, 
however, models are now showing the system opening into a trough and 
dissipating by day 4, and this is reflected in the official 
forecast. 


FORECAST POSITIONS AND MAX WINDS

INIT  28/1500Z 20.0N  46.0W   45 KT  50 MPH
12H  29/0000Z 20.5N  47.3W   45 KT  50 MPH
24H  29/1200Z 21.1N  48.6W   40 KT  45 MPH
36H  30/0000Z 21.8N  49.4W   40 KT  45 MPH
48H  30/1200Z 22.2N  49.6W   35 KT  40 MPH
60H  01/0000Z 22.6N  49.7W   30 KT  35 MPH
72H  01/1200Z 23.1N  49.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
96H  02/1200Z...DISSIPATED

$$
Forecaster Bucci