Tropical Storm Joyce Discussion Number   2
NWS National Hurricane Center Miami FL       AL112024
500 PM AST Fri Sep 27 2024

Deep convection has increased and become more concentrated near the 
center of Joyce this afternoon. A cold dense overcast has developed 
and expanded over the low-level center of the tropical cyclone. As a 
result, the latest satellite intensity estimates have risen, and the 
initial intensity is brought up to 45 kt. This is consistent with a 
T3.0/45-kt Dvorak classification from TAFB, as well as a blend of 
recent UW-CIMSS objective estimates that range from 36-52 kt. 

Additional near-term strengthening is possible while Joyce remains 
in an environment of strong upper-level divergence and moderate 
shear over warm SSTs. However, the storm is forecast to encounter 
increasing shear and a progressively drier mid-level environment 
during the next couple of days, which should induce a weakening 
trend later this weekend and into early next week. The updated NHC 
intensity forecast peaks at 55 kt in 12 h, with gradual weakening 
shown thereafter based on the less favorable environmental 
conditions that are anticipated. Simulated satellite imagery from 
the latest ECMWF run shows Joyce maintaining organized convection 
through Monday, but the GFS suggests it could degenerate to a 
remnant low even sooner. This forecast shows Joyce degenerating into 
a post-tropical remnant low in 72 h and dissipating by day 5, but 
future timing changes may be necessary.

The storm continues to move northwestward (305/11 kt) around the 
southwestern periphery of a low- to mid-level ridge over the eastern 
Atlantic. A slight turn toward the west-northwest is expected during 
the next day or two, along with a slower forward speed as the 
steering currents weaken. There is more spread in the track guidance 
thereafter, with some model disagreement about whether and how 
quickly the storm turns northward ahead of an upper trough over the 
central Atlantic. For now, the NHC track forecast is shifted 
slightly to the left and is a bit slower between 48-72 h, following 
the latest HCCA and and TVCA trends.


FORECAST POSITIONS AND MAX WINDS

INIT  27/2100Z 18.6N  44.0W   45 KT  50 MPH
12H  28/0600Z 19.1N  45.3W   55 KT  65 MPH
24H  28/1800Z 19.5N  47.1W   50 KT  60 MPH
36H  29/0600Z 20.1N  48.5W   45 KT  50 MPH
48H  29/1800Z 20.7N  49.5W   40 KT  45 MPH
60H  30/0600Z 21.4N  49.9W   35 KT  40 MPH
72H  30/1800Z 22.0N  49.8W   30 KT  35 MPH...POST-TROP/REMNT LOW
96H  01/1800Z 23.0N  49.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  02/1800Z...DISSIPATED

$$
Forecaster Reinhart