ZCZC MIATCDEP5 ALL
TTAA00 KNHC DDHHMM
 
Tropical Storm Irwin Discussion Number   5
NWS National Hurricane Center Miami FL       EP102023
500 PM HST Sun Aug 27 2023
 
Cloud tops associated with Irwin's deep convection have warmed 
during the past few hours, possibly due to the tropical cyclone 
moving over cooler waters. The intensity estimate is still 35 kt, 
based primarily on the latest Dvorak Final-T analysis from TAFB.

No substantial changes were made to the NHC track or intensity 
forecast with this advisory. Along the forecast track, the sea 
surface temperatures are in the 25-26 deg C range for the next 2-3 
days. This could be warm enough for Irwin to sustain just enough 
deep convection to retain its status as a tropical cyclone, as shown 
in simulated satellite imagery from several dynamical models. 
However that should also prevent Irwin from strengthening. After 
that time, a combination of cool waters and a dry atmsopheric 
environment should cause Irwin to become a post-tropical remnant 
low. It's possible that transition could occur much sooner than 
currently forecast. Irwin should turn westward tonight and continue 
generally westward until it becomes a remnant low later this week. 
The NHC track forecast is a little south of the various consensus 
models for the first 48 hours based on recent satellite imagery 
indicating that Irwin's westward turn has already begun, but is 
close to them after that. The intensity forecast is directly in line 
with the consensus aids.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  28/0300Z 17.4N 122.5W   35 KT  40 MPH
 12H  28/1200Z 17.9N 123.9W   35 KT  40 MPH
 24H  29/0000Z 18.3N 126.0W   35 KT  40 MPH
 36H  29/1200Z 18.4N 128.7W   35 KT  40 MPH
 48H  30/0000Z 18.4N 131.6W   35 KT  40 MPH
 60H  30/1200Z 18.3N 133.9W   35 KT  40 MPH
 72H  31/0000Z 18.5N 136.1W   30 KT  35 MPH
 96H  01/0000Z 19.0N 140.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  02/0000Z 19.0N 142.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 
$$
Forecaster D. Zelinsky
 
NNNN