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Tropical Storm Irwin Discussion Number  10
NWS National Hurricane Center Miami FL       EP102023
1100 PM HST Mon Aug 28 2023
 
Irwin's convective renaissance was short lived. Deep convection 
associated with the tropical storm has decreased substantially since 
0300 UTC. However, ASCAT data around 0500 UTC showed an area of 
winds near or just above 35 kt to the north of Irwin, suggesting 
that the cyclone had briefly (and very slightly) strengthened. Since 
then, the decrease in convection has likely been accompanied by a 
slight decrease in the winds, so the advisory intensity remains at 
35 kt.
 
The tropical storm has finally turned toward the west, and there is
no change to the track forecast thinking. For the next several days
Irwin will be steered generally westward by a mid- to low-level
ridge to the north of Irwin. The NHC track forecast is very near
the TVCN and GFEX consensus models. Likewise, there's no change to
the intensity forecast reasoning. A combination of cool sea surface
temperatures and dry surrounding air should cause Irwin to slowly
weaken. The tropical cyclone could continue to produce enough
convection to remain a tropical cyclone for another day or so, but
it should become post-tropical by around mid-week, if not much
sooner.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  29/0900Z 19.5N 127.1W   35 KT  40 MPH
 12H  29/1800Z 19.5N 129.4W   35 KT  40 MPH
 24H  30/0600Z 19.2N 132.2W   35 KT  40 MPH
 36H  30/1800Z 19.1N 134.4W   30 KT  35 MPH
 48H  31/0600Z 19.2N 136.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  31/1800Z 19.4N 137.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  01/0600Z 19.5N 139.2W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  02/0600Z 19.6N 141.4W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  03/0600Z 20.5N 143.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
$$
Forecaster D. Zelinsky
 
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