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Tropical Storm Philippe Discussion Number   3
NWS National Hurricane Center Miami FL       AL172023
1100 PM AST Sat Sep 23 2023
 
Philippe is still a disorganized tropical storm.  Geostationary 
satellite imagery shows that deep convection is displaced to the 
northeast of the low-level center.  Recent satellite-derived wind 
data revealed that the surface circulation is still elongated and 
winds in the southwest quadrant are quite weak.  The initial 
intensity is held at 35 kt for this advisory, based on the ASCAT 
observations.
 
The tropical storm is moving westward at an estimate 12 kt.  This 
general motion should continue for the next two days, as Philippe 
moves along the south side of a mid-level ridge.  By 60 h, the storm 
should gradually turn to the west-northwest and northwest as it 
reaches a weakness in the ridge.  The latest track forecast is 
similar to the previous advisory through day 3, and has shifted to 
the west and slightly slower at days 4 and 5.

Model guidance suggests Philippe should gradually organize and thus 
slowly strengthen in the next few days.  This is possibly due to 
some mid-level vertical wind shear and upstream dry air.  Beyond day 
3, Philippe is expected to approach a mid- to upper-level trough, 
that should increase deep-layer vertical wind shear, but could also 
increase upper-level difluence.  The intensity guidance generally 
favors some slight intensification during this period.  The latest 
NHC forecast is similar to the previous advisory, and lies slightly 
above the consensus aid, IVCN.  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/0300Z 15.4N  40.9W   35 KT  40 MPH
 12H  24/1200Z 15.5N  42.6W   40 KT  45 MPH
 24H  25/0000Z 15.9N  44.8W   40 KT  45 MPH
 36H  25/1200Z 16.3N  47.1W   40 KT  45 MPH
 48H  26/0000Z 16.7N  49.1W   45 KT  50 MPH
 60H  26/1200Z 17.4N  50.7W   45 KT  50 MPH
 72H  27/0000Z 18.3N  52.0W   50 KT  60 MPH
 96H  28/0000Z 21.2N  53.9W   55 KT  65 MPH
120H  29/0000Z 23.5N  54.5W   60 KT  70 MPH
 
$$
Forecaster Bucci
 
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