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WTNT42 KNHC 281436

TCDAT2

 

Tropical Storm Philippe Discussion Number  21

NWS National Hurricane Center Miami FL       AL172023

1100 AM AST Thu Sep 28 2023

 

Philippe remains a very disorganized and elongated storm.

Geostationary and microwave satellite images show a low-level

circulation center well to the west of the mid-level center, where

most of the deep convection is currently concentrated.  The

estimated center position shown in this advisory is roughly midway

between those features, however confidence is very low on the

storm's position. In fact, it is possible that Philippe no longer

has a well-defined center. The initial intensity is held at 45 kt,

which is near the high end of the satellite intensity estimates.

 

The initial motion is highly uncertain since the storm is elongated 

and confidence in the initial position is very low.  The track 

forecast is challenging, in part due to Philippe's close proximity 

to newly formed Tropical Storm Rina.  In the short term, a slow 

southwestward motion seems likely as Philippe moves in weak steering 

currents between a mid- to upper-level trough to its northeast and 

Rina to its east-southeast.  By late in the weekend, a mid-level 

ridge is anticipated to build over the subtropical central Atlantic, 

and that feature should cause Philippe to turn sharply northward 

east of the northern Leeward Islands.  The NHC track forecast has 

been adjusted to the south for the first couple of days, but lies to 

the east of the previous forecast at days 4 and 5.  This prediction 

is closest to the ECMWF model.

 

The environmental conditions for Philippe no longer seem unfavorable

given its expected to track to the east of the islands and not

within a region of strong shear.  Therefore, the NHC intensity

forecast has been adjusted upward and generally shows little change

in strength during the next several days.  This prediction still

lies near the low end of the model guidance, however, so future

advisories might show a higher intensity forecast if the guidance

persists.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  28/1500Z 18.6N  54.6W   45 KT  50 MPH

 12H  29/0000Z 18.7N  55.1W   45 KT  50 MPH

 24H  29/1200Z 18.6N  55.6W   45 KT  50 MPH

 36H  30/0000Z 18.4N  56.1W   45 KT  50 MPH

 48H  30/1200Z 18.0N  56.7W   45 KT  50 MPH

 60H  01/0000Z 17.6N  57.2W   45 KT  50 MPH

 72H  01/1200Z 17.3N  57.5W   45 KT  50 MPH

 96H  02/1200Z 17.7N  58.2W   45 KT  50 MPH

120H  03/1200Z 20.0N  58.9W   40 KT  45 MPH

 

$$

Forecaster Cangialosi/A Reinhart