Official Discussion issued by the National Hurricane Center

Philippe (AL172023) DATA RELEASED: 10/3/2023 9:00:00 AM UTC

Copy of official data

Tropical Storm Philippe Discussion Number  40
NWS National Hurricane Center Miami FL       AL172023
500 AM AST Tue Oct 03 2023

High clouds from a recent convective burst just southeast of
Philippe's center has obscured the low-level center for much of the 
night.  However, surface observations and microwave imagery indicate 
that the center is still located near the northwestern edge of the 
large convective mass, and it is passing very near Anguilla in the 
northern Leeward Islands.  Most of the stronger winds are located
over the southern and southeastern portions of the circulation
where a wind gust to 41 kt was reported on Antigua a few hours ago.
The Leeward Islands are likely to experience strong gusty winds and
heavy rains even as the center moves north of those islands this
morning.  The intensity of the cyclone remains 45 kt, based on
earlier SFMR and dropwindsonde data from an Air Force Reserve
reconnaissance aircraft.  The next mission into Philippe is
scheduled for later this morning.

Philippe's motion has been wobbling between west-northwest and 
northwest at about 7 kt.  A more definitive northwestward heading is 
expected to begin today as Philippe moves around the western portion 
of a mid-level ridge over the central subtropical Atlantic. The 
storm's motion should become north-northwestward to northward on 
Wednesday and Wednesday night as it moves between the ridge to its 
east and trough off the southeastern United States coast. By late in 
the forecast period, there is significant bifurcation in the track 
guidance with the GFS slowing the system down, while the ECMWF and 
UKMET show the cyclone moving quickly northward into Atlantic Canada 
ahead of a deep-layer trough.  The GFS track appears to be an 
eastern outlier at this time. Thus, the NHC track forecast was 
shifted westward at days 4 and 5 to be closer to the multi-model 
consensus aids. Additional adjustments in the long-range track 
forecast may be required in subsequent advisories.

Strong vertical shear is forecast to linger over Philippe during
the next two to three days, and little change in strength is
forecast during that time.  The system could encounter a region of
diffluent upper-level winds later in the period which could support
some strengthening.  The NHC intensity forecast shows a slightly
lower peak than before as the intensity guidance and global models
generally show less strengthening than before.


1. Tropical storm conditions are expected across Barbuda, Antigua,
and Anguilla this morning. Strong gusty winds are also likely
elsewhere in the Leeward Islands today.

2. Heavy rainfall from Philippe is expected to produce scattered
flash flooding across portions of the Leeward and northern Windward
Islands, particularly between Barbuda and Dominica, into early


INIT  03/0900Z 18.5N  62.9W   45 KT  50 MPH
12H  03/1800Z 19.2N  63.4W   45 KT  50 MPH
24H  04/0600Z 20.6N  64.0W   45 KT  50 MPH
36H  04/1800Z 22.1N  64.4W   45 KT  50 MPH
48H  05/0600Z 23.9N  64.7W   45 KT  50 MPH
60H  05/1800Z 26.0N  64.6W   45 KT  50 MPH
72H  06/0600Z 28.3N  64.1W   50 KT  60 MPH
96H  07/0600Z 32.8N  62.3W   55 KT  65 MPH
120H  08/0600Z 38.5N  61.5W   55 KT  65 MPH

Forecaster Brown