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Tropical Storm Philippe Discussion Number  51
NWS National Hurricane Center Miami FL       AL172023
1100 PM AST Thu Oct 05 2023
 
Satellite imagery of Philippe shows little change in structure with 
the center still exposed to the west of a growing area of deep 
convection. Radar data from Bermuda indicate outer rain bands from 
the system are moving across Bermuda. However, the winds so far are 
below tropical storm force. The initial wind speed remains 45 kt, 
which is near the high end of the latest satellite intensity 
estimates. 
 
Philippe is moving northward at 14 kt. The storm is currently
moving between an upper-level cutoff low off the Florida coast, and
a ridge over the central Atlantic. This flow is expected to
accelerate Philippe further northward during the next few days. The
center of Philippe is expected to pass by Bermuda on Friday, and
reach the coast of Maine and Atlantic Canada Saturday night or
early Sunday. This forecast track has been shifted slightly to the
left of the previous advisory, closer to the HCCA and ECMWF models.
 
Philippe is behaving like a hybrid system. Even though the cyclone 
is facing strong wind shear and lower SSTs during the next couple 
of days, Philippe may pull most of its energy from an upper-level 
cutoff low just to its west. Due to these conditions, some 
intensification is predicted during the next day or so. Weakening 
is expected as Philippe moves inland over New England and Atlantic 
Canada this weekend. The official NHC intensity forecast is near 
the middle of the guidance envelope.
 
Based on the forecast for Philippe to become post-tropical by
Saturday, and after coordination with National Weather Service
offices in New England and the Canadian Hurricane Centre, the
current plan is for hazards in New England and Atlantic Canada to
be handled via local non-tropical statements and not issue tropical
watches or warnings.  We will continually assess this plan if the
forecast evolves and tropical watches or warnings become warranted.
 
 
KEY MESSAGES:
 
1. Tropical storm conditions are expected on Bermuda beginning
early Friday morning, and a Tropical Storm Warning remains in
effect.  Heavy rainfall is expected to affect the island into
early Friday.  This could produce flash flooding.
 
2. Philippe is expected to move over portions of Atlantic Canada and 
New England as a post-tropical cyclone this weekend.  Regardless of 
Philippe's intensity or structure, interests in those areas should 
be prepared for the possibility of strong winds and heavy rainfall 
and monitor statements from their local weather office.  The 
rainfall could produce isolated to scattered instances of urban and 
flash flooding.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/0300Z 28.2N  66.0W   45 KT  50 MPH
 12H  06/1200Z 30.5N  65.8W   45 KT  50 MPH
 24H  07/0000Z 33.6N  65.9W   50 KT  60 MPH
 36H  07/1200Z 36.7N  66.5W   50 KT  60 MPH
 48H  08/0000Z 40.5N  66.9W   50 KT  60 MPH...POST-TROP/EXTRATROP
 60H  08/1200Z 45.7N  69.2W   45 KT  50 MPH...POST-TROP/INLAND
 72H  09/0000Z 49.5N  73.0W   35 KT  40 MPH...POST-TROP/INLAND
 96H  10/0000Z...DISSIPATED
 
$$
Forecaster Cangialosi
 
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