Official Discussion issued by the National Hurricane Center

(AL172023) DATA RELEASED: 10/6/2023 3:00:00 PM UTC

Copy of official data

Post-Tropical Cyclone Philippe Discussion Number  53
NWS National Hurricane Center Miami FL       AL172023
1100 AM AST Fri Oct 06 2023

The center we were following overnight has become untrackable this 
morning and appears to have become absorbed by the nearby frontal 
zone.  In addition, the overall cloud pattern now has the look of a 
classic extratropical cyclone, with Philippe's center resembling 
the triple point of an occlusion.  Based on these recent 
developments, Philippe is being declared a post-tropical cyclone.  
The intensity remains 45 kt, mainly based on continuity.

The initial motion is estimated to be north-northeastward, or 
020/14 kt, but this movement is becoming less representative as the 
larger storm system takes over.  Philippe's remnant center and 
another non-tropical low to the west are likely to interact and/or 
merge with each other during the next day or two, but the overall 
system is expected to move northward or north-northwestward at 
increasing forward speed into the weekend.  This will bring the 
center of the post-tropical cyclone to the coast of Nova Scotia or 
Maine in about 48 hours, and then inland toward eastern Quebec 
before it becomes absorbed by a separate but larger extratropical 

The post-tropical cyclone still has an opportunity to strengthen a 
bit over the next day or so due to baroclinic influences.  Due to 
the system's structure and forward motion, the strongest winds are 
expected to be on the eastern side of the circulation and will 
most likely affect portions of Atlantic Canada.  Weakening is 
forecast after the system moves inland.

Future information on potential flooding impacts in the Northeast 
United States can be found in products issued by the Weather 
Prediction Center on the web at, and 
in products issued by local National Weather Service Forecast 
Offices on the web at

Additional information on marine impacts can be found in High Seas
Forecasts issued by the National Weather Service, under AWIPS
header NFDHSFAT1, WMO header FZNT01 KWBC, and online at  


1. The post-tropical cyclone is expected to move over portions of 
Atlantic Canada and New England this weekend.  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 may produce isolated to scattered instances of 
urban and flash flooding.


INIT  06/1500Z 30.7N  64.6W   45 KT  50 MPH...POST-TROP/EXTRATROP
12H  07/0000Z 33.1N  64.9W   45 KT  50 MPH...POST-TROP/EXTRATROP
24H  07/1200Z 36.3N  66.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
36H  08/0000Z 40.0N  66.3W   50 KT  60 MPH...POST-TROP/EXTRATROP
48H  08/1200Z 44.9N  67.5W   45 KT  50 MPH...POST-TROP/INLAND
60H  09/0000Z 49.1N  70.9W   35 KT  40 MPH...POST-TROP/INLAND
72H  09/1200Z...DISSIPATED

Forecaster Berg