Tropical Cyclone Discussion

980
WTNT45 KNHC 221436
TCDAT5
 
Subtropical Storm Josephine Discussion Number   4
NWS National Hurricane Center Miami FL       AL102026
1100 AM AST Thu Oct 22 2026

Satellite imagery this morning indicates that an area of convection 
has developed to the north of the center of Josephine, although the 
convective curvature is less than it was last night.  Just- received 
scatterometer data suggests the convective cluster is near or just 
west of a developing frontal boundary. Satellite intensity estimates 
have changed little since the previous advisory, and the 
scatterometer shows winds near 50 kt west of the center. The initial 
intensity remains 55 kt based on a subtropical cyclone intensity 
estimate from TAFB and the possibility of the scatterometer 
undersampling the maximum wind.

The initial motion is northeastward or 040/10 kt.  GOES RGB airmass 
imagery shows a mid- to upper-level trough extending from eastern 
Canada southwestward into the northeastern US, and Josephine should 
accelerate northeastward during the next 12-24 h as this trough 
amplifies and approaches the cyclone. After 24 h or so, Josephine 
should turn more eastward as it becomes embedded in the mid- 
latitude westerlies. On the forecast track, the center of Josephine 
will move away from the New England states today and pass south of 
Nova Scotia and Newfoundland tonight and Saturday. The guidance is 
again tightly clustered, and the new forecast track is similar to 
the previous forecast.

The interaction between Josephine and the aforementioned trough 
should cause the cyclone to develop fronts and become extratropical 
during the next 12 h, and the scatterometer data suggests this 
process is already underway. However, intensification is expected 
during this transition and Josephine will become a hurricane-force 
extratropical low later tonight and on Friday. The dynamical models 
are in good agreement that the cyclone should steadily weaken after 
24 h, and they forecast Josephine to dissipate between 72 and 96 h 
as it is absorbed by a new low pressure area developing to its 
northeast. The new intensity forecast is based mainly on the global 
physical models and it has only minor adjustments from the last 
forecast.  The wind radii forecasts have also been revised based on 
the global model forecasts.
 
Since the coastal wind hazards associated with this system have been
covered for the last several days through non-tropical products
issued by local National Weather Service offices, those products
will remain in effect until the threat diminishes and Josephine
moves farther away from the U.S. coast over the next day or so.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/1500Z 39.2N  67.3W   55 KT  65 MPH
 12H  23/0000Z 40.5N  64.6W   65 KT  75 MPH...POST-TROP/EXTRATROP
 24H  23/1200Z 42.3N  60.2W   65 KT  75 MPH...POST-TROP/EXTRATROP
 36H  24/0000Z 43.4N  56.9W   60 KT  70 MPH...POST-TROP/EXTRATROP
 48H  24/1200Z 43.7N  54.3W   55 KT  65 MPH...POST-TROP/EXTRATROP
 60H  25/0000Z 43.9N  50.4W   50 KT  60 MPH...POST-TROP/EXTRATROP
 72H  25/1200Z 43.6N  45.2W   45 KT  50 MPH...POST-TROP/EXTRATROP
 96H  26/1200Z...DISSIPATED