000
WTNT45 KNHC 071735
TCDAT5

Hurricane Dorian Special Discussion Number  58
NWS National Hurricane Center Miami FL       AL052019
200 PM AST Sat Sep 07 2019

This special advisory is being issued instead of the normal
intermediate advisory to update the intensity and wind radii of
Dorian.  A recent ASCAT-B overpass shows a large area of hurricane-
force winds southwest and south of the center of Dorian, with many
vectors of 80 kt or more.  This area of wind is likely due to
baroclinic effects during the ongoing extratropical transition.
The initial intensity is being increased to 85 kt and the 12-h
intensity to 75 kt, after which the forecast intensities are the
same as in the previous advisory.  Some changes were also made to
the initial and 12-h wind radii based on the scatterometer data.

There is no change to the forecast track from the previous advisory.


Key Messages:

1. Regardless of whether it is a hurricane or a post-tropical
cyclone, Dorian is expected to have a significant impact in portions
of eastern Canada beginning during the next several hours. Dangerous
storm surge impacts are likely in portions of the Gulf of St.
Lawrence, southwestern Newfoundland and eastern Nova Scotia.
Hurricane-force winds are also likely in Nova Scotia, Prince Edward
Island and Newfoundland later today and tonight. Refer to
information from the Canadian Hurricane Centre for more information
on these hazards.


FORECAST POSITIONS AND MAX WINDS

INIT  07/1800Z 42.8N  64.9W   85 KT 100 MPH
 12H  08/0000Z 45.1N  63.0W   75 KT  85 MPH...INLAND
 24H  08/1200Z 48.9N  59.7W   65 KT  75 MPH...POST-TROP/EXTRATROP
 36H  09/0000Z 51.7N  54.6W   55 KT  65 MPH...POST-TROP/EXTRATROP
 48H  09/1200Z 54.2N  47.8W   45 KT  50 MPH...POST-TROP/EXTRATROP
 72H  10/1200Z...DISSIPATED

$$
Forecaster Beven