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POST-TROPICAL CYCLONE HERMINE DISCUSSION NUMBER 30
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092016
500 PM AST SUN SEP 04 2016
Satellite images continue to show that practically all of the deep
convection continues to occur well to the north and northeast of
the low-level center of the cyclone. This indicates that
Hermine remains a post-tropical cyclone. The current intensity
estimate remains 60 kt based on continuity from the previous
aircraft data. Another Air Force reconnaissance plane is scheduled
to investigate the system in a few hours. The intensity trends
shown by the global models suggest that a weakening trend should
begin in 24 hours or so, and this is reflected in the latest
official forecast.
Visible satellite images show that the center has continued to
track farther east than previous estimates, and the motion is a
rather uncertain 070/4 kt. A shortwave trough is approaching
Hermine from the west, and the associated vorticity is predicted to
move just to the south of the post-tropical cyclone within the next
day or so. This should cause Hermine to turn toward the north and
northwest while moving rather slowly over the next 24-48 hours.
After that time, Hermine should begin to move east-northeastward
within the southern portion of the mid-latitude westerlies. The
official track forecast is a blend of the latest GFS and ECMWF
solutions, with the former model much farther east than the latter
one. The forecast for Hermine has been coordinated with the NOAA
Ocean Prediction Center.
Although the NHC forecast track has been shifted eastward today,
there is still a threat of tropical storm conditions, coastal
flooding and large waves along portions of the mid-Atlantic and
northeastern United States coast during the next couple of days.
FORECAST POSITIONS AND MAX WINDS
INIT 04/2100Z 37.2N 69.1W 60 KT 70 MPH...POST-TROPICAL
12H 05/0600Z 37.9N 69.2W 60 KT 70 MPH...POST-TROPICAL
24H 05/1800Z 38.5N 70.0W 60 KT 70 MPH...POST-TROPICAL
36H 06/0600Z 39.1N 70.5W 55 KT 65 MPH...POST-TROPICAL
48H 06/1800Z 39.6N 70.5W 45 KT 50 MPH...POST-TROPICAL
72H 07/1800Z 40.2N 69.2W 45 KT 50 MPH...POST-TROPICAL
96H 08/1800Z 41.5N 65.5W 40 KT 45 MPH...POST-TROPICAL
120H 09/1800Z 43.5N 61.0W 35 KT 40 MPH...POST-TROPICAL
$$
Forecaster Pasch
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