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Post-Tropical Cyclone Zeta Discussion Number  21
NWS National Hurricane Center Miami FL       AL282020
500 PM EDT Thu Oct 29 2020
 
Zeta lost tropical characteristics and was declared post-tropical a
few hours ago.  The surface pressure field has become elongated
with the center now embedded within a frontal zone over the
Mid-Atlantic states.  The maximum sustained winds are still
estimated to be 45 kt, based on an observation received from
northeastern North Carolina a few hours ago, and winds have been
increasing at marine sites located just off the Mid-Atlantic coast.
 
Zeta is zooming toward the east-northeast (060/48 kt), and its
center is just about to move off the Delmarva Peninsula over the
western Atlantic waters.  This motion should continue for the next
day or so since Zeta is embedded within fast westerly flow ahead of
a strong mid-level trough.
 
Some baroclinic re-intensification is expected over the next day or
so while Zeta moves farther out over the western Atlantic, and the
12-hour forecast intensity is based on the GFS and ECMWF global
models.  Zeta's center is expected to dissipate within the frontal
zone by 24 hours, with another strong low pressure area likely to
develop and move toward the north Atlantic over the next several
days.  The forecast wind radii are based on guidance from the
Ocean Prediction Center.
 
This is the last advisory issued on Zeta.  Additional information
on this system can be found in High Seas Forecasts issued by the
National Weather Service, under AWIPS header NFDHSFAT1, WMO header
FZNT01 KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php
 
 
KEY MESSAGES:
 
1.  Strong wind gusts are still possible over portions of extreme
eastern North Carolina, southeastern Virginia, and the southern
Delmarva Peninsula during the next couple of hours.
 
2.  Through this evening, the last of the heavy rainfall along the 
track of Zeta is expected over the Mid-Atlantic. This rainfall may 
lead to flash, urban, small stream, and isolated minor river 
flooding. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  29/2100Z 38.8N  75.3W   45 KT  50 MPH...POST-TROP/EXTRATROP
 12H  30/0600Z 41.0N  66.1W   50 KT  60 MPH...POST-TROP/EXTRATROP
 24H  30/1800Z...DISSIPATED
 
$$
Forecaster Berg
 
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