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Post-Tropical Cyclone Gert Discussion Number  20
NWS National Hurricane Center Miami FL       AL082017
500 PM AST Thu Aug 17 2017

Gert is now post-tropical.  The circulation has become quite
elongated, and the remaining deep convection appears to be primarily
associated with frontal boundaries.  A pair of late-arriving ASCAT
passes from around 1300 and 1400 UTC indicated that Gert was weaker
than previously estimated.  Based on the ASCAT data, the initial
intensity has been lowered to 55 kt.  The initial wind radii were
also adjusted based on the ASCAT data.

The initial motion estimate is a brisk 060/34 kt.  Gert should
move quickly northeastward for the next 12 to 24 h while
gradually spinning down.  After that time, it should slow down and
turn more toward the north while merging with or being absorbed by
another extratropical low.  The track, intensity, and wind radii
forecasts have incorporated guidance from NOAA's Ocean Prediction
Center.

Swells from Gert should continue to affect the coast of the
northeastern U.S. and Atlantic Canada through tonight.  These swells
are likely to produce dangerous surf and rip current conditions.
Please consult products from your local weather forecast office for
more information.

This is the last NHC advisory on Gert.  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 available on the Web at
http://www.opc.ncep.noaa.gov/shtml/NFDHSFAT1.shtml.

FORECAST POSITIONS AND MAX WINDS

INIT  17/2100Z 44.8N  46.0W   55 KT  65 MPH...POST-TROPICAL
 12H  18/0600Z 47.8N  40.5W   45 KT  50 MPH...POST-TROP/EXTRATROP
 24H  18/1800Z 50.6N  36.2W   40 KT  45 MPH...POST-TROP/EXTRATROP
 36H  19/0600Z 52.5N  35.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
 48H  19/1800Z...DISSIPATED

$$
Forecaster Zelinsky

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