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WTNT41 KNHC 181436

1100 AM AST THU SEP 18 2014

A 0906 UTC SSMIS pass showed that the eyewall of Edouard had opened
up on the southwest side and the circulation was becoming somewhat
tilted with height. This tilt was confirmed by an ASCAT pass around
1230 UTC. The coverage of cold convective tops is gradually
decreasing, and the initial intensity is lowered to 70 kt based on a
blend of subjective and objective Dvorak estimates from TAFB, SAB,
and UW-CIMSS. Given that the cyclone will be moving over cooler
waters and experiencing increased vertical wind shear, steady
weakening is expected during the next 24 hours. Edouard should lose
its deep convection in 36 to 48 hours and become post-tropical by
that time. Global model fields show the circulation of Edouard
dissipating by the end of the period, and that is reflected in the
official forecast. The new NHC intensity forecast is an update of
the previous one and is close to the IVCN multi-model consensus.

The initial motion estimate is now eastward, or 085/22, as Edouard
is currently located north of a mid-level ridge over the central
Atlantic. The cyclone will move eastward and then southeastward
around this ridge during the next 72 hours, and then turn southward
by day 4. Most of the track model guidance remains in good agreement
on this scenario, with the continued exception of the GFDL and
UKMET which show a more northeastward and southward motion,
respectively. The new NHC track forecast is close to a consensus of
the GFS and ECMWF models, and is similar to the previous advisory.

The initial wind radii were modified based on data from the
above-mentioned ASCAT pass.


INIT  18/1500Z 39.9N  42.7W   70 KT  80 MPH
 12H  19/0000Z 40.1N  39.9W   60 KT  70 MPH
 24H  19/1200Z 39.9N  37.8W   45 KT  50 MPH
 36H  20/0000Z 40.0N  36.2W   35 KT  40 MPH
 48H  20/1200Z 40.0N  34.3W   35 KT  40 MPH...POST-TROPICAL
 72H  21/1200Z 37.5N  30.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  22/1200Z 33.0N  30.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  23/1200Z...DISSIPATED

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