Tropical Storm EDOUARD
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TROPICAL STORM EDOUARD DISCUSSION NUMBER 31
NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014
1100 PM AST THU SEP 18 2014
Edouard has not changed much during the past several hours.
Microwave images indicate that the low-level center is located on
the western side of the main area of deep convection due to about
30 kt of westerly shear. Despite being in a strong shear environment
and over cool waters, an ASCAT pass just before 0000 UTC indicated
that Edouard has not weakened significantly. Maximum reliable winds
seen in the ASCAT data are in the 55 to 60 kt range, and dropsonde
wind reports from the NASA Global Hawk suggest a similar intensity.
Therefore, the initial wind speed is held at 60 kt for this
advisory. The storm is expected to remain in hostile conditions,
therefore, steady weakening is anticipated and Edouard is forecast
to become post-tropical in about 24 hours. The global models show
the post-tropical cyclone degenerating into a trough by 96 hours,
and this is reflected in the official forecast.
Satellite fixes suggest that Edouard is moving eastward at about 15
kt on the north side of a subtropical high. A continued eastward
motion with a decrease in forward speed is predicted for the next
day or so, followed by a turn to the southeast when the cyclone
becomes embedded in the flow between the subtropical high and a deep
layer low over the northeast Atlantic Ocean. The NHC track
forecast is nudged a little to the north of the previous one, and
lies very close to the multi-model consensus, TVCA.
The 34- and 50-kt wind radii were updated based on the ASCAT pass
and the NASA Global Hawk dropsonde data.
FORECAST POSITIONS AND MAX WINDS
INIT 19/0300Z 39.9N 39.2W 60 KT 70 MPH
12H 19/1200Z 39.9N 37.8W 50 KT 60 MPH
24H 20/0000Z 39.9N 36.1W 40 KT 45 MPH...POST-TROPICAL
36H 20/1200Z 40.0N 34.0W 35 KT 40 MPH...POST-TROPICAL
48H 21/0000Z 39.5N 31.5W 35 KT 40 MPH...POST-TROPICAL
72H 22/0000Z 36.0N 29.5W 30 KT 35 MPH...POST-TROP/REMNT LOW