Subtropical Storm FAY

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SUBTROPICAL STORM FAY DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072014
500 PM AST FRI OCT 10 2014

Satellite imagery and data from an Air Force Reserve reconnaissance
aircraft indicate that the subtropical cyclone has become a little
better organized since the previous advisory. Deep convection has
gradually been developing closer to the low-level circulation
center, and a maximum SFMR surface wind measured thus far by the
aircraft has been 35 kt. Based on this information, plus a
subtropical satellite classification of ST2.5/35 kt from TAFB, this
system has been upgraded to Subtropical Storm Fay. The Hurricane
Hunter aircraft will continue investigating Fay for the next hour
or so.

The initial motion estimate is 330/10 kt. Fay is expected to move
steadily northwestward and then northward around the western
periphery of a deep-layer subtropical ridge located along 29N-30N
latitude for the next 24 hours. By 36 hours, the cyclone is expected
to recurve toward the northeast and accelerate when it becomes
embedded in the strong mid-latitude flow ahead of an approaching
shortwave trough that is currently located near the U.S. east coast.
The latest NHC model guidance has shifted somewhat to the west,
especially the ECMWF model, but the models remain tightly clustered
and in good agreement on the aforementioned track scenario,
including absorption by a frontal system by 72 hours. The official
track has been shifted to the left of the previous forecast and lies
just to the west of and a little slower than the consensus track
model TVCN.

The large size of Fay, along with strong southeasterly to southerly
vertical wind shear, should inhibit much in the way of
intensification, despite the cyclone being over anomalously warm 29C
sea-surface temperatures. If the recent trend in the development of
inner-core convection continues, then Fay could transition into a
tropical cyclone within the next 12 hours or so. However, this
transition would have virtually no effect on the size of the
tropical-storm-force wind field. The NHC intensity forecast closely
follows a blend of the statistical-dynamical models SHIPS and LGEM.

FORECAST POSITIONS AND MAX WINDS

INIT  10/2100Z 24.7N  64.2W   35 KT  40 MPH
 12H  11/0600Z 26.0N  65.0W   40 KT  45 MPH
 24H  11/1800Z 28.5N  65.2W   45 KT  50 MPH
 36H  12/0600Z 31.7N  63.7W   45 KT  50 MPH
 48H  12/1800Z 33.7N  60.4W   45 KT  50 MPH
 72H  13/1800Z...ABSORBED BY FRONTAL SYSTEM

$$
Forecaster Stewart

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