000
WTNT41 KNHC 020241
TCDAT1

TROPICAL STORM FRED DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL062015
1100 PM AST TUE SEP 01 2015

The deep convection near the center of Fred has decreased during
the past few hours, with the low-level center now partially exposed
to the west of the convection.  An ASCAT-B overpass near 0000 UTC
probed the western side of the circulation and showed 40-kt winds
near the center.  Based on this, the initial intensity remains 45
kt.

The initial motion estimate is now 295/11.  There is no change to
the track forecast philosophy since the previous advisory.  Fred
should continue moving west-northwestward to the south of a low-
to mid-level ridge over the eastern Atlantic during the next 2 to 3
days.  Thereafter, the western portion of the ridge is expected to
weaken when a trough deepens over the central Atlantic.  This
evolution should steer Fred or its remnants generally
northwestward. There has been little change in the forecast guidance
since the last advisory.  Based on this, the new forecast track is
an update of the previous track through 72 hours and lies just north
of the consensus models.  After 72 hours, the track has been
adjusted westward, but still lies to the east of the center of the
guidance envelope as a compromise between the current guidance and
the previous forecast.

The intensity forecast philosophy remains unchanged.  Fred is over
sea surface temperatures of about 26 deg C and is about to encounter
strong westerly vertical wind shear.  In addition, the cyclone is
entraining a drier and more stable air mass.  This combination
should cause weakening over the next several days.  The new
intensity forecast is unchanged from the previous forecast, and it
calls for Fred to weaken to a depression in 30 to 36 hours and
degenerate into a remnant low after 48 hours.

FORECAST POSITIONS AND MAX WINDS

INIT  02/0300Z 19.4N  29.1W   45 KT  50 MPH
 12H  02/1200Z 19.8N  30.3W   40 KT  45 MPH
 24H  03/0000Z 20.4N  31.8W   35 KT  40 MPH
 36H  03/1200Z 21.0N  33.3W   30 KT  35 MPH
 48H  04/0000Z 21.4N  34.9W   30 KT  35 MPH
 72H  05/0000Z 22.0N  38.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  06/0000Z 23.0N  41.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  07/0000Z 25.0N  43.0W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven