ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM CELIA DISCUSSION NUMBER  31
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP042016
200 AM PDT THU JUL 14 2016

Although conventional satellite imagery indicates some decrease in
overall deep convection coverage this morning, a 0558 UTC ASCAT
overpass revealed numerous 45 kt winds over the northern half of the
system.  West-southwesterly shear appears to be undercutting the
upper easterly diffluent flow aloft, subsequently, creating a
structural tilt and displacing the circulation center to the
south of the convective mass.  The initial intensity is held at 45
kt based on the aforementioned scatterometer pass.  Celia is
traversing gradually decreasing sea surface temperatures, and the
large-scale models all indicate that the cyclone will encounter
moderate to strong westerly shear by the 72 hour forecast period.
Therefore, the cyclone should commence a weakening trend today, and
become a depression by tonight.  The official forecast is based
primarily on a blend of the LGEM and decay SHIPS and reflects a
degeneration of the cyclone into a remnant low in 36 hours.

The initial motion is estimated to be west-northwestward, or 295/11
kt, around the southwestern periphery of a subtropical ridge
anchored to the north of the cyclone.  Guidance shows that Celia
should turn westward by the 36 hour period as the cyclone decays
into a shallow system and is steered by the low-level trades.  The
NHC forecast is weighed heavily on the multi-model consensus, and is
adjusted slightly to the south of the previous forecast beyond day
3.

FORECAST POSITIONS AND MAX WINDS

INIT  14/0900Z 20.3N 135.8W   45 KT  50 MPH
 12H  14/1800Z 21.0N 137.4W   35 KT  40 MPH
 24H  15/0600Z 21.6N 139.7W   30 KT  35 MPH
 36H  15/1800Z 21.9N 142.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 48H  16/0600Z 22.2N 144.6W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  17/0600Z 22.9N 149.2W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  18/0600Z 23.5N 153.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  19/0600Z 24.5N 158.6W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Roberts

NNNN