ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM KAY DISCUSSION NUMBER  10
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP122016
900 PM MDT SAT AUG 20 2016

Kay's cloud pattern features a somewhat uniform CDO displaced to the
west of the low-level center as seen in a 0051 UTC GPM overpass.
This structure is consistent with some easterly shear analyzed by
the SHIPS model.  The cloud pattern has not changed much during the
past few hours, and the initial intensity remains 45 kt in agreement
with the latest Dvorak CI numbers from TAFB and SAB. While the shear
is forecast to decrease and remain low, Kay will be moving over
progressively cooler SSTs through the forecast period and cross the
26C isotherm in 36 to 48 hours.  These factors should result in slow
weakening during that time period.  By 72 hours, the mid-level
atmosphere becomes quite dry, which in combination with SSTs at or
below 24C should result in Kay becoming a remnant low.  The global
models show the low dissipating by day 5, and so does the NHC
forecast, which is close to the latest LGEM guidance through 72
hours.

Earlier AMSR-2 and SSMIS passes, along with the above-mentioned GPM
pass, were helpful in establishing the initial motion of 305/05.
Overall, the synoptic reasoning remains unchanged, as Kay should
turn west-northwestward in the next 12 to 24 hours under the
influence of a mid-level ridge to the north.  This motion is
expected to continue until late in the period when the shallow
remnant low of Kay turns westward in the low-level trade wind flow.
The new NHC track forecast is essentially an update of the previous
one and is close to the latest GFS/ECMWF blend.

FORECAST POSITIONS AND MAX WINDS

INIT  21/0300Z 20.6N 113.3W   45 KT  50 MPH
 12H  21/1200Z 21.0N 114.0W   45 KT  50 MPH
 24H  22/0000Z 21.5N 115.1W   40 KT  45 MPH
 36H  22/1200Z 22.0N 116.4W   40 KT  45 MPH
 48H  23/0000Z 22.5N 117.7W   35 KT  40 MPH
 72H  24/0000Z 23.4N 120.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  25/0000Z 23.5N 123.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  26/0000Z...DISSIPATED

$$
Forecaster Brennan

NNNN