000 WTPZ42 KNHC 210233 TCDEP2 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