000 WTPZ42 KNHC 182035 TCDEP2 TROPICAL STORM PAINE DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL EP172016 300 PM MDT SUN SEP 18 2016 Paine has strengthened significantly today, with increasingly better defined convective bands wrapping at least 3/4 of the way around the circulation. The intensity is set, perhaps conservatively, to 50 kt which is the average of Dvorak estimates from TAFB and SAB. Vertical shear has relaxed, and the tropical cyclone has about 24 hours over warm water. The official intensity forecast now calls for Paine to become a hurricane within that time frame, in close agreement with the SHIPS guidance. By tomorrow night, the cyclone will be encountering SSTs below 24 deg C, so a weakening trend should be underway by that time. Paine will continue to move over progressively cooler waters thereafter, and should decay into a remnant low in about 72 hours. The initial motion estimate, 310/12 kt, is not much different than in the earlier advisory. The track forecast philosophy has not changed. Paine should move along the southwestern periphery of a mid-tropospheric high pressure system centered near Texas for the next couple of days and remain offshore of the Baja California peninsula. In 72 hours, the remnant low is forecast to approach the northern portion of the peninsula, but it should dissipate before reaching land. Deep-layer moisture associated with Paine or its remnants is expected to spread over portions of the southwestern United States in a couple of days. This could enhance the rainfall potential in these areas. FORECAST POSITIONS AND MAX WINDS INIT 18/2100Z 18.5N 112.9W 50 KT 60 MPH 12H 19/0600Z 19.8N 114.4W 60 KT 70 MPH 24H 19/1800Z 21.9N 116.1W 65 KT 75 MPH 36H 20/0600Z 23.9N 117.2W 55 KT 65 MPH 48H 20/1800Z 25.8N 117.4W 40 KT 45 MPH 72H 21/1800Z 28.9N 117.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 22/1800Z...DISSIPATED $$ Forecaster Pasch