000 WTPZ42 KNHC 082032 TCDEP2 Hurricane Aletta Discussion Number 13 NWS National Hurricane Center Miami FL EP022018 300 PM MDT Fri Jun 08 2018 Aletta remains a formidable category 4 hurricane, although there has been some weakening of the core convection during the day. The current intensity is held at 120 kt which is a blend of subjective Dvorak estimates from TAFB and SAB along with objective Dvorak values. After the notable strengthening episode over the last 24 hours, it appears that the intensity has leveled off. This is also consistent with GOES-16 measurements of increased inner-core lightning observed to be occurring to the east of the eastern eyewall, which some research suggests corresponds to a halting of the intensification process. Since vertical shear is expected to increase in 12 to 24 hours, a weakening trend is forecast to begin late tonight or tomorrow. A more rapid weakening will likely commence on Sunday as Aletta begins to traverse cooler waters. The official intensity forecast is at the upper bound of the numerical guidance. The hurricane has moved on a more westward course today, and the initial motion estimate is now 290/5 kt. Aletta is moving along the southwestern periphery of a mid-level high pressure area and should continue to do so over the next day or two. Later in the forecast period, the weakening and increasingly shallower cyclone should turn westward and south of westward, following the low-level tradewind flow. The official forecast is close to the dynamical model consensus TVCE and is somewhat south of the previous NHC track. FORECAST POSITIONS AND MAX WINDS INIT 08/2100Z 16.0N 111.7W 120 KT 140 MPH 12H 09/0600Z 16.5N 112.6W 120 KT 140 MPH 24H 09/1800Z 17.2N 113.6W 100 KT 115 MPH 36H 10/0600Z 17.9N 114.5W 75 KT 85 MPH 48H 10/1800Z 18.3N 115.4W 55 KT 65 MPH 72H 11/1800Z 18.6N 117.5W 30 KT 35 MPH 96H 12/1800Z 18.6N 119.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 13/1800Z 18.0N 121.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Pasch