ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Hurricane John Discussion Number 11 NWS National Hurricane Center Miami FL EP122018 300 AM MDT Wed Aug 08 2018 As mentioned in the previous discussion, the eye of John passed about 9 nmi northeast of Socorro Island around 0030 UTC, with the island possibly being within or just outside the eyewall. Additional data from an automated station on the island indicate that the highest sustained wind reported in 15-minute intervals was 48 kt at 0230 UTC, with another 70-kt gust reported at 0200 UTC. The lowest pressure measured was 970 mb at 0015 UTC, which is probably a 4-5 mb too low. Since that time, John's eye has occasionally become cloud-filled, but deep convection has recently developed in the eyewall. The initial intensity is only decreased slightly to 85 kt based on a UW-CIMSS ADT estimate of 87 kt and due to the recent uptick in eyewall convection. Although John should remain over warm waters for another 12 hours or so, the general trend calls for steady weakening due to the ingestion of more stable air to the north, which is expected to decrease the instability and inner-core convection. The official intensity forecast is lower than the previous intensity forecast, and is similar to a blend of the FSSE and HCCA models. The initial motion estimate is north-northwestward or 330/10 kt. John is expected to return to a northwestward motion at a slightly faster forward speed later this morning, and then continue that motion for the next 72 hours. After that time, a turn toward the west-northwestward is forecast due to the weakening and shallow cyclone being steered by the low-level trade wind flow. The new official forecast remains in close agreement with the previous advisory, and lies down the middle of the guidance envelope. Although the core of John is forecast to remain well offshore of the Baja California Peninsula, a surge of moisture around John's outer circulation is expected to bring some locally heavy rainfall to portions of Baja California Sur during the next couple of days. Therefore, interests in the southern portion of the Baja California Peninsula should monitor the progress of John. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 20.0N 111.6W 85 KT 100 MPH 12H 08/1800Z 21.1N 112.8W 80 KT 90 MPH 24H 09/0600Z 22.8N 114.8W 75 KT 85 MPH 36H 09/1800Z 24.2N 116.8W 65 KT 75 MPH 48H 10/0600Z 25.3N 119.0W 50 KT 60 MPH 72H 11/0600Z 26.8N 122.9W 35 KT 40 MPH...POST-TROPICAL 96H 12/0600Z 27.0N 125.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 13/0600Z 27.3N 127.2W 15 KT 15 MPH...POST-TROP/REMNT LOW $$ Forecaster Stewart NNNN
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