000 WTPZ43 KNHC 121458 TCDEP3 Hurricane Bud Discussion Number 12 NWS National Hurricane Center Miami FL EP032018 900 AM MDT Tue Jun 12 2018 Satellite imagery indicate that Bud peaked in intensity around 0600 UTC, and cloud tops surrounding the well-defined, 20-nmi-diameter eye have been steadily warming since then. The intensity estimate of 110 kt is based on a blend of TAFB T- and CI-numbers, and a UW-CIMSS ADT estimate of 110 kt. Bud has continued to make a trochoidal motion in the general direction of 320/05 kt during the past 6 hours. Overall, no significant changes were required to the previous advisory track due to the latest NHC model guidance remaining very tightly packed. Bud is forecast to move slowly in a north-northwestward direction around a large mid-level ridge extending westward across central Mexico for the next 36 hours or so, followed by a gradual turn toward the north by late Thursday. On the forecast track, Bud is expected to move across Baja California Sur as a tropical storm on Thursday. The official track forecast is essentially just an extension of the previous advisory track, and lies close to a blend of the various consensus models. Although Bud has an impressive upper-level outflow pattern and is forecast to remain in very low wind shear conditions for the next 48 hours, the cyclone will be moving over cooling SSTs of 26C or less and ocean heat content values near zero. This should result in significant cold upwelling beneath the cyclone, which may already be happening based on erosion of the northern eyewall noted in recent SSMI/S microwave satellite imagery. Due to the expected poor oceanic conditions and upwelling, rapid weakening is forecast to begin shortly and continue through the remainder of the forecast period. By 96 hours, Bud is expected to be inland or near the western coast of mainland Mexico, and likely have dissipated by 120 hours over northwestern Mexico. However, a 120h point has been priovided for continuity purposes. The official intensity forecast is close to a blend of the intensity consensus models IVCN, HCCA, and FSSE. Based on the forecast track and 34-kt wind radii, a Tropical Storm Watch could be required for portions of Baja California Sur on the next advisory package. FORECAST POSITIONS AND MAX WINDS INIT 12/1500Z 18.4N 108.4W 110 KT 125 MPH 12H 13/0000Z 18.9N 108.8W 95 KT 110 MPH 24H 13/1200Z 19.6N 109.2W 80 KT 90 MPH 36H 14/0000Z 20.5N 109.5W 65 KT 75 MPH 48H 14/1200Z 21.6N 109.9W 55 KT 65 MPH 72H 15/1200Z 24.4N 110.7W 40 KT 45 MPH 96H 16/1200Z 28.5N 111.1W 25 KT 30 MPH...INLAND 120H 17/1200Z 32.1N 111.0W 15 KT 15 MPH...POST-TROP/INLAND $$ Forecaster Stewart