ZCZC HFOTCDCP1 ALL TTAA00 PHFO DDHHMM Hurricane Erick Discussion Number 15 NWS Central Pacific Hurricane Center Honolulu HI EP062019 500 PM HST Tue Jul 30 2019 The rapid intensification of Erick has waned this afternoon, but it still remains a powerful category 4 hurricane. Satellite images show that the eye has become cloud-filled and elongated since the last advisory, with outflow somewhat restricted in the southwestern semicircle. On the other hand, outflow in the northeastern semicircle appears optimal, and the eyewall convection has been a prolific lightning producer through the day. Subjective Dvorak current intensity estimates range from 6.0/115 kt from SAB/PHFO to 6.5/127 kt from PGTW, while ADT is also now near 6.0. The initial intensity estimate for this advisory has been held at 115 kt. A gradual turn toward the west-northwest has taken place today, and the initial motion estimate for this advisory is 290/13 kt. There is not much change to the ongoing track forecast philosophy, and only minor changes were made to the official forecast, despite increasing model spread in the later forecast periods. A track toward the west-northwest is expected over the next 24 hours or so, with a subtle turn toward the west on days 2 and 3, before a turn back to the west-northwest occurs on days 4 and 5. Initially, the strong hurricane will be steered by the deep-layer flow, with southwest winds in the upper levels helping Erick to gain latitude. As these winds shear the cyclone, it is expected to become increasingly shallow, steered by a low- to mid-level ridge to the north, which will induce the westward track. As the weakened cyclone reaches the western edge of the ridge on days 4 and 5, it is expected to resume a motion toward the west-northwest, but forecast models disagree as to the extent of the poleward motion. The official forecast lies closest to HCCA guidance, with the 5 day forecast point almost on top of the UKMET ensemble guidance. The window for further intensification appears to be closing, as increased vertical wind shear (20 kt increasing to 40 kt) lies along the forecast track, especially after about 24 hours. Once Erick encounters this southwesterly to westerly shear, associated with a semi-permanent trough aloft northwest of Hawaii, significant weakening is expected. In the meantime, Erick is expected to change little, but it wouldn't be surprising to see the eye clear out again overnight. The updated intensity forecast closely follows HCCA and FSSE guidance. An 1845Z partial ASCAT pass was used to expand 34 kt wind radii, mainly in the northern semicircle. FORECAST POSITIONS AND MAX WINDS INIT 31/0300Z 14.0N 145.4W 115 KT 130 MPH 12H 31/1200Z 14.5N 147.0W 115 KT 130 MPH 24H 01/0000Z 15.1N 149.2W 100 KT 115 MPH 36H 01/1200Z 15.6N 151.7W 90 KT 105 MPH 48H 02/0000Z 16.1N 154.0W 70 KT 80 MPH 72H 03/0000Z 17.1N 158.9W 40 KT 45 MPH 96H 04/0000Z 18.6N 163.1W 35 KT 40 MPH 120H 05/0000Z 20.0N 166.0W 35 KT 40 MPH $$ Forecaster Birchard NNNN