ZCZC HFOTCDCP1 ALL TTAA00 PHFO DDHHMM Hurricane Walaka Discussion Number 14...Corrected NWS Central Pacific Hurricane Center Honolulu HI CP012018 500 PM HST Tue Oct 02 2018 Walaka's eye has become less distinct in conventional satellite imagery over the last couple of hours, with subjective intensity estimates and CIMSS-ADT unanimous at 6.0. Thus, the current intensity has been lowered to 115 kt for this advisory. Despite these recent trends, a 0151 UTC SSMI pass continued to show a well- developed eyewall, and there are well-developed outflow channels to the northeast and southeast of the hurricane. Outflow is much more restricted in the western semicircle. The initial motion estimate is 010/11, as Walaka moves generally toward a vertically-stacked low pressure area near 31N 170W. Walaka is expected to soon begin accelerating toward the north-northeast as it gets caught up in the warm conveyor belt on the east side of the low. As Walaka begins to get tangled up with this extratropical feature, the guidance shows the center will dramatically slow it's forward motion in the 48 to 72 hour time frame and may take a brief bend back toward the north-northwest, then kick northeast rapidly again at 96 hours and beyond as the circulation becomes more shallow. The track guidance remains in remarkably good agreement considering the rather complex interaction between Walaka and the extratropical low, and this forecast track is similar to the previous advisory package. The UW-CIMSS shear analysis shows that Walaka will be coming under the influence of moderate to strong shear relatively soon. The shear is expected to peak at greater than 30 kt by 36 hours, which should continue the weakening trend. Although the shear diminishes beyond 36 hours, the cyclone will begin moving over increasingly cool sea surface temperatures. There is some uncertainty as to how Walaka's interaction with the extratropical low will play out. The global models seem to be in good agreement that some semblance of a warm core will remain even afterward, and so the forecast maintains Walaka as a tropical cyclone through 96 hours. It would not be surprising if the system becomes extratropical sooner, however. The forecast shows a slower rate of weakening than most of the dynamical models, in best agreement with the ECMWF through 48 hours, then aligns with SHIPS guidance afterward. FORECAST POSITIONS AND MAX WINDS INIT 03/0300Z 16.7N 170.2W 115 KT 130 MPH 12H 03/1200Z 18.7N 169.7W 110 KT 125 MPH 24H 04/0000Z 21.9N 168.5W 105 KT 120 MPH 36H 04/1200Z 25.5N 167.4W 95 KT 110 MPH 48H 05/0000Z 28.9N 167.6W 85 KT 100 MPH 72H 06/0000Z 32.0N 166.4W 65 KT 75 MPH 96H 07/0000Z 38.7N 160.6W 50 KT 60 MPH 120H 08/0000Z 46.8N 152.1W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster R Ballard NNNN