ZCZC HFOTCDCP5 ALL TTAA00 PHFO DDHHMM HURRICANE MADELINE DISCUSSION NUMBER 16 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP142016 500 AM HST TUE AUG 30 2016 Madeline's satellite presentation degraded overnight, with the eye becoming cloud covered. The CDO has lost much of its symmetry, with outflow becoming impaired to the south and west. Outflow remains excellent to the north and northeast. Deep convection around the LLCC remains robust, with cloud top temperatures colder than -70 degrees Celsius. Subjective Dvorak satellite intensity estimates range from 5.5/102 kt from JTWC and SAB to 6.0/115 kt from PHFO, while UW-CIMSS provided a noticeably lower ADT of 5.2/95 kt. We will assign Madeline an initial intensity of 105 kt for this advisory cycle, based on a rough average of the intensity estimates. Hurricane hunters from the 53rd Weather Reconnaissance Squadron are slated to begin flying investigative flights into Madeline later this morning, which will give us valuable information as to Madeline's actual intensity and size. Initial motion is 280/09 kt. However, Madeline's westward track component keeps increasing as six hour motion is closer to 270/09 kt. Madeline is tracking along the southern flank of the subtropical ridge, but an upper trough northwest of the main Hawaiian Islands allowed this system to gain latitude over the past few days. Global models show this upper trough will lift northward through 48 hours, giving the ridge a larger steering role by nudging Madeline westward and west southwestward through day 2. Beyond 72 hours, the upper trough is forecast to begin digging southward again, causing another track bend to the west northwest on day 3 and beyond. Like before, there are a few models that take Madeline over southern portions of the Big Island, notably GFDL and ECMWF. However other models, notably GFS, take Madeline noticeably farther south of the Big Island. Small cosmetic changes were made to the forecast track at 48, 96 and 120 hours to keep it aligned with TVCN consensus, which has handled this system superbly so far and lies firmly within the guidance envelope. Madeline reached peak intensity last evening but is now beginning what is expected to be a gradual weakening trend through day 5. All guidance shows weakening at various rates. The global models, especially ECMWF, want to keep Madeline a hurricane through the entire forecast period. In contrast, SHIPS reduces Madeline to a tropical storm by 48 hours, due mainly to low SST potential and 20 kt of vertical shear depicted after 24 hours. Our forecast weakens Madeline to a tropical storm after day 3 along a trend slightly stronger than TCVN consensus. Most importantly, we keep this system at hurricane strength as it passes just south of the Big Island of Hawaii between 36 and 48 hours. Users are reminded to not focus too closely on the deterministic forecast track, and that hazards associated with hurricanes can extend well away from the center. FORECAST POSITIONS AND MAX WINDS INIT 30/1500Z 19.3N 148.3W 105 KT 120 MPH 12H 31/0000Z 19.4N 149.7W 95 KT 110 MPH 24H 31/1200Z 19.1N 151.7W 90 KT 105 MPH 36H 01/0000Z 18.8N 153.7W 80 KT 90 MPH 48H 01/1200Z 18.5N 155.7W 75 KT 85 MPH 72H 02/1200Z 18.6N 159.9W 65 KT 75 MPH 96H 03/1200Z 19.4N 164.4W 55 KT 65 MPH 120H 04/1200Z 20.2N 169.5W 50 KT 60 MPH $$ Forecaster Powell NNNN