Tropical Cyclone Discussion
646 WTPA43 PHFO 230239 TCDCP3 Tropical Storm Moke Discussion Number 11 NWS Central Pacific Hurricane Center Honolulu HI CP022026 Issued by NWS National Hurricane Center Miami FL 500 PM HST Sat Aug 22 2026 Moke has weakened slightly during the past several hours. The persistent deep convection that had been located over and north of the circulation overnight and through the morning hours has largely collapsed, with cloud tops warming noticeably. This deterioration appears to be due, at least in part, to persistent southwesterly vertical wind shear and dry mid-level air. Peak 700-mb flight-level winds from the reconnaissance aircraft have been around 43 kt, while a UAS measured peak winds of about 38 kt while sampling near the surface in the northeast quadrant. These data, along with the deteriorating satellite presentation, support lowering the initial intensity to 40 kt for this advisory. Moke continues to move west-northwestward, with an initial motion of 280/12 kt. A general west-northwestward motion is expected to continue during the next several days as a low- to mid-level ridge strengthens to the north of the cyclone. This track should bring the center of Moke a couple of hundred miles south of the Big Island on Sunday and then well south of the smaller main Hawaiian Islands thereafter. The track guidance remains in good agreement, and the NHC forecast is very similar to the previous forecast. Despite the center of Moke remaining south of the Hawaiian Islands, the cyclone is expected to pass close enough to produce a period of gusty winds and heavy rainfall across portions of the islands during the next couple of days. Moke appears to be near its peak intensity, if it has not already reached it. Although vertical wind shear is forecast to decrease somewhat during the next day, an increasingly dry and stable surrounding environment should limit additional strengthening and likely cause Moke to begin weakening on Sunday. Thereafter, increasing vertical wind shear and continued entrainment of dry air should result in a gradual weakening trend through early next week. By around 96 h, both the GFS and ECMWF depict Moke becoming largely devoid of deep convection, and the cyclone could degenerate into a remnant low by Wednesday, then dissipate by day 5. The latest NHC intensity forecast is similar to the previous advisory and lies near the middle to upper end of the guidance envelope. Key Messages: 1. Heavy rainfall associated with Tropical Storm Moke will begin to impact the Big Island of Hawaii late tonight, with rain spreading westward across the remainder of the Hawaiian Islands Sunday into Monday. This rainfall may produce life-threatening flooding and mudslides for the windward and southeast Big Island, especially in steep terrain and over areas that were affected recently by Lala. 2. Although the strongest winds associated with Moke are expected to pass south of the Hawaiian Islands, strong gusty winds are likely, particularly in areas within and downslope of higher terrain. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 15.3N 152.1W 40 KT 45 MPH 12H 23/1200Z 15.6N 153.8W 40 KT 45 MPH 24H 24/0000Z 15.9N 156.3W 40 KT 45 MPH 36H 24/1200Z 16.3N 158.9W 40 KT 45 MPH 48H 25/0000Z 16.8N 161.3W 35 KT 40 MPH 60H 25/1200Z 17.3N 163.9W 35 KT 40 MPH 72H 26/0000Z 18.0N 166.5W 35 KT 40 MPH 96H 27/0000Z 18.9N 172.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 28/0000Z...DISSIPATED