000 WTPA43 PHFO 160834 TCDCP3 Tropical Storm Greg Discussion Number 10 NWS Central Pacific Hurricane Center Honolulu HI EP082023 1100 PM HST Tue Aug 15 2023 Satellite continues to show Greg's convection sheared to the west and northwest of the low level circulation. Subjective Dvorak intensities ranged from 2.5/35 kt to 3.5/55 kt, and objective intensities ranged from 33 to 48 kt. Using a blend of these estimates initial intensity held at 45 kt. The initial motion is 280/12 kt as Greg takes on a slightly north of west track. Greg continues to move along the southern edge of the subtropical ridge to the north. There remains little change in the guidance through the forecast period and as such, the forecast remains very close to the previous track. This closely follows the HCCA and TVCA guidance which remains near the middle of the relatively tightly clustered guidance envelope. Along this track, Greg is expected to move a little north of west overnight, and then to the west through Thursday, before turning to the west-southwest Thursday night and Friday in response to a deep ridge to the north. Along this track, Greg will pass far south of Hawaii Thursday through Friday with no direct impacts to the islands expected. The environmental conditions will remain relatively unchanged in the short term, with light south to southeast shear, and SSTs around 27-28C. It is during this time that the system has the greatest chance for any strengthening. Between hours 36 and 48, the system will move over slightly cooler waters, and encountering some additional deep layer shear. This is expected to contribute to a weakening of the system. The latest intensity guidance has shown an overall weakening trend, but given the small window of possible development, have maintained the slight strengthening for the first 24 hours. Beyond that, the intensity forecast follows the weakening trend of most of the guidance, loosely following the IVCN. Greg looks to weaken to a post tropical system by hour 96. FORECAST POSITIONS AND MAX WINDS INIT 16/0900Z 11.8N 149.6W 45 KT 50 MPH 12H 16/1800Z 12.2N 151.5W 50 KT 60 MPH 24H 17/0600Z 12.6N 153.9W 50 KT 60 MPH 36H 17/1800Z 12.5N 156.4W 45 KT 50 MPH 48H 18/0600Z 12.3N 159.0W 40 KT 45 MPH 60H 18/1800Z 12.0N 161.6W 35 KT 40 MPH 72H 19/0600Z 11.6N 164.2W 30 KT 35 MPH 96H 20/0600Z 10.7N 169.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 21/0600Z...DISSIPATED $$ Forecaster M Ballard