Central Pacific Basin Tropical Cyclones

Tropical Storm Greg Forecast Discussion

WTPA43 PHFO 170834

Tropical Storm Greg Discussion Number  14
NWS Central Pacific Hurricane Center Honolulu HI   EP082023
1100 PM HST Wed Aug 16 2023

Deep convection associated with Greg continues to pulse, and is 
sheared to the north of the low level center. Subjective Dvorak
intensities from PHFO, JTWC and SAB range from 2.0 to 3.0 (30 to 45
kt), with objective intensities ranging from 31 to 45 kt. A blend
of these estimates support holding the intensity at 40 kt. 

The initial motion is 280/10 kt, as Greg continues to move just 
north of west. This westward path will continue for the next 24 
hours as Greg moves along the southern boundary of a low- to mid-
level ridge to the north. In 24 to 36 hours, a deepening ridge to 
the north of Greg will steer the system to the west-southwest. 
Greg will pass well south of Hawaii during this time. The official 
forecast track remains close to the previous advisory, following 
closely the TVCE in the middle of the tightly clustered guidance.

Greg remains over sufficiently warm SSTs, in an environment of light
southerly shear. While the system should remain over sufficiently 
warm waters, an increase in northerly shear is expected beyond 24 
hours. As such, the official forecast holds the system steady for 
the next 12 hours, and then follows the dynamical models with steady
weakening thereafter. Greg is expected to become a post-tropical 
remnant low by late Friday.


INIT  17/0900Z 12.1N 154.5W   40 KT  45 MPH
 12H  17/1800Z 12.3N 156.2W   40 KT  45 MPH
 24H  18/0600Z 12.2N 158.7W   35 KT  40 MPH
 36H  18/1800Z 11.9N 161.3W   35 KT  40 MPH
 48H  19/0600Z 11.5N 163.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  19/1800Z 11.1N 166.6W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  20/0600Z 10.5N 168.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  21/0600Z...DISSIPATED

Forecaster M Ballard

Source link