Skip Navigation Links
NOAA NOAA United States Department of Commerce

Tropical Storm Greg Forecast Discussion


Home   Public Adv   Fcst Adv   Discussion   Wind Probs   Graphics   Archive  


000
WTPZ42 KNHC 240257
TCDEP2

Tropical Storm Greg Discussion Number  27
NWS National Hurricane Center Miami FL       EP072017
800 PM PDT Sun Jul 23 2017

Greg has changed little since the previous advisory, with the
cyclone still producing intermittent bursts of deep convection near
the center. Subjective and objective satellite intensity estimates
remain at T3.0/45 kt, so the initial intensity will remain
unchanged at 45 kt for this advisory.

Greg's initial motion estimate is 275/12 kt. No significant changes
to the previous forecast track were required through 72 hours. Greg
is expected to continue moving west-northwestward to westward for
the next 3 days while it skirts along the southern periphery of a
deep-layer subtropical ridge centered northeast of the Hawaiian
Islands. The small cyclone is forecast to weaken to a remnant low
around 72 hours, with the shallow system being forced
west-southwestward by brisk northeasterly tradewind flow. The new
NHC forecast track closely follows the TVCN consensus model.

Little change in strength is expected for the next 24 hours or so.
Gradual weakening is expected thereafter due to drier and more
stable air getting entrained into the cyclone, followed by
increasing vertical wind shear. By 72 hours and beyond, the shear is
expected to exceed 25-30 kt, which should result in Greg
degenerating into a remnant low. The new intensity forecast is
similar to the previous advisory, and closely follows the intensity
consensus model ICON and IVCN.

FORECAST POSITIONS AND MAX WINDS

INIT  24/0300Z 14.4N 131.4W   45 KT  50 MPH
 12H  24/1200Z 14.6N 132.9W   45 KT  50 MPH
 24H  25/0000Z 15.0N 134.7W   45 KT  50 MPH
 36H  25/1200Z 15.6N 136.2W   40 KT  45 MPH
 48H  26/0000Z 16.4N 137.6W   35 KT  40 MPH
 72H  27/0000Z 17.0N 140.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  28/0000Z 16.9N 143.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  29/0000Z 16.1N 146.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Stewart