WTPA41 PHFO 030251
TCDCP1

HURRICANE LESTER DISCUSSION NUMBER  38
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP132016
500 PM HST FRI SEP 02 2016
 
Deep convection has increased around the center this afternoon,
although the eye has become cloud filled during the past couple of
hours. Southerly vertical wind shear has increased slightly to 12 to
21 kt, according to the SHIP and CIMSS, respectively, and an AMSR2
pass at 2214 UTC suggested that Lester is tilting northward with
height. Dvorak current intensity estimates range from 5.0/90 kt from
SAB and CIMSS ADT to 5.5/102 kt out of HFO and JTWC. Given data from
an earlier aircraft reconnaissance mission, the initial intensity
will be held at 90 kt, which could be generous. U.S. Air Force
reconnaissance aircraft will begin conducting missions into Lester
every six hours beginning this evening.

Lester continues to move west-northwestward, and the initial motion
is set at 290/12 kt. The cyclone remains to the south of a low to
mid level ridge and is between an upper level anticyclone to the
east and an upper level trough near 160W. Lester is expected to
continue along a general west-northwestward track through Saturday
as it passes near the Hawaiian Islands. A turn toward the northwest
is forecast later Sunday and Monday as the system increasingly feels
the effects of the upper level trough to the west. On Tuesday and
Wednesday, Lester will interact with a deep North Pacific trough,
causing a turn toward the north and an eventual extra-tropical
transition. The official track has changed little from the last
advisory. During the time when Lester will be passing near the main
Hawaiian Islands, the forecast remains near a rather tight cluster
including the GFS, HWRF, ECMWF, GFDL, and TVCN. Beyond Sunday, the
guidance spread increases, though all show a gradual northward turn.

A gradual weakening trend is expected through the next four days.
Lester's intensity remained nearly unchanged this afternoon as it
moved over slightly warmer SSTs of around 26.5C and a well defined
outflow channel remained to the north. An increase in vertical wind
shear is expected to produce gradual weakening during the next three
days, followed by little change as Lester begins an extra-tropical
transition on day four or five. The intensity forecast has been
changed little from the prior advisory and closely follows SHIPS and
LGEM, keeping Lester a hurricane as it passes near the state. 

A Hurricane Watch remains in place for Oahu and Maui County, as the
official forecast still brings the system close to portions of the
main Hawaiian Islands. Model guidance has been stable for the past
couple of days, and probabilities for tropical storm and hurricane
conditions have been dropping slowly. However, any westward
deviation from the official forecast track could bring profound
impacts to Hawaii, and users are reminded that impacts from
hurricanes can occur well away from the center.
 
 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  03/0300Z 20.5N 151.0W   90 KT 105 MPH
 12H  03/1200Z 21.3N 153.0W   80 KT  90 MPH
 24H  04/0000Z 22.5N 155.6W   70 KT  80 MPH
 36H  04/1200Z 23.8N 158.1W   65 KT  75 MPH
 48H  05/0000Z 25.4N 160.6W   60 KT  70 MPH
 72H  06/0000Z 28.9N 164.6W   55 KT  65 MPH
 96H  07/0000Z 32.8N 166.6W   55 KT  65 MPH
120H  08/0000Z 37.0N 166.0W   50 KT  60 MPH
 
$$
Forecaster Wroe