TCDCP2
Hurricane Lane Discussion Number 18
NWS Central Pacific Hurricane Center Honolulu HI EP142018
1100 PM HST Sat Aug 18 2018
Lane completely lost its eye in the last visible satellite imagery,
which was available earlier this evening. In addition, microwave
passes from SSMIS at 0339z and AMSU at 0644z indicated the eyewall
appeared to be open on the southwestern side of the system. Vertical
wind shear estimates are 18 knots from the west-southwest according
to the latest SHIPS and UW-CIMSS. This is likely a major culprit in
the weakening of Lane. The latest subjective Dvorak intensity
estimates are T5.5/102 knots from SAB, T6.0/115 knots from JTWC and
T6.5/127 knots from PHFO. The most recent ADT from UW-CIMSS is
weaker at 5.7/107 knots. Based on a blend of this guidance, the
latest initial intensity has been adjusted downward slightly to 110
kt for this advisory. Note that a warm spot appears to be developing
in the infrared satellite imagery during the past couple of hours.
Lane's initial motion for this advisory is 280/14 kt. A large
subtropical ridge to the north will continue to keep Lane moving
along this same general track, but at a slightly slower forward
speed during the next two days. A shift back toward the
west-northwest should occur from 96 through 120 hours as Lane
approaches the western portion of the ridge. Track guidance shows
some spread beyond 72 hours. The most recent forecast is very
similar to the previous through 72 hours, with a shift to the right
on days 4 and 5. These changes in track were based on nudging toward
HWRF and HSSE, as well as the GFEX and TVCN consensus.
The intensity forecast closely follows ICON consensus guidance,
depicting a gradual weakening through 120 hours. SSTs will remain
in the 27 to 28 degrees C range, but with 10 to 15 knots of vertical
wind shear expected through the forecast period, a forecast for
gradual weakening seems realistic at this time. The latest intensity
forecast is close to the previous, except that Lane is kept slightly
stronger on days 4 and 5.
Lane is forecast to pass south of the main Hawaiian Islands
Wednesday and Thursday, potentially causing local impacts as it
tracks west northwestward. Interests in those islands should watch
the progress of Lane closely, since long-range forecast track and
intensity errors can be large.
FORECAST POSITIONS AND MAX WINDS
INIT 19/0900Z 12.9N 142.3W 110 KT 125 MPH
12H 19/1800Z 13.2N 143.9W 100 KT 115 MPH
24H 20/0600Z 13.5N 146.0W 100 KT 115 MPH
36H 20/1800Z 13.7N 147.9W 95 KT 110 MPH
48H 21/0600Z 13.9N 149.7W 90 KT 105 MPH
72H 22/0600Z 14.3N 153.1W 80 KT 90 MPH
96H 23/0600Z 15.2N 156.6W 70 KT 80 MPH
120H 24/0600Z 17.0N 160.0W 60 KT 70 MPH
$$
TCDCP2
Hurricane Lane Discussion Number 19
NWS Central Pacific Hurricane Center Honolulu HI EP142018
500 AM HST Sun Aug 19 2018
Lane has not had a distinct eye in satellite imagery since late
Saturday afternoon. However, a small warm spot appears to be
indicative of an eye trying to form. In addition, a 1253z SSMI
microwave pass shows a small eye completely surrounded by deep
convection, which suggests that Lane remains rather well organized
early this morning. This is despite southwesterly vertical wind
shear of near 20 knots according to the latest UW-CIMSS output,
while it is close to 10 knots based on the most recent SHIPS
guidance. The latest subjective Dvorak intensity estimates are
T5.0/90 knots from SAB, T6.0/115 knots from JTWC and T6.5/127
knots from PHFO. The most recent ADT from UW-CIMSS is now
T5.4/100 knots. Based on a blend of this guidance, the latest
initial intensity has been adjusted downward slightly to 105 knots
for this advisory.
Lane's initial motion for this advisory is 280/13 kt. The latest
forecast track has been adjusted slightly to the right of the
previous track during the 12-36 hour and 96-120 hour time periods. A
large subtropical ridge to the north of Lane will continue to keep
the system moving along the same general track during the next 12
hours, but at a slightly slower forward speed during the 24-72 hour
time periods. A shift toward the west-northwest will likely begin
beyond 72 hours as Lane approaches the western end of the ridge. The
forecast models are showing this western end of the ridge will
erode due to an upper-level trough digging down northwest of the
Hawaiian Islands. Due to increasing uncertainty about the strength
of the ridge, the model spread has increased dramatically tonight.
The changes in the current forecast track were based on nudging
toward the latest HWRF and HCCA guidance, as well as the GFEX and
TVCN consensus models. A NOAA G-IV aircraft plans to do a synoptic
sampling in the environment around the Hawaiian Islands and Lane
later today. The valuable data collected during this mission will be
available to better initialize the forecast models.
The latest intensity forecast has been nudged up slightly,
especially during days 4 and 5. This forecast closely follows the
IVCN, which shows gradual weakening from 48 through 120 hours. The
ocean water temperatures will remain in the 27-28 degrees C
range along the forecast track, but there may still be 10 to 15
knots of vertical wind shear through most of the forecast period.
Note that the latest CIRA analysis of Ocean Heat Content shows a
local maximum along the track between 72 and 96 hours. If this
verifies, this may allow Lane to remain stronger than anticipated
beyond day 3.
Lane is forecast to pass south of the main Hawaiian Islands
Wednesday and Thursday, potentially causing local impacts as it
tracks west-northwestward. Interests in these islands should watch
the progress of Lane closely, since long-range track and intensity
forecast errors can be large.
FORECAST POSITIONS AND MAX WINDS
INIT 19/1500Z 13.2N 143.5W 105 KT 120 MPH
12H 20/0000Z 13.5N 145.1W 100 KT 115 MPH
24H 20/1200Z 13.8N 147.1W 100 KT 115 MPH
36H 21/0000Z 14.0N 148.9W 100 KT 115 MPH
48H 21/1200Z 14.2N 150.8W 95 KT 110 MPH
72H 22/1200Z 14.8N 154.4W 80 KT 90 MPH
96H 23/1200Z 16.0N 157.5W 70 KT 80 MPH
120H 24/1200Z 17.6N 160.5W 65 KT 75 MPH