590
WTPA32 PHFO 211443
TCPCP2

BULLETIN
Hurricane Lane Advisory Number 27
NWS Central Pacific Hurricane Center Honolulu HI EP142018
500 AM HST Tue Aug 21 2018

…MAJOR HURRICANE LANE STILL MOVING WEST BUT EXPECTED TO MAKE A
TURN TOWARD THE HAWAIIAN ISLANDS LATER THIS WEEK…
…HURRICANE WATCH ISSUED FOR HAWAII AND MAUI COUNTIES…

SUMMARY OF 500 AM HST…1500 UTC…INFORMATION
———————————————-
LOCATION…14.1N 152.3W
ABOUT 450 MI…725 KM SSE OF KAILUA-KONA HAWAII
ABOUT 620 MI…995 KM SE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS…150 MPH…240 KM/H
PRESENT MOVEMENT…W OR 275 DEGREES AT 12 MPH…19 KM/H
MINIMUM CENTRAL PRESSURE…950 MB…28.06 INCHES

WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY:

A Hurricane Watch has been issued for Hawaii county and Maui
County.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Watch is in effect for…
*Maui County…including the islands of Maui, Lanai, Molokai and
Kahoolawe
*Hawaii County

A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours before
the anticipated first occurrence of tropical-storm-force winds,
conditions that make outside preparations difficult or dangerous.

Interests elsewhere in the main Hawaiian Islands, and across the
Northwestern Hawaiian Islands, should continue to closely monitor
the progress of Hurricane Lane. Additional Tropical Storm or
Hurricane Watches will likely be issued later today or tonight.

For storm information specific to your area, please monitor
products issued by the National Weather Service office in
Honolulu Hawaii.

DISCUSSION AND OUTLOOK
———————-
At 500 AM HST (1500 UTC), the eye of Hurricane Lane was located
by satellite near latitude 14.1 North, longitude 152.3 West. Lane is
moving toward the west near 12 mph (19 km/h) and this motion is
expected to continue through tonight, with a slight decrease in
forward speed. A turn toward the northwest is expected Wednesday
into Thursday. On the forecast track, the center of Lane will pass
close to Hawaii and Maui counties on Thursday.

Maximum sustained winds are near 150 mph (240 km/h) with higher
gusts. Lane is a category 4 hurricane on the Saffir-Simpson
Hurricane Wind Scale. Slight weakening is expected the next couple
of days, but Lane is forecast to remain a dangerous hurricane as it
draws closer to the Hawaiian Islands.

Hurricane-force winds extend outward up to 40 miles (65 km) from the
center and tropical-storm-force winds extend outward up to 140 miles
(220 km).

The estimated minimum central pressure is 950 mb (28.06 inches).

HAZARDS AFFECTING LAND
———————-
WIND: Hurricane conditions are possible within the Hurricane Watch
area on Thursday.

RAINFALL: Excessive rainfall associated with Lane is expected
to affect portions of the Hawaiian Islands from Wednesday into the
weekend, leading to flash flooding and landslides. Lane is expected
to produce total rain accumulations of 10 to 15 inches with isolated
maximum amounts of 20 inches over the Hawaiian Islands.

SURF: Large swells generated by Lane will impact the Hawaiian
Islands this week. These swells will produce large and potentially
damaging surf along exposed south and west facing shorelines.

NEXT ADVISORY
————-
Next intermediate advisory at 800 AM HST.
Next complete advisory at 1100 AM HST.

$$
Forecaster Birchard

274
WTPA42 PHFO 211457
TCDCP2

Hurricane Lane Discussion Number 27
NWS Central Pacific Hurricane Center Honolulu HI EP142018
500 AM HST Tue Aug 21 2018

Lane remains a powerful hurricane this morning, with a well-
developed warm eye completely surrounded by persistent cold cloud
tops. Subjective Dvorak current intensity estimates were a
unanimous 6.5/127 kt while ADT was in relative agreement. The
initial intensity for this advisory remains at 130 kt as Lane’s
satellite signature has changed little since last sampled by
Hurricane Hunters and the NOAA P-3 Monday evening.

The initial motion for this advisory is 275/10 kt, with Lane
continuing to be steered by a mid-level ridge to the north. Over
the next day or two, Lane is expected to reach the western periphery
of the ridge, and into an area of relatively light steering flow.
This is expected to allow the cyclone to gain latitude as its
forward speed diminishes. In this scenario, Lane will begin to make
a gradual turn to the west-northwest on Wednesday, with a more
decided turn toward the northwest on Thursday. After this point, the
track and intensity forecast become increasingly uncertain, as a
bulk of the model guidance is depicting interaction between Lane and
the terrain of the islands. This interaction then leads to a
weakened Lane increasingly being steered by the low-level trade wind
flow. The updated track forecast is essentially an update of the
previous official forecast, and lies very close to the multi-model
consensus HCCA.

Water temperatures along the forecast track will be sufficiently
warm to support a major hurricane, and thus any significant
weakening before Lane draws closer to the Hawaiian Islands will
likely be due to shear. In the short-term, shear is expected to
remain light, and subtle intensity fluctuations associated with
inner-core dynamics will likely lead to little overall change in
intensity. By 72 hours, the forecast anticipates an increase in
shear as Lane lies between the ridge to the east and a trough
aloft to the northwest of the main Hawaiian Islands. The updated
intensity forecast is close to the previous, and although it is on
the higher end of the guidance envelope, it closely follows
the trends presented by the multi-model consensus IVCN.

In addition to an increasing number of storm penetrations by the
Hurricane Hunters of the 53rd Weather Reconnaissance, the NOAA G-IV
will once again be sampling the larger scale environment to help
forecast models better initialize. The NOAA P-3 mission slated for
this morning has been scrapped as the aircraft needs to be examined
after encountering strong turbulence last night.

KEY MESSAGES:

1. Lane is forecast to move dangerously close to the main Hawaiian
Islands as a hurricane later this week, potentially bringing
damaging winds and life-threatening flash flooding from heavy
rainfall. As Lane is expected to be slow-moving as it nears the
islands, it will produce large and damaging surf, mainly along
exposed south and west facing shores. A Hurricane Watch has been
issued for Hawaii and Maui counties, and additional Tropical
Storm or Hurricane Watches may be required later today or tonight.

2. It is much too early to confidently determine which, if any, of
the main Hawaiian Islands will be directly impacted by Lane. Even
if the center of Lane were to remain offshore, it is important to
remember that impacts from a hurricane can extend well away from
the center. Interests throughout Hawaii are urged to closely
monitor the progress of Lane the next couple of days.

FORECAST POSITIONS AND MAX WINDS

INIT 21/1500Z 14.1N 152.3W 130 KT 150 MPH
12H 22/0000Z 14.4N 153.4W 125 KT 145 MPH
24H 22/1200Z 15.0N 154.6W 120 KT 140 MPH
36H 23/0000Z 15.9N 155.6W 110 KT 125 MPH
48H 23/1200Z 17.0N 156.5W 100 KT 115 MPH
72H 24/1200Z 19.7N 157.6W 85 KT 100 MPH
96H 25/1200Z 21.5N 159.5W 65 KT 75 MPH
120H 26/1200Z 21.5N 163.0W 50 KT 60 MPH

$$
Forecaster Birchard