529
WTPA32 PHFO 240555
TCPCP2

BULLETIN
Hurricane Lane Intermediate Advisory Number 38A
NWS Central Pacific Hurricane Center Honolulu HI EP142018
800 PM HST Thu Aug 23 2018

…DANGEROUS HURRICANE LANE MOVING NORTH TOWARD THE MAIN HAWAIIAN
ISLANDS…

SUMMARY OF 800 PM HST…0600 UTC…INFORMATION
———————————————-
LOCATION…18.0N 157.9W
ABOUT 170 MI…280 KM SW OF KAILUA-KONA HAWAII
ABOUT 230 MI…370 KM S OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS…120 MPH…195 KM/H
PRESENT MOVEMENT…N OR 350 DEGREES AT 6 MPH…9 KM/H
MINIMUM CENTRAL PRESSURE…959 MB…28.32 INCHES

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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

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

A Tropical Storm Warning is in effect for…
* Hawaii County

A Hurricane Watch is in effect for…
* Kauai County…including the islands of Kauai and Niihau

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. Preparations to protect life and
property should be rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

Interests in the Northwestern Hawaiian Islands should monitor
the progress of Hurricane Lane.

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

DISCUSSION AND OUTLOOK
———————-
At 800 PM HST (0600 UTC), the eye of Hurricane Lane was located by
radar and satellite imagery near latitude 18.0 North, longitude
157.9 West. Lane is moving toward the north near 6 mph (9 km/h). A
slow general northward motion is expected to continue through
Friday. A turn toward the west is anticipated Saturday and Sunday,
with an increase in forward speed. On the forecast track, the center
of Lane will move over, or dangerously close to portions of the main
Hawaiian islands later tonight and Friday.

Maximum sustained winds are near 120 mph (195 km/h) with higher
gusts. Lane is a category 3 hurricane on the Saffir-Simpson
Hurricane Wind Scale. Some weakening is forecast during the next 48
hours, but Lane is expected to remain a hurricane as it approaches
the islands.

Hurricane-force winds extend outward up to 35 miles (55 km) from
the center and tropical-storm-force winds extend outward up to 125
miles (205 km).

The estimated minimum central pressure is 959 mb (28.32 inches).

HAZARDS AFFECTING LAND
———————-
WIND: Tropical storm conditions are already occurring on the Big
Island and parts of Maui County. These conditions will likely
persist tonight. Hurricane conditions are expected over some areas
of Maui County on Friday. Tropical storm conditions are expected to
begin on Oahu later tonight, with hurricane conditions expected from
Friday into Friday night. Tropical storm or hurricane conditions are
possible on Kauai on Saturday.

RAINFALL: Rain bands will continue to overspread the Hawaiian
Islands well ahead of Lane. Excessive rainfall associated with this
slow moving hurricane will continue to impact the Hawaiian Islands
into the weekend, leading to significant and life-threatening flash
flooding and landslides. Lane is expected to produce total rain
accumulations of 10 to 20 inches, with localized amounts of 30 to 40
inches possible over portions of the Hawaiian Islands. Over two feet
of rain has already fallen at a couple of locations on the windward
side of the Big Island.

SURF: Very large swells generated by the slow moving hurricane will
severely impact the Hawaiian Islands over the next couple of days.
These swells will produce extremely large and damaging surf along
exposed west and south facing shorelines. A prolonged period of high
surf will likely lead to significant coastal erosion.

STORM SURGE: The combination of a dangerous storm surge and large
breaking waves will raise water levels by as much as 2 to 4 feet
above normal tide levels along south and west facing shores near
the center of Lane. The surge will be accompanied by large and
destructive waves.

NEXT ADVISORY
————-
Next complete advisory at 1100 PM HST.

$$
Forecaster Houston

656
WTPA42 PHFO 240311
TCDCP2

Hurricane Lane Discussion Number 38
NWS Central Pacific Hurricane Center Honolulu HI EP142018
500 PM HST Thu Aug 23 2018

The weakening trend is underway. Over the past several hours, the
CDO of Lane has become elliptical as strong shear, 25 to 35 kt in
the UW-CIMSS shear analysis, begins to impinge on the core of the
hurricane. Outflow has become very restricted in the southwest The
eye, while still clearly evident on radar, is becoming indistinct in
the visible and infrared satellite imagery. The satellite intensity
estimates from HFO, JTWC, TAFB and SAB were a unanimous 5.5, and the
CIMSS FT number was 5.6 with the CI being held up by constraints.
Based the current intensity of 105 kt on these estimates.

The initial motion estimate is 330/5. There is no change to the
forecast philosophy with this package. Lane continues to be steered
toward the north on the western side of a mid-level ridge which is
located to the east of Hawaii. The consensus guidance continues to
show a northward motion, or even a motion toward just east of due
north, as the ridge builds south and possibly southwest of the
cyclone. The official forecast is similar to the previous track, and
remains a bit left of the consensus tracks. As the inner core
continues to deteriorate, Lane will come increasingly under the
influence of the low level easterlies and begin tracking westward.
However, the exact time when this will occur is still rather
uncertain, and only a small delay in this decoupling could bring
Lane farther north, with considerably worse conditions over the
islands. Even if Lane remains along the forecast track, some
significant impacts are expected.

Our intensity forecast shows weakening, but continues to trend on
the high side of the intensity guidance through 72 hours owing to
how organized Lane’s core has been in recent days. During the later
periods of the forecast, it is possible that Lane will not survive
the shear and may become a remnant low even sooner than forecast.

KEY MESSAGES:

1. It is vital that you do not focus on the exact forecast track or
intensity of Lane, and remain prepared for adjustments to the
forecast. Although the official forecast does not explicitly
indicate Lane’s center making landfall over any of the islands, this
remains a very real possibility. Even if the center of Lane remains
offshore, severe impacts could still be realized as they extend well
away from the center.

2. Lane will pass dangerously close to the main Hawaiian Islands as
a hurricane on Friday, and is expected to bring damaging winds.
Terrain effects can cause strong localized acceleration of the wind
through gaps and where winds blow downslope. These acceleration
areas will shift with time as Lane passes near or over the islands.
Winds will also be stronger at the upper floors of high rise
buildings.

3. The slow movement of Lane also greatly increases the threat for
prolonged heavy rainfall and extreme rainfall totals. This is
expected to lead to major, life-threatening flash flooding and
landslides over all Hawaiian Islands.

4. Large and damaging surf can be expected along exposed
shorelines, especially along south and west facing coasts, with
localized storm surge exacerbating the impacts of a prolonged period
of damaging surf. This could lead to severe beach erosion.

FORECAST POSITIONS AND MAX WINDS

INIT 24/0300Z 17.8N 157.9W 105 KT 120 MPH
12H 24/1200Z 18.7N 157.9W 95 KT 110 MPH
24H 25/0000Z 19.6N 158.1W 85 KT 100 MPH
36H 25/1200Z 20.1N 158.6W 75 KT 85 MPH
48H 26/0000Z 20.3N 159.6W 65 KT 75 MPH
72H 27/0000Z 20.2N 162.4W 55 KT 65 MPH
96H 28/0000Z 20.8N 165.1W 35 KT 40 MPH
120H 29/0000Z 23.2N 167.3W 30 KT 35 MPH

$$
Forecaster R Ballard