Skip Navigation Links
NOAA NOAA United States Department of Commerce

Hurricane LANE


ZCZC HFOTCDCP2 ALL
TTAA00 PHFO DDHHMM
 
Hurricane Lane Discussion Number  41
NWS Central Pacific Hurricane Center Honolulu HI   EP142018
1100 AM HST Fri Aug 24 2018
 
Lane continues to struggle against 30 to 40 kt of southwesterly 
shear as analyzed by the UW-CIMSS shear analysis. The CDO continues 
to be very asymmetric and elliptical. Radar, lightning data, and 
1645z Windsat pass indicated that the active convection has been 
shunted to the northwest through north of the low level circulation 
center, indicating that the core of the tropical cyclone is getting
torn apart by the shear. Subjective current intensity estimates were
unanimous at 5.0, and CIMSS-ADT had 5.1. The initial intensity was
lowered to 90 kt for this advisory.

The initial motion estimate a rather uncertain 360/4. The changes to
Lane's structure make the near term track forecast very difficult,
as the steering layer will be rapidly evolving in the short term.
The proximity to island terrain makes the steering flow even more
complex, at least until the vortex completely seperates from the
persistent convection as a shallow low level circulation. Until
then, the motion is likely to be somewhat slow and erratic. The
reliable track guidance suggests a slow north or north-northeastward
drift for the next 12 hours, followed by an abrupt shift toward the
west at some point afterward. The consensus models show a general
westward motion from 24 through 96 hours, then turning more toward
the northwest. The only significant change to the track forecast
during this time was to slow Lane's forward motion. If anything is
left of Lane between 96 and 120 hours, the low level circulation
may gain latitude and try to merge with a large upper low over the
Northwestern Hawaiian Islands.

As long as Lane can maintain central deep convection, the weakening
trend will remain more gradual. More rapid weakening will commence
within 12 to 24 hours, once the convection is no longer able to
remain anchored to the low level circulation center. All of the
guidance indicates rather rapid weakening in the near term, and our
forecast agrees though is at the high end of the guidance in
deference to Lane's persistent core. Although the current forecast
retains Lane as a tropical cyclone through 5 days, it's very
possible that Lane will not last that long as the low level
circulation crosses underneath a band of very strong wind shear.

 
KEY MESSAGES:
 
1. One should not interpret the forecast westward turn south of the 
islands as a lower threat to the islands. If Lane retains central 
core convection longer than anticipated, the westward turn would 
happen later, which could bring hurricane conditions to Maui County 
or Oahu. This solution is still plausible at this time. Regardless 
of whether Lane makes landfall, severe impacts are still possible 
and the effects can extend far to the north and east of the center 
of Lane.
 
2. Lane will remain dangerously close to the central Hawaiian
Islands as a hurricane today into tonight bringing damaging winds
to some areas. 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 greatly increases the threat for
prolonged heavy rainfall. This is expected to lead to major flash
flooding and landslides in some areas.
 
4. Life-threatening and damaging surf can be expected along exposed
shorelines with localized storm surge exacerbating the impacts of a
prolonged period of damaging surf. The prolonged period of large
surf will also likely produce severe beach erosion.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/2100Z 19.1N 157.9W   90 KT 105 MPH
 12H  25/0600Z 19.7N 157.7W   75 KT  85 MPH
 24H  25/1800Z 20.2N 158.1W   65 KT  75 MPH
 36H  26/0600Z 20.2N 159.4W   55 KT  65 MPH
 48H  26/1800Z 20.1N 160.8W   45 KT  50 MPH
 72H  27/1800Z 20.4N 163.4W   35 KT  40 MPH
 96H  28/1800Z 22.4N 165.7W   30 KT  35 MPH
120H  29/1800Z 26.7N 168.5W   30 KT  35 MPH
 
$$
Forecaster R Ballard
 
NNNN