867
WTPA44 PHFO 072048
TCDCP4

Hurricane Lowell Discussion Number  47
NWS Central Pacific Hurricane Center Honolulu HI   EP122026
Issued by NWS National Hurricane Center Miami FL
1100 AM HST Mon Sep 07 2026

The satellite presentation of Lowell has slightly degraded during
the past several hours, with the Air Force Hurricane Hunter showing
slowly rising central pressures.  There is also a tilt on recent
microwave imagery due to increasing southwesterly shear, and the
low-level center is a bit west of the ragged eye in conventional
satellite data.  Although the peak flight-level winds at 700 mb
were 113 kt, the plane also reported the loss of an eyewall, which
suggests the standard 90 percent rule will be too high for a
surface wind reduction.  Thus, the initial wind speed is set to
95 kt, which also is close to the most recent JTWC and HFO
classifications.

The initial motion is north-northeastward or 030/15 kt.  Lowell`s
motion should gradually bend leftward due to the steering from a
mid- to upper-level low north of Hawaii and a building ridge to the
northeast.  The latest guidance is almost the same as before,
moving the center just west of Niihau tonight, and the new NHC
track in the short-term is only nudged slightly eastward.  After
passing the main Hawaiian Islands, Lowell will likely get wrapped
around the aforementioned upper-level low and take a westward turn
after 48 hours.  At long range, the system could turn northwestward
due to a new trough interaction, but hopefully it won`t survive due
to its weakened state.  The new forecast is very similar to the
previous one, and south of the latest GFS/ECMWF models.

Lowell should slowly weaken today due to increasing shear and
decreasing SSTs. A more rapid weakening should occur after it
passes Hawaii overnight as shear gets quite high, and it moves
over even cooler waters.  Model guidance is showing a much weaker
system by midweek, and the new NHC forecast follows that trend.
Beyond Wednesday, only a gradual loss of strength is forecast due
to shear lessening while the system is over marginally warm waters.
Lowell could be transitioning to a post-tropical cyclone at day 5,
but the possible trough interaction is leading to a wide range of
solutions from re-strengthening to a quick dissipation.  For now,
the forecast will follow the guidance mean, and it should be
mentioned this is a low-confidence long-range prediction.


KEY MESSAGES:

1. Kauai County: The core of Lowell is forecast to pass near Niihau
tonight and early Tuesday, and damaging hurricane conditions are
expected during that time, with the highest winds atop mountains and
on windward and leeward slopes. Large damaging waves will impact
exposed portions of the coastline, producing dangerous coastal
flooding and inundation of low-lying areas through early Tuesday.

2. Periods of heavy rainfall will increase in coverage over the
Hawaiian Islands today and continue through Wednesday. This
may produce significant flash flooding and mudslides, especially
across Kauai County and portions of the Big Island.

3. Oahu: Tropical storm conditions are expected to begin tonight.
Strong, damaging wind gusts could cause tree damage and power
outages, especially in areas of higher terrain.

4. Large swells will produce life-threatening surf and rip current
conditions during the next several days across portions of the
Hawaiian Islands.


FORECAST POSITIONS AND MAX WINDS

INIT  07/2100Z 18.7N 161.8W   95 KT 110 MPH
 12H  08/0600Z 20.9N 161.1W   85 KT 100 MPH
 24H  08/1800Z 23.8N 160.8W   65 KT  75 MPH
 36H  09/0600Z 25.9N 161.1W   55 KT  65 MPH
 48H  09/1800Z 27.5N 162.4W   50 KT  60 MPH
 60H  10/0600Z 27.9N 164.8W   45 KT  50 MPH
 72H  10/1800Z 27.6N 167.4W   40 KT  45 MPH
 96H  11/1800Z 27.6N 171.0W   40 KT  45 MPH
120H  12/1800Z 30.0N 172.0W   35 KT  40 MPH

$$
Forecaster Blake