Tropical Cyclone Discussion

553
WTPA42 PHFO 200839
TCDCP2
 
Hurricane Lala Discussion Number  32
NWS Central Pacific Hurricane Center Honolulu HI   CP012026
Issued by NWS National Hurricane Center Miami FL
1100 PM HST Wed Aug 19 2026
 
Satellite imagery indicates that Lala has lost organization during
the evening hours, with most of the deepest convection shifting
into the northern semicircle.  Microwave data also show this change
in structure, with the mid-level center a bit north of the
low-level circulation, presumably due to shear.  Satellite estimates
have noticeably fallen recently, and the current intensity is set
to 90 kt as a consensus of the available values.  A pair of recent 
SAR and ASCAT passes were helpful in expanding the wind radii.
 
Lala has turned north-northwestward as it feels the steering by an
an approaching mid- to upper-level trough from the northwest.  The
hurricane should turn northward tomorrow but then move back to the
northwest by Saturday as the trough becomes absorbed by Lala and a
new ridge forms over the northwestern Central Pacific, blocking
any fast exit.  For such a complex pattern, the models are in
pretty good agreement, and only a small northeastward nudge was
made to the official forecast after 36 hours.
 
The hurricane is expected to remain powerful as it tracks through
the Papahanaumokuakea Marine National Monument through Thursday.
After moving north of those waters, gradually cooling sea-surface
temperatures, and moderate shear is expected to promote slow
weakening during the next several days.  The absorption of the
upper-level trough by the weekend should provide an unusual amount
of instability through cold upper-level temperatures, despite
waters at 25C or below.  Additionally, the shear becomes quite low,
limiting the potential dry-air entrainment into the center.  These
factors suggest it will maintain hurricane strength at quite a high
latitude for the Central Pacific.  The new NHC intensity forecast
is basically just an update of the previous one, adjusted for a
lower initial wind speed.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/0900Z 23.5N 171.9W   90 KT 105 MPH
 12H  20/1800Z 24.5N 172.3W   85 KT 100 MPH
 24H  21/0600Z 26.1N 172.0W   85 KT 100 MPH
 36H  21/1800Z 28.0N 171.4W   80 KT  90 MPH
 48H  22/0600Z 29.8N 171.8W   75 KT  85 MPH
 60H  22/1800Z 31.0N 173.0W   70 KT  80 MPH
 72H  23/0600Z 31.9N 174.1W   65 KT  75 MPH
 96H  24/0600Z 33.4N 176.3W   55 KT  65 MPH
120H  25/0600Z 35.4N 178.2W   50 KT  60 MPH