Tropical Cyclone Discussion

297
WTPA42 PHFO 210852
TCDCP2
 
Hurricane Lala Discussion Number  36
NWS Central Pacific Hurricane Center Honolulu HI   CP012026
Issued by NWS National Hurricane Center Miami FL
1100 PM HST Thu Aug 20 2026

A ragged eye has reappeared in infrared satellite imagery, which
resulted in subjective Dvorak estimates from HFO and JTWC bumping
up to T4.5/77 kt and T5.0/90 kt, respectively. The initial intensity 
is therefore estimated to be 85 kt, which is also near the middle 
of the range of objective estimates from UW-CIMSS (75-95 kt).

Lala's center has passed Laysan Island and is now beginning to move 
away from the islands of the Papahanaumokuakea Marine National 
Monument. The hurricane is interacting with a mid- to upper-level 
trough to its northwest, which has induced a north-northeastward 
motion of 020/8 kt. This motion should continue through early 
Friday, but a relatively quick turn to the north and then northwest 
is expected late Friday and early Saturday when Lala rotates around 
to the northern side of the trough. A developing mid-tropospheric 
high south of the Aleutian Islands should then keep Lala on a slow 
northwestward trajectory through Tuesday. Mainly as a result of 
Lala turning more to the north-northeast than previously expected, 
the track guidance has shifted a bit to the right on this cycle. 
The new NHC track forecast blends the previous forecast with the 
latest TVCN, HCCA, and GDMI aids.

Various shear diagnostics suggest that the trough near Lala is 
causing 30-40 kt of deep-layer southwesterly shear over the 
hurricane, but this is apparently being compensated by strong 
upper-level divergence. These conditions are expected to flip in 
the next 24-36 hours, with shear decreasing significantly and 
upper-level divergence becoming more neutral. Lala will also 
gradually move over cooler waters in the coming days, with sea 
surface temperatures falling below 26 degrees Celsius in 2 to 3 
days. As a result, only slow weakening is anticipated for much of 
the 5-day forecast period, and the NHC intensity forecast most 
closely follows the gradual trend shown by the IVCN intensity 
consensus. By day 5, mid-level moisture and instability, along with 
relatively low shear, could still be sufficient enough to support 
some deep convection and keep Lala going as a tropical cyclone, but 
the storm will probably be getting very close to becoming 
post-tropical.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/0900Z 26.6N 171.7W   85 KT 100 MPH
 12H  21/1800Z 28.1N 171.3W   80 KT  90 MPH
 24H  22/0600Z 29.8N 171.7W   75 KT  85 MPH
 36H  22/1800Z 30.9N 172.7W   70 KT  80 MPH
 48H  23/0600Z 31.8N 173.6W   65 KT  75 MPH
 60H  23/1800Z 32.5N 174.5W   60 KT  70 MPH
 72H  24/0600Z 33.1N 175.3W   55 KT  65 MPH
 96H  25/0600Z 34.6N 176.9W   50 KT  60 MPH
120H  26/0600Z 36.6N 178.7W   45 KT  50 MPH