Tropical Cyclone Discussion

187
WTPA42 PHFO 161455
TCDCP2
 
Tropical Storm Lala Discussion Number  17
NWS Central Pacific Hurricane Center Honolulu HI   CP012026
Issued by NWS National Hurricane Center Miami FL
500 AM HST Sun Aug 16 2026

Lala is showing ill effects from land interaction with the Hawaiian 
Islands and dry air intrusions this morning. The coverage of deep 
convection has diminished and become displaced to the north of the 
center. The southern half of the circulation is partially exposed in 
proxy-visible satellite images, with drier mid-level air apparent in 
water vapor imagery to the south of the storm. Radar data from 
Kohala (PHKM) indicate bands of heavy rainfall continue across Maui 
County and are beginning to reach Oahu. The initial intensity has 
been lowered to 60 kt this morning, which is supported by a blend of 
the data-T and final-T Dvorak numbers from HFO and JTWC and some of 
the UW-CIMSS objective estimates between 55-60 kt.
 
The long-term motion of the storm is still northwestward (305/12
kt). Lala is expected to turn westward later today and continue
westward for the next couple of days along the southern extent of a
subtropical ridge to its north. The track models are in good
agreement on this portion of the forecast. The updated NHC track
prediction lies slightly north of the previous one, mainly because
the current position is north of the previous forecast track. The
longer-range track forecast is highly uncertain, with a bifurcation
in the track guidance related to whether a weakness develops in the
subtropical ridge to induce a northward turn. The ECMWF and UKMET
models show a westward motion through the period, while the GFS
depicts a sharp northward turn at days 4-5. For now, the NHC
forecast continues to split the difference and generally lies
between the simple (TVCN) and corrected (HCCA) consensus aids.
 
Given the current structure of Lala and the drier air surrounding
the storm, some additional near-term weakening is forecast. However,
the intensity guidance this cycle was more aggressive with
restrengthening during the middle part of this week, particularly
the hurricane regional models. The shear diagnosed from the SHIPS
guidance does not appear prohibitive, and SSTs along the track are
warm enough to support intensification if Lala can become better
organized within a slightly better mid-level moisture environment.
Therefore, the updated NHC intensity forecast has been increased
from 48-120 h, though it still lies below the simple intensity
consensus (IVCN).
 
 
Key Messages:
 
1. Strong wind gusts are expected to continue across the Big Island
of Hawaii this morning, particularly over areas of higher terrain.
Across portions of the smaller islands, tropical-storm-force winds
accompanied by gusts to near hurricane strength will persist through
today.
 
2. Rain will continue to taper across the Big Island and Maui this
morning, however additional areas of flash flooding and mudslides
will be possible. Otherwise, heavy rainfall and the potential for
flooding from Lala will continue to spread westward across the
island chain through today.
 
3. Large and dangerous waves are expected to persist across portions
of the Hawaiian Islands today. Surf is building along east-facing
shores and will increase along exposed southern shores as Lala
passes through the region. This heavy surf may cause localized
coastal flooding and significant beach erosion.
 
4. Use caution after Lala passes as deadly hazards remain, including
flooded areas and downed power lines. If you use a generator, be
sure it is placed outside at least 20 feet away from doors, windows,
and garages to avoid deadly carbon monoxide poisoning.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  16/1500Z 20.2N 158.1W   60 KT  70 MPH
 12H  17/0000Z 20.7N 160.2W   55 KT  65 MPH
 24H  17/1200Z 20.9N 162.8W   55 KT  65 MPH
 36H  18/0000Z 20.8N 165.0W   55 KT  65 MPH
 48H  18/1200Z 20.6N 167.0W   60 KT  70 MPH
 60H  19/0000Z 20.7N 168.9W   60 KT  70 MPH
 72H  19/1200Z 21.0N 170.8W   65 KT  75 MPH
 96H  20/1200Z 22.4N 174.0W   70 KT  80 MPH
120H  21/1200Z 23.5N 176.0W   75 KT  85 MPH