Tropical Cyclone Discussion

288
WTPA45 PHFO 042039
TCDCP5
 
Hurricane Karina Discussion Number  34
NWS Central Pacific Hurricane Center Honolulu HI   EP112026
Issued by NWS National Hurricane Center Miami FL
1100 AM HST Fri Sep 04 2026

Recent conventional satellite images show Karina has a ragged eye
with fragmented inner core convection surrounding its center. A
comparison of 89- and 37-GHz GMI and AMSR3 passive microwave images
from earlier today show the vortex is tilted with height, likely the
result of some mid-level west-southwesterly shear impinging on the
hurricane. These trends suggest Karina has continued to weaken, and
its initial intensity is lowered to 75 kt. This agrees well with a
blend of the latest Dvorak CI numbers from HFO and JTWC (4.5/77 kt
and 4.0/65 kt, respectively), as well as D-PRINT and AiDT estimates
ranging from 70-75 kt.
 
The hurricane is being steered westward (280/9 kt) by a subtropical
ridge to the north of the hurricane. A northwestward motion is shown
between 24-48 h as the narrow ridge becomes reoriented to the
northeast of Karina, followed by a slight turn toward the
west-northwest as the ridge builds to the north of the system. A
small right-of-track adjustment was made to the NHC forecast from
36-72 h based on the latest multi-model consensus trends, but
otherwise this prediction is very similar to the previous forecast.
 
Karina is moving over marginal SSTs slightly lower than 26 deg C
within a dry mid-level environment (relative humidity less than 40
percent). With southwesterly shear likely to increase over Karina
during the next couple of days, these hostile conditions should
cause continued weakening. Karina is forecast to become a tropical
storm in 24 h and post-tropical between 60-72 h as its remaining
convection is sheared away. Shortly thereafter, what's left of
Karina will become absorbed by the outer circulation of Hurricane
Lowell, well to the north of the Hawaiian Islands.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/2100Z 20.6N 141.1W   75 KT  85 MPH
 12H  05/0600Z 21.0N 142.2W   65 KT  75 MPH
 24H  05/1800Z 21.7N 143.3W   60 KT  70 MPH
 36H  06/0600Z 22.5N 144.1W   55 KT  65 MPH
 48H  06/1800Z 23.2N 145.2W   45 KT  50 MPH
 60H  07/0600Z 23.7N 146.8W   40 KT  45 MPH
 72H  07/1800Z 24.1N 149.0W   35 KT  40 MPH...POST-TROPICAL
 96H  08/1800Z...DISSIPATED