Tropical Cyclone Discussion

704
WTPA45 PHFO 061448
TCDCP5
 
Tropical Storm Karina Discussion Number  41
NWS Central Pacific Hurricane Center Honolulu HI   EP112026
Issued by NWS National Hurricane Center Miami FL
500 AM HST Sun Sep 06 2026
 
Karina's convection has decreased significantly in coverage and 
intensity.  Deep convection is nearly completely gone, but moderate 
convection with cloud tops between -10C and -30C remain on Karina's 
north side.  The latest subjective and objective satellite intensity 
estimates range from 35-45 kt.  However, out of respect for the 
large area of 50-53 kt wind vectors on the two ASCAT passes from 
around 07Z, the intensity is held at 50 kt for this advisory.
 
Moderate west-southwesterly shear, sea-surface temperatures in the 
25-26C range and the dry air mass Karina is embedded in will cause 
the cyclone to continue weakening.  It is possible that the dry 
airmass could prevent any deep convection from re-forming.  The GFS 
and ECMWF models both agree that Karina should lose its convection 
in 12 to 24 h.  Although the NHC forecast for Karina becoming 
post-tropical has moved up to 24 h, the gales should continue a bit 
longer.  The low is expected to dissipate by hour 60 as it gets 
sheared apart by the combination of a powerful mid- to upper-level 
trough and outflow from Hurricane Lowell.

Karina's initial motion is northwestward, or 305 degrees at 6 kt.  A 
turn toward the west-northwest or west is expected by tonight as 
Karina gets pulled westward by a mid-level low to its west and 
ridging builds in to the north of Karina. The track forecast is 
similar to the previous one and is close to the HCCA and the GDMI.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/1500Z 22.7N 145.0W   50 KT  60 MPH
 12H  07/0000Z 23.0N 146.0W   45 KT  50 MPH
 24H  07/1200Z 23.2N 147.8W   40 KT  45 MPH...POST-TROPICAL
 36H  08/0000Z 23.5N 150.3W   35 KT  40 MPH...POST-TROPICAL
 48H  08/1200Z 24.2N 152.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  09/0000Z...DISSIPATED