Tropical Cyclone Discussion

278
WTPZ41 KNHC 010836
TCDEP1
 
Hurricane Karina Discussion Number  20
NWS National Hurricane Center Miami FL       EP112026
1100 PM HST Mon Aug 31 2026

Karina is maintaining a well-defined eye surrounded by very deep 
convection with cloud tops to -80 deg C or even colder.  Subjective 
Dvorak estimates indicate that the hurricane is maintaining its 
intensity.  In fact, the objective satellite consensus intensity 
estimate, SATCON, from UW-CIMSS suggests that Karina has become 
slightly stronger with an estimated maximum wind speed near 120 kt 
for this advisory.  There is not much evidence of concentric 
eyewalls at this time, and Karina still has some potential to become 
an annular hurricane.

The estimated motion continues to be west-northwestward, or    
285/9 kt.  A narrow mid-tropospheric subtropical ridge to the north 
of Karina should keep the system on a west-northwestward to westward 
track at about the same forward speed through 72 hours or so.  By 
days 4-5 a weak mid-level low to the north of the Hawaiian Islands 
should induce a slightly more northwestward motion.  The official 
track forecast is similar to the previous one, and is close to the 
simple model consensus.  The corrected consensus is a little north 
of the NHC track in the latter part of the forecast period.

Karina is likely to remain over marginally warm ocean waters with 
low vertical wind shear for the next couple of days.  This should 
keep the system as a major hurricane through the next 36 hours or 
so.  Although a slightly drier low- to mid-level air mass and 
gradually cooling SSTs should result in slow weakening, Karina 
could maintain its intensity more than expected if it takes on an 
annular structure.  The official intensity forecast is similar to 
the model consensus and on the high side of the guidance envelope.


FORECAST POSITIONS AND MAX WINDS
 
INIT  01/0900Z 18.0N 127.9W  120 KT 140 MPH
 12H  01/1800Z 18.5N 129.3W  120 KT 140 MPH
 24H  02/0600Z 18.9N 131.3W  110 KT 125 MPH
 36H  02/1800Z 19.3N 133.2W  100 KT 115 MPH
 48H  03/0600Z 19.6N 135.0W   90 KT 105 MPH
 60H  03/1800Z 19.9N 136.9W   85 KT 100 MPH
 72H  04/0600Z 20.2N 138.7W   80 KT  90 MPH
 96H  05/0600Z 20.8N 142.3W   70 KT  80 MPH
120H  06/0600Z 22.4N 145.4W   65 KT  75 MPH