Tropical Cyclone Discussion

013
WTPZ41 KNHC 310255
TCDEP1
 
Hurricane Karina Discussion Number  15
NWS National Hurricane Center Miami FL       EP112026
500 PM HST Sun Aug 30 2026
 
Warm sea surface temperatures, minimal wind shear and sufficiently 
moist mid-level air have allowed for Major Hurricane Karina to 
rapidly intensify this evening. A recent SSMIS microwave pass 
revealed a vertically aligned center with a well-defined eyewall. 
However, the latest infrared imagery is beginning to show warming 
cloud tops and slight erosion of the convective structure north of 
the eye, which may indicate that this period of rapid 
intensification is beginning to level off. Recent objective 
intensity estimates from UW-CIMSS range from 91 to 122 kt. The 
intensity is set at 110 kt for this advisory.

Karina is moving steadily westward around 8 kt, steered by a ridge 
of high pressure centered to the northwest of the cyclone. A turn 
toward the west-northwest is forecast Monday night into Tuesday as a 
strong upper-level trough begins to weaken this ridge. The latest 
NHC forecast is similar to the previous advisory through 72 h. 
Beyond that point, a large spread develops among the model guidance, 
attributed to differences in the strength and position of another 
ridge building to the north and northwest. The forecast track has 
been adjusted to the left of the previous forecast advisory, towards 
HCCA and the Google DeepMind. Of note, Karina's track could have 
some influence on Tropical Storm Lowell's motion as the two systems 
move through the central Pacific. 
 
The major hurricane is moving over very warm waters, with sea 
surface temperatures near 29 C. Additional strengthening remains 
possible over the next 12-24 h as Karina encounters sufficiently 
warm waters with ample mid-level moisture and low wind shear. 
Gradual weakening is expected to begin on Tuesday as the cyclone 
moves over cooler waters and drier air. Following Karina's rapid 
intensification this evening, the forecast lies near the upper end 
of the intensity guidance envelope, and is consistent with the 
latest HCCA aid. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  31/0300Z 17.1N 123.8W  110 KT 125 MPH
 12H  31/1200Z 17.1N 124.9W  125 KT 145 MPH
 24H  01/0000Z 17.4N 126.6W  125 KT 145 MPH
 36H  01/1200Z 17.9N 128.4W  120 KT 140 MPH
 48H  02/0000Z 18.4N 130.3W  110 KT 125 MPH
 60H  02/1200Z 18.9N 132.1W  105 KT 120 MPH
 72H  03/0000Z 19.3N 134.0W  100 KT 115 MPH
 96H  04/0000Z 20.2N 137.2W   90 KT 105 MPH
120H  05/0000Z 20.9N 140.4W   75 KT  85 MPH