Tropical Cyclone Discussion
748 WTPA45 PHFO 051441 TCDCP5 Hurricane Karina Discussion Number 37 NWS Central Pacific Hurricane Center Honolulu HI EP112026 Issued by NWS National Hurricane Center Miami FL 500 AM HST Sat Sep 05 2026 Dvorak Current Intensity estimates from HFO and JTWC for Karina at 1200 UTC were still 65 kt, while the most recent DMINT and DPRINT estimates from UW-CIMSS are 62 and 69 kt, respectively. This is the basis for the 65 kt initial intensity, though the ragged convective structure of Karina and other lower objective estimates from UW-CIMSS (like a SATCON of 56 kt) over the past few hours suggest this could be a generous estimate. Locating the center of Karina has become somewhat difficult, but the motion is believed to still be toward the northwest at a slightly slower forward speed (305/7 kt). A deep-layer trough located to the north and northeast of Karina is allowing the cyclone to move more toward the northwest since last night, but the combination of the cyclone weakening and becoming shallow plus a ridge building over the north-central Pacific will likely cause Karina to turn westward by late Sunday. Models have generally shifted southward since yesterday, showing this turn occuring sooner than previously forecast, so the NHC forecast has been adjusted in that direction. It should be noted, however, that Karina is still expected to move well north or northeast of the Hawaiian Islands as a weak cyclone before it dissipates early next week. A combination of southwesterly shear, dry air, and marginal SSTs should cause Karina to quickly weaken during the next several days. In fact, there are indications in satellite imagery that the low- and mid-level center of Karina are beginning to stretch apart due to that shear. No significant changes were made to the NHC intensity forecast, which is near the middle of the intensity guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 05/1500Z 21.7N 143.0W 65 KT 75 MPH 12H 06/0000Z 22.1N 143.7W 55 KT 65 MPH 24H 06/1200Z 22.6N 144.6W 50 KT 60 MPH 36H 07/0000Z 23.0N 145.8W 45 KT 50 MPH 48H 07/1200Z 23.4N 147.7W 35 KT 40 MPH 60H 08/0000Z 23.9N 150.2W 30 KT 35 MPH...POST-TROPICAL 72H 08/1200Z...DISSIPATED