000 WTPA41 PHFO 150242 TCDCP1 Hurricane Darby Discussion Number 23 NWS Central Pacific Hurricane Center Honolulu HI EP052022 500 PM HST Thu Jul 14 2022 Darby is becoming less organized on satellite with pulses of increasingly ragged deep convection starting to become sheared from the low level center. The UW-CIMSS deep layer shear analysis suggests the core of Darby is now experiencing shear of 20 to 25 knots. Dvorak estimates from PHFO, SAB, PGTW all agree with the latest UW-CIMSS ADT estimate of 77 kt, thus giving good confidence with an initial intensity of 80 kt with this advisory. The initial motion is 290/13. Little has changed with the synoptic situation, with Darby continuing along the southwest periphery of a mid-level ridge. Darby is moving on a track just north of west, partly in response to an upper level trough to the northwest of the system. As it moves further west over the next 24 hours, the upper level trough will lose some of its influence on the system, allowing Darby to take a more due west heading. During this time, the system will weaken further, and the track will be influenced more by the low level trade wind flow. After 24 hours, a high pressure system north of the Hawaiian islands will help drive Darby to the west. The track guidance remains tightly clustered. Our official track remains close to the previous forecast track, which remains just a bit north of the middle of the guidance envelope. The forecast track into Saturday keeps Darby over sea surface temperatures (SST) of 25-26C. Deep layer shear near the system is expected to remain 20-25 kt for the next few days. This combination of shear and marginal SST continue to support weakening. The intensity guidance agrees and remains tightly clustered as well. Initially our forecast remains on the higher side of the guidance envelope, with Darby still expected to become a remnant low by Saturday night. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 17.5N 143.4W 80 KT 90 MPH 12H 15/1200Z 17.7N 145.4W 70 KT 80 MPH 24H 16/0000Z 17.7N 148.6W 60 KT 70 MPH 36H 16/1200Z 17.6N 151.9W 50 KT 60 MPH 48H 17/0000Z 17.4N 155.4W 40 KT 45 MPH 60H 17/1200Z 17.2N 158.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 18/0000Z...DISSIPATED $$ Forecaster M Ballard/R Ballard