Hurricane Iona Forecast Discussion Number 14
Issued at 500 AM HST Wed Jul 30 2025
000 WTPA41 PHFO 301433 TCDCP1 Hurricane Iona Discussion Number 14 NWS Central Pacific Hurricane Center Honolulu HI CP012025 Issued by NWS National Hurricane Center Miami FL 500 AM HST Wed Jul 30 2025 Iona has continued to rapidly weaken since the last advisory. A GPM microwave overpass showed an exposed low-level center located well to the northwest of the mid-level center apparent in geostationary imagery, with little or no organized convection near the low-level center. Subjective and objective satellite intensity estimates have decreased significantly and currently are in the 45-75 kt range. Based on a blend of these estimates, the initial intensity is reduced to a likely generous 65 kt. The initial motion is now 280/17 kt. This general motion is expected to continue during the next day or two as the cyclone moves along the southern periphery of a low- to mid-level subtropical ridge to the north. A turn toward the west-northwest and a gradual decrease in forward speed are expected late in the week and over the weekend, as the system is steered into a weakness in the ridge. The official forecast is nudged just a little north of the previous track and lies near the center of the track guidance envelope. Iona has stayed well south of the Hawaiian Islands, and the cyclone is forecast to move farther away from the islands during the next couple of days. Rapid weakening is expected to continue for the next 12-24 h due to increasing westerly vertical shear and a track over cooler sea surface temperatures. After that, the intensity forecast shows a period of little change in strength as sea surface temperatures begin to warm along the forecast track and the atmospheric conditions become a little more favorable. By the end of the forecast period, Iona should again weaken as it encounters mid-level dry air and another bout of vertical shear. The intensity forecast was lowered below the previous forecast mainly in response to the current intensity trends. FORECAST POSITIONS AND MAX WINDS INIT 30/1500Z 11.5N 160.2W 65 KT 75 MPH 12H 31/0000Z 11.8N 162.8W 55 KT 65 MPH 24H 31/1200Z 12.2N 166.4W 45 KT 50 MPH 36H 01/0000Z 12.8N 169.8W 45 KT 50 MPH 48H 01/1200Z 13.5N 173.2W 45 KT 50 MPH 60H 02/0000Z 14.5N 176.3W 45 KT 50 MPH 72H 02/1200Z 15.4N 179.2W 45 KT 50 MPH 96H 03/1200Z 17.3N 176.0E 40 KT 45 MPH 120H 04/1200Z 19.2N 171.1E 35 KT 40 MPH $$ Forecaster Beven
