Current Snapshot

The Pacific Disaster Center’s (PDC Global) Wednesday, August 9, 2023, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 05E (Dora)…is located about 930 miles southwest of Honolulu, Hawaii

Tropical Cyclone 06W (Khanun)…is located approximately 19 NM south-southeast of Chinhae, South Korea

Tropical Cyclone 07W (Lan)…is located approximately 143 NM east of Iwo To, Japan

Northeast Pacific Ocean:

Central East Pacific…

A tropical wave is producing a large area of disorganized showers and thunderstorms several hundred miles south of the coast of southwestern Mexico.

Environmental conditions are expected to be conducive for gradual development of this system, and a tropical depression is likely to form by the weekend or early next week while it moves generally westward at about 15 mph across the central portion of the basin.

* Formation chance through 48 hours…low…20 percent
* Formation chance through 7 days…high…70 percent

Western East Pacific…

Another tropical wave located well to the southwest of the southern tip of the Baja California peninsula is producing some disorganized showers and thunderstorms.

Environmental conditions could support some gradual development of this system during the next several days while it moves generally westward at 10 to 15 mph across the far western portion of the basin and into the Central Pacific basin.

* Formation chance through 48 hours…low…near 0 percent
* Formation chance through 7 days…low…20 percent

Off the coast of southern Mexico…

An area of low pressure is forecast to form early next week offshore of Central America.

Some gradual development of this system is possible during the early and middle parts of next week while it moves generally west-northwestward, roughly parallel to the coast of southern Mexico.

* Formation chance through 48 hours…low…near 0 percent
* Formation chance through 7 days…low…20 percent

Central Pacific Ocean:

Tropical Cyclone 05E (Dora)

DORA MOVING WESTWARD AND BEGINNING TO PASS FAR SOUTH OF JOHNSTON ISLAND

According to the NHC advisory number 39…

Dora is moving toward the west near 22 mph (35 km/h) and this motion is expected to continue and swing toward the west-northwest over the next few days

Maximum sustained winds are near 130 mph (215 km/h) with higher gusts. Dora is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Slow weakening is forecast during the next few days.

Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 120 miles (195 km).

HAZARDS AFFECTING LAND SURF:

Swells generated by Dora are currently impacting Johnston Island or expected very soon and will likely produce large and life-threatening surf there through Thursday.

>>> Approximately 2200 miles southeast of Hilo, Hawaii…

A tropical wave is producing a few disorganized showers and thunderstorms.

Environmental conditions could support some gradual development of this system during the next several days while it moves generally westward at 10 to 15 mph across the far western portion of the East Pacific basin and into the Central Pacific basin.

* Formation chance through 48 hours…low…near 0 percent
* Formation chance through 7 days…low…20 percent

Western Pacific, Indian Ocean and adjacent Seas:

Western Pacific…

Tropical Cyclone 06W (Khanun)

According to the JTWC Warning number 56…

Sustained winds were 45 knots…with gusts to near 55 knots

Animated enhanced infrared satellite imagery depicts an overall asymmetric system with a mass of deep convection largely on the northern semicircle with a partially exposed low level circulation center. Additionally, water vapor imagery shows strong poleward outflow streaming toward the northeast away from the systems center. An earlier image depicts a deep convective band over the northern quadrant, wrapping into the core of the system.

The overall track of ts 06W remains consistent with the previous forecast, as the system transits quickly northwestward within environmental conditions which remain marginally favorable with good equatorward and poleward outflow and low vertical wind shear, warm sea surface temperatures offset by dry air entrainment.

Landfall is expected to the west of Busan after 12 hours, interaction with the Korean Peninsula will lead to deterioration to 35 knots by 36 hours and then to eventual dissipation by 72 hours.

Tropical Cyclone 07W (Lan)

According to the JTWC Warning number 10…

Sustained winds were 65 knots…with gusts to near 80 knots

Animated enhanced infrared satellite imagery depicts multiple deep convective bands surrounding the center and obscuring the low-level circulation center. Water vapor imagery also indicates equatorward outflow and eastward outflow into a tutt cell to the east. Thus, environmental conditions remain favorable.

Environmental conditions remain favorable for intensification due to warm sea surface temperatures, low (0-5 knot) vertical wind shear, and good outflow aloft.

TS 07W (Lan) will track northwestward along the southwestern periphery of the deep-layered subtropical ridge (str) positioned to the northeast through 24 hours. By 36 hours, the str will shift east and erode slightly as a mid-latitude trough propagates eastward north of Hokkaido.

By 48 hours, the str will reorient which will generally accelerate the system north-northwestward within the enhanced flow on the western periphery of the ridge. By 72 hours, the str is expected to extend westward which will then steer 07W northwestward toward Yokosuka, Japan through the end of the forecast.

In terms of intensity, the favorable environment will fuel a steady intensification to a peak of 85 knots between 48-72 hours. Afterward, cooling sea surface temperatures due to upwelling in relatively shallow waters near the coast of Honshu will gradually weaken the system, down to 65 knots by 120 hours.