Current Snapshot

The Pacific Disaster Center’s (PDC Global) Sunday, August 27, 2023, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 10E (Irwin)…is located about 900 NM west-southwest of the southern tip of Baja California

Tropical Cyclone 08W (Damrey)…is located approximately 194 NM southeast of Misawa, Japan

Tropical Cyclone 09W (Saola)…is located approximately 232 NM northeast of Manila, Philippines

Northeast Pacific Ocean:

Tropical Cyclone 10E (Irwin)

LARGE IRWIN FORECAST TO HEAD WESTWARD FOR THE NEXT SEVERAL DAYS

According to the NHC advisory number 5…

Irwin is moving toward the west-northwest near 12 mph (19 km/h). A turn toward the west is expected tonight. Irwin is forecast to continue moving westward at a similar forward speed after that.

Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Small fluctuations in intensity are possible through mid-week. Irwin will likely become a remnant low within the next few days.

Tropical-storm-force winds extend outward up to 230 miles (370 km) from the center.

Central North Pacific…

The National Hurricane Center in Miami, Florida is issuing advisories on Tropical Storm Irwin, centered about 2200 miles east of Hilo, Hawaii. Irwin is forecast to move into the Central Pacific Hurricane Center area of responsibility as a post-tropical remnant low on Thursday.

>>> Approximately 900 miles southeast of Hilo, Hawaii…

An area of low pressure is producing a large area of disorganized
showers and thunderstorms. Environmental conditions are marginally
conducive for some slow development of this system over the next few
days before conditions become less conducive as it continues
westward at 15 to 20 mph.

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

Elsewhere, no tropical cyclones are expected during the next 7 days.

Western Pacific, Indian Ocean and adjacent Seas:

Western Pacific…

Tropical Cyclone 08W (Damrey)

According to the JTWC Warning number 21…

Sustained winds were 60 knots…with gusts to near 75 knots

Animated enhanced infrared satellite imagery depicts shows a medium sized system that has slightly improved with deepened central convection over the last six hours as it continued to accelerate northwestward.

Analysis indicates a favorable environment with warm sea surface temperatures, low vertical wind shear, and strong ventilation aloft.

TY Damrey will track more north-northwestward under the ridge (str) as a mid-latitude trough transiting from the northwest weakens the str. The cyclone will crest the str axis in around 12 hours, then accelerate northeastward.

The favorable environment will sustain the current intensity of 65 knots up to 12 hours. Afterward, increasing vertical wind shear and cooling sea surface temperatures will begin to erode the system. Concurrently by 24 hours, TY 08W will enter the cold baroclinic zone and begin extra-tropical transition and, by 36 hours, will transform into a cold-core low with expanding storm-force winds.

Tropical Cyclone 09W (Saola)

According to the JTWC Warning number 18…

Sustained winds were 115 knots…with gusts to near 140 knots

Animated enhanced infrared satellite imagery shows a medium-sized, highly-symmetrical system that has further deepened around the eyewall as it maintained a 17 NM, sharply outlined eye that was concentric with a defined circulation on a composite weather radar loop.

Analysis indicates a favorable environment with very warm sea surface temperatures in the Philippine Sea, low vertical wind shear, and moderate radial outflow aloft, offset only by localized ocean upwelling.

TY Saola will begin to slowly track east-northeastward as the ridge to the south assumes steering. After 12 hours, a north-south extension of a secondary deep-layer str to the northeast will assume steering and drive the system northward, then after 24 hours, this same str will build and speed up the system northwestward toward Taiwan via the Luzon Strait.

The favorable environment, tempered by localized ocean upwelling, will become marginal with the onset of dry air intrusion in the low levels and will slightly weaken the system to 120 knots at 12-24 hours. Afterward, as the cyclone speeds northwestward, ocean upwelling and dry air intrusion will diminish and fuel a secondary intensification to a peak of 135 knots around 48 hours.

After 48 hours, increasing vertical wind shear and land interaction will gradually weaken the system down to 70 knots by 120 hours after it crosses the Taiwan Strait and makes landfall over eastern China northeast of Hong Kong.

>>> There’s an area of disturbed weather being referred to as Invest 93W…which is located approximately 316 NM north of Guam

Animated enhanced infrared satellite imagery depict a broad area of sharp troughing with persistent, deep convective banding hiding the prospective low level circulaton center.

Environmental analysis reveals favorable conditions for development with warm sea surface temperatures and robust poleward outflow aloft offset by moderate (15-20 knot) vertical wind shear.

The system will likely stall near the west of the Northern Marianas with strong monsoonal flow persisting over the region, aiding in its deepening and development.

Maximum sustained surface winds are estimated at 18 to 23 knots.

The potential for the development of a significant tropical cyclone within the next 24 hours is upgraded to high.