By PDC’s Senior Weather
Specialist Glenn James
The Pacific Disaster Center’s (PDC Global) Saturday, August 26, 2023, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas
Current Tropical Cyclones:
Tropical Cyclone 08W (Damrey)…is located approximately 609 NM southeast of Yokosuka, Japan
Tropical Cyclone 09W (Saola)…is located approximately 194 NM northeast of Manila, Philippines
Northeast Pacific Ocean:
>>> South of Southwestern Mexico…
>>> Central East Pacific…
Showers and thunderstorms continue to show signs of organization in association with a low pressure system located about 700 miles south-southwest of the southern tip of the Baja California Peninsula. Environmental conditions are conducive for additional development, and a tropical depression or storm is expected to form in the next day or so while the system moves west-northwestward or northwestward at 10 to 15 mph over the central portion of the
tropical eastern Pacific.
* Formation chance through 48 hours…high…90 percent
* Formation chance through 7 days…high…90 percent
Central North Pacific…
The National Hurricane Center in Miami, Florida is monitoring a low pressure area (EP92) located about 2400 miles east-southeast of the main Hawaiian Islands. Showers and thunderstorms continue to show signs of organization in association with this low. Environmental conditions are conducive for additional development, and a tropical depression or storm is expected to form during the next day or so while the system moves west-northwestward or
northwestward at 10 to 15 mph. This system could move into the Central Pacific Hurricane Center area of responsibility around the middle of next week.
Elsewhere, no tropical cyclones are expected during the next 7 days.
Western Pacific, Indian Ocean and adjacent Seas:
Tropical Cyclone 08W (Damrey)
According to the JTWC Warning number 16…
Sustained winds were 55 knots…with gusts to near 70 knots
Animated enhanced infrared satellite imagery shows an elongated system that has mostly maintained its overall convective structure as it continued to accelerate northwestward.
Analysis indicates a marginally favorable environment with warm sea surface temperatures, low vertical wind shear, and strong ventilation aloft.
TS Damrey will continue on a fast track north-northwestward under the ridge (str). After 24 hours, a mid-latitude trough transiting from the northwest will weaken the str and allow the system to track more northward then accelerate northeastward
after 36 hours.
The marginally favorable environment will fuel a modest intensification to a peak of 65 knots by 36 hours as it crests the str axis. Afterward, increasing vertical wind shear and cooling sea surface temperatures will begin to erode the system.
Concurrently by 36 hours, TS 08W will enter the cold baroclinic zone and begin extra-tropical transition and, by 72 hours, will transform into a cold-core low with expanding gale-force winds.
Tropical Cyclone 09W (Saola)
According to the JTWC Warning number 13…
Sustained winds were 120 knots…with gusts to near 145 knots
Animated enhanced infrared satellite imagery shows a medium-sized, highly-symmetrical system that has deepened over the last six hours with cloud top cold temperatures around the eyewall as it maintained a 10 NM, sharply outlined eye that was concentric with a defined circulation on a composite 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.
TY Saola will continue on its current track under the str to the west. After 12 hours, a near equatorial ridge to the south will assume steering and drive the cyclone eastward.
Around 36 hours, a north-south extension of a secondary deep-layer str to the northeast will assume steering and drive the system northward, then around 48 hours, this same str will build and accelerate the system northwestward toward Taiwan via the Luzon Strait.
The favorable environment, tempered by localized ocean upwelling and some dry air intrusion will sustain the current intensity up to 36 hours; afterward, as the cyclone speeds up, a slight intensification to a peak of 115 knots at 36-48 hours is expected. Afterward, increasing vertical wind shear and land interaction will gradually weaken the system down to 90 knots by 120 hours after it reaches the Taiwan Strait.
>>> There’s an area of disturbed weather being referred to as Invest 93W…which is located approximately 150 NM northwest of Guam
Animated multi-spectral satellite imagery and a microwave pass depict a broad and highly disorganized low level circulation with intense convective bursts associated with strong (20-25 knot), convergent monsoonal westerlies.
Environmental analysis reveals favorable conditions with a point source over the system enhancing radial outflow aloft. Additionally, warm sea surface temperatures and low (5-10 knot) vertical wind shear are conducive for development.
Global models indicate 93W will track slowly eastward with steady development over the next 24-36 hours. The system will likely stall or reorganize to the west of the Northern Marianas with strong monsoonal flow persisting over the region.
Maximum sustained surface winds are estimated at 15 to 20 knots.
The potential for the development of a significant tropical cyclone within the next 24 hours remains low.