By PDC’s Senior Weather
Specialist Glenn James
The Pacific Disaster Center’s (PDC Global) Sunday, August 13, 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 204 miles east of Wake Island
Tropical Cyclone 07E (Fernanda)…is located about 695 miles southwest of the southern tip of Baja California
Tropical Cyclone 08E…is located about 1273 miles east-southeast of Hilo, Hawaii
Tropical Cyclone 07W (Lan)…is located approximately 237 NM south-southwest of Yokosuka, Japan
Northeast Pacific Ocean:
Tropical Cyclone 07E (Fernanda)
FERNANDA CONTINUES TO RAPIDLY INTENSIFY…NOW FORECAST TO BECOME A CATEGORY 4 HURRICANE
According to the NHC advisory number 6…
Fernanda is moving toward the west-northwest near 9 mph (15 km/h). A general west to west-northwest motion is expected to continue with some increase in forward speed over the next few days.
Maximum sustained winds have increased to near 105 mph (165 km/h)
with higher gusts. Additional rapid intensification is forecast
over the next day or so, and Fernanda is now forecast to become a
category 4 hurricane by tomorrow. Gradual weakening is expected to
Hurricane-force winds extend outward up to 15 miles (30 km) from the
center and tropical-storm-force winds extend outward up to 70 miles
Tropical Cyclone 08E
TROPICAL DEPRESSION FORMS OVER THE FAR WESTERN PORTION OF THE EAST PACIFIC BASIN
According to the NHC advisory number 1…
The depression is moving toward the west-northwest near 14 mph and this general motion is expected to continue during the next few days.
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Slow strengthening is forecast during the next couple of days, and the depression could become a tropical storm tonight or on Monday.
>>> Off the coast of southern Mexico…
A tropical wave continues to produce a large area of disorganized showers and thunderstorms over the far eastern portion of the east Pacific. Environmental conditions appear conducive for development during the next several days, and a tropical depression is expected to form by midweek while the system moves west-northwestward, roughly parallel to the coast of southern and southwestern Mexico.
* Formation chance through 48 hours…low…30 percent
* Formation chance through 7 days…high…90 percent
Central Pacific Ocean: There are no tropical cyclones at the time of this writing
Western Pacific, Indian Ocean and adjacent Seas:
Tropical Cyclone 05E (Dora)
According to the JTWC warning number 55…
Sustained winds are 40 knots…with gusts to 50 knots
Animated enhanced infrared satellite imagery shows a rapidly deteriorating system with its central convection decapitated and severely sheared northeastward.
Analysis indicates the environment has become highly unfavorable with warm sea surface temperatures and strong poleward outflow greatly offset by strong southwesterly vertical wind shear.
TS Dora will continue on a more northwestward track passing Wake Island approximately 147 NM to the southwest. The highly unfavorable environment will erode the system to dissipation by 48 hours, possibly sooner.
Tropical Cyclone 07W (Lan)
According to the JTWC Warning number 26…
Sustained winds were 85 knots…with gusts to near 105 knots
Animated enhanced infrared satellite imagery shows a medium-sized symmetrical cyclone that has mostly maintained its overall convective and wrap structure with a large 60×40 NM banding eye, exposing a ragged but defined low level circulation center.
Typhoon Lan will continue on its current track toward central Honshu, Japan, making landfall just before 36 hours near Wakayama Prefecture. Afterward, it will track more northward as the ridge recedes in response to a mid-latitude trough approaching from the northwest, exit into the Sea of Japan, crest the ridge axis by 60 hours, then accelerate northeastward on the poleward side of the ridge clipping the northern tip of Hokkaido just before 120 hours.
The marginally favorable environment will promote a modest intensification to a peak of 80 knots at 12-24 hours; afterward, increasing vertical wind shear, dry air intrusion, then land interaction will reduce it to 50 knots by 48 hours.
Despite the relatively warm sea surface temperatures in the Sea of Japan, increasing vertical wind shear, then interaction with the baroclinic zone as TY 07W begins extra-tropical transition around 72 hours will gradually erode it to a 45 knot cold core low by 120 hours.