By PDC’s Senior Weather
Specialist Glenn James
The Pacific Disaster Center’s (PDC Global) Thursday, August 3, 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 1070 miles west-southwest of the southern tip of Baja California
Tropical Cyclone 06W (Khanun)…is located approximately 174 NM west of Kadena AB, Okinawa, Japan
Northeast Pacific Ocean:
Tropical Cyclone 05E (Dora)
DORA REACHES CATEGORY 4 INTENSITY AGAIN…EXPECTED TO CONTINUE TRAVERSING THE EASTERN AND CENTRAL PACIFIC
AS A HURRICANE FOR AWHILE
According to the NHC advisory number 14…
Dora is moving toward the west near 18 mph (30 km/h), and this general motion is expected to continue during the next several days.
Maximum sustained winds have increased to near 140 mph (220 km/h) with higher gusts. Dora is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some weakening is forecast during the next day or so, but Dora is forecast to be near or at major hurricane intensity through much of the weekend.
Dora is a small hurricane. Hurricane-force winds extend outward up to 15 miles (30 km) from the center and tropical-storm-force winds extend outward up to 45 miles (75 km).
>>>Off the coast of Southern Mexico…
Showers and thunderstorms continue to show some signs of organization in association with a broad area of low pressure located a few hundred miles south of the coast of southwestern
Environmental conditions appear conducive for further development and a tropical depression is likely to form over the weekend as it moves west-northwestward or northwestward, parallel to but not far offshore of the southwestern coast of Mexico.
Interests along the southwestern coast of Mexico should monitor the progress of this system during the next few days.
* Formation chance through 48 hours…medium..60 percent
* Formation chance through 7 days…high…80 percent
Central Pacific Ocean:
The National Hurricane Center in Miami, Florida is issuing advisories on Hurricane Dora, located about 2100 miles east-southeast of Hilo, Hawaii. Dora is expected to move into the Central Pacific Hurricane Center’s area of responsibility Sunday, then pass well south of the Hawaiian Islands early next week on a westward track.
Elsewhere, no tropical cyclones are expected during the next 7 days.
Western Pacific, Indian Ocean and adjacent Seas:
Tropical Cyclone 06W (Khanun)
According to the JTWC Warning number 32…
Sustained winds were 65 knots…with gusts to near 80 knots
Typhoon 06W has rapidly intensified 40 knots over the past 24 hours, from 50 knots to the initial intensity of 90 knots.
Animated enhanced infrared (eir) satellite imagery depicts a quasi-stationary motion with major degradation to the eye and eyewall as well as warming cloud tops over the past six hours. There’s been an erosion of the eyewall over the northwest semicircle, with the eyewall remaining intact over the southeast semicircle. The innermost eye and eyewall have entirely dissipated, likely due to deep ocean upwelling restricting necessary energy transfer into the tropical system.
Typhoon Khanun (06W) has likely begun the previously forecast eastward motion, and will continue an east-northeastward track through 72 hours, at which time the system is forecast to turn slightly left on a northeastward trajectory through 120 hours.
Over the next 36 hours, the system will continue to see a reduction in maximum winds to around 60 knots by 36 hours. Once the system encounters higher ocean heat content and lower values of vertical wind shear on its projected path of travel, re-intensification is likely to occur from 48 through 120 hours.
The system’s size is also forecast to expand, which may provide an outlet aloft for enhanced poleward outflow into the deep westerly flow to the north.
>>> There’s an area of disturbed weather being referred to as Invest 93W…which is located approximately 414 NM east of Yokosuka, Japan
The system is currently classified as a subtropical depression, generally characterized as having both tropical and mid-latitude cyclone features.
Animated multi-spectral satellite imagery shows deep convection and shallow rain bands wrapping into a fully-exposed low-level circulation (llc). The asymmetric wind band and associated deep convection are confined north and east of the llc due to a strong upper-level trough just to the southwest.
Environmental analysis indicates invest 93W is in a marginal area for development under strong southerly flow aloft with high (30-40 knot) vertical wind shear offset by warm sea surface temperatures.
Global models are in general agreement that 93W will track northward over the next 72 hours well east of Honshu, accompanied closely by the aforementioned upper-level trough, which is expected to maintain strong southerly vertical wind shear and dry air over the cyclone.
Maximum sustained surface winds are estimated at 30 to 35 knots.
The potential for the development of a significant tropical cyclone within the next 24 hours remains low.