Current Snapshot

The Pacific Disaster Center’s (PDC Global) Saturday, August 31, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 01C (Hone)…is located about 1160 miles west of Honolulu, Hawaii

Tropical Cyclone 11W (Shanshan)…is located approximately 176 NM southwest of Yokosuka, Japan – Final Warning

Tropical Cyclone 02A (Asna)…is located approximately 343 NM east-northeast of Masirah Island

Northeast Pacific Ocean: There are no Tropical Cyclones…nor any areas of disturbed weather under investigation by the National Hurricane Center (NHC)

Central North Pacific: 

Tropical Cyclone 01C (Hone)

HONE BECOMES A TROPICAL STORM AGAIN AS IT MOVES NORTHWEST SLOWLY

According to the CPHC Advisory number 37

Hone is moving toward the northwest near 3 mph (6 km/h) and this motion is expected to continue through today. A gentle turn towards the west
northwest Sunday will transition to a more northerly track Monday and afterward as Hone’s forward motion increases a bit.

Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Some strengthening is forecast through Tuesday, with gradual weakening expected afterward.

Tropical-storm-force winds extend outward up to 45 miles (75 km) from the center.

Western Pacific, Indian Ocean, and adjacent Seas:

Tropical Cyclone 11W (Shanshan) – Final Warning

According to the JTWC Warning number 40, sustained winds are 25 knots with gusts to near 35 knots

Animated multi-spectral satellite imagery depicts an exposed, defined low-level circulation center (llcc) embedded within an area of stratocumulus. A microwave image indicates weakly defined low-level structure associated with the llcc, with limited convective banding displaced to the north.

Surface winds along the coast of Honshu are weak, generally less than 10 knots, reflecting the weakening overall nature of the system. TD 11W
is forecast to track generally poleward over the next 24 hours, dissipating as it tracks south of and over central Honshu.

Tropical Cyclone 02A (Asna)

According to the JTWC Warning number 7, sustained winds are 45 knots with gusts to near 55 knots

A partially exposed low level circulation center (llcc) made an appearance on animated mult-ispectral satellite imagery as TC 02A (Asna) tracked westward and became partially obscured by an area of deep convection to the immediate west of the llcc. The overall symmetric shape, supported by well-wrapped bands would result in a much more impressive storm if the system could hang onto its moisture, however, dry air entrainment remains the biggest hindrance.

The source of the low relative humidity (50 pct and below) air is due to persistent dry air wrapping into the system from the arid regions of the Arabian Peninsula to the west, as well as some degree of land interaction with Pakistan to the north because of the relatively expanded nature of the system.

A tight core never quite congealed for TC 02A, and now the broad, vulnerable core is suffering the effects of mid-level dry air entrainment limiting further development. Outflow is strongest in an equatorward channel, with little to support outflow aloft in the poleward direction.

Any further development of TC 02A will be limited to the next 6-12 hours, and a marginal environment will contribute to the gradual weakening as it turns southwestward to south-southwestward after 24 hours. As it moves equatorward, vertical wind shear of initially 8-15 knots will strengthen to a marginally unfavorable 20 knots by 36 hours.

Marginally favorable but cooling sea surface temperatures and low ocean heat content are insufficient to continue to power the storm as it is overcome by dry air streaming into the system as described above. As the system nears the Arabian Peninsula, dry air from the west will quickly choke off the necessary supply of moisture that allowed this system to initially thrive. The mid-level dry air that has already begun to intrude into the core, as evidenced by animated msi, will further expose the llcc as it dissipates by 36 hours.

>>> An area of convection, being referred to as Invest 92W, is located approximately 290 NM northwest of Palau.

Animated multi-spectral satellite imagery depicts an area of broad cyclonic turning, with exposed low-level clouds and multiple weak spinners. A microwave image shows limited, formative convective banding over the southern quadrant.

Upper air data from Palau indicates vigorous (20-25 knot) southerly flow above the gradient level, along the eastern flank of the system. Upper-level conditions are marginally favorable with low to moderate (15-20 knot) vertical wind shear and broad diffluence.

Global models show a west-northwestward to northwestward track over the next two days with ECMWF aggressively developing a tropical depression (TD) in the next 24-36 hours while GFS is less aggressive showing TD development in 2-3 days.

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 is low.