Tropical Cyclone 12W (Hinnamnor) / Invest 98W
Monday, August 29, 2022

Current Snapshot

For all the latest updates visit: DisasterAWARE

By PDC’s Senior Weather
Specialist Glenn James

Tropical Cyclone 12W (Hinnamnor)…is located approximately 242 NM west-northwest of Iwo To, Japan

Northeast Pacific:

offshore of Southwest Mexico:

An area of disturbed weather has formed a few hundred miles south of Acapulco, Mexico.

Gradual development of this system is possible during the next several days while it moves west-northwestward or northwestward, well offshore of the coast of Mexico.

* Formation chance through 48 hours…low…20 percent
* Formation chance through 5 days…medium…40 percent

South of southern Mexico:

An area of low pressure is forecast to form south of southern coast of Mexico by late this week.

Some gradual development of this system is possible over the weekend while it moves westward or west-northwestward near the coast of southern Mexico.

* Formation chance through 48 hours…low…10 percent
* Formation chance through 5 days…low…30 percent

Central Pacific:

There are no tropical cyclones nor any areas of disturbed weather under investigation by the CPHC

Northwest and Southwest Pacific Ocean, Indian Ocean, Arabian Sea:

Tropical Cyclone 12W (Hinnamnor)

According to the JTWC Warning number 8, sustained winds were 115 knots with gusts to near 140 knots.

Typhoon 12W has leveled off in its intensification.

Animated enhanced infrared satellite imagery depicts a compact, 140 NM diameter central dense overcast feature with a 8 NM pinhole eye and spiral banding over the eastern semicircle.

Environmental conditions are highly favorable with radial outflow, low vertical wind shear and very warm sea surface temperature values.

TY 12W is forecast to track quickly westward to west-southwestward over the next two days as it tracks along the southern periphery of the ridge, transitioning from the eastern ridge to the western ridge positioned over the East China Sea.

Environmental conditions remain favorable with low vertical wind shear and warm sea surface temperature values.

A mid-latitude  shortwave trough is still expected to dig over the Korean Peninsula, however, the trough is too far north and propagates northeastward quickly with little impact on TY 12W’s track.

TY 12W is expected to rapidly intensify over the next 24 to 36 hours reaching a peak intensity of 145 knots by 36 hours. Near 72 hours, TY 12W will encounter a competing steering synoptic pattern with a ridge to the  northeast and west and the near-equatorial ridge to the south, which
will essentially box the system in, leading to an extended period of slow, quasi-stationary motion.

As the system slows, upwelling cooler water will serve to gradually weaken the system through 120 hours. Due to the competing steering, there is high uncertainty in the exact track of the center. Regardless, the system is expected to transition into a large system with a 400-500 NM diameter.

>>> There’s an area of disturbed weather, being referred to as Invest 98W which is located approximately 469 NM southeast of Kadena AB, Okinawa.

Maximum sustained surface winds are estimated at 20 to 25 knots.

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