Tropical Cyclone 14W (Muifa) / Tropical Cyclone 15W (Merbok) / Tropical Cyclone 16W / Invest 94E
Monday, September 12, 2022

Current Snapshot

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By PDC’s Senior Weather
Specialist Glenn James

Tropical Cyclone 14W (Muifa)…is located approximately 224 NM west-southwest of Kadena AB, Okinawa, Japan

Tropical Cyclone 15W (Merbok)…is located approximately 310 NM northwest of Wake Island

Tropical Cyclone 16W…is located approximately 242 NM southwest of Iwo To, Japan


Northeast Pacific: .

Southwest of southwestern Mexico:

>>> Shower activity associated with a small area of low pressure located a few hundred miles southwest of Manzanillo, Mexico has become a little better organized since yesterday.

Although environmental conditions are only marginally conducive, some
additional gradual development is possible during the next day or two.

The system is forecast to move little through mid-week, then merge with the disturbance to its east shortly thereafter.

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

Near the coast of southern Mexico:

Invest 94E

>>> A trough of low pressure located along the coast of southern Mexico is producing disorganized cloudiness and showers.

This system is forecast to interact and merge with the disturbance off the southwestern coast of Mexico around midweek, and environmental conditions are expected to become more conducive for development by that time.

A tropical depression is likely to form during the latter part of this week while the system moves slowly westward near the coast of southern and southwestern Mexico.

* Formation chance through 48 hours…low…20 percent
* Formation chance through 5 days…high…80 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:

Northwest Pacific

Tropical Cyclone 14W (Muifa)

According to the JTWC Warning number 27, sustained winds were 90 knots with gusts to near 110 knots.

Animated enhanced infrared (eir) satellite imagery shows a medium sized typhoon with a symmetrical deep central convection that appears to be undergoing a second eyewall replacement cycle as evidenced by the onset of a secondary eyewall that is surrounding the current eye.

Analysis indicates a marginal environment with medium radial outflow and light to moderate vertical wind shear offset by cooling localized sea surface temperatures due to upwelling brought on by the current slow storm motion.

A mid-latitude shortwave trough exiting China via the Yellow Sea has weakened the steering ridge and allowed the system to track more northward. Behind the trough, a secondary, albeit weak, ridge to the west is competing for steering causing the slow storm motion.

After 12 hours, the ridge to the northeast will build anew and regain full steering and accelerate TY 14W north-northwestward.

The marginal environment will very slowly weaken the system down to 65 knots by 48 hours. Afterward, cooling sea surface temperatures in the East China Sea, increasing vertical wind shear, and landfall into northeast China via Shanghai will rapidly erode the system and by 96 hours will dissipate just south of Shandong Bandao Peninsula.

Tropical Cyclone 15W (Merbok)

According to the JTWC Warning number 10, sustained winds were 55 knots with gusts to near 70 knots.

Animated enhanced infrared satellite imagery shows the system has significantly deepened and expanded and became more consolidated as poleward outflow into a tutt cell to the north increased.

The environment is favorable with moderate radial outflow and warm sea surface temperatures slightly offset by light to moderate vertical wind shear.

TS Merbok will continue on its current track under the steering influence of the ridge until 12 hours. Afterward, the low- to mid-layered sub-tropical ridge to the east will assume steering and drive the cyclone more poleward.

After 48 hours, TS 15W will crest the ridge axis and accelerate northeastward. The favorable conditions will fuel a steady intensification to a peak of 85 knots by 72 hours. Afterward, increasing vertical wind shear and cooling sea surface temperatures will rapidly erode the system.

Concurrently by 48 hours, it will begin extra-tropical transition (ett) as it approaches the baroclinic zone. By 96 hours, 15W will complete ett and transform into a 55 knot cold-core low with an expansive wind field.

Tropical Cyclone 16W

According to the JTWC Warning number 2, sustained winds were 25 knots with gusts to near 35 knots.