Western Pacific Tropical Weather Update – November 12, 2026

Typhoon Cempaka Reaches Final Warning Stage as Powerful Winds and Dangerous Seas Persist Across the Northwest Pacific

By Paul Harrison | Orbis Weather

Published: Thursday, November 12, 2026
Region: Western North Pacific, Philippine Sea, South China Sea, Philippines, Taiwan, Japan, Guam and Micronesia

🌏 Western Pacific Tropical Weather Overview

The Western Pacific is entering a quieter period of organized tropical cyclone activity on Thursday, November 12, following the rapid weakening of Typhoon Cempaka (31W), which has been accelerating east-northeastward across the open Northwest Pacific.

The Joint Typhoon Warning Center (JTWC) issued its final warning for Cempaka on November 11 as the storm began losing its tropical characteristics through interaction with a mid-latitude frontal system.

At its final reported position, Cempaka was still producing typhoon-force winds, demonstrating that a tropical cyclone can remain dangerous even as its circulation approaches dissipation.

The latest reviewed JTWC basin-wide advisory identified no other tropical cyclones, tropical disturbances or subtropical systems across the Western North Pacific.

The primary concerns are now:

• Dangerous offshore winds and large waves associated with the weakening Cempaka circulation.

• Residual marine hazards across remote waters east of Japan.

• Seasonal northeast monsoon conditions affecting parts of the Philippines and surrounding seas.

• Continued surveillance for new tropical disturbances across the Philippine Sea, South China Sea and Micronesia.

🌀 1. Typhoon Cempaka (31W): Latest Confirmed Storm Information

The final JTWC warning identified Cempaka at approximately 30.2°N, 154.1°E, around 360 nautical miles (414 miles / 667 kilometres) north of Minami-Tori-shima, Japan.

The cyclone was moving east-northeastward at approximately 36 knots, equivalent to 41 mph (67 km/h).

Final reported storm analysis — November 11, 12:00 UTC

These measurements describe the storm’s last reported tropical cyclone analysis, not a newly confirmed November 12 position.

Why is Cempaka weakening?

Several atmospheric factors have contributed to the cyclone’s deterioration.

Increasing wind shear: Upper-level winds exceeding 30 knots have disrupted the storm’s structure and displaced its strongest thunderstorms away from the low-level circulation.

Cooler ocean waters: Sea-surface temperatures along the storm’s path have fallen to approximately 25–26°C (77–79°F), reducing the energy available to maintain its tropical circulation.

Dry-air intrusion: Cooler, drier air associated with a frontal boundary has entered the storm, weakening its organized convection.

Frontal interaction: Cempaka has begun interacting with a mid-latitude weather system, causing its circulation to elongate and lose its tropical characteristics.

JTWC forecast that the circulation would open and dissipate into the larger frontal feature rather than complete a conventional extratropical transition as an identifiable cyclone.

🧭 2. Where Is Cempaka Heading?

The final forecast indicated that Cempaka would continue accelerating northeastward over the open Northwest Pacific.

Its movement was being controlled by a subtropical ridge to the east and a mid-latitude trough to the northwest.

The November 13–16 outlook is a broader meteorological assessment, not an extension of an official JTWC cyclone track.

Could Cempaka threaten Japan?

The final JTWC analysis placed the storm well east of mainland Japan and moving farther into the open Pacific.

A direct mainland Japan landfall was not indicated by the reviewed track.

However, large offshore waves and hazardous conditions could remain a concern for vessels operating near the storm’s former circulation.

🌊 3. Dangerous Marine Conditions Continue Across the Northwest Pacific

Although Cempaka was weakening, the cyclone retained a substantial wind field during its final tropical phase.

Earlier JTWC analysis on November 11 reported significant wave heights of approximately 30 feet (9.1 metres) near the storm.

Significant wave height is the average height of the highest one-third of waves, meaning individual waves can be considerably larger.

The JTWC also warned that an expansive area of gale-force winds could remain as the cyclone dissipated into the frontal system.

Marine hazards to monitor

• Strong winds over exposed offshore shipping routes.

• Large swells and dangerous seas around the former cyclone circulation.

• Rapidly changing weather near the developing frontal boundary.

• Difficult conditions for commercial shipping and smaller vessels.

Marine operators should obtain current forecasts from the Japan Meteorological Agency and appropriate maritime warning services before entering affected waters.

🇵🇭 4. Philippines: Northeast Monsoon and Localized Rainfall Risks

With Cempaka moving away from the Philippine region, attention shifts toward seasonal weather patterns.

November is an important transition period for the Philippines as the northeast monsoon, locally known as the Amihan, becomes increasingly influential.

The monsoon can bring cooler winds, changing sea conditions and periods of rainfall, particularly across northern and eastern parts of the country.

Northern Luzon

Batanes, Cagayan and the Babuyan Islands should continue monitoring northeast monsoon winds and coastal conditions.

Exposed northern and eastern shorelines can experience rough seas during stronger monsoon surges.

Eastern Visayas and Bicol

Easterly winds and localized convergence may produce showers and thunderstorms.

Where heavier rainfall develops, localized flooding remains possible in low-lying and poorly drained areas.

Central and Southern Philippines

Thunderstorms can develop independently of tropical cyclones, particularly where moist air and local atmospheric convergence are present.

Important: These are seasonal hazards to monitor, not confirmation of active November 12 rainfall warnings or flooding incidents. For official local advisories, consult PAGASA.

🇹🇼 5. Taiwan: Coastal Winds and Marine Conditions

Taiwan remains within the broader Western Pacific monitoring region, although Cempaka’s final position and movement do not indicate a direct approach.

During November, northeast monsoon surges can strengthen winds along northern and northeastern Taiwan.

Potential seasonal concerns include rough coastal seas, intermittent rainfall and hazardous conditions for smaller vessels.

The Taiwan Central Weather Administration provides official forecasts and marine warnings.

No Cempaka-related Taiwan warning is being asserted in this report.

🇯🇵 6. Japan: Offshore Storm Hazards and Autumn Weather

Japan’s principal connection to Cempaka is the cyclone’s passage across remote ocean waters east of the country.

The Ogasawara region and offshore shipping routes require particular attention to changing marine conditions.

Elsewhere, November weather across Japan is increasingly influenced by mid-latitude low-pressure systems, cold fronts and seasonal pressure patterns.

These systems can produce strong winds, heavy precipitation and rough seas without being classified as tropical cyclones.

Residents and maritime operators should follow the Japan Meteorological Agency for updated local forecasts.

🇬🇺 7. Guam, Northern Mariana Islands and Micronesia

The Mariana Islands and Micronesia remain important monitoring areas within the Western Pacific tropical cyclone basin.

Warm ocean waters and tropical atmospheric disturbances can support thunderstorm development throughout the region.

Guam and Northern Mariana Islands

Seasonal concerns include passing showers, thunderstorms, localized heavy rainfall and changes in coastal wave conditions.

Federated States of Micronesia

Tropical convergence and easterly disturbances can produce periods of heavy showers, even when no named tropical cyclone is present.

Palau

Localized thunderstorms and heavy tropical rainfall remain possible seasonal hazards.

The latest reviewed JTWC advisory did not identify an organized tropical disturbance across these areas.

That does not guarantee settled weather or eliminate the possibility of new development later in the week.

Official forecasts are available through National Weather Service Guam.

🌊 8. South China Sea: Tropical Development Monitoring

The South China Sea remains an important area for tropical cyclone surveillance during November.

Although activity generally decreases as the Northern Hemisphere moves toward winter, tropical cyclones can still form or move through the region late in the season.

Areas requiring continued monitoring include waters near Vietnam, the Philippines, southern China and the Malay Peninsula.

What could influence future development?

Sea-surface temperatures: Warm water provides energy for tropical convection.

Vertical wind shear: Strong upper-level winds can prevent thunderstorms from organizing around a developing circulation.

Monsoon patterns: Changes in northeast monsoon strength can affect low-level winds and convergence.

Atmospheric moisture: Deep tropical moisture supports sustained thunderstorm development.

The latest reviewed JTWC advisory did not identify a tropical disturbance in the Western North Pacific, including the South China Sea.

This is a current disturbance assessment, not a guarantee that tropical cyclone formation will remain absent over the next several days.

📊 9. Western Pacific Tropical Activity Summary

Based on the latest reviewed JTWC basin-wide advisory and Cempaka’s final warning.

The distinction between a final tropical cyclone warning and the disappearance of all associated weather hazards is important. A weakening circulation may lose its tropical classification while strong winds and large waves continue within the surrounding frontal system.

🔭 10. Western Pacific Tropical Outlook: November 12–17, 2026

Thursday, November 12

Cempaka is expected to lose its identity as a discrete tropical cyclone as it becomes absorbed into the larger frontal system.

Hazardous marine conditions may continue near its former circulation.

No additional organized tropical cyclone was identified in the latest reviewed JTWC advisory.

Friday, November 13

Attention turns toward residual frontal weather over the open Northwest Pacific and routine monitoring of tropical waters farther south.

Any remaining strong winds or high seas associated with the former Cempaka system require updated marine forecasts.

Saturday, November 14

The Philippine Sea, South China Sea and tropical western Pacific remain under routine surveillance for new areas of disturbed weather.

No specific new cyclone development is established by the reviewed advisory.

Sunday, November 15

Seasonal northeast monsoon winds and localized tropical rainfall remain relevant hazards across portions of Southeast Asia.

New disturbances cannot be ruled out solely because none were identified in the latest available bulletin.

Monday–Tuesday, November 16–17

The longer-range outlook remains uncertain.

Changes in monsoon circulation, ocean temperatures, wind shear and tropical convection could influence development.

No verified storm-specific track or intensity forecast is available for these dates from the reviewed JTWC bulletin.

🛰️ 11. Official Western Pacific Tropical Weather Sources

Orbis Weather uses recognized meteorological agencies and official warning services when assessing tropical cyclone activity.

Understanding differences between storm agencies

Tropical cyclone wind speeds can vary between agencies because different measurement standards are used.

JTWC generally reports maximum sustained winds averaged over one minute, while JMA uses a ten-minute averaging period.

These measurements should not be directly compared without accounting for their different definitions.

📝 12. Methodology, Forecast Uncertainty and Editorial Standards

How this report was prepared

This report draws primarily on the JTWC Western Pacific Significant Tropical Weather Advisory issued November 11, 2026, and its final warning information for Typhoon Cempaka.

The report also uses JTWC prognostic reasoning to explain the storm’s weakening, environmental conditions and expected dissipation.

The source advisory is reproduced in the Western Pacific Tropical Weather Discussion.

Regional information concerning the Philippines, Taiwan, Japan, Guam, Micronesia and the South China Sea provides broader meteorological context rather than claiming that unverified local weather warnings are active.

Data cutoff

The latest reviewed basin-wide JTWC advisory was issued November 12 at 06:00 UTC, while the last confirmed Cempaka storm position in the reviewed information was valid November 11 at 12:00 UTC.

This report does not establish a new November 12 storm position or independently confirm all current local warnings.

Forecast uncertainty

Tropical cyclone forecasts can change as new satellite observations and numerical weather prediction guidance become available.

Forecast confidence generally decreases over longer periods.

The absence of an identified disturbance does not mean tropical cyclone formation is impossible during the following week.

Editorial standards and corrections

Orbis Weather aims to provide original, accessible weather reporting supported by recognized meteorological sources.

Observed conditions, official forecasts, seasonal hazards and editorial interpretation are distinguished wherever possible.

No unverified casualty figures, damage estimates, rainfall totals, evacuation orders or transportation disruptions are presented as confirmed events.

Material factual errors should be corrected when identified, with significant changes clearly reflected in the article.

Safety notice: Orbis Weather is an independent weather information publisher and does not issue official meteorological warnings. Readers should follow national weather agencies and local emergency management authorities for decisions affecting personal safety.

📰 13. Final Outlook: Cempaka Fades, but Western Pacific Monitoring Continues

The Western Pacific’s most significant tropical weather development on Thursday, November 12, is the expected dissipation of Typhoon Cempaka following its rapid movement into the open Northwest Pacific.

The cyclone was still producing sustained winds of approximately 75 mph (120 km/h) in its final reported analysis, despite undergoing substantial structural weakening.

Increasing wind shear, cooler ocean temperatures, dry air and interaction with a frontal system have contributed to the storm’s decline.

The JTWC has issued its final warning, and no additional tropical cyclones or organized disturbances were identified in the latest reviewed basin-wide advisory.

However, offshore marine hazards may persist even after Cempaka loses its tropical identity.

Across the wider Western Pacific, the Philippines, Taiwan, Japan, Guam, Micronesia and the South China Sea remain subject to seasonal weather patterns that can produce heavy rainfall, thunderstorms, strong winds and rough seas independently of named tropical cyclones.

The key message for November 12: Cempaka is reaching the end of its tropical cyclone life cycle, but dangerous offshore conditions remain possible, and routine tropical weather monitoring must continue.

Orbis Weather will continue following developments across the Western Pacific, including new tropical disturbances, changing marine conditions and significant regional weather hazards.

Reported for Orbis Weather by Paul Harrison.