WESTERN PACIFIC Tropical Weather Update – November 11, 2026

Typhoon Cempaka Weakens East of Japan as Dangerous Seas Continue Across the Northwest Pacific

By Paul Harrison | Orbis Weather

Published: Wednesday, November 11, 2026

Region: Western North Pacific, Philippine Sea, South China Sea, Philippines, Taiwan, Japan, Guam and Micronesia

🌏 Western Pacific Tropical Weather Overview

The Western Pacific remains active on Wednesday, November 11, as Typhoon Cempaka (31W) continues moving rapidly east-northeastward away from Japan.

Although the storm has weakened considerably from its earlier intensity, Cempaka remains a significant maritime hazard, generating powerful winds and extremely rough seas across the open Northwest Pacific.

According to the Joint Typhoon Warning Center (JTWC), Cempaka was located approximately 339 nautical miles (390 miles / 628 kilometres) east-northeast of Iwo To at 00:00 UTC on November 11.

Maximum sustained winds were estimated at 70 knots, approximately 81 mph (130 km/h), with gusts reaching 85 knots, approximately 98 mph (157 km/h).

The storm is expected to continue weakening as it encounters stronger wind shear, cooler ocean waters and increasing interaction with a mid-latitude frontal system.

The JTWC’s November 11 basin-wide advisory identified Cempaka as the only active tropical cyclone in the Western North Pacific, with no additional tropical disturbances or subtropical systems listed.

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

JTWC analysis valid November 11, 2026, 00:00 UTC (9:00 a.m. Japan Standard Time)

Source: JTWC Warning No. 020, issued November 11 at 03:00 UTC. Wind estimates use a one-minute averaging period. Figures are rounded.

🌬️ Why is Cempaka weakening?

Several atmospheric and oceanic factors are contributing to the storm’s deterioration.

Increasing wind shear: Upper-level winds exceeding 30 knots are disrupting the storm’s vertical structure and displacing thunderstorms away from its circulation centre.

Drier air: Satellite observations indicate that dry air is entering the circulation, limiting the development of sustained deep convection.

Changing ocean temperatures: Sea-surface temperatures near the storm are approximately 26–27°C (79–81°F), with cooler waters expected along its northeastward path.

Frontal interaction: Cempaka is approaching a mid-latitude weather system that will increasingly alter its tropical structure.

Despite weakening, the typhoon remains capable of generating hazardous conditions over a large ocean area.

🧭 2. Where Is Typhoon Cempaka Heading?

The latest JTWC forecast indicates that Cempaka will continue accelerating east-northeastward across the open Northwest Pacific.

The storm is being steered between a mid-latitude trough to its northwest and a subtropical high-pressure ridge to its east.

Forecast development

The JTWC expects Cempaka’s closed circulation to deteriorate into an open frontal wave rather than complete a conventional extratropical transition as an identifiable cyclone.

Importantly, the disappearance of a tropical cyclone classification does not mean that dangerous marine conditions immediately disappear.

Strong winds and large waves can persist within the surrounding frontal system.

Forecast confidence is high for the short-term weakening and east-northeastward track.

🇯🇵 3. Japan: Ogasawara Islands and Offshore Marine Hazards

Cempaka has moved east-northeast of Iwo To, taking its centre farther away from Japan’s remote Ogasawara Islands.

The storm’s latest position and movement indicate that its principal circulation is moving into the open Pacific rather than toward mainland Japan.

Main concerns

• 🌊 Large ocean swells: Significant wave heights near the storm were estimated at 34 feet (10.4 metres).

• 🌬️ Strong offshore winds: Dangerous conditions remain possible for ships operating near the cyclone.

• ⛴️ Marine transportation: Operators should monitor official forecasts and any confirmed service advisories.

• 🌧️ Residual showers: Weather conditions around the wider Ogasawara region should continue to be monitored locally.

The JTWC’s significant wave height represents an average of the highest one-third of waves. Individual waves can be substantially higher.

There is no indication in the reviewed JTWC track analysis that Cempaka is heading for mainland Japan.

Residents and marine operators should consult the Japan Meteorological Agency for official local warnings.

🇵🇭 4. Philippines: Northeast Monsoon and Rainfall Concerns

Although Cempaka is moving away from the Philippines, the country can still experience hazardous weather unrelated to a direct tropical cyclone strike.

During November, the northeast monsoon, locally known as the Amihan, becomes increasingly influential across northern portions of the Philippines.

Seasonal wind patterns, easterly airflow and localized convergence zones can produce rain, thunderstorms and changing sea conditions.

Areas requiring routine monitoring

These are seasonal monitoring concerns, not verified November 11 warnings for every listed region.

🌧️ Flooding and landslide risks

Periods of heavy tropical rainfall can cause rapid rises in rivers and streams, particularly in mountainous terrain.

Communities in flood-prone areas should pay attention to official rainfall warnings rather than relying exclusively on tropical cyclone classifications.

🌊 Marine conditions

Northeasterly winds can produce rough seas along exposed eastern and northern coastlines.

Small fishing vessels should check the latest PAGASA gale warnings and coastal forecasts before departure.

Verification note: A current November 11 PAGASA rainfall or gale-warning bulletin was not independently confirmed for this report. Specific rainfall amounts, warning levels and wave heights are therefore not presented as current observations.

Official source: PAGASA – Philippine Atmospheric, Geophysical and Astronomical Services Administration.

🇹🇼 5. Taiwan: Tropical Cyclone Threat Remains Offshore

Taiwan is not located along Cempaka’s latest forecast central track.

The typhoon’s east-northeastward movement is carrying it farther away from Taiwan and the northern Philippine Sea.

However, changing seasonal wind patterns can still affect marine conditions around the island.

Weather considerations

• 🌬️ Northeasterly winds can strengthen over exposed coastal areas.

• 🌊 Rough seas may affect offshore fishing and shipping.

• 🌧️ Seasonal rainfall can occur along windward terrain.

• 🚢 Marine operators should monitor local wind and wave forecasts.

No direct Cempaka landfall threat to Taiwan is indicated by the reviewed JTWC analysis.

For official warnings, consult the Taiwan Central Weather Administration.

🇨🇳 6. South China Sea and Coastal China

The South China Sea remains an important region for tropical cyclone monitoring during November.

However, the November 11 JTWC basin-wide advisory did not identify an additional tropical cyclone or organized tropical disturbance in the region.

This does not eliminate the possibility of heavy rainfall, thunderstorms or rough marine conditions.

Seasonal weather influences

Northeast monsoon: Stronger northeasterly winds can affect exposed coastal waters and shipping routes.

Localized convection: Warm ocean waters and atmospheric convergence can support thunderstorms even without an organized tropical system.

Coastal rainfall: Rainfall distribution can vary considerably between coastal and inland locations.

Development outlook

No separate tropical disturbance was identified in the JTWC advisory reviewed for November 11.

This is an observation about the advisory’s issuance time, not a guarantee that tropical development will remain absent throughout the week.

🇬🇺 7. Guam, Palau and Micronesia

Across Guam, the Northern Mariana Islands, Palau and the Federated States of Micronesia, tropical weather monitoring continues despite the absence of an additional classified disturbance in the latest JTWC basin summary.

The tropical western Pacific can experience frequent showers, thunderstorms and locally strong wind gusts without a named cyclone.

Regional monitoring priorities

These describe potential regional hazards, not confirmed warnings or daily forecasts for each island.

Residents should monitor the National Weather Service in Guam and their local emergency management agencies for updated forecasts.

Official source: National Weather Service Guam.

📊 8. Western Pacific Tropical Activity Summary

Based on JTWC November 11 basin-wide analysis

The distinction between a current disturbance inventory and a multi-day development forecast is important. The absence of identified disturbances today does not establish zero formation probability for the coming days.

🔭 9. Western Pacific Tropical Outlook: November 11–16, 2026

Wednesday, November 11

Typhoon Cempaka continues east-northeastward across the open Pacific.

Its weakening structure and increasing interaction with a frontal boundary are expected to reduce its tropical characteristics.

Dangerous offshore winds and seas remain the primary concern.

Thursday, November 12

Cempaka is forecast to lose its identity as a discrete tropical cyclone as its circulation becomes increasingly disrupted.

Marine hazards may persist within the developing frontal weather pattern.

Friday, November 13

The former cyclone’s surrounding frontal environment may continue affecting portions of the open North Pacific.

Specific wind and wave impacts beyond the JTWC forecast period require updated marine guidance.

Saturday–Monday, November 14–16

The broader Western Pacific remains under routine tropical cyclone surveillance.

The November 11 JTWC advisory does not identify another organized tropical disturbance, but it does not provide a verified day-by-day zero-development forecast through November 16.

New disturbances can develop as atmospheric conditions change.

The Philippines, South China Sea, Mariana Islands and tropical waters east of Micronesia remain areas where routine monitoring is appropriate.

🌡️ 10. El Niño and Western Pacific Tropical Cyclones

Large-scale Pacific Ocean temperature patterns can influence where tropical cyclones form and how they move.

El Niño conditions generally involve unusually warm sea-surface temperatures across portions of the central and eastern equatorial Pacific.

These changes can affect atmospheric circulation, tropical convection and the distribution of cyclone formation across the western and central Pacific.

Weathernews’ September 2026 seasonal outlook projected above-normal Northwest Pacific tropical cyclone activity, estimating approximately 28–29 tropical storms or typhoons for the full year.

However, seasonal forecasts should not be interpreted as predictions of individual storms.

The track and intensity of Typhoon Cempaka depend on its immediate atmospheric environment, including wind shear, surrounding pressure systems and ocean temperatures.

Seasonal outlooks also do not replace updated warnings from national meteorological agencies.

⚠️ 11. Western Pacific Safety and Preparedness

Even when a tropical cyclone is weakening, dangerous conditions can continue.

For shipping and fishing vessels: Review the latest wind and wave warnings before departure. Avoid assuming that weakening wind speeds automatically mean safe seas.

For coastal communities: Monitor official warnings for high surf, coastal flooding and strong winds.

For Philippine residents: Pay particular attention to PAGASA rainfall and flood advisories during periods of monsoon activity.

For travellers: Check airline and ferry operators directly for confirmed service disruptions.

For island communities: Maintain emergency supplies, monitor local weather bulletins and follow instructions issued by local authorities.

Orbis Weather provides weather reporting and analysis, not official emergency instructions.

🛰️ 12. Official Weather Sources and Editorial Methodology

Orbis Weather prepares its tropical weather reports using recognized meteorological authorities, publicly available forecasts and scientific information.

Primary reference sources

How this report was prepared

The principal storm-specific information comes from the JTWC’s November 11, 2026, 03:00 UTC prognostic reasoning bulletin and the associated November 11 basin-wide tropical weather advisory reproduced by TropicalInfo.

These advisories provide the storm’s analysed position, wind intensity, movement, significant wave height, environmental conditions and forecast evolution.

The latest source information reviewed identified only one active tropical cyclone across the Western North Pacific.

Regional sections distinguish between confirmed tropical cyclone information and broader seasonal weather hazards.

No unverified rainfall totals, local wind warnings, casualties, evacuations or transportation disruptions have been presented as confirmed events.

Understanding wind measurements

The JTWC generally reports maximum sustained winds averaged over one minute.

The Japan Meteorological Agency uses a ten-minute averaging standard.

As a result, wind estimates from the two agencies may differ even when describing the same storm.

Forecast uncertainty

Tropical cyclone forecasts can change as new satellite observations, atmospheric measurements and numerical model guidance become available.

Forecast confidence generally decreases over longer periods.

The absence of a classified disturbance does not eliminate the possibility of new tropical cyclone development.

Data cutoff: JTWC storm reasoning issued November 11 at 03:00 UTC, with basin-wide information valid November 11 at 06:00 UTC. This is a dated editorial report, not a continuously updating live warning service.

Editorial standards and corrections

Orbis Weather aims to distinguish verified meteorological observations from forecasts, seasonal risks and editorial interpretation.

Where a current official local warning cannot be independently confirmed, the report identifies that limitation rather than presenting an assumed warning as fact.

Material factual errors should be corrected transparently, with significant changes identified in the published article.

📰 13. Final Outlook: Cempaka Weakening, but Offshore Hazards Remain

The Western Pacific’s main tropical weather development on November 11 is the continued weakening of Typhoon Cempaka as it accelerates east-northeastward away from Japan.

The storm remains a maritime hazard, with significant wave heights of approximately 34 feet (10.4 metres) reported near its circulation in the latest reviewed JTWC analysis.

Increasing wind shear, cooler waters and interaction with a frontal system are expected to bring further weakening, with the storm forecast to lose its identity as a discrete tropical cyclone.

Elsewhere across the basin, the JTWC has not identified another active tropical cyclone or organized tropical disturbance in its latest reviewed advisory.

Nevertheless, seasonal rainfall, thunderstorms and northeast monsoon winds remain important weather considerations for communities across the Philippines, South China Sea and tropical western Pacific.

The key message for November 11: Cempaka is moving away from populated areas, but dangerous offshore conditions remain possible as the storm weakens.

Orbis Weather will continue monitoring significant developments across the Western Pacific, including changes in tropical cyclone activity, marine hazards and regional weather patterns.

Orbis Weather | Global Weather, Tropical Cyclones & Natural Hazards

Written by Paul Harrison

This report is provided for public weather awareness and should not replace official forecasts, marine warnings or emergency instructions