🌪️ WESTERN PACIFIC Tropical Weather Update: November 7, 2026

Tropical Depression 31W Moves Away From the Mariana Islands as Forecasters Predict Typhoon Development South of Japan

By Paul Harrison | Orbis Weather

Saturday, November 7, 2026 | Western North Pacific, Philippine Sea and South China Sea

The Western Pacific is entering another period of significant tropical activity as Tropical Depression 31W moves west-northwestward away from the Mariana Islands, with the Japan Meteorological Agency (JMA) forecasting that the system will strengthen into a typhoon.

The developing cyclone is expected to intensify over the open western Pacific before turning northeastward south of Japan. The forecast raises concerns about increasingly dangerous marine conditions, heavy rainfall near the cyclone’s path and the possibility of strong winds affecting remote island communities.

The latest JMA advisory, issued at 10:15 a.m. Japan Standard Time on November 7, places the tropical depression near the Mariana Islands, with maximum sustained winds of approximately 55 km/h (35 mph).

Importantly, the system is not yet classified as a typhoon in that advisory. Typhoon development is forecast, rather than confirmed.

This report examines the cyclone’s latest position, expected intensification, potential impacts across the Western Pacific, and the weather hazards residents and maritime operators should monitor during the coming five days.

📋 1. Western Pacific Tropical Weather at a Glance

The most important development is the potential for the cyclone to intensify significantly while remaining over the ocean.

Although the forecast track currently favors a northeastward turn before reaching the Philippines or Taiwan, forecast uncertainty remains, particularly beyond the next 48 hours.

🌀 2. Tropical Depression 31W: Latest Position and Movement

According to the JMA’s November 7 analysis, the developing tropical cyclone was centered near 18.9° north latitude and 144.1° east longitude.

The system was moving west-northwest at approximately 35 km/h (22 mph), taking it away from the northern Mariana Islands and toward waters south of Japan.

At the time of the advisory, the estimated central pressure was 1006 hectopascals, with maximum sustained winds of 15 meters per second, equivalent to approximately 30 knots.

The cyclone is expected to continue organizing as it moves across the western Pacific.

Why further strengthening is possible

Tropical cyclones draw energy from warm ocean water and the release of heat during thunderstorm development.

Several environmental factors can influence the strengthening of 31W:

• Warm sea surface temperatures that provide energy for convection.

• Vertical wind shear, which can either support or disrupt the storm’s circulation.

• Upper-level atmospheric outflow, allowing rising air to spread away from the storm.

• Moisture availability within the surrounding atmosphere.

• The structure and organization of thunderstorms around the circulation center.

These factors can change over relatively short periods, meaning a cyclone’s intensity forecast can evolve quickly.

The JMA forecast indicates substantial strengthening through November 9–10, followed by a northeastward turn over the open Pacific.

📈 3. Official JMA Forecast: November 7–12

The following forecast positions and intensities are drawn from the JMA advisory issued November 7 at 10:15 a.m. JST.

Forecast values, not observed future conditions. Converted from JMA wind speeds and rounded.

The JMA forecast suggests the cyclone could reach a central pressure of approximately 975 hPa by November 10–11.

A particularly important feature of the forecast is the expected change in direction.

Rather than continuing westward toward the Philippines or Taiwan, the cyclone is projected to turn east-northeastward south of Japan.

This would keep the system largely over open water, although dangerous conditions could develop along shipping routes and near remote islands.

🧭 4. Why the Forecast Track Matters

The projected track has two distinct phases.

First phase: West-northwest movement

During November 7–9, the cyclone is expected to travel west-northwestward while strengthening.

This period could bring increasingly dangerous seas around the developing circulation.

Second phase: Northeastward turn

Around November 9–10, the JMA forecast indicates a turn toward the east-northeast.

By November 11, the forecast center is located near the Ogasawara region, before continuing farther northeast into the open Pacific.

This change in direction is significant because it could reduce the likelihood of the cyclone approaching densely populated coastal areas of East Asia.

However, the forecast track should not be interpreted as a guarantee.

The JMA’s forecast circles represent areas within which the cyclone center is expected to lie with approximately 70% probability. They do not represent the full area of potentially hazardous weather.

Residents should continue following updated advisories rather than relying on a single forecast track.

🇬🇺 5. Guam and the Northern Mariana Islands

The Mariana Islands have been among the first areas to monitor the developing system.

As 31W moves away from the region, attention turns to the possibility of lingering showers, gusty conditions and hazardous marine weather.

Potential hazards

🌧️ Heavy rainfall: Tropical moisture and thunderstorms can produce localized downpours, particularly where rainbands move repeatedly over the same location.

💨 Gusty winds: Squalls may produce sudden increases in wind speed, even outside the cyclone’s strongest circulation.

🌊 Rough seas: Swells generated by a strengthening tropical cyclone can travel considerable distances from its center.

⛵ Marine disruption: Small boats and recreational vessels are particularly vulnerable to rapidly changing winds and sea conditions.

These are potential hazards, not a confirmation that every island is currently experiencing them.

Residents of Guam, Saipan, Tinian and Rota should consult the National Weather Service Guam for location-specific warnings and forecasts.

🇵🇭 6. Philippines: Monitoring the Longer-Range Track

The Philippines remains an important monitoring area because tropical cyclones developing over the western Pacific can sometimes move toward the Philippine Area of Responsibility (PAR).

However, the current JMA forecast favors a northeastward turn well before 31W reaches the Philippine archipelago.

Is the Philippines facing a direct typhoon threat?

Based on the November 7 JMA forecast, a direct landfall in the Philippines is not the favored scenario.

That assessment could change if the steering pattern evolves.

Even without a direct tropical cyclone impact, the Philippines can experience hazardous weather from other atmospheric systems.

The northeast monsoon, known locally as Amihan, began on October 27, according to PAGASA information reported earlier this week.

During the northeast monsoon, parts of the Philippines can experience stronger coastal winds, rough seas and periods of rainfall independently of tropical cyclone activity.

Mariners should monitor local gale warnings and coastal forecasts.

For official Philippine forecasts, consult PAGASA.

🇹🇼 7. Taiwan and the Northern Philippine Sea

Taiwan lies west of the cyclone’s currently forecast path.

The JMA forecast does not indicate a direct approach to Taiwan, with the cyclone instead expected to turn northeastward south of Japan.

Nevertheless, tropical cyclones can generate long-period swells that spread beyond their immediate circulation.

The principal consideration for Taiwan is therefore monitoring possible changes in the forecast track and regional marine conditions.

There is insufficient verified information in this update to declare an active cyclone-related coastal warning for Taiwan.

Official warnings should be obtained from Taiwan’s Central Weather Administration.

🇯🇵 8. Japan and the Ogasawara Islands

Japan’s southern island territories are particularly relevant to the developing forecast.

By November 11, the JMA projects the cyclone’s center near 25.7°N, 143.2°E, in the vicinity of the Ogasawara region.

At that stage, the system is forecast to maintain maximum sustained winds of approximately 126 km/h (78 mph).

The forecast center is expected to move farther northeast by November 12.

Potential impacts

• 🌊 Large ocean swells and dangerous seas.

• 💨 Strong winds near the cyclone’s circulation.

• 🌧️ Heavy showers and squalls along its path.

• 🚢 Hazardous conditions for commercial and recreational shipping.

• 🏝️ Possible disruption to marine activities around remote islands.

The extent of any impacts on individual islands will depend on the cyclone’s actual track, size and intensity.

Mainland Japan is not shown as a direct landfall destination in the cited forecast.

🇨🇳 9. China, Hong Kong and the South China Sea

The South China Sea is another important part of the Western Pacific tropical cyclone basin.

For November 7, the main verified cyclone development in this report is 31W near the Mariana Islands.

The current forecast does not place 31W on a direct track toward southern China, Hong Kong or Vietnam.

However, that does not establish that the entire South China Sea is free of significant weather.

During November, the northeast monsoon can influence coastal winds and sea conditions across the northern South China Sea.

What to monitor

Coastal communities and shipping operators should pay attention to changes in monsoon winds, developing areas of low pressure, marine warnings and locally heavy rainfall.

No additional active tropical cyclone in the South China Sea has been independently confirmed for this reporting cutoff.

For regional information, consult the Hong Kong Observatory and the relevant national meteorological agencies.

🌊 10. Western Pacific Marine Weather Outlook

Marine hazards are a major concern when tropical cyclones intensify over open water.

As 31W strengthens, the strongest winds will be concentrated around the developing circulation, but the resulting waves may affect a much larger area.

Important marine hazards

High seas: Strong winds transfer energy into the ocean, creating increasingly large waves.

Long-period swell: Swells can propagate far from the cyclone and reach areas experiencing relatively light local winds.

Thunderstorm squalls: Convective bands may bring abrupt wind shifts, heavy rainfall and reduced visibility.

Dangerous navigation: Commercial shipping and smaller vessels may need to alter routes based on official marine forecasts.

No specific significant wave-height measurements have been independently verified for this report. Mariners should use current official high-seas forecasts rather than assume a particular wave height from the cyclone’s wind speed.

🌡️ 11. Seasonal Context: November Typhoons

Although the Western North Pacific’s most active tropical cyclone months generally occur during summer and early autumn, November remains part of the region’s tropical cyclone season.

Unlike the Atlantic hurricane season, which has an established June 1–November 30 convention, western North Pacific tropical cyclones can form throughout the year.

Late-season storms can still become powerful.

Why tropical cyclones remain possible in November

Warm tropical waters can continue supplying energy to developing systems.

The seasonal position of the monsoon trough, changes in atmospheric circulation and variations in wind shear all influence tropical cyclone formation.

Storm tracks can also change during autumn as midlatitude weather systems become more influential.

This helps explain why a developing tropical cyclone may initially move westward before turning north or northeast.

🌏 12. El Niño and Western Pacific Tropical Activity

The El Niño–Southern Oscillation (ENSO) can influence tropical cyclone activity across the Pacific.

During some El Niño events, tropical cyclone formation tends to shift farther east within the western North Pacific, potentially allowing storms more time over warm ocean water before approaching land.

However, ENSO does not determine the exact track or strength of an individual cyclone.

Other factors, including wind shear, atmospheric moisture, ocean heat content and steering currents, remain important.

The Japan Meteorological Agency’s October 2026 ENSO outlook covers conditions through April 2027, with the next scheduled update on November 10.

Readers should avoid attributing the development or strengthening of 31W solely to El Niño.

📅 13. Western Pacific Five-Day Tropical Outlook

November 7–12, 2026 | Based on the November 7 JMA forecast

This outlook is a summary of one official forecast cycle, not a guarantee of future conditions.

The forecast becomes progressively less certain at longer lead times, particularly where a cyclone is expected to change direction.

🔎 14. What Orbis Weather Is Monitoring

The next 24–72 hours will be especially important for determining how 31W develops.

Orbis Weather is focusing on five questions:

1. Will 31W strengthen into a typhoon on the JMA’s projected schedule?

2. How quickly will the cyclone intensify between November 8 and 10?

3. Will the anticipated northeastward turn occur as forecast?

4. How close could the cyclone pass to Japan’s remote southern island territories?

5. Could changes in the cyclone’s wind field create wider marine hazards than currently anticipated?

Additional monitoring will focus on new tropical disturbances across the Philippine Sea, South China Sea and broader western Pacific basin.

🛡️ 15. Tropical Cyclone Safety and Preparedness

Residents and travelers in cyclone-prone areas should continue monitoring official warnings.

For communities potentially affected by strong winds or heavy rain, practical preparations include securing loose outdoor items, checking emergency supplies, charging mobile devices and reviewing local evacuation information.

People living in flood-prone areas should avoid driving through flooded roads.

Coastal residents should be particularly cautious around beaches, reefs and exposed shorelines when large swells are forecast.

Boaters should consult official marine warnings before departure.

A developing cyclone does not need to make landfall to create dangerous marine conditions.

📚 16. Official Weather Sources and Forecast Verification

Orbis Weather prioritizes operational meteorological agencies and distinguishes confirmed observations from forecast scenarios.

Editorial methodology

This report is independently prepared for Orbis Weather using publicly available official meteorological information and explanatory analysis.

The principal storm position, wind estimates, central pressure and forecast track are based on the JMA advisory issued at 10:15 a.m. JST on November 7, 2026, valid for observations at 9:00 a.m. JST.

JMA and JTWC classifications may differ because of their respective operational procedures and wind-averaging conventions.

Potential hazards discussed for individual countries do not necessarily represent active warnings.

Forecast scenarios are identified as forecasts and are not presented as observed events.

No unverified landfall prediction, storm damage report, casualty figure or evacuation order has been included.

Reporting cutoff: November 7, 2026, 10:15 a.m. Japan Standard Time (01:15 UTC). The report does not incorporate advisories issued after that time.

Corrections and updates

Orbis Weather aims to provide accurate, clearly sourced and understandable weather reporting.

If an official meteorological agency revises the cyclone’s classification, position or forecast, the information in this article may become outdated.

Material factual errors should be corrected transparently, with the nature of the correction identified.

This report is an informational weather analysis and does not replace official emergency instructions or warnings.

🌪️ 17. Final Outlook: Western Pacific Cyclone Threat Develops

The Western Pacific’s primary tropical weather concern on November 7 is Tropical Depression 31W, which is forecast to strengthen into a typhoon as it moves away from the Mariana Islands.

The JMA anticipates significant intensification through November 9–10, followed by a northeastward turn south of Japan.

The forecast currently favors a track over open water rather than a direct approach toward the Philippines, Taiwan or mainland Japan.

Nevertheless, the developing cyclone could create dangerous marine conditions, particularly near its projected path and around remote island territories.

The most important developments to monitor are the cyclone’s intensification, the timing of its northeastward turn and any changes to the potential impact area.

Orbis Weather will continue monitoring official Western Pacific tropical cyclone advisories as the system develops.