Typhoon Shanshan Strengthens as It Heads North: Japan Braces for Heavy Rain and Winds

2024/08/23 16:11 WeatherNews

As of 15:00 on August 23 (Friday), Typhoon No. 10 (Shanshan) is slowly moving northward over the Mariana Islands. The typhoon is showing signs of development, with a storm area with wind speeds of over 25 m/s appearing since this morning.

▼ Typhoon No. 10 August 23 (Friday) 15:00
　Center Position　　　Mariana Islands
　Size Classification　　／／
　Intensity Classification　　　／／
　Movement　　　　　North, slowly
　Central Pressure　　　985 hPa
　Maximum Wind Speed　　　30 m/s (near the center)
　Maximum Gust Speed　　45 m/s
» Latest Typhoon Information

Expected to Develop to “Very Strong” Intensity

Typhoon No. 10 is expected to continue developing and become a “strong” typhoon by tomorrow, August 24 (Saturday).

Furthermore, around August 26 (Monday), it is forecasted to temporarily reach “very strong” intensity.

Looking at the projected path, Typhoon No. 10 is expected to initially move northward before shifting westward, advancing northwest until it reaches around 30 degrees north latitude. Afterward, it is anticipated to change its direction to north-northeast and is likely to approach and make landfall from Kanto to Shikoku around August 27 (Tuesday) to 28 (Wednesday). It may continue heading north-northeast, taking on characteristics of a temperate low-pressure system as it heads towards northern Japan.

There are concerns that strong winds and heavy rain will significantly affect regions near the projected path. Additionally, even areas that are distanced from the path may experience strong winds and severe weather, necessitating caution.

Reference: Numerical simulation results of the projected path calculated by meteorological agencies worldwide

Each thin line shown in this diagram represents the results of numerical simulations computed by meteorological agencies around the world. These results come from calculations of the low-pressure center using an ensemble forecasting method, which introduces intentional errors into the initial values to examine materials such as the certainty of predictions.

Comparing these, there is a general trend of movement northward south of Honshu, indicating that there is a considerably high likelihood of affecting Japan. Although there is a relatively small variation considering the forecast period, possible paths range from courses that pass west of Kinki to those that pass near Kanto, making it increasingly difficult to narrow down specific areas to anticipate impacts.

Even slight differences in the path can lead to large discrepancies in affected regions and severity, so it is necessary to pay attention to changes in forecasts. As time goes on, the error is expected to decrease, so please stay tuned for future updates.

Probability of Entering the Typhoon’s Storm Area

The following prefectural forecast areas have a probability of entering the typhoon’s storm area of 3% or more within the next five days. (Japan Meteorological Agency)
　Amami Region　　　2 %
　Okinawa Main Island Region　13 %
　Miyako Island Region　　54 %
　Yaeyama Region　　72 %

Risk of Heavy Rain Before Typhoon Approaches

Starting this weekend, a pressure trough in the upper atmosphere is expected to linger over the western side of the Japanese archipelago, facilitating humid air circulating around the edges of the Pacific high pressure to flow into the vicinity of Japan. This will activate the frontal activities stagnating near Honshu.

In addition, moist air from Typhoon No. 10 will contribute to an unstable atmospheric state, leading to the possibility of increasing rainfall and heavy downpours even before the typhoon approaches.

Although it is difficult to predict the specific locations and duration of the rain intensifying, please remain attentive to weather information even if situated away from the typhoon’s path.

Furthermore, a similar pressure configuration is expected to continue after the passage of the typhoon.
» Point Forecast Weekly Weather Report
» Radar Wind Flow Mode

The 6th Typhoon to Form This Month

The formation of this typhoon marks the first occurrence since Typhoon No. 9 formed on the 19th of this week, making it a three-day gap since then. It is the sixth typhoon to form this month.

The average number of typhoons forming in August is 5.7, making it the time of year with the highest frequency of typhoon formation. With six typhoons already formed this year, it seems to be on pace with or exceeding the average.

As we transition from summer to autumn, it is possible that more typhoons will approach the area around Honshu, marking the beginning of the full-fledged typhoon season. Therefore, it is essential to prepare measures against typhoons and heavy rain.
» Radar Satellite Cloud Image Mode

Typhoon Name

The names of typhoons are predetermined, with 140 names proposed by member countries of the international organization “Typhoon Committee,” assigned in the order they are formed.

The name of Typhoon No. 10, “Shanshan (珊珊),” was suggested by Hong Kong, and the name originates from a girl’s name.
» Radar Typhoon Mode

Reference Materials, etc.