At noon on August 29, local time, Category 4 hurricane "Ida" made landfall near the Port of Fulchong, Louisiana, USA. The wind speed at the time of landfall was about 67 meters per second, which was equivalent to a super typhoon. According to reports, "Ada" is the fifth largest hurricane to hit the continental United States in history. Using the upcoming GRAPES_GFS global assimilation forecasting system, the China Meteorological Administration has forecast for the first time tropical cyclones affecting other sea areas outside of my country.
On the eve of the GRAPES_GFS global model upgrade, the hurricane Ida (IDA), which is generally considered "extremely dangerous", affected the United States. The picture shows the targeted forecast of hurricanes "Ada" and "NORA" (NORA) carried out by the China Meteorological Administration using the global model, predicting their movement path and wind impact within 120 hours from 0:00 UTC on August 28 . Picture/Yue Jian Text/Gu Xingyue
Typhoon is one of the most serious natural disasters in the world. Accurate forecasting is the basic guarantee for accurate disaster prevention and mitigation measures. On September 1, my country's self-developed GRAPES_GFS global assimilation forecast system realized a version upgrade. After the upgrade, my country will have the ability to predict tropical cyclones on a global scale. While empowering the “Belt and Road” and building a maritime power, it will also benefit countries and people affected by tropical cyclones around the world.
"This is a change from nothing." said Dr. Ma Suhong, the team leader of the key technology development and operational system construction of global tropical cyclone numerical forecasting. After the version upgrade, my country’s forecast range for tropical cyclones will be expanded from the previous Northwest Pacific and South China Sea to the world. Not only can it fill in the gaps in tropical cyclone forecasts in the Northwest Pacific and South China Sea, but it also marks that my country has global tropical cyclone monitoring. Forecast service capabilities.
In addition to expanding the forecast range, the upgraded global model has better forecasting capabilities for tropical cyclones. The R&D team developed a new vortex initialization technology based on the four-dimensional variational assimilation system, which refines the tropical cyclone data with a coarse time interval into hourly data and continuous assimilation, which significantly reduces the tropical cyclone path forecast error and the forecasting ability Significantly improved. In addition, the upgraded global model also solves the problem of difficulty in identifying and positioning the “wind eye” of tropical cyclones when the circulation conditions become weak or the underlying surface conditions are more complicated, and further enhances the tropical cyclone path prediction capabilities.
According to the demand for service products from global forecasts, the R&D team not only specially developed products such as global infrared and water vapor cloud maps, tropical cyclone path superimposed 120 hours cumulative wind, tropical cyclone intensity, etc., but also targeted at the Northwest Pacific, , northern Indian Ocean, and northern Indian Ocean. The development of regional products in key sea areas such as the Atlantic Ocean and the Northeast Pacific strongly supports the development of global monitoring, global forecasting, and global services.
For my country's typhoon forecasting business, the upgraded global model can complement the regional typhoon model. The global model can provide more accurate mid- and long-term path forecasts, while the regional typhoon model "sees" more clearly for typhoon intensity, structure forecasts, and wind and rain forecasts of landing typhoons.
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