Extended Abstract

Cycle Forecasting System in China. Guangzhou Institute of Tropical Oceanic Meteorologybuilt CHAF on the base of GRAPES model and its assimilation system. In this system,non-conventional detecting data of high spatial-temporal resolution such as satellite, radar,automatic station data are assimilated to generate a high -quality grid field for weatheranalysis. And such hourly 3D fine initial field with multi factors is also provided to forecastmodel, which establishes a good base to fine prediction. Beijing Institute of UrbanMeteorology developed WRF-RUC, a 3h Rapid Update Cycle assimilation analysis and3km-resolution fine numerical model forecasting system based on WRF model and itsassimilation system, which uses local dense observation and remote sensing data inBeijing and is suit for Northern China. This system plays an important role in 2008Olympic Games weather service.AREM (Advanced Regional η-coordinated Model) model is a meso-scale heavyrain numerical forecasting model with Chinese own intellectual property rights. It showsevident advantages in East-Asia heavy rain forecast and is widely used in many operationand research organizations. In 2009 Wuhan Institute of Heavy Rain developed a RapidUpdate Cycle Forecasting System Based on AREM Model (AREM-RUC), which issignificant to promote the development of AREM and improve precipitation prediction.2. Development of AREM-RUCAREM model is a heavy rain numerical forecasting model and play a veryimportant role in rainfall forecast in China, which has a special process for the large andhigh topography in China and takes climatic features in East Asia into consideration.Several faults are still not solved: (1) the model is initialized in a cold-start way, whichusually lead to model SPIN-UP problem. (2) Radar detections are not applied in the modeldue to the limitation of data assimilation system. (3) A large amount of high-frequencyobservational data is not used due to its two-time run in a day, which results in the fact thatthe model forecast cannot be updated in time.LAPS(Local Analysis Prediction System, Mcginley,et al,1992,Albers,et al,1996)is developed by NOAA/FSL which can assimilate effectively multi kinds of dataincluding satellite, radar, GPS, radio sonde, automatic station, wind profiler, microwaveradiometer data etc., and provide a high special-temporal meso-scale 3D grid analysisfield, which is one of the most advanced meso-scale analysis systems.Aimed at above-mentioned faults, Wuhan Institute of Heavy Rain of CMA (ChinaMeteorological Administration) introduced LAPS (Local Analysis and Prediction System)system and set up a 3-hourly rapid update cycle based on AREM model (AREM-RUC). Ithas three advantages when compared with AREM model: (1) the model is initialized in ahot-start way and the model SPIN-UP phenomena is reduced. (2) High-frequency data areused in the model, such as radar detections and intensive automatic weather stationobservations. The initial field contains much more mesoscale information and the modelrainfall forecast is improved. (3) The AREM-RUC gives a new forecast every 3 hoursaccording to latest observational data, which improves rainfall now-casting and short-timeforecast.3. Result of AREM-RUC real-time forecast in 2009AREM-RUC began to run operationally on 20 May 2009 and its forecast productswere broadcast every 3 hours through the website of Institute of Heavy Rain. The processis shown as Fig.1.AREM-RUC runs for 8 times per day and provides 36h forecast. Its initial field isprovided by LAPS analysis field and side-boundary condition by NCEP 3h forecast field.At 00UTC and 12UTC, LAPS assimilates the data of radio sonde, automatic station andradar, and at the else time(03、06、09、15、18、21UTC), the data of automatic station andradar are assimilated.AREM-RUC began to run operationally on 20 May 2009 and its forecast productswere broadcast every 3 hours through the website of Institute of Heavy Rain, whichplayed a very important role in flooding-season of 2009.-249-