Torrential Rain Of A Cold Eddy

The North-East Cold Whorl (NECW) is one important weather systems, which inflect the weather and climate of the North-East, and is wide studied by meteorological workers, they make many progress. They make sure the definite of the NECW, the spread of the NECW, the start time of the NECW. Above all, the study of the meso-scale system gives much help in analysis the NECW. Mr. Shou Shaowen studied the wet whorl Q-vector divergence and relative whorl' in several rainstorms, which occurred in Guizhou, and get some useful conclusions. Mrs. Wu Haiying studied the different time of a cyclone, and fined the relations of the rainstorm and a cyclone. Mrs. Yuan Jiashuang studied the warm quantity in a cyclone' life. Mr. Yue Caijun studied all the Q-vector parameters, and compared them, searched their relationship. He find that the semi-earth Q-vector, the half-earth Q-vector, the non-earth Q-vector, the wet Q-vector, some are useful in analysis the cyclone, others are not.By using the data from 9210 broadcast system and T213 numeric forecast re-analysis data, we studied the starting and developing of one NECW, and discussed the mechanism of West-Liaoning rainstorm at a definite NECW circumstance. We can see, although the NECW is weather scale system, the distribution at difference level contacts very important information. Thus it makes various weathers at definite region. By analysis physical diagnose quantities, we can easily find that the vertical movement, the vapor transfer, the stability at T-LOGP chart, all related with the precipitation when rainstorm occurs. They gave plus effects to the rainstorm.After, we analyses the related physical and diagnose quantity when the rainstorm occurred. At the end, we calculated the rainstorm progress by using MM5 meso-scale forecasting system model, and compared the result with the fact data. The result is excited. The calculating circle is very near compared with the fact. And many physical diagnose quantities thus as high vertical movement, Q-vector divergence, 0-6 km shear etc. all contact with the rainstorm. We can use the MM5 model in definite time, definite area weather forecasting.We conclude that: : □ The moving route of this NECW in its developing progress was direct-south along latitude, the cold air is rough, and just this made the rough vertical velocity; □ The NECW southern moving and conflicting with the West Pacification Sub-Tropical High makes rough jet steam. The plenty south-west warm and wet air made by the jet stream gave the rainstorm demanded vapor; □ .The rough vertical velocity by jet stream is a main reason in this rainstorm; □ The MM5 model uses four-direction analysis data as its input, this avoids some errors occurred in observe and transfer, thus made the result more useful. The circumstance calculated by MM5 forecast system is very near compared with the real one; □. The physical quantity and precipitation calculated by MM5 forecast system should be well used in work; □ The area and numeric of the precipitation forecasted by MM5 have some difference compared with the fact, that needs more some more work to make progress.