莫拉克颱風(2009)僅為一中度轉輕度颱風，卻於2009年8月7日至9日帶來遠超過許多強烈颱風之雨量，在台灣造成過去50年來最嚴重的氣象災害，其累積雨量(2855mm)甚至與世界紀錄相去不遠。各預報中心以及許多模式都顯示在即時預報的降水和累積雨量的預測都有嚴重不足的情況。
本研究採用的雲解析風暴模式（Cloud-Resolving Storm Simluator；簡稱CReSS），為一先進的高解析度模式，使用NCEP FNL分析資料作為初始及邊界條件之模擬(解析度為3 km)顯示，最早從8月3日0000 UTC就能成功模擬出莫拉克颱風的環流發展、雨帶演變以及影響台灣的降水時間和空間分布，累積24小時的定量降水預報(QPFs)之TS得分於8月7日與8日在門檻值為0.05~25 mm、50-100 mm、250mm、500 mm，分別有0.8-1.0、0.6-0.9、≧0.5、≧0.2的表現，為相當少見之高得分，此良好結果源於非常小的路徑誤差與在台灣地形上產生的相位鎖定降水機制。
另一方面，小區域即時預報實驗和大區域事後預報實驗顯示，初始時間從8月6日0000 UTC開始，也就是在南台灣發生最大降水的兩天前，模式已能預報出實際累積總降水的67%-80%，並有良好的QPFs技術得分。而初始時間在8月6日0000 UTC之前的預報實驗中，全球模式(模式之初始及邊界資料)的預報誤差是颱風路徑誤差的主要來源，也是造成定量降水預報不佳的主要原因。因此，使用高解析度並選取適當的預報範圍在預報上來說是有其重要性的，如此一來，在路徑誤差小的情況下，能夠提供更多的前置時間作因應，在極端降水事件發生前有更多時間去做防範、減少生命財產損失。
而針對初始時間在8月6日0000 UTC之前的預報實驗及GFS預報場本身，颱風均有提前北轉的現象而未登陸台灣，分析颱風半徑700公里內之深層平均氣流與綜觀場中高壓的相對位置得知，副熱帶高壓的位置是影響颱風能否登陸台灣的關鍵。此外，使用12小時平均之颱風移動向量與颱風的不對稱性作關聯，可以發現，颱風轉向前後、移速較慢之時，颱風之不對稱性也較為顯著。

Buckingham, C., Marchok, T., Ginis, I., Rothstein, L., Rowe, D., 2010. Short- and medium-range prediction of tropical and transitioning cyclone tracks within the NCEP Global Ensemble Forecasting System. Wea. Forecasting, 25(6), 1736-1754.
Charles, M.E., Colle, B.A., 2009. Verification of extratropical cyclones within the NCEP operational models. Part I: Analysis errors and short-term NAM and GFS Forecasts. Wea. Forecasting, 24(5), 1173-1190.
Chen, T.C., Yang, Y.S., Wei, C.H., Lin, P.L., Liou, Y.C., Chang, W.Y., Chou, C.B., Ji, B.T., Lin, C.Y., 2010. The precipitation characteristics of Typhoon Morakot (2009) from radar analyses. Atmos. Sci., 38(1), 39-61. (in Chinese with English abstract)
Chien, F.C., Kuo, Y.H.,and Yang, M.J., 2002:Precipitation forcast of MM5 in the Taiwan area during the 1998 Mei-yu season.Wea. Forecasting., 17, 739-754.
Chien, F .C.,and B. J. Jou,2004:MM5 emsemble mean precipitation in the Taiwan area for three early summer convective (Mei-Yu) seasons.Wea. Forecasting, 19, 735-750.
Chien, F.C., Kuo, H.C., 2011. On the extreme rainfall of Typhoon Morakot (2009). J. Geophys. Res., 116, D05104, doi:10.1029/2010JD015092.
Doswell, C. A., R.Davies-Jones, and D. K. Keller, 1990: On summary measures of skills in rare event forecasting based on contingency tables.Wea.Forecasting, 5, 576-585.
Fang, X., Kuo, Y.H., Wang, A., 2011. The impact of Taiwan topography on the predictability of Typhoon Morakot’s record-breaking rainfall: A high-resolution ensemble simulation. Wea. Forecasting, 26(5), 613-633.
Fritsch, J.M., Carbone, R.E., 2004. Improving quantitative precipitation forecasts in the warm season. A USWRP research and development st 1 rategy. Bull. Amer. Meteor. Soc., 85, 955-965.
Ge, X., Li, T., Zhang, S., Peng, M.S., 2010. What causes the extremely heavy rainfall in Taiwan during Typhoon Morakot (2009)? Atmos. Sci. Lett., 11, 46-50.
Hendricks, E.A., Moskaitis, J.R., Jin, Y., Hodur, R.M., Doyle, J.D., Peng, M.S., 2011. Prediction and diagnosis of Typhoon Morakot (2009) using the Naval Research Laboratory’s mesoscale tropical cyclone model. Terr. Atmos. Oceanic Sci., 22, 579-594.
Hong, C.C., Lee, M.Y., Hsu, H.H., Kuo, J.L., 2010. Role of submonthly disturbance and 40-50 day ISO on the extreme rainfall event associated with Typhoon Morakot (2009) in Southern Taiwan. Geophys. Res. Lett., 37, L08805, doi:10.1029/2010GL042761.
Huang, C.Y., Wong, C.S., Yeh, T.C., 2011. Extreme rainfall mechanisms exhibited by Typhoon Morakot (2009). Terr. Atmos. Oceanic Sci., 22(6), 613-632.
Hsu, J., 1998. ARMTS up and running in Taiwan. Väisälä News, 146, 24-26.
Jou, B.J.D., Yu, Y.C., Feng, L., Chen, Y.M., Lee, C.S., Cheng, M.D., 2010. Synoptic environment and rainfall characteristics of Typhoon Morakot (0908). Atmos. Sci., 38(1), 21-38. (in Chinese with English abstract)
Kuo, H.C., Yang, Y.T., Chang, C.P., 2010. Typhoon Morakot (2009): Interplay of southwest monsoon, terrain, and mesoscale convection. International Workshop on Typhoon Morakot (2009), 24-25 March 2010, Taipei, Taiwan, 55.
Lee, C.S., Huang, L.R., Shen, H.S., Wang, S.T., 2006. A climatology model for forecasting typhoon rainfall in Taiwan. Nat. Hazards, 37, 87-105.
Liang, J., Wu, L., Ge, X., Wu, C.C., 2011. Monsoonal influence on Typhoon Morakot (2009). Part II: Numerical study. J. Atmos. Sci., 68, 2222-2235.
Mesinger, F.,and T.L.Black,1992:On the impact on forecast accuracy of the step-mountain(eta) vs. sigma coordinate. Meteor. Atmos. Phys., 50, 47-60.
Nguyen, H.V., Chen, Y.L., 2011. High resolution initialization and simulations of Typhoon Morakot (2009). Mon. Wea. Rev 1 . (in press, early online release)
Wang, C.C., Kuo, H.C., Chen, Y.H., Huang, H.L., Chung, C.H., Tsuboki, K., 2012. Effects of asymmetric latent heating on typhoon movement crossing Taiwan: The case of Morakot (2009) with extreme rainfall. J. Atmos. Sci. (in press)
Wu, C.C., Kuo, Y.H., 1999. Typhoons affecting Taiwan: Current understanding and future challenges. Bull. Amer. Meteor. Soc., 80(1), 67-80.
Wu, C.C., Yen, T.H., Kuo, Y.H., Wang, W., 2002. Rainfall simulation associated with Typhoon Herb (1996) near Taiwan. Part I: The topographic effect. Wea. Forecasting, 17(5), 1001-1015.
Wu, C.C., Huang, C.Y., Yang, M.J., Chien, F.C., Hong, J.S., Yen, T.H., 2010. Typhoon Morakot (2009) and a special review on the current status and future challenge of tropical cyclone simulation. Atmos. Sci., 38(1), 99-134. (in Chinese with English abstract)
Wu, L., Liang, J., Wu, C.C., 2011. Monsoonal influence on Typhoon Morakot (2009). Part I: Observational analysis. J. Atmos. Sci., 68(10), 2208-2221.
Yeh, T.C., Kuo, H.C., Lu, K.C., Wang, S.C., Chen, Y.L., 2010. Verification on the typhoon Morakot track and rainfall forecast issued by the Central Weather Bureau. Atmos. Sci., 38(1), 85-98. (in Chinese with English abstract)
Zhang, F., Weng, Y., Kuo, Y.H., Whitaker, J.S., Xie, B., 2010. Predicting Typhoon Morakot’s catastrophic rainfall with a convection-permitting mesoscale ensemble system. Wea. Forecasting, 25(6), 1816-1825.
許牧豪，2011。雙眼牆颱風與西南季風探討。
陳台琦、魏志憲、林沛練、廖宇慶等，2010:莫拉克颱風雷達觀測中尺度雨帶特徵。國科會莫拉克颱風科學報告。莫拉克颱風科學小組，許晃雄等編，53-81。
葉天降，1998:嘉南地區1997年梅雨期降水之特性與作業模式預測校驗。大氣科學，26，41-61。
簡芳菁、柳懿秦、周仲島、林沛練、洪景山、及蕭玲鳳，2005:2003年梅雨季MM5系集降水預報。大氣科學，33，255-275。