1. 1 The Asian-Australian Monsoon System: Recent Evolution, Current Status and Prediction Update prepared by Climate Prediction Center / NCEP November 7, 2010 For more information, visit: http://www.cpc.ncep.noaa.gov/products/Global_Monsoons/Asian_Monsoons/Asian_Monsoons.shtml http://www.cpc.ncep.noaa.gov/products/Global_Monsoons/Asian_Monsoons/Asian_Monsoons.shtml

2. 2 Outline Recent Evolution and Current Conditions Monsoon Prediction Summary Climatology

3. 3 Precip Patterns: Last 90 Days During the past 90 days, above-average rainfall was observed over much of southern Asia, tropical central-eastern Indian Ocean, far western North Pacific, northern Australia, and other equatorial regions. Above-average rainfall was also seen over the Koreas. On the other hand, below-average rainfall was observed over southern India, southern Indo-China peninsula, Malaysia, southern Japan, equatorial western Pacific (east of 140E), and Madagascar.

4. 4 Precip Patterns: Last 30 Days During the past 30 days, above-average rainfall occurred over much of 10S-20N, 80E- 140E. The southern Tropics including northern Australia experienced highly above average rainfall. On the other hand, below-average rainfall was observed much of the regions west of 80E and east of 140E and over eastern China and Korea.

5. 5 Precip Patterns: Last 5 Days Above-average rainfall was observed over southern India, tropical eastern Indian Ocean, southern South China Sea, Japan, and part of Southeast Asia. On the other hand, below-average rainfall was found over tropical central Indian Ocean, southern and eastern China, and part of western Pacific Ocean (east of 140E).

6. 6 Atmospheric Circulation Anomalous cyclonic patterns were observed over southern Japan, southern South China Sea, southern India, and tropical eastern Southern Indian Ocean. An anomalous anti-cyclonic pattern was seen over eastern China. In addition, convergence was implied over eastern Southeast Asia.

7. 7 NCEP/GFS Model Forecasts Bias-Corrected Precip. Anom. for Weak 1 & Week 2 Week-1 Week-2

8. 8 Prediction of Large-Scale Monsoon Circulation Upper panel: Webster-Yang monsoon index (Webster and Yang 1992) defined as U850 (0- 20ºN, 40-110ºE) – U200 (0-20ºN, 40-110ºE). Positive (negative) values indicate strong (weak) than normal monsoon. Lower panel: Correlation between rainfall and Webster-Yang monsoon index (Webster and Yang 1992; shading) and regression of 850-mb winds on the monsoon index (vectors) for November. Green (brown) shading indicates increase (decrease) in rainfall associated with strong monsoon. The NCEP Global Forecast System predicts that the Webster-Yang monsoon index will be above normal in the next two weeks.

9. 9 Prediction of East Asia – NW Pacific Monsoon Upper panel: East Asia – Western North Pacific (EAWNP) monsoon index (Wang et al. 2008) defined as U850 (5-15ºN, 40-80ºE) – U850 (20-30ºN, 70-90ºE). Positive (negative) values indicate strong (weak) than normal monsoon. Lower panel: Correlation between rainfall and East Asia – Western North Pacific monsoon index (Wang et al. 2008; shading) and regression of 850-mb winds on the monsoon index (vectors) for November. Green (brown) shading indicates increase (decrease) in rainfall associated with strong monsoon. The NCEP Global Forecast System predicts that, in the next two weeks, the monsoon circulation over Southeast Asia and northwestern Pacific will be near normal.

10. 10 Prediction of Australian Monsoon Upper panel: Australian monsoon index (Hung and Yanai 2004) defined as U850 averaged over 2.5ºS-15ºS, 110-150ºE. Positive (negative) values indicate strong (weak) than normal monsoon. Lower panel: Correlation between rainfall and Australian monsoon index (Hung and Yanai 2004; shading) and regression of 850-mb winds on the monsoon index (vectors) for November. Green (brown) shading indicates increase (decrease) in rainfall associated with strong monsoon. The NCEP Global Forecast System predicts that, in the next two weeks, the Australian monsoon index will be near or below normal.

11. 11 Summary Above-average rainfall was observed over southern India, tropical eastern Indian Ocean, southern South China Sea, Japan, and part of Southeast Asia. On the other hand, below- average rainfall was found over tropical central Indian Ocean, southern and eastern China, and part of western Pacific Ocean (east of 140E). The NCEP Global Forecast System predicts that the monsoon circulation will be near or stronger than normal over southern Asia and near or weaker than normal over northern Australia in the next two weeks.

12. 12 Demise of the Asian Monsoon

13. 13 Onset of the Australian Monsoon

14. 14 Climatology