1. 1 The Asian-Australian Monsoon System: Recent Evolution, Current Status and Prediction Update prepared by Climate Prediction Center / NCEP May 9, 2011 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, precipitation has been generally near normal over much of the monsoon region, except for below normal rainfall over south eastern China, Japan, and over eastern Papua New Guinea. Extreme rainfall deficits over large parts of southeast China continue. Over central and northern Australia, 90 day mean precipitation has been above normal. Note: Occasionally when the update date of the land+ocean precip maps are not close enough to the release date of this weekly scheduled monsoon ppt. we use the more recent land -only precip maps.

4. 4 Precip Patterns: Last 30 Days The 30-day precipitation accumulation is still seriously deficient over interior southeastern China, and southern Japan, but improved somewhat over southeastern coastal China. Elsewhere the precipitation is at or above normal levels, particularly all along northern Australia. Interior southern and central eastern India got some pre monsoon rain. There were widespread rainfall over the middle eastern Asian countries too. Please see Note in Slide three.

5. 5 Precip Patterns: Last 7 Days During the last seven days, southeastern coastal China got some drought relief from some heavy rains. Elsewhere, the rainfall is widespread and at normal or slightly below normal levels. Please see Note in Slide three. If land only maps are used, this map corresponds to the last seven days.

6. 6 Rainfall Time Series over 5x5 lat-lon boxes Note: This unified land-only daily precipitation dataset is different from the CMAP dataset used in the previous three spatial maps. The time series of precipitation over the various regions is quite consistent with the spatial maps shown earlier, even though as noted above, the rainfall data sets are from different sources and are processed differently.

7. 7 Atmospheric Circulation Southwest monsoon or the so called Summer monsoon is or getting established over northern sub-tropical southeast Asia, before it moves over to South Asia/India. Note: These maps are not upto date due to technical problems.

8. 8 NCEP/GFS Model Forecasts Bias-Corrected Precip. Anom. for Weak 1 & Week 2 Week-1 Week-2

9. 9 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 March. 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 hang around near-normal or slightly below-normal values.

10. 10 Prediction of South Asian Monsoon Index Upper panel: South Asian monsoon index (Goswami et al. 1999) ) defined as v850 (10- 30ºN, 70-110ºE) – v200 (10-30ºN, 70-110ºE). Positive (negative) values indicate strong (weak) than normal monsoon. Lower panel: Correlation between rainfall and South Asian monsoon index (Goswami et al., 1999; shading) and regression of 850-mb winds on the monsoon index (vectors) for March 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 Southeast Asian and northwestern Pacific monsoon index will be at or slightly below normal level in the next two weeks.

11. 11 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 March 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 Southeast Asian and northwestern Pacific monsoon index will be at or slightly above normal level in the next two weeks.

12. 12 Summary During the past 90 days, precipitation has been generally near normal over much of the monsoon region, except for below normal rainfall over south eastern China, Japan, and over eastern Papua New Guinea. Extreme rainfall deficits over large parts of southeast China continue. The 30-day precipitation accumulation is still seriously deficient over interior southeastern China, and southern Japan, but improved somewhat over southeastern coastal China. Elsewhere the precipitation is at or above normal levels. Interior southern and central eastern India got some pre monsoon rain. There was widespread rainfall over the middle eastern Asian countries too. During the last seven days, southeastern coastal China got some drought relief from heavy rains. Elsewhere, the rainfall is widespread. The NCEP GFS model predicts below normal rainfall activity over equatorial southeast Asia, but slightly above normal rainfall over southeast Asia including Myanmar, Laos, Vietnam and Cambodia in the upcoming weeks.

13. 13 Demise of the Asian Monsoon

14. 14 Onset of the Australian Monsoon

15. 15 Climatology