1 The Asian-Australian Monsoon System: Recent Evolution, Current Status and Prediction Update prepared by Climate Prediction Center / NCEP September 14, 2015 For more information, visit:

2 Outline Recent Rainfall and Current Conditions Monsoon Prediction Summary Climatology

3 Precip Patterns: Last 90 Days For the past 90 days rainfall amounts have generally been below normal across the southern and east Asia monsoon region consistent with the ongoing strong El Nino conditions. However, northeast India, Bangladesh, Burma, and parts of eastern China have received above normal rainfall amounts.

4 Precip Patterns: Last 30 Days For the past 30 days, rainfall was considerably below normal everywhere except along northeastern India, parts of Burma and to some extent along southern China. According to the India Met. Dept. (IMD), the SW summer monsoon rainfall over India as whole since the 1st of June, as of today September 14th, is now 16 % below normal. With only 2 weeks left before the official end of the Indian summer monsoon, these conditions are expected to continue. The impacts of the Pacific El Nino are quite obvious with generally decreased rainfall over south/east Asia and increased rainfall across the equatorial Pacific.

5 Precip Patterns: Last 7 Days In this past week the rainfall amounts over most of central and northern India and elsewhere across the monsoon region was below normal.

6 Atmospheric Circulation Generally these CDAS maps are two days behind. But sometimes, as it is today, due to technical issues, these maps are further behind.

7 Rainfall Time Series over 5x5 lat-lon boxes The time series of precipitation over the various regions is pretty much consistent with the spatial maps shown earlier.

8 NCEP/GFS Model Forecasts Accumulated Precip. for Week 1 & Week 2 Week-1 Week-2

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

10 Summary For the past 90 days rainfall amounts have generally been below normal across the southern and east Asia monsoon region consistent with the ongoing strong El Nino conditions. However, northeast India, Bangladesh, Burma, and parts of eastern China have received above normal rainfall amounts. For the past 30 days, rainfall was considerably below normal everywhere except along northeastern India, parts of Burma and to some extent along southern China. According to the India Met. Dept. (IMD), the SW summer monsoon rainfall over India as whole since the 1st of June, as of today September 14th, is now 16 % below normal. With only 2 weeks left before the official end of the Indian summer monsoon, these conditions are expected to continue. The impacts of the Pacific El Nino are quite obvious with generally decreased rainfall over south/east Asia and increased rainfall across the equatorial Pacific. In this past week the rainfall amounts over most of central and northern India and elsewhere across the monsoon region was below normal. In the next couple of weeks, the NCEP GFS model is predicting a gradual retreat of the Indian summer monsoon from the west and north of India into central and southern India, more rainfall over southern and eastern China, but less rainfall over southeast Asian countries of Thailand, Laos, Vietnam and Cambodia particularly in the second week.

11 Demise of the Asian Monsoon

12 Onset of the Australian Monsoon

13 Climatology