# Presentation: 306741

## The Asian-Australian Monsoon System: Recent Evolution, Current Status and Prediction

**Update prepared by**
**Climate Prediction Center / NCEP**
**   ****9 February 2009**

**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)_

## Outline

** **
** ****Recent Evolution and Current Conditions**
** ****Monsoon Prediction**
** ****Summary**
** ****Climatology**

## Rainfall Patterns: Last 90 Days

**The CMAP precipitation dataset shows that, during the past 90 days, above normal precipitation occurred over most of the tropical eastern Indian Ocean, southern South China Sea, maritime continent, and the Australian monsoon region. Precipitation was also above normal over the waters east-southeast of Japan. Precipitation was below normal over western Asia, eastern India, southern-eastern China, Korea, Madagascar, subtropical southern Indian Ocean, and western Pacific. **

## Rainfall Patterns: Last 30 Days

**During the past 30 days, above normal precipitation occurred over the maritime continent and a band extending from the tropical eastern Indian Ocean, southern South China Sea, and East China Sea to the waters east of Japan. The Australian monsoon rainfall was above normal. Below normal precipitation was observed over much of tropical-subtropical Asia (especially over China), New Guinea, subtropical-extratropical Australia, Madagascar, and subtropical southern Indian Ocean.**

## Rainfall Patterns: Last 5 Days

**During the past week, rainfall was above normal over the tropical eastern Indian Ocean (off Sumatra), part of maritime continent, northeastern Australia and the waters east of it. Below normal precipitation was found over Madagascar, subtropical southern Indian Ocean, eastern Australia, and southeastern China.**

## Rainfall Time Series over 5x5 lat-lon boxes

**Rainfall Time Series ****over 5x5 lat-lon boxes**

** *****This unified land-only daily precipitation dataset is different from the CMAP dataset used in the previous three spatial maps.**
** ****Monsoon rainfall has been continuously above normal over northern Australia and much of the maritime continent, consistent with the general features associated with La Nina.**

## Atmospheric Circulation

**A remarkable feature is that the lower-tropospheric circulation over East-Southeast  Asia, the maritime continent, and the Australian monsoon region was stronger than normal. The organized anomalous cyclonic pattern over the monsoon region and the other cyclonic pattern over eastern Indian Ocean are likely accompanied by heavy monsoon rainfall.**

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

**Week-1**

**Week-2**

## Predictions of Australian Monsoon

_**Upper panel:**_** Australian monsoon index (Hung and Yanai 2004) defined as mean U850 over 15S-2.5S, 110E-150E. The NCEP Global Forecast System predicts that the Australian monsoon circulation will be stronger than normal in the next week. **

_** **__**Lower panel:**_** Correlation between precipitation and the Australian monsoon index (Hung and Yanai 2004; shading) and regression of 850-mb winds on the monsoon index (vectors) for February.**

## Summary

**During the past week, rainfall was above normal over the tropical eastern Indian Ocean (off Sumatra), part of maritime continent, northeastern Australia and the waters east of it. Below normal precipitation was found over Madagascar, subtropical southern Indian Ocean, eastern Australia, and southeastern China.**
**The Australian monsoon tends to be stronger than normal in the next two weeks.**

## Retreat of Australian Monsoon 

## Climatology