Saraju K. Baidya Department of Hydrology and Meteorology Nepal

1. Monsoon of Nepal Saraju K. BaidyaDepartment of Hydrology and MeteorologyNepal First session of South Asian Climate Outlook Forum (SASCOF-1), Pune, India, 13-15 April 2010

2. Turkmenistan Afghanistan China Iran Pakistan Nepal Bhutan Bangladesh India Oman Myanmar Laos 26º 22' N - 30º 27' N Lat. 80º 4'E - 88º 12'E Long. Thailand Cambodia 0 100 200 400 Kilometers 0 65 130 260 Kilometers Sri Lanka Malaysia Westerly systems Summer Monsoon South West Monsoon

3. Wettest month Monsoon

7. Monthly, correlation of ANMR with Nino 3.4 SST Bold values represent correlation at 95% significant level During the monsoon season (June-September) the largest correlation with Nino 3.4 is seen in June suggesting that the beginning month of the season is more perturbed by changes in slowly varying boundary conditions (e.g. SST). The lower correlations during July and August imply that the established phase is less susceptible to forcing from the central Pacific SST

8. Correlation of ANMR with individual months Bold values represent above 95% confidence level During extreme monsoon years, the correlation with June and July increases substantially. This implies that the early parts of the season (onset phase and the subsequent month July) are most important in determining the seasonal rainfall anomaly in extreme years The correlation with July rainfall is highest suggesting its major role in the seasonal total.

9. Rainfall during the first three weeks of July was very weak Onset on 23rd June, delayed by 13 day Rainfall below normal in large parts of the country Rainfall during the first and the third week of August was particularly intense and widespread

11. Spatial distribution of Coefficient of variation Monsoon rainfall Change of CV between1991-2008 and 1971-1990

15. Urgent need to develop local Seasonal Forecast for better management in the agriculture sector and in turn strengthening the food security in Nepal • The long winter drought devastated winter wheat and maize • 30 % - 70% of main summer crops failed (paddy, maize) in many places during 2009

16. Thank You !

17. EXTREME RAINFALL IN AUGUST AT DIPAYAL 200 183.9 EXTREME RAINFALL IN AUGUST AT DADELDHURA Extreme rainfall ever recorded: 183.9 mm on 18th August 2009 180 Extreme rainfall ever recorded: 226.2 mm on 18th August 2009 226.2 240 160 220 187.4 200 140 180 120 160 Rainfall (mm) 100 140 Rainfall (mm) 120 80 100 60 80 40 60 40 20 20 0 0 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 1982 1956 1958 1960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 Year Year EXTREME RAINFALL IN JULYAT DANG EXTREME RAINFALL IN AUGUST AT DHANGADHI Extreme rainfall ever recorded: 195 mm on 13th June 1999 300 269.4 Extreme rainfall ever recorded: 269.4 mm on 18th August 2009 180 265 270 155.6 160 240 140 210 116.0 120 180 Rainfall (mm) 150 100 Rainfall (mm) 120 80 90 60 60 40 30 20 0 0 1958 1960 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 1956 1962 1964 1966 1968 1970 1972 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Year YEAR Record break extreme rainfall in August 2009