The relationship between upper wind directions and the onset date of South-West monsoon has been investigated. Monthly upper prevailing wind directions at the level of 700hPa 500hPa and 300hPa at 0700LT in March and April and daily rainfall amount in April and may during the period 1981-1996 of four locations in upper Thailand were obtained from Climatology Division, Meteorological Department. In this paper, the relationship between upper wind directions and the onset date of South-West monsoon at each location has been calculated and analyzed by using the method of correlation and regression analysis.
From this study, regression equations using correlated upper wind directions in March and April have been developed to estimated the onset dates. It is found that the actual onset date at each location in 1997 relatively close to the calculated date from the equation.
Submittal Information
Name :
Date :
Mr. Chamnong Kaeochada
09-Jul-01-19:31:21
Organization :
Theme :
Senior Meteorologist, Climatology Division, Meteorological Department
