Initial and Transitional Probabilities

Initial and transitional rainfall probabilities were determined using the Markov Chain (Robertson, 1976; Oldeman, 1982). These were then used to estimate the most probable sequences of wet and dry days for any three-day period in a decade.

Initial Probabilities

W - probability of a day being wet (5 mm rainfall or more)

D - probability of a day being dry (less than 5 mm rainfall)

Transitional Probabilities

DD - probability of a dry day given that the previous day was dry

DW - probability of a dry day given that the previous day was wet

WD - probability of a wet day given that the previous day was dry

WW - probability of a wet day given that the previous day was wet

DDD - probability that three consecutive days are dry

WWW - probability that three consecutive days are wet

WWD - probability that two consecutive days are wet and the third day is dry

WDW - probability that within three days the second day is dry