Probability of a wet day following a wet day in the month
The probability is calculated as
Pi(W⁄W)=dayswet,idaysW⁄W,i
where Pi(W⁄W) is the probability of a wet day following a wet day in month i, daysW⁄W,i is the number of times a wet day followed a wet day in month i for the entire period of record, and dayswet,i is the number of wet days in month i during the entire period of record. A wet day is a day with > 0 mm precipitation.