One-week forecasts for individual prefectures are issued at 11:00 and 17:00 JST every day. The latest daily forecasts are displayed in the columns for the first and second days. The probability of precipitation for today and tomorrow is displayed with six hours as a unit (i.e., 00 – 06/06 – 12/12 – 18/18 – 24 JST).
Figures shown in parentheses in the low and high temperature rows indicate the ranges of error in degrees Celsius. The reliability for the day is represented as A, B or C in descending order of expected accuracy. The results of precipitation forecast accuracy verification for the period from 1 April 2002 to 31 March 2007 indicate an average accuracy of 86% for A, 72% for B and 56% for C.
Values in the normal precipitation column represent the range of normal cumulative precipitation amounts for the coming seven days, while the figures in the normal low/high temperature columns represent those for the fourth day of the period.