Central Weather Bureau One-Month Outlook Issued every Friday

Date issued : September 24, 2021 Valid period : 4 weeks from September 25, 2021 to October 22, 2021

1. Weather outlook Models show that the weather will be stable in the next 2 weeks, except some local brief showers in northern and eastern when the northeasterly wind is strong. Weather in other parts of the island will be cloudy to sunny, with local afternoon thundershowers all over Taiwan. In addition, large scale conditions are favorable for tropical depression developing around the western North Pacific in the next two weeks. As model predictability for tropical storm is limited, the public is advised to pay attention to the CWB's weather forecasts at all times a). Sep25~Oct1 : Mean temperature has the largest probability of being above normal, while accumulative precipitation has the largest probability of being near normal all over Taiwan. b). Oct2~Oct8 : Mean temperature has the largest probability of being above normal, while accumulative precipitation has the largest probability of being near normal all over Taiwan. c). Sep25~Oct22 : For next 4 weeks, mean temperature has the largest probability of being above normal all over Taiwan. The accumulative precipitation has the largest probability of being near normal all over Taiwan.

2. Probability Forecast for Temperature (left panel; unit:%) and Precipitation (right panel; unit:%) 1st week 2nd week 4 weeks 1st week 2nd week 4 weeks T (Sep25~Oct1) (Oct2~Oct8) (Sep25~Oct22) R (Sep25~Oct1) (Oct2~Oct8) (Sep25~Oct22) Below Normal Above Below Normal Above Below Normal Above Below Normal Above Below Normal Above Below Normal Above N 0：30：70 0：30：70 0：40：60 N 40：50：10 30：50：20 30：50：20 C 0：20：80 0：30：70 0：30：70 C 0：80：20 0：70：30 30：50：20 S 0：10：90 0：30：70 0：30：70 S 0：80：20 0：70：30 30：50：20 E 0：30：70 0：40：60 0：40：60 E 40：50：10 30：50：20 30：50：20 Note: The N(north), C(central), S(south), and E(east) parts are using , , , and Hualien, respectively as the reference weather stations.

3. Normal Range of Climate for Temperature (left panel; unit:℃) and Precipitation (right panel; unit:mm)

1st week 2nd week 4 weeks 1st week 2nd week 4 weeks T (Sep25~Oct1) (Oct2~Oct8) (Sep25~Oct22) R (Sep25~Oct1) (Oct2~Oct8) (Sep25~Oct22) N 25.7～27.2 25.0～26.1 24.7～25.7 N 10.9～68.9 4.9～50.4 88.6～263.1 C 26.8～27.7 26.2～27.1 26.0～26.6 C 0.0～12.7 0.0～1.7 7.0～29.4 S 27.8～28.5 27.4～28.1 27.3～27.7 S 0.0～22.5 0.0～8.3 6.0～89.4 E 25.8～26.7 25.3～26.2 25.1～25.7 E 8.8～89.5 11.5～97.5 172.8～411.3 Note: The N(north), C(central), S(south), and E(east) parts are using Taipei, Taichung, Kaohsiung, and Hualien, respectively as the reference weather stations.