PEAC seasonal Rainfall Outlook

The PEAC seasonal Rainfall Outlook is an experimental consenus forecast, produced monthly for 14 stations within Hawaii and the USAPI. The PEAC Outlook uses data from the following 7 models: UKMO, NASA GMAO, ECMWF, IRI, NCEP Constructed Analog, NCEP Coupled Model and APCC MME.

The PEAC seasonal Rainfall Outlook is a probabalistic forecast displayed in tercile form (3 categories). The three categories represent the chances of an event falling into the "Below Average", "Near Average" and "Above Average" categories, respectively. For example, a seasonal rainfall forecast of 20:30:50 should be interpreted as follows: There is a 20% chance of "Below Average" rainfall for the season; a 30% chance of "Near Average" rainfall for the season; and a 50% chance of "Above Average" rainfall for the season.

For more information on terciles, click here.

September, October, November (SON) 2024

Forecast Discussion

Koror: Rainfall for September-October-November 2024 is expected to be Above for Airai. There is a 25% chance that rainfall during the SON season will be less than 29 inches; a 30% chance that rainfall will be between 29 inches and 43.09 inches; and a 45% chance that rainfall will be greater than 43.09 inches.

Yap: Rainfall for September-October-November 2024 is expected to be Above for Yap. There is a 20% chance that rainfall during the SON season will be less than 28.84 inches; a 30% chance that rainfall will be between 28.84 inches and 44.24 inches; and a 50% chance that rainfall will be greater than 44.24 inches.

Chuuk: Rainfall for September-October-November 2024 is expected to be Avg-Above for Chuuk. There is a 25% chance that rainfall during the SON season will be less than 31.41 inches; a 35% chance that rainfall will be between 31.41 inches and 43.55 inches; and a 40% chance that rainfall will be greater than 43.55 inches.

Pohnpei: Rainfall for September-October-November 2024 is expected to be Avg-Above for Pohnpei. There is a 30% chance that rainfall during the SON season will be less than 38.6 inches; a 35% chance that rainfall will be between 38.6 inches and 47.16 inches; and a 35% chance that rainfall will be greater than 47.16 inches. 

Kosrae: Rainfall for September-October-November 2024 is expected to be Avg-Above for Kosrae. There is a 30% chance that rainfall during the SON season will be less than 35.31 inches; a 35% chance that rainfall will be between 35.31 inches and 46.8 inches; and a 35% chance that rainfall will be greater than 46.8 inches.

Kwajalein: Rainfall for September-October-November 2024 is expected to be Avg-Below for Kwajalein. There is a 35% chance that rainfall during the SON season will be less than 28.21 inches; a 35% chance that rainfall will be between 28.21 inches and 37.82 inches; and a 30% chance that rainfall will be greater than 37.82 inches.

Majuro: Rainfall for September-October-November 2024 is expected to be Avg-Above for Majuro. There is a 30% chance that rainfall during the SON season will be less than 32.56 inches; a 35% chance that rainfall will be between 32.56 inches and 43.92 inches; and a 35% chance that rainfall will be greater than 43.92 inches.

Guam: Rainfall for September-October-November 2024 is expected to be Avg for Guam. There is a 30% chance that rainfall during the SON season will be less than 28.51 inches; a 40% chance that rainfall will be between 28.51 inches and 37.82 inches; and a 30% chance that rainfall will be greater than 37.82 inches.

Saipan: Rainfall for September-October-November 2024 is expected to be Avg  for Saipan. There is a 30% chance that rainfall during the SON season will be less than 21.41 inches; a 40% chance that rainfall will be between 21.41 inches and 30.85 inches; and a 30% chance that rainfall will be greater than 30.85 inches.

Pago Pago: Rainfall for September-October-November 2024 is expected to be Avg-Above for Pago Pago. There is a 30% chance that rainfall during the SON season will be less than 21.67 inches; a 35% chance that rainfall will be between 21.67 inches and 35.12 inches; and a 35% chance that rainfall will be greater than 35.12 inches.

Lihue: Rainfall for September-October-November 2024 is expected to be Avg-Below for Lihue. There is a 35% chance that rainfall during the SON season will be less than 5.75 inches; a 35% chance that rainfall will be between 5.75 inches and 11.53 inches; and a 30% chance that rainfall will be greater than 11.53 inches.

Honolulu: Rainfall for September-October-November 2024 is expected to be Avg-Below for Honolulu. There is a 35% chance that rainfall during the SON season will be less than 1.55  inches; a 35% chance that rainfall will be between 1.55 inches and 4.37 inches; and a 30% chance that rainfall will be greater than 4.37 inches.

Kahului: Rainfall for September-October-November 2024 is expected to be Avg-Below for Kahului. There is a 35% chance that rainfall during the SON season will be less than 1.3 inches; a 35% chance that rainfall will be between 1.3 inches and 3.15 inches; and a 30% chance that rainfall will be greater than 3.15 inches.

Hilo: Rainfall for September-October-November 2024 is expected to be Avg-Below for Hilo. There is a 35% chance that rainfall during the SON season will be less than 22.62 inches; a 35% chance that rainfall will be between 22.62 inches and 38.57 inches; and a 30% chance that rainfall will be greater than 38.57 inches.

The PEAC seasonal Rainfall Outlook is an experimental consensus forecast, produced monthly by the Pacific ENSO Applications Climate (PEAC) Service's for 14 stations within Hawaii and the USAPI. Tercile cut-offs for each location and season are based on Pacific Rainfall Climatologies (Climate Prediction Center) 1991-2020. Last Updated: September 16, 2024