A slow moving cold front continues to move eastward across the U.S. this weekend. Behind the cold front is unseasonably cold weather and high elevation snows; ahead of the front, temperatures are more typical of midsummer. The front separating these extremes will help focus heavy rain, with the potential for flash flooding extending from eastern New Mexico and western Texas to the Upper Midwest. Read More >
PEAC Seasonal Rainfall OutlookThe PEAC Seasonal Rainfall Outlook is an expirimental 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) 2017 





Forecast Discussion 

Koror: Rainfall for September  October  November 2017 is expected to be Above Average for Koror. There is a 25% chance that rainfall during the SON season will be less than 30.65 inches; a 35% chance that rainfall will be between 30.65 inches and 41.38 inches; and a 40% chance that rainfall will be greater than 41.38 inches. Yap: Rainfall for September  October  November 2017 is expected to be Above Average for Yap. There is a 25% chance that rainfall during the SON season will be less than 32.05 inches; a 35% chance that rainfall will be between 32.05 inches and 38.09 inches; and a 40% chance that rainfall will be greater than 38.09 inches. Chuuk: Rainfall for September  October  November 2017 is expected to be Average or Above Average for Chuuk. There is a 30% chance that rainfall during the SON season will be less than 32.73 inches; a 35% chance that rainfall will be between 32.73 inches and 38.35 inches; and a 35% chance that rainfall will be greater than 38.35 inches. Pohnpei: Rainfall for September  October  November 2017 is expected to be Average or Above Average for Pohnpei. There is a 30% chance that rainfall during the SON season will be less than 41.51 inches; a 35% chance that rainfall will be between 41.51 inches and 47.07 inches; and a 35% chance that rainfall will be greater than 47.07 inches. Kosrae: Rainfall for September  October  November 2017 is expected to be Below Average or Average for Kosrae. There is a 35% chance that rainfall during the SON season will be less than 38.03 inches; a 35% chance that rainfall will be between 38.03 inches and 43.49 inches; and a 30% chance that rainfall will be greater than 43.49 inches. Kwajalein: Rainfall for September  October  November 2017 is expected to be Average for Kwajalein. There is a 30% chance that rainfall during the SON season will be less than 30.69 inches; a 40% chance that rainfall will be between 30.69 inches and 34.83 inches; and a 30% chance that rainfall will be greater than 34.83 inches. Majuro: Rainfall for September  October  November 2017 is expected to be Average for Majuro.There is a 30% chance that rainfall during the SON season will be less than 37.74 inches; a 40% chance that rainfall will be between 37.74 inches and 42.55 inches; and a 30% chance that rainfall will be greater than 42.55 inches. Guam: Rainfall for September  October  November 2017 is expected to be Average or Above Average for Guam. There is a 30% chance that rainfall during the SON season will be less than 30.44 inches; a 35% chance that rainfall will be between 30.44 inches and 33.78 inches; and a 35% chance that rainfall will be greater than 33.78 inches. Saipan: Rainfall for September  October  November 2017 is expected to be Average or Above Average for Saipan. There is a 30% chance that rainfall during the SON season will be less than 26.19 inches; a 35% chance that rainfall will be between 26.19 inches and 29.77 inches; and a 35% chance that rainfall will be greater than 29.77 inches. Pago Pago: Rainfall for September  October  November 2017 is expected to be Average or Above Average for Pago Pago. There is a 30% chance that rainfall during the SON season will be less than 26.91 inches; a 35% chance that rainfall will be between 26.91 inches and 31.48 inches; and a 35% chance that rainfall will be greater than 31.48 inches. Lihue: Rainfall for September  October  November 2017 is expected to be Average for Lihue. There is a 30% chance that rainfall during the SON season will be less than 9.17 inches; a 40% chance that rainfall will be between 9.17 inches and 11.22 inches; and a 30% chance that rainfall will be greater than 11.22 inches. Honolulu: Rainfall for September  October  November 2017 is expected to be Average for Honolulu. There is a 30% chance that rainfall during the SON season will be less than 2.52 inches; a 40% chance that rainfall will be between 2.52 inches and 5.59 inches; and a 30% chance that rainfall will be greater than 5.59 inches. Kahului: Rainfall for September  October  November 2017 is expected to be Average for Kahului. There is a 30% chance that rainfall during the SON season will be less than 2.08 inches; a 40% chance that rainfall will be between 2.08 inches and 4.76 inches; and a 30% chance that rainfall will be greater than 4.76 inches. Hilo: Rainfall for September  October  November 2017 is expected to be Below Average or Average for Hilo. There is a 35% chance that rainfall during the SON season will be less than 24.29 inches; a 35% chance that rainfall will be between 24.29 inches and 40.81 inches; and a 30% chance that rainfall will be greater than 40.81 inches. 

The PEAC Seasonal Rainfall Outlook is an experimental consensus forecast, produced monthly by the Pacific ENSO Applications Climate (PEAC) Center for 14 stations within Hawaii and the USAPI. Tercile cutoffs for each location and season are based on Pacific Rainfall Climatologies (Climate Prediction Center) 19812010. The PEAC Seasonal Rainfall Outlook for September  October  November (SON) 2017 was made available on 14 September 2017. 