National Weather Service United States Department of Commerce

Atmospheric River in the Pacific Northwest and Northwest California Early This Week

An atmospheric river event will bring heavy rains and rising snow levels to the Pacific Northwest and northwest California early this week. Snow levels will rise above 8,000 feet, and 4 to 7 inches of rain is forecast for the southwest facing slopes of the mountains. Minor river and localized flooding will be possible. In the east, winds decrease by Monday, and the week will be relatively dry. Read More >

 

PEAC Seasonal Rainfall Outlook

The 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: UKMONASA GMAOECMWFIRINCEP Constructed AnalogNCEP 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.

 


November - December - January (NDJ) 2017

Model:
Final Outlook
Final Probabilities
 
Republic of Palau
 

Koror

L 7 ° 22' N,
λ 134° 32' E
Above
Above
Above
Avg-Above
Above
Above
Above
Avg-Above
Above
20:35:45
 
Federated States of Micronesia
 
Yap
L 9° 29' N,
λ 138° 05' E
Above
Above
Above
Avg-Above
Above
Above
Above
Above
Above
25:30:45
Chuuk
L 7° 28' N,
λ 151° 51' E
Above
Above
Above
Avg-Above
Above
Above
Above
Avg-Above
Above
25:30:45
Pohnpei
L 6 ° 59' N,
λ 158° 12' E
Above
Above
Above
Avg
Above
Above
Above
Avg-Above
Above
30:30:40
Kosrae
L 5 ° 21' N,
λ 162° 57' E
Avg-Above
Above
Above
Avg
Above
Above
Above
Below
Above
30:30:40
 
Republic of the Marshall Islands
 
Kwajalein
L 8 ° 43' N,
λ 167° 44' E
Above
Above
Above
Above
Above
Above
Above
Avg-Above
Avg-Above
30:35:35
Majuro
L 7° 04' N,
λ 171° 17' E
Above
Above
Avg-Above
Above
Avg-Above
Above
Above
Avg-Above
Avg-Above
30:35:35
 
Guam and CNMI
 
Guam
L 13 ° 29' N,
λ 144° 48' E
Above
Above
Above
Avg
Above
Above
Above
Avg-Above
Above
25:35:40
Saipan
L 15 ° 06' N,
λ 145° 48' E
Above
Above
Above
Avg
Above
Above
Above
Avg-Above
Above
25:35:40
 
American Samoa
 
Pago Pago
L 14 ° 20' S,
λ 170° 43' E
Above
Above
Avg
Avg-Below
Avg
Above
Above
Avg-Above
Above
25:35:40
 
State of Hawaii
 
Lihue
L 21 ° 59' N,
λ 159 ° 20' E
Avg-Above
Above
Avg
Above
Avg
Clim
Above
Clim
Avg-Above
30:35:35
Honolulu
L 21 ° 19' N,
λ 157° 56' W
Avg-Above
Above
Avg
Above
Avg
Clim
Above
Avg-Above
Avg-Above
30:35:35
Kahului
L 20 ° 54' N,
λ 156° 26' E
Avg-Above
Above
Avg
Above
Avg
Clim
Above
Avg-Above
Avg-Above
30:35:35
Hilo
L 19 ° 43' N,
λ 155° 03' E
Avg-Above
Above
Avg
Above
Avg
Clim
Above
Avg-Above
Above
30:30:40

 


Forecast Discussion

Koror: Rainfall for November - December - January 2017 is expected to be Above for Koror. There is a 20% chance that rainfall during the NDJ season will be less than 29.21 inches; a 35% chance that rainfall will be between 29.21 inches and 38.94 inches; and a 45% chance that rainfall will be greater than 38.94 inches.

Yap: Rainfall for November - December - January 2017 is expected to be Above  for Yap. There is a 25% chance that rainfall during the NDJ season will be less than 21.82 inches; a 30% chance that rainfall will be between 21.82 inches and 28.08 inches; and a 45% chance that rainfall will be greater than 28.08 inches.

Chuuk: Rainfall for November - December - January 2017 is expected to be Above  for Chuuk. There is a 25% chance that rainfall during the NDJ season will be less than 30.16 inches; a 30% chance that rainfall will be between 30.16 inches and 36.49 inches; and a 45% chance that rainfall will be greater than 36.49 inches.

Pohnpei: Rainfall for November - December - January 2017 is expected to be Above  for Pohnpei. There is a 30% chance that rainfall during the NDJ season will be less than 38.94 inches; a 30% chance that rainfall will be between 38.94 inches and 47.32 inches; and a 40% chance that rainfall will be greater than 47.32 inches.

Kosrae: Rainfall for November - December - January 2017 is expected to be Above for Kosrae. There is a 30% chance that rainfall during the NDJ season will be less than 44.10 inches; a 30% chance that rainfall will be between 44.10 inches and 55.78 inches; and a 40% chance that rainfall will be greater than 55.78 inches.

Kwajalein: Rainfall for November - December - January 2017 is expected to be Average or Average Above  for Kwajalein. There is a 30% chance that rainfall during the NDJ season will be less than 21.12 inches; a 35% chance that rainfall will be between 21.12 inches and 25.30 inches; and a 35% chance that rainfall will be greater than 25.30 inches.

Majuro: Rainfall for November - December - January 2017 is expected to be Average or Average Above for Majuro.There is a 30% chance that rainfall during the NDJ season will be less than 32.31 inches; a 35% chance that rainfall will be between 32.31 inches and 36.56 inches; and a 35% chance that rainfall will be greater than 36.56 inches.

Guam: Rainfall for November - December - January 2017 is expected to be Above  for Guam. There is a 25% chance that rainfall during the NDJ season will be less than 14.88 inches; a 35% chance that rainfall will be between 14.88 inches and 21.97 inches; and a 40% chance that rainfall will be greater than 21.97 inches.

Saipan: Rainfall for November - December - January 2017 is expected to be Above for Saipan. There is a 25% chance that rainfall during the NDJ season will be less than 11.78 inches; a 35% chance that rainfall will be between 11.78 inches and 16.53 inches; and a 40% chance that rainfall will be greater than 16.53 inches.

Pago Pago: Rainfall for November - December - January 2017 is expected to be Above  for Pago Pago. There is a 25% chance that rainfall during the NDJ season will be less than 32.98 inches; a 35% chance that rainfall will be between 32.98 inches and 47.68 inches; and a 40% chance that rainfall will be greater than 47.68 inches.

Lihue: Rainfall for November - December - January 2017 is expected to be Average or Above Average for Lihue. There is a 30% chance that rainfall during the NDJ season will be less than 8.57 inches; a 35% chance that rainfall will be between 8.57 inches and 16.95 inches; and a 35% chance that rainfall will be greater than 16.95 inches.

Honolulu: Rainfall for November - December - January 2017 is expected to be Average or Above Average for Honolulu. There is a 30% chance that rainfall during the NDJ season will be less than 3.89 inches; a 35% chance that rainfall will be between 3.89 inches and 8.76 inches; and a 35% chance that rainfall will be greater than 8.76 inches.

Kahului: Rainfall for November - December - January 2017 is expected to be Average or Above Average for Kahului. There is a 30% chance that rainfall during the NDJ season will be less than 5.16 inches; a 35% chance that rainfall will be between 5.16 inches and 9.46 inches; and a 35% chance that rainfall will be greater than 9.46 inches.

Hilo: Rainfall for November - December - January 2017 is expected to be Above for Hilo. There is a 30% chance that rainfall during the NDJ season will be less than 26.44 inches; a 30% chance that rainfall will be between 26.44 inches and 42.99 inches; and a 40% chance that rainfall will be greater than 42.99 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 cut-offs for each location and season are based on Pacific Rainfall Climatologies (Climate Prediction Center) 1981-2010. The PEAC Seasonal Rainfall Outlook for November - December - January (NDJ) 2017 was made available on 13 October 2017.