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Severe Thunderstorms and Heavy Rain for the South-Central U.S.

Severe thunderstorms capable of very large hail, damaging wind, and a couple of tornadoes will be possible Monday afternoon into the night from portions of the central and southern High Plains into southwest Texas. A heavy rain event with flooding is expected in the southern Plains into western Arkansas through the end of the week. Read More >

 

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, ECMWFIRINCEP 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.

PEAC services is no longer providing the in house model, PEAC CCA as of January 2021. 

 


May-June-July (MJJ) 2021

Model:
UKMO
ECMWF

NCEP CA

NASA GMAO
NCEP Coupled
IRI
APCC
PEAC CCA
Final Outlook
Final Probabilities
 
Republic of Palau
 

Airai

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

 


Forecast Discussion

 

Airai: Rainfall for May-June-July 2021 is expected to be Avg-above for Airai. There is a 30% chance that rainfall during the MJJ season will be less than 42.33 inches; a 35% chance that rainfall will be between 42.33 inches and 55.62 inches; and a 35% chance that rainfall will be greater than 55.62 inches.

Yap: Rainfall for May-June-July 2021 is expected to be Avg-above for Yap. There is a 30% chance that rainfall during the MJJ season will be less than 31.95 inches; a 35% chance that rainfall will be between 31.95 inches and 39.5 inches; and a 35% chance that rainfall will be greater than 39.5 inches.

Chuuk: Rainfall for May-June-July 2021 is expected to be Avg-above for Chuuk. There is a 30% chance that rainfall during the MJJ season will be less than 34.01 inches; a 35% chance that rainfall will be between 34.01 inches and 37.92 inches; and a 35% chance that rainfall will be greater than 37.92 inches.

Pohnpei: Rainfall for May-June-July 2021 is expected to be Above for Pohnpei. There is a 25% chance that rainfall during the MJJ season will be less than 45.79 inches; a 35% chance that rainfall will be between 45.79 inches and 54.28 inches; and a 40% chance that rainfall will be greater than 54.28 inches.

Kosrae: Rainfall for May-June-July 2021 is expected to be Avg-Above for Kosrae. There is a 30% chance that rainfall during the MJJ season will be less than 45.01 inches; a 35% chance that rainfall will be between 45.01 inches and 50.14 inches; and a 35% chance that rainfall will be greater than 50.14  inches.

Kwajalein: Rainfall for May-June-July 2021 is expected to be Avg-Above for Kwajalein. There is a 30% chance that rainfall during the MJJ season will be less than 20.99 inches; a 35% chance that rainfall will be between 20.99 inches and 26.52 inches; and a 35% chance that rainfall will be greater than 26.52 inches.

Majuro: Rainfall for May-June-July 2021 is expected to be  for Above  Majuro. There is a 30% chance that rainfall during the MJJ season will be less than 30.51 inches; a 30% chance that rainfall will be between 30.51 inches and 33.4 inches; and a 40% chance that rainfall will be greater than 33.4 inches.

Guam: Rainfall for May-June-July 2021 is expected to be Avg-Above for Guam. There is a 30% chance that rainfall during the MJJ season will be less than 18.47 inches; a 35% chance that rainfall will be between 18.47 inches and 25.81 inches; and a 35% chance that rainfall will be greater than 25.81 inches.

Saipan: Rainfall for May-June-July 2021 is expected to be Avg-Above for Saipan. There is a 30% chance that rainfall during the MJJ season will be less than 13.58 inches; a 35% chance that rainfall will be between 13.58 inches and 18.53 inches; and a 35% chance that rainfall will be greater than 18.53 inches.

Pago Pago: Rainfall for May-June-July 2021 is expected to be Avg-below for Pago Pago. There is a 35% chance that rainfall during the MJJ season will be less than 18.47 inches; a 35% chance that rainfall will be between 18.47 inches and 26.83 inches; and a 30% chance that rainfall will be greater than 26.83 inches.

Lihue: Rainfall for May-June-July 2021 is expected to be Avg-below  for Lihue. There is a 35% chance that rainfall during the MJJ season will be less than 4.87 inches; a 35% chance that rainfall will be between 4.87 inches and 5.93 inches; and a 30% chance that rainfall will be greater than 5.93 inches.

Honolulu: Rainfall for May-June-July 2021 is expected to be Avg-below for Honolulu. There is a 35% chance that rainfall during the MJJ season will be less than 0.84 inches; a 35% chance that rainfall will be between 0.84 inches and 1.62 inches; and a 30% chance that rainfall will be greater than 1.62 inches.

Kahului: Rainfall for May-June-July 2021 is expected to be Avg-below for Kahului. There is a 35% chance that rainfall during the MJJ season will be less than 0.7 inches; a 35% chance that rainfall will be between 0.7 inches and 1.83 inches; and a 30% chance that rainfall will be greater than 1.83 inches.

Hilo: Rainfall for May-June-July 2021 is expected to be  Avg-below for Hilo. There is a 35% chance that rainfall during the MJJ season will be less than 20.190 inches; a 35% chance that rainfall will be between 20.19 inches and  29.13 inches; and a 30% chance that rainfall will be greater than 29.13 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) 1981-2010. (Last Updated 7 May 2021- Pre-Conference and subject to change)