Forecast Skill in Prediction of the East Asia Summer Monsoon using S2S DB Sang-Min Lee, Yu-Kyong Hyun, Hyun-Suk Kang and Young-Hwa Byun
Climate Research Division, National Institute of Meteorological Sciences, KMA
East Asia Summer Monsoon (EASM)
Subseasonal to Seasonal (S2S) DB
Concept of Lead Time
Weekly precipitation climatology of GPCP
30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4
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★ ★ ★ ★
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● ● ● ●
■ ■ ■ ■ ■ ■ ■ ■ ■ ■
- S2S Hindcast DB
•NCEP/CMA: Daily [ㆍ]
•KMA/UKMO: 1, 9, 17, 25 (4/month) [★]
•BOM: 1, 6, 11, 16, 21, 26 (6/month) [▲]
•JMA: 10, 20, last day of month (3/month) [●]
•ECMWF: Sunday and Wednesday a week (2/week) [■]
Resolution Rfc Ens. Size Rfc Frequency Time range Rfc length
KMA N216L85 (432x325)
3 4/month (1,9,17,25)
d 0-60 1996-2009
BoM T47L17 (144x72)
33 6/month (1,6,11,16,21,26)
d 0-62 1981-2013
CMA T106L40 4 daily d 0-60 1994-2014
ECMWF T639/319 L91 11 2/week d 0-46 past 20 years
NCEP T126L64 4 day d 0-44 1999-2010
JMA T319L60 5 3/month d 0-33 1981-2010
240x121 (1.5°) 1 week 2000-2009 (10yrs)
Meiyu
Changma
Baiu
- EASM Period: from the first week to the last week with above +1𝛔 in the
average of precipitation in EASM area
- In average, the EASM starts in early June (23W) and ends in late August
(35W), so that it continues during 13 weeks
Forecast Skill of the accumulated PRCP
Acknowledgement: This work has been supported by the Research and Development for KMA Weather, Climate, and Earth system Services
- Lead Time: The Closest date of forecast
•1-week lead time
•2-week lead time
•3-week lead time
Zonal Average Precipitation Climatology & Synoptic Characteristics of EASM
Fractions Skill Score of Precipitation
The East Asian Summer Monsoon
(EASM) is characterized by the
heaviest seasonal precipitation in
South Korea, China and Japan. It is
also an important water resources and
the fluctuations of the monsoon are
often associated with floods, droughts,
and other climate extreme events.
Recently, Subseasonal to Seasonal (S2S)
numerical models have played a vital
role in improvement forecast skill and
understanding on the subseasonal to
seasonal timescale on high-impact
weather events.