Climate Outlook for Summer 2020 over KOREA SEO Taegun, KIM - - PowerPoint PPT Presentation

FOCRAII, 7 May 2020

Climate Outlook for Summer 2020 over KOREA

SEO Taegun, KIM Samyoung, KIM Hyeonjeong,

and LEE Hyunsoo

Climate Prediction Division

ENSO condition and prediction

Weekly(4.19.~25.) SST anomaly over Niño3.4 Model Predictions of ENSO from Apr. 2020

▶ Recently, the weekly SST anomaly over Nino3.4 region shows +0.7 ℃ ▶ Forecast model predict ENSO-neutral is likely to continue this summer.

500hPa GPH (GloSea5. 4.20)

▶ June. The Subtropical high will be stronger than normal, and it’s western edge is expected to extend westward than normal. Positive anomaly is predicted over the northwest of Lake Baikal. ▶ July & Aug. The Subtropical high will expands northwest than normal June July Aug

850hPa Wind Anomaly(GloSea5, 4.20.)

June July Aug

▶ JJA(summer)

• Anti-cyclonic anomaly over the sea east of Philippines.
• Cyclonic anomaly over the East of Korea.

JJA AC

C

AC

C

AC

C C

AC

C

AC

Ensemble prediction (GloSea5, 4.20.)

Ensemble mean for 2m temperature

June July Aug. June July Aug.

Ensemble mean for precipitation ratio

JJA JJA

Western North Pacific-East Asian Summer Monsoon(GloSea5)

WNPSM Index

U850

[5-15N, 100-130E] - [20-30N, 110-140E]

(Wang and Fan, 1999)

JJA 850hpa wind Anomaly

▶ East Asian Summer Monsoon in WNP is weaker than normal in summer

WNPSM_2 WNPSM_1

WNP Subtropical High Index(850hPa)

WNPSH Index

H850

[15-25N, 115-150E]

(Wang et al., 2013)

▶ Western North Pacific Subtropical High(WNPSH) is stronger than normal but expands westward in early summer

MME Prediction (WMO LC)

June July Aug.

Ensemble mean for 2m temperature

Probability of 2m-temperature(JJA) June July Aug.

Ensemble mean for precipitation ratio

Probability of precipitation (JJA)

Summary

▣ Summer Monsoon

• Westward expansion of WNPSH will be stronger than normal in early summer.
• The influence of Summer Monsoon is expected to be weaker than

normal over Korea ▣ 2020 Summer outlook

• Temperatures will be higher than normal, and

precipitation will be near or below normal over Korea ▣ ENSO is expected to be neutral during the coming this summer

Temperature Precipitation

Below Normal Near normal Above normal Below Normal Near normal Above normal

Summer 20 30 50 40 40 20

Thank you !!

500hPa GPH (WMO LC MME)

JJA June July Aug.

Positive anomaly is located near of Korea.

More than 60% positive anomaly expected during this summer(Jun 74%, Jul 62%, Aug 60%)

Trend of Observed Temperature

Trend of Mean Temperature over R. of Korea

1.3℃ / 47yr 1.0℃ / 47yr 1.0℃ / 46yr June July Aug.

▶ The temperature of Korea has increasing trend for each month of summer ▶ Recently, the temperature rise in June is large

Snow cover

○ The snow cover in Tibetan has been more than normal since late fall last year (Similar to 2009)

⇒ delayed development of Tibetan anticyclone

Snow cover anomaly Snow cover anomaly in Tibetan Snow depth anomaly 2017/18년 2018/19년 2019/20년

• 2020. 3.