2013 Macau Rainy Season Forecast

Macau Meteorological & Geophysical Bureau

Apr 2013

Climate normal (1981-2010) - Precipitation(mm)

Month Average Below normal Normal Above normal

Jan 26.5 < 7.0 7.0-35.6 > 35.6

Feb 59.5 < 8.4 8.4-55.7 > 55.7

Mar 89.3 < 44.9 44.9-88.5 > 88.5

Apr 195.2 < 105.5 105.5-222.6 > 222.6

May 311.1 < 200.1 200.1-386.8 > 386.8

June 363.8 < 235.2 235.2-431.9 > 431.9

July 297.4 < 175.7 175.7-354.3 > 354.3

Aug 343.1 < 233.7 233.7-393.5 > 393.5

Sept 219.5 < 123.2 123.2-278.0 > 278.0Oct 79.0 < 20.5 20.5-92.1 > 92.1

Nov 43.7 < 7.4 7.4-54.2 > 54.2

Dec 30.2 < 6.8 6.8-35.8 > 35.8

Annual 2058.1 < 1798.8 1798.8-2271.0 > 2271.0

Climate normal (1981-2010) - Temperature(℃)

Month Average Below normal Normal Above normalJan 15.1 ≤14.5 14.5-15.7 >15.7

Feb 15.8 ≤14.6 14.6-16.6 >16.6

Mar 18.3 ≤17.8 17.8-19.0 >19.0

Apr 22.1 ≤21.7 21.7-22.6 >22.6

May 25.6 ≤25.0 25.0-26.2 >26.2

June 27.6 ≤27.2 27.2-28.0 >28.0

July 28.6 ≤28.3 28.3-29.0 >29.0

Aug 28.4 ≤28.1 28.1-28.7 >28.7

Sept 27.4 ≤27.2 27.2-27.8 >27.8Oct 25.0 ≤24.7 24.7-25.4 >25.4

Nov 20.9 ≤20.4 20.4-21.6 >21.6

Dec 16.8 ≤16.2 16.2-17.5 >17.5

Annual 22.6 ≤22.4 22.4-22.9 >22.9

Precipitation & Temperature Anomaly in Macau(1952-2012)

(1) Pre-flood season (Apr-June)

(2) Post-flood season (July-Sept)

Review of 2012 flood season in MacauPrecipitation(mm)Apr-June

Precipitation(mm)July-Sept

Temperature( )℃Apr-June

Temperature( )℃July-Sept

Climate normal(1981-2010) 540.8-1041.3 532.6-1025.8 24.6-25.6 27.9-28.5

Average 870.1 860 25.1 28.1

Amount(2012) 679.6 611.2 25.5 27.9

Anomaly -21.9% -28.9% +0.4 -0.2

Forecast(last year) Normal Normal Normal Normal

Model prediction for last year(2012) - ECMWF

2013 rainy season forecast for Macau

Model prediction- ECMWF

Model prediction - NCEP

NCEP预测 : 4-6月雨量接近气候正常值

NCEP预测 : 7-9月雨量接近气候正常值

Model prediction - NCEP

System & Circulation Analysis

Historical pattern composite – AMJ

Historical pattern composite – JAS

Geopotential height – 500hPa

Streamline Anomaly – 850hPa

Precipitation Anomaly

ITCZ - OLR

数据源 : Linear Inverse Modeling Tropical OLR and SST Anomalies Pentads 12,18,24,30,36,42 Forecasts, NOAA

Results Analysis

•Subtropical-high is stronger than normal, which is not favored for precipitation but favored for high temperature in South China.•The convection between the eastern Indian Ocean and South China Sea which extends east to the Western Pacific is stronger than normal, which may imply the ITCZ is stronger than normal and is further north.

ENSO prediction throughout 2013

ENSO-neutral is favored into Northern Hemisphere fall 2013.

ENSO condition vs. Rainy season in Macau

Source: Running 3-month mean ONI values,http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml Nino Normal Lina

0%

10%

20%

30%

40%

50%

60%

70%

1952-2012 前冬 ENSO狀態對本澳後汛期氣溫影響

BelowNormalAbove

Nino Normal Lina0%

10%20%30%40%50%60%70%80%

1952-2012 前冬 ENSO狀態對本澳後汛期降雨影響

BelowNormalAbove

Nino Normal Lina0%5%

10%15%20%25%30%35%40%45%50%

1952-2012 前冬 ENSO狀態對本澳前汛期降雨影響

BelowNormalAbove

Nino Normal Lina0%10%20%30%40%50%60%70%

1952-2012 前冬 ENSO狀態對本澳前汛期氣溫影響

BelowNormalAbove

Conclusion Apr-June (Prec.)

Apr-June (Temp.)

July-Sept

(Prec.)July-Sept (Temp.)

ECMWF below normal

above normal normal above

normal

NCEP above normal normal above

normal normal

IRI no signal above normal

no signal

above normal

ENSO reference normal normal normal normal

System analysis

below normal

above normal normal normal

Conclusion

below normal

above normal normal normal

Thank you !