Monthly Discussion on Seasonal Climate Outlooks (No. 15)

Monthly Discussion on
Seasonal Climate Outlooks (No. 16)
(24 June 2015)
Tokyo Climate Center (TCC)
Japan Meteorological Agency (JMA)
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Outline
1. Summary and Discussion
<Slides 3>
2. Latest State of the Climate System (May. 2015) <Slides 4 – 13>
3. Three-month Predictions (Jul – Sep. 2015)
4. Explanatory Notes
<Slides 14 – 20>
<Slides 21 – 25>
Notes:
• The present monthly discussion is intended to assist National Meteorological and
Hydrological Services (NMHSs) in WMO RA II (Asia) in interpreting GPC Tokyo’s
seasonal prediction products. It does not constitute an official forecast for any nation.
Seasonal outlooks for individual countries should be obtained from the relevant NMHS.
• Seasonal predictions are based on a JMA’s Seasonal Ensemble Prediction System (EPS),
which is based on the coupled atmosphere-ocean general circulation model (CGCM).
• JMA provides three-month prediction products around the 20th of every month with
warm-season (Jun. – Aug.) prediction products in February, March and April, and with
cold-season (Dec. – Feb.) prediction products in September and October.
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1. Summary and Discussion
ENSO
• El Niño conditions continue and are gradually strengthening in the equatorial Pacific.
• It is likely that El Niño conditions will continue until the Northern Hemisphere winter.
Prediction for July-August-September 2015 (JAS 2015)
• In the upper troposphere, large-scale divergence anomalies over the central to eastern
Pacific and large-scale convergence anomalies from the Indian Ocean to the western
Pacific are predicted.
• In the sea level pressure field, a general pattern of positive anomalies in the Indian Ocean
against negative anomalies in the Pacific is predicted. In the 850 hPa wind field,
anticyclonic circulation anomalies from South Asia through to Southeast Asia are
predicted. These patterns are combined to indicate a shallower-than-normal monsoon
trough and weaker-than-normal monsoon circulations.
• A high probability of below-normal rainfall is predicted across the Maritime Continent.
• A slightly high probability of below-normal rainfall is predicted over South Asia.
• A high probability of above-normal temperatures is predicted for a wide swath of areas
from Middle East through South Asia to the northern part of Southeast Asia.
• A slightly high probability of above-normal temperatures is predicted over East Asia.
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2. Latest State of the Climate System
May 2015
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<May 2015> Extreme Climate Events
1.High temperature from Japan to the Korean Peninsula
2.Heavy precipitation from southeastern China to Taiwan
3.High temperature from southern China to the Indochina Peninsula
4.Light precipitation from the Philippines to the southern Indochina
Peninsula
5.Heat wave in India
6.High temperature from the northern part of Western Siberia to
northwestern Russia
7.Heavy precipitation from the southern Scandinavian Peninsula to
Ireland
8.Low temperature from the southern Scandinavian Peninsula to
northeastern Greenland
9.Light precipitation from southern France to Spain
10.High temperature from southwestern Europe to the western part
of Northern Africa
10.High temperature from southwestern Europe to the western part of
Northern Africa
11.High temperature from the southern part of Western Africa
12.High temperature in South Africa
13.High temperature and light precipitation in and around western
Canada
14.High temperature in and around the northeastern USA
15.Heavy precipitation and tornado from the southern USA to central
Mexico
16.Light precipitation around the eastern Caribbean Sea
17.Landslide in northwestern Colombia
18.High temperature in northern and northwestern South America
19.High temperature in northeastern Brazil
20.High temperature from Chile to Argentina
<Monthly Climate in the World> http://ds.data.jma.go.jp/tcc/tcc/products/climate/monthly.html
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<May 2015> Temperature
• Temperatures were well above normal in a number of regions including Northern Africa,
Western Africa, Western Russia to Western Siberia, Middle East, Madagascar, Southeast
Asia, Japan, northwestern North America, and Argentina.
• Temperatures were well below normal in Iceland and the UK .
Normalized anomaly of monthly mean temperature
<Monthly Climate in the World> http://ds.data.jma.go.jp/tcc/tcc/products/climate/monthly.html
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<May 2015> Precipitation
• Precipitation amounts were above normal in the UK, Scandinavia, Central Asia,
Southeastern China, the western to central USA, Mexico, and eastern Brazil.
• Precipitation amounts are below normal in western Europe, the Maritime Continent, and
the Caribbean countries.
Monthly precipitation ratio
<Monthly Climate in the World> http://ds.data.jma.go.jp/tcc/tcc/products/climate/monthly.html
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<May 2015> Sea Surface Temperature (SST)
• SSTs were above normal across the wide areas of the equatorial Pacific and the Indian
Ocean, while below normal around the Maritime Continent.
Monthly mean SST anomaly (˚C)
<Monthly mean SST anomalies (Global)> http://ds.data.jma.go.jp/tcc/tcc/products/elnino/ocean/sst-ano-global_tcc.html
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ENSO Monitoring Indices
• El Niño conditions continue and are
gradually strengthening in the
equatorial Pacific.
• In May, the index for NINO.3 was
above normal at +1.2oC. The
indices for NINO.WEST and the
Indian Ocean Basin Wide (IOBW)
were below and above normal,
respectively.
• The Southern Oscillation Index
(SOI) was negative at -1.2,
consistent with weaker-than-normal
trade winds.
NINO.3
SOI
NINO.WEST
IOBW
Monthly values (thin lines) and five-month running means (thick lines). The shading indicates El Niño (red) and La Niña (blue) events.
< El Niño Monitoring and Outlook> http://ds.data.jma.go.jp/tcc/tcc/products/elnino/elmonout.html
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<May 2015> Upper-level Circulation
• Convective activity (inferred from OLR) was enhanced across the equatorial Pacific, and was
suppressed over the Maritime Continent.
• In the 200 hPa stream function field, equatorial symmetric anticyclonic circulation anomalies
were widely seen over the Pacific.
Monthly average 200 hPa velocity potential,
divergent wind vector, and outgoing
longwave radiation (OLR) anomalies
Vector: divergent wind vector anomalies (m/s)
Shading: OLR anomalies (W/m2)
D and C indicate the centers of large-scale divergence and
convergence anomalies, respectively.
Monthly average 200 hPa stream
function & OLR anomalies
Contour: stream function anomalies (106 m2/s)
Vector: wave activity flux (m2/s2)
Shading: OLR anomalies (W/m2)
A and C indicate the centers of anti-cyclonic and cyclonic
circulation anomalies, respectively.
<Animation Maps (Global Area)> http://ds.data.jma.go.jp/tcc/tcc/products/clisys/anim/anim_tp.html
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<May 2015> Lower-level Circulation
• In the 850 hPa stream function field, equatorial symmetric cyclonic circulation anomalies
were widely seen across the Pacific. Anticyclonic circulation anomalies were pronounced
over South China Sea, where convective activity was suppressed.
• In the surface wind field, westerly wind anomalies were dominant over the equatorial
western to central Pacific.
850 hPa stream function and OLR anomalies
Contour: stream function anomalies (106 m2/s)
Vector: wave activity flux (m2/s2)
Shading: OLR anomalies (W/m2)
A and C indicate the centers of anti-cyclonic and cyclonic circulation
anomalies, respectively.
Sea level pressure (contours; hPa),
surface temperature (shading; ˚C), and
surface wind vector (m/s) anomalies
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Equatorial Intraseasonal Oscillation
• The active phase of the Madden-Julian Oscillation (MJO) propagated eastward from the
Maritime Continent into the equatorial Pacific during the first half of May.
• Thereafter the phase of the MJO became less discernible as enhanced convection anomalies
were persistent over the central to eastern Pacific in the second half of May.
Time-longitude cross section of seven-day running
mean 200 hPa velocity potential anomalies (5˚S – 5˚N)
<MJO> http://ds.data.jma.go.jp/tcc/tcc/products/clisys/mjo/moni_mjo.html
MJO diagram
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<May 2015> Northern Hemisphere Circulation
• In the 500-hPa height field, positive anomalies were observed in western Europe, Western
and Central Siberia, and northwestern and eastern North America. Negative anomalies
were seen in the northern North Atlantic, Eastern Siberia, and the western USA.
• In the sea level pressure field, positive anomalies were seen in western Europe and across
northern North America. Negative anomalies were seen in the western USA, the northern
North Atlantic and over the areas from East Asia to the Bering Sea.
Monthly mean 500 hPa geopotential height
Contour: geopotential height
Shading: geopotential height anomalies
Monthly mean sea level pressure (SLP)
Contour: SLP
Shading: SLP anomalies
<Monthly mean Maps (N.H.)> http://ds.data.jma.go.jp/tcc/tcc/products/clisys/figures/db_hist_mon_tcc.html
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3. Three-month Predictions
July-August-September 2015
(JAS 2015)
(Initial date for EPS: 10 June 2015)
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<JAS 2015> Sea Surface Temperature (SST)
• It is likely that El Niño conditions will continue until the Northern Hemisphere winter.
• It is likely that the NINO.WEST SST will be near normal or below normal until the
Northern Hemisphere winter.
• It is likely that the IOBW SST will be above normal until the Northern Hemisphere winter.
Sea surface temperature (SST)
Contour: three-month average (˚C); Shading: anomalies.
Outlook of the SST deviation for
NINO.3
Verification based on hindcast
(Left panel) http://ds.data.jma.go.jp/tcc/tcc/products/model/hindcast/CPS2/index.html
(Right panel) http://ds.data.jma.go.jp/tcc/tcc/products/model/hindcast/CPS2/shisu/shisu.html
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<JAS 2015> Global Circulation
• In the 200 hPa velocity potential field, negative (large-scale divergence) anomalies over the
central to eastern Pacific and positive (large-scale convergence) anomalies from the Indian
Ocean to the western Pacific are predicted.
• In the 200 hPa stream function field, anticyclonic circulation anomalies extending across the
central Pacific straddling the equator are predicted. Cyclonic anomalies are predicted across
Eurasia, indicating that the Tibetan High will be weaker than normal and the subtropical jet
stream over Eurasia will be displaced southward of its normal position.
200 hPa velocity potential (106 m2/s)
Contour: three-month average
Shading: anomalies
200 hPa stream function (106 m2/s)
Contour: three-month average
Shading: anomalies
Verification based on hindcast
http://ds.data.jma.go.jp/tcc/tcc/products/model/hindcast/CPS2/index.html
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<JAS 2015> Asian Circulation
• In the sea level pressure field, a general pattern of positive anomalies in the Indian Ocean against negative
anomalies in the Pacific is predicted. In the 850 hPa wind field, anticyclonic circulation anomalies from
South Asia through to Southeast Asia are predicted. These patterns are combined to indicate a shallowerthan-normal monsoon trough and weaker-than-normal monsoon circulations.
• Over the western to central Pacific, pronounced cyclonic circulation anomalies and westerly wind
anomalies are predicted, as is expected from the predicted El Niño conditions.
PSI850
& wind
Rainfall
m/s
SLP
Tsurf
Top-left: 850 hPa stream function (106 m2/s) and wind vector anomalies (m/s); Top-right: rainfall amounts (mm/day),
Bottom-left: sea level pressure (hPa); Bottom-right: surface air temperature (˚C)
Contour: three-month average; Shading: anomalies. A and C indicate the centers of anti-cyclonic and cyclonic circulation anomalies, respectively.
Verification based on hindcast http://ds.data.jma.go.jp/tcc/tcc/products/model/hindcast/CPS2/index.html
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<JAS 2015> Northern Hemisphere circulation
• In the 500 hPa height field, positive anomalies are predicted to be dominant in the global
tropics, reflecting the predicted El Niño conditions. In East Asia and the northern North
Pacific, negative anomalies in relative terms are predicted, consistent with circulation
anomalies expected in light of the past El Niño events.
• In the 850 hPa temperature field, positive anomalies over South Asia are predicted with
high/moderate skill, reflecting the weaker-than-normal southwest monsoon.
• In the sea level pressure field, the North Pacific subtropical high is predicted to be weaker
than normal in most of its extension.
500 hPa geopotential height
850 hPa temperature
Sea level pressure
Left: 500 hPa geopotential height (m); Center: 850 hPa temperature (˚C); Right: SLP (hPa)
Contour: three-month average; Shading: anomalies
Verification based on hindcast http://ds.data.jma.go.jp/tcc/tcc/products/model/hindcast/CPS2/index.html
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<JAS 2015> Probability Forecasts (precipitation)
• A high probability of belownormal rainfall is predicted
across the Maritime Continent.
• A slightly high probability of
below-normal rainfall is
predicted over South Asia.
• A high probability of abovenormal rainfall is predicted in
the equatorial Pacific straddling
the date line.
• A slightly high probability of
above-normal rainfall is
predicted over East Asia.
Verification based on hindcast
http://ds.data.jma.go.jp/tcc/tcc/products/model/probfcst/3-mon/hind/html/skill_reg_3-mon.html
http://ds.data.jma.go.jp/tcc/tcc/products/model/probfcst/3-mon/hind/html/skill_2d_3-mon.html
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<JAS 2015> Probability Forecasts (temperature)
• A high probability of abovenormal temperatures is
predicted for a wide swath of
areas from Middle East through
South Asia to the northern part
of Southeast Asia.
• A slightly high probability of
above-normal temperatures is
predicted over East Asia.
Verification based on hindcast
http://ds.data.jma.go.jp/tcc/tcc/products/model/probfcst/3-mon/hind/html/skill_reg_3-mon.html
http://ds.data.jma.go.jp/tcc/tcc/products/model/probfcst/3-mon/hind/html/skill_2d_3-mon.html
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5. Explanatory Notes (1)
Latest state of the climate system
• Extreme climate events and surface climate conditions are based on CLIMAT messages.
For details, see http://ds.data.jma.go.jp/tcc/tcc/products/climate/index.html
• SST products are based on COBE-SST data.
For details, see http://ds.data.jma.go.jp/tcc/tcc/products/elnino/index.html
• Atmospheric circulation products are based on JRA-55 data:
http://jra.kishou.go.jp/JRA-55/index_en.html
For details, see http://ds.data.jma.go.jp/tcc/tcc/products/clisys/index.html
• The base period for the normal is 1981 – 2010.
Three-month predictions and warm/cold season predictions
• Products are generated using JMA’s seasonal EPS which is based on the CGCM.
For details, see http://ds.data.jma.go.jp/tcc/tcc/products/model/index.html
• Unless otherwise noted, atmospheric circulation prediction products are based on the
ensemble mean, and anomalies are deviations from the 1981 – 2010 average for hindcasts.
Contact: [email protected]
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5. Explanatory Notes (2)
SST monitoring indices (NINO.3, NINO.WEST and IOBW)
• The SST baseline for NINO.3 region (5˚S – 5˚N, 150˚W – 90˚W) is defined as a monthly
average over a sliding 30-year period (e.g., 1984 – 2013 for 2014). The thresholds of
above the baseline, near the baseline, and below the baseline categories are +0.5 and -0.5.
• The SST baselines for the NINO.WEST region (Eq. – 15˚N, 130˚E – 150˚E) and the
IOBW region (20˚S – 20˚N, 40˚E – 100˚E) are defined as linear extrapolations with respect
to a sliding 30-year period in order to remove the effects of significant long-term warming
trends observed in these regions. The thresholds of above the baseline, near the baseline,
and below the baseline categories are +0.15 and -0.15.
Contact: [email protected]
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Names of world regions
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WMO Regional Association regions
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TCC website
El Niño
Monitoring
World
Climate
Climate System
Monitoring
Global
Warming
NWP Model
Prediction
Climate in
Japan
Training
Materials
http://ds.data.jma.go.jp/tcc/tcc/index.html
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