1. JMA Monthly and Seasonal Forecast Systems
Yuhei Takaya
Climate Prediction Division
Japan Meteorological Agency
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

2. Outline Designing Operational Forecast Systems
Targets (Phenomena, Time scales, Applications)
Requirements/Limitations
Current JMA Operational Systems
Monthly (uncoupled) and Seasonal (coupled) forecast systems
Practical Examples
Future Directions
Required Activities
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

3. “Designing” Operational Forecast Systems
Operational Forecast Systems are to be oriented to phenomena, user applications. 10
102
103
104
Time scale (hours)
Horizontal scale (km) 2 20
200
2,000
20,000 1d
10d 1m 3m
Monsoon
MJO
ENSO
Synoptic
Weather
Systems
Teleconnections
Seasonal EPS
(CGCM TL km)
Tropical Cyclone
Monthly EPS , Early Warning on Extreme
Events (TL km)
Mesoscale Weather System
Weekly /Typhoon EPS (TL km)
Deterministic (JMA-GSM, TL km)
Atmospheric convection
JMA-NHM (5 km)
LFM (2 km)
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

4. Current JMA Sub-seasonal to Seasonal Prediction Systems
1 month 　　　　　　3 months 　　　　7 months　　
operated models
Early warning information on
extreme events
2 weeks
AGCM
TL159L60 50 member
Issued on Tuesday/Friday
1-month forecast
week 1
Week 2
Week 3&4
Issued on Friday
3-month forecast
1 month
CGCM JMA/MRI-CGCM
AGCM: TL95L40 OGCM:
deg x 1 deg 51 member
Issued every month
3 months
Warm/cold season
forecast
3 months
(summer/winter)
Issued in Feb. Sep.
ENSO
outlook
ENSO, Indian Ocean SST
Issued every month
The seasonal forecast system and ENSO prediction system were integrated with an atmosphere-ocean coupled model in Feb
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

5. Requirements and Limitations
Higher Resolution
Higher Frequency
More Members
Computer Resources
Costs & Benefits
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

6. JMA Monthly EPS SST X200 and Div Wind Precipitation, PSI200, WAF200
Z500&WAF200
T850

7. JMA Monthly EPS Precipitation, PSI200, WAF200 SST X200 and Div Wind
Z500&WAF200
T850

8. Predictability in the Midst of Chaos - Predictability at SSS Time Scale- (Shukla 1998 Science )
Better Atmosphere, Ocean, Land, Sea-ice initialization
Initial value problems (predictability of 1st kind)
Inertia or memory (ocean heat content, snow…)
External forcing (volcanic eruption, solar activity, green house gases…)
Boundary condition problems (predictability of 2nd kind)
Feedback between boundary conditions and atmospheric internal dynamics gives an additional predictability.
Interaction between predictabilities of 1st and 2nd kind
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

9. JMA Monthly Forecast System
Atmospheric I. C.
Atmospheric perturbations
Trop.&Ext.-trop. bred vector
25 members start from Wednesday.
25 members start from Thursday.
50 members in total
Atmospheric General Circulation Model
(JMA-GSM0803C)
TL159L60 (~110km)
JMA Global Data Assimilation System
JMA Land Surface Analysis
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

10. Arctic Oscillation during Dec. 2009-Feb. 2010
Jan. 2010
Feb. 2010
[m]
A negative phase of the Arctic Oscillation (AO) pattern was dominant through Winter 2009/2010.

11. Forecast Skill of Operational JMA Monthly Forecast
Anomaly Correlation
Week 1
Week 2
Week 3-4
Week 1-4
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

12. AO index in Winter 2009/2010
Index of EOF1 score (500hPa GPH, DJF mean)
(1) 2009/12/10 　
(2) 2010/1/28
The winter 2009/2010 was the most prominent period during
Spatial Pattern of GPH500 EOF1
(Area weighted Covariance, 22.6 %)
Computed with DJF mean 500-hPa GPH.
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

13. Prediction for negative AO Case Initial Date: 2009/12/10
1-month （4-week） mean 500-hPa GPH Anomaly
Analysis (JRA-25)
Forecast
120 90 60 30
-30
-60
-90
-120
[m]
0.84
1-month (4-week) mean Anomaly Correlation 0.84
Week , Week , Week
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

14. 200-hPa Westerly Jet Initial Date: 2009/12/10
200-hPa Zonal Wind Anomaly 4-Week Mean Forecasts
Analysis (12/12-1/8)
Forecast I.C.; 2009/12/09
Forecast I.C.:2009/12/10 14
Strong Sub-tropical Jet
Weak Polar Front Jet
[m/s]
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

15. E-vector (Hoskins et al. 1983 JAS)
Momentum Transport Diagnostics: E-vector E=(v’2-u’2, -u’v’)
Cyclonic Circulation
Anti-Cyclonic
Circulation E
Divergence
Convergence
Anti-Cyclonic
Circulation
Cyclonic Circulation
Ian N. James (1994) “Introduction to Circulating Atmospheres”
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

16. Divergence of E-vector
Mid-latitude 30N-40N
North Atlantic 30N-40N, 90W-0
x104 [m s-2]
x104 [m s-2]
●　Hindcast (Initial Date: 10 Dec.)
　　 Operational Forecast (2009/12/10)
○　JRA-25/JCDAS Analysis
North Pacific 30N-40N, 170E-120W
x104 [m s-2]

17. JMA Seasonal EPS
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

18. JMA Seasonal EPS
The seasonal forecast relies on the predictability that comes from the ENSO variability.
The East Asian monsoon is essentially an ocean-atmosphere-land coupled system.
Coupled models are suitable for predicting its variability at a seasonal time scale.
The new JMA coupled forecast system has been up and running for the JMA ENSO prediction system since Feb. 2008, and was introduced to the JMA seasonal forecast in Feb
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

19. New JMA Seasonal Forecast System
coupler
(w/ flux adjustment)
Climate Data Assimilation JRA-25/JCDAS
Atmosphere-Ocean Coupled model (JMA/MRI-CGCM)
JMA GSM
（TL95L40: ~180km）
Ocean model (MRI.COM )
1.0°×(0.3°-1.0°), 51 levels
Ocean Data Assimilation System MOVE/MRI.COM-G
Atmospheric perturbations
Trop.&Ext. trop bred vector
Atmospheric I. C.
Oceanic I. C.
Atmospheric BGM + Lagged Averaging Forecast
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

20. Operational Schedule Ocean Data Assimilation Forecasts
9 members / 5 days
LAF
10 days
Window
NINO3 SSTA
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

21. South China Flood in 2010
BBC News
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

22. Precipitation Forecasts for June 2010 (I.C. : May)
Beijing ECMWF Exeter Melbourne
Montreal Moscow Seoul Tokyo
Toulouse Washington
Observation; OLR anomaly
Original data are provided by NOAA.
(mm/day)
WMO LC website

23. JMA future plan on the next HPC
Weekly EPS
TL479L100 (~40 km) in 2013
Monthly EPS
TL319L100 (~60 km) in 2013
Development of integrated Weekly EPS and Monthly EPS (Seamless system) is under discussion.
Seasonal EPS
AGCM: TL159L60 (80?) (~110 km) in 2014
OGCM: Tripolar grid, 1deg x deg. 53 levels.
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

24. Forecast Skill wrt Lead Time
The lead time is important at a 1-month time scale.
ACC (Daily 500-hPa GPH)
ACC (7-day mean 500-hPa GPH)
50 ensembles
50 ensembles
Scores if forecasts 3-day before used.
Based on verification of real-time JMA operational forecasts in 2006.
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

25. Toward “Seamless Prediction System”
Week-1
Week-2
Week-3
Week-4
Weekly EPS
(TL479L100)
2-Week EPS (Early Warning)
Monthly EPS (TL319L100)
reforecast
FY2013-
2-Week EPS (TL479L100)
reforecast
Monthly EPS (TL319L100)
FY ?
FY ???
2-Week EPS (TL479L100)
reforecast
Monthly EPS (TL319L100)
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

26. Required Activities for Further Improvement of SSS time scale
International research projects to investigate predictability at monthly time scale 　(extended TIGGE ???)
International research projects for key processes of predictability, MJO, ENSO, etc… 　(CLIVAR MJO WG etc. )
Standard verification framework for operational forecasts at sub-seasonal (monthly) time scale. (under WMO, CBS? SVS?)
Research community
Operational Community
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

27. Thank you for your kind attention.
END
Thank you for your kind attention.
Hope this talk to help the coming discussion.
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

28. Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec

29. EOF1(AO), REOF(PNA, NAO) Scores Initial Date: 2009/12/10
(a) EOF %
AO, NAO, PNA Indices were well predicted.
Red： Ensemble mean
Blue： Analysis
Grey： Each realization
(b) REOF %
(c) REOF %

30. High-Frequency Wave Activity Anomaly K=½(u’2+v’2)　Initial Date: 2009/12/10
K anomaly and U300 Anomalies Analysis (JRA-25 , 12/12-1/8)
K anomaly and U300　Anomalies Ensemble Forecast ( I.C. 12/10)
Contours: 300-hPa Zonal Wind Anomaly [m s-1] Colors: High-Frequent Wave Activity Anomaly x 10-5 [m2 s-2]
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

31. Convergence of Momentum Flux ∂y (-u’v’) and U300 Initial Date: 2009/12/10
∂y (-u’v’), U300 Anomaly Analysis (JRA-25 , 12/12-1/8)
∂y (-u’v’), U300 Anomaly Ensemble Forecast ( I.C. 12/10)
Contours; Convergence of Eddy Momentum Flux by High-Frequency Variation ∂y (-u’v’) (contour interval: 2・10-4 [m s-2] ) Colors: 300-hPa Zonal Wind Anomaly [m s-1]
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

32. Ensemble Perturbations
The JMA monthly forecast system produces initial perturbations using the Bred Vectors, which is specially intended to obtain large-scale growing modes in the tropics.
Chikamoto et al. 2007, GRL
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

33. Tropical Bred Vector Perturbation
The space-time spectrum of the 200-hPa velocity potential of the tropical bred vector averaged over the 10S–10N region.
Hovmoeller diagrams of 200-hPa velocity potential averaged over the 10S–10N region for (a) the observed field, (b) the bred vector
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

34. Perturbation (500-hPa GPH Spread)
OLD
NEW
NEW-OLD
Old
Singular Vector with a simplified model (NH only)
New
Combination of BV method in the tropics and extra-tropics (NH only).
[m]
Courtesy: M.
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

35. Perturbation and Spread-Skill Relationship
N. H.
S. H.
New RMSE
Old Spread
Perturbations in tropics contribute to increase of the spread in extra-tropics.
Courtesy: M.
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

36. Precipitation in June 2010 Ratio to Normals Zhejiang 174 %
Fuzhou 157 %
Based on CLIMAT reports
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

37. Index of 1st Mode Index of the 1st Mode
The 1st mode is well correlated with Wang and Fan Index (Wang and Fan ,1999).
Wand and Fan Index :
U850 (5-15N,90-130E) –
U850 ( N, E)
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

38. 2009/12/10 Z500 Analysis (12/12-1/8) Forecast I.C.; 2009/12/10
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

39. 2009/12/10 T850 Analysis (12/12-1/8) Forecast I.C.; 2009/12/10
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

40. 2009/12/10 SLP Analysis (12/12-1/8) Forecast I.C.; 2009/12/10
Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010