1. MJO Forecasting Discussion
Are we happy with the WH04 combined EOF index?
other metrics?
Comments on the calculation recipe,
precip vs OLR
Comments on display of phase plot
interannual “in” versus “out” for past data and forecasts
Require hindcasts and benchmark to evaluate models
Forecast skill of index (e.g., 0.5 vs 0.75)
Forecast skill as function of MJO phase
simple statistical versus linear inverse model benchmark
case study approach?
Requirements for multi-model ensemble?
data dissemination, hindcasts/reforecasts, CPC visit
How much increased skill should we expect from MJO?
PSD ensemble
experience from global hazards assessment

2. Regression RMM1 and 2 at initial time with week 2 verification, forecast or forecast error
1 m/s
3 m/s
RMM1 >0 Phase 4-5 Indo; <0 phase 8-1 WH
RMM2 >0 Phase 6-7 wPac; <0 phase 2-3 IO
Week 2 forecast
Week 2 verification

4. The global wind oscillation (GWO) is lurking!
MJO’s global teleconnection pattern 250 mb , DJF , 8 phases, ~27 cases/phase L H L L
Indian
Ocean 2 6
Western
Pacific
Ocean L H H L H H H L
Rossby wave
dispersion
“fm trough”
Blade et. al., 2007
nonlinear 3 vs. 7
Signals:  
for > 1
index
4-7 days
between
phases 3 7 L H L H L H L L L H H
The 3-6 days is supported by the RMM1,2 spectra Wheeler and Hendon.
The wave energy arrow in phase 3 is supported by Matthews and Kiladis.
There is a nonlinearity between phase 2 and 6 that may be explained by Blade et al, 2007.
Looks like nonlinear southwest USA between phase 4 and 8 also.
Matthews and Kiladis, 1999
RWD into east Pac
Maritime
Continent 4 8
Western
Hemisphere
Africa
Weickmann et. al, 1997
tilts imply sources/sinks 5 1
The global wind oscillation (GWO) is lurking!

5. Indices used for composites MJO ->120d rm removed; GWO –> 100d hp filter
MJO <– eight phases –> GWO

6. Proposed recipe (either to be computed by each Centre themselves, or by a single volunteering Centre):
a) Use WH04 EOFs (or equivalent precip structures; some Centres may choose to try both)
b) WH04 normalization factors for each field (OLR=15.1 Wm-2, u850=1.81 ms-1, u200=4.81 ms-1)
c) All use the same climatology computed from NCEP Reanalysis and observed OLR/precip.
d) All use the same methodology for removal of ENSO and other low-frequency variability (i.e., the removal of variability linearly related to an ENSO SST index and removal of mean of previous 120 days).

7. statistical
benchmark
PSD
ensemble

8. CPC Global Tropics Benefits/Hazards Assessment
Description: Week 1-2 outlooks for enhanced/suppressed rainfall and favorable/unfavorable conditions for TC activity
Purpose: Provides regional planners with global interests advanced notice on potential hazards/impacts
Physical Basis: MJO, GWO, ENSO, other coherent and/or persistent anomalies, interaction with the extratropics
Outside Collaboration: ESRL, TPC, NWS WR/CR, and others
Tools: Detailed monitoring, ENSO/MJO/GWO composites, MJO objective forecasts (statistical/dynamical), GFS/CFS forecasts
Plans: Product more objective in nature, evaluate and apply input associated with subseasonal variability from additional dynamical models, exploit the seasonal cycle more
“models
don’t
predict
the
MJO
very
well”