Subseasonal to seasonal tropical forecasts using a Coupled Linear Inverse Model (C-LIM)
(Experimental NOAA/ESRL PSD and CIRES/U. of Colorado Forecast)
C-LIM VERSION 3.2beta: Interim update. Resolution improved to 2x2 degree, replaced NCEP R1 winds with CFSR winds, and updates one day sooner. STILL IN BETA; SOME PARTS INCOMPLETE.
Forecasts and verifications of Tropical Convection, Wind, and SST anomalies:
- Pentads 1-12
- Months 2-9
- Separation of tropical anomalies into coupled and uncoupled fields, 1982-present
- How we make these Tropical forecasts
Current initialization and a few selected forecast anomalies of OLR (W/m2), winds (m/s), 20 C isotherm depth (m, blue=positive), and SST (oC):
One key benefit of the C-LIM is that the eigenvectors of its
dynamical evolution operator separate into two distinct, but
nonorthogonal, subspaces: one governing the nearly uncoupled
subseasonal dynamics, and the other governing the strongly coupled
longer term dynamics. This results in a dynamically-based filter
that, unlike bandpass or EOF-based filtering, can distinguish
between variability having similar spatial structures but very
different time scales due to differences between coupled air-sea
and internal atmospheric dynamics. We project the tropical data
onto these two subspaces, producing a real-time clean split of
OLR, wind, and SST anomalies into subseasonal variations including the MJO
("internal"), and longer term variations including ENSO
("coupled"). Hovmullers of the filtered datasets are updated
daily; also available is an atlas of the C-LIM filtered data going
back to 1982.
For a full description
of the C-LIM methodology and a detailed analysis of the previous
C-LIM
version (v1.0),
see:
Standard disclaimer: these forecasts are experimental. NOAA/PSD and CIRES/University of Colorado are not responsible for any loss occasioned by the use of these forecasts.