Forecasts of Tropical Convection, Wind, and SST Pentads using a Coupled Linear Inverse Model (C-LIM)
(Experimental NOAA/ESRL PSD and CIRES/U. of Colorado Forecast)
C-LIM VERSION 3.0: New LIM, now with thermocline depth! Base period is also updated to 1982-2011. Improved forecast skill for multi-month forecast leads. Forecast of forecast skill (using pattern correlation throughout Tropics as skill measure) also included.
New forecasts running and updated daily, but archives of past forecasts/verifications before 2014 are not installed yet.
Forecasts and verifications:
- Pentads 1-8
- Pentads 12, 18, 24, 30, 36, 42, 48, 54, 60
- 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.