Forecasts of 500mb Height Teleconnection Indices, from ESRL/PSD GEFS Reforecast2 Data
The PNA, NAO, WPO and EPO indices represent four patterns of low-frequency tropospheric height variability, as classified in the study of Barnston and Livezey (MWR, 1987). The indices are based on centers-of-action of 500mb height patterns as defined below. The calculation of these teleconnection indices utilize the mean of the 11-member ESRL/PSD GEFS reforecast2 ensemble forecasts, initialized daily at 00 UTC. The height fields are spectrally truncated to total wavenumber 10 in order to emphasize large_scale variations.
These forecasts will usually (but not always) be updated by 16 UTC each day. They likely will not be available as consistently as operational products from the National Weather Service. Also please note that this is an experimental forecast product, and is not an official forecast of NOAA or its National Weather Service.
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Latest Forecasts of Teleconnection Indices
Daily Forecasts of Teleconnection Indices for Last 120 Days
- Pacific North America Pattern (PNA) [(15-25N, 180-140W)-(40-50N, 180-140W)+(45-60N, 125W-105W)-(25-35N, 90W-70W)]
- PNA Composite Positive Phase Map
- North Atlantic Oscillation(NAO) [(35-45N, 70W-10W) - (55-70N, 70W-10W)]
- NAO Composite Positive Phase Map
- Western Pacific Oscillation(WPO) [(25-40N, 140E-150W) - (50-70N, 140E-150W)]
- WPO Composite Positive Phase Map
- Eastern Pacific Oscillation(EPO) [(20-35N, 160W-125W) - (55-65N, 160W-125W)]
- EPO Composite Positive Phase Map
Daily forecasts of teleconnection indices produced at NCEP's Climate Prediction Center can be found here.
Daily Teleconnection Indices: Historical Values from NCAR/NCEP Reanalysis
The NAO, PNA, WPO and EPO daily indices are available from 1948 onwards and are updated regularily. The data used in computing these teleconnection patterns are from the daily averaged NCAR/NCEP Reanalysis. The 1981-2010 period was used as climatology.