Examples of Extreme Combinations of ENSO, PNA,
and NAO Phases
Tables From (Hagemeyer, 2005)
| ENSO, PNA and NAO Scenarios | ||||
| PNA (-) | PNA (0) | PNA (+) | ||
| El Nino | NOV 1965 | MAR 1958 | FEB 1998 / FEB 1983 | NAO (-) |
| NOV 1972 JAN 1973 | MAR 1983 | NAO (0) | ||
| DEC 1965 (weak) | DEC 1982 | JAN 1983 (weak) | NAO (+) | |
| Neutral | MAR 1965 | MAR 1962 / APR 97 | FEB 1978 | NAO (-) |
| MAR 2002 | FEB 1961 / FEB 1972 | JAN 1981 / APR 1984 | NAO (0) | |
| APR 2002 / JAN 1952 | NOV1978 | MAR 1986 | NAO (+) | |
| La Nina | NOV1973 | FEB 1968 | NAO (-) | |
| FEB 1974 / JAN 1976 | NAO (0) | |||
| FEB 1989 | FEB 2000 | NAO (+) | ||
| PNA (-) | PNA (0) | PNA (+) | ||
Table 1. Matrix of 27 possible combinations of PNA, NAO, and ENSO phase. Months illustrative of extreme and neutral cases are given for each combination observed in the historical
record. Combinations with no strong cases on the scale of months are shaded and left empty.
| Theoretical Maxima/Actual Cases | |||||||
| PNA (-) | PNA (0) | PNA (+) | |||||
| El Nino | 14 | 9 | 16 | 17 | 17 | 18 | NAO (-) |
| 12 | 14 | 6 | 16 | 16 | NAO (0) | ||
| 10 | 12 | 8 | 13 | 6 | NAO (+) | ||
| Neutral | 6 | 7 | 8 | 9 | 10 | 8 | NAO (-) |
| 5 | 5 | 6 | 4 | 8 | 13 | NAO (0) | |
| 2 | 1 | 4 | 5 | 6 | 9 | NAO (+) | |
| La Nina | 2 | 5 | 4 | 6 | 5 | NAO (-) | |
| 0 | 2 | 3 | 4 | NAO (0) | |||
| 0 | 1 | 0 | 4 | 1 | NAO (+) | ||
| PNA (-) | PNA (0) | PNA (+) | |||||
Table 4. Comparison of forecasts of dry season storminess using Equation 1 for extreme combinations of seasonal ENSO, PNA, and NAO from the historical record (red numbers) versus actual observed scenarios (blue numbers).
|
National Weather Service Melbourne, Florida 421 Croton Road Melbourne, Florida 32935 Page last modified July 24, 2005 by Bart Hagemeyer |
Disclaimer | Privacy Policy |