Physical Basis For The Winter 01-02 Forecast. OPIS 2000 National Supply Summit. Recent Winter Temperature Anomalies (DJFM). El Nino 97/98. Average of La Nina 98/99. and 99/00. ENSO Neutral Winters. Decade of the 1990’s. Degrees Celsius. El Nino Southern Oscillation Phenomena.
El Nino 97/98
La Nina 98/99
ENSO Neutral Winters
Decade of the 1990’s
High Index Phase
Low Index Phase
AO Index (JFM 1950-1999)
Global Temperatures the Past Three Years Were Primarily a Result of ENSO and the Underlying Warm Trend
Of Climate Variability This Winter
Implications for Winter Forecast:
Seasonal Forecasts are referenced to a 1961-1990 base period, i.e. a relatively cool period
This graphic will be updated with
the forecast issued Oct 12, 2000
Probability forecasts indicate changes in the likelihood of the favored category (i.e. above normal, normal, below normal). For example a value of “20” needs to be added to 33% (climatological odds) to arrive at the forecast odds of 53% change of being above normal.
Forecasts are relative to the 1961-1990 climatology.
“CL” indicates the forecast tools give no guidance, i.e. be prepared.
Class limits for standardized anomalies *100: upper 33% (45)
upper 20% (85)