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North-east Brazil rainfall
Forecasts are produced for the north-east part of Brazil between 0° S to 10° S and east of 50° W. The wet season is between February and May with considerable year-to-year and decade-to-decade variability. The forecasts are produced using a combination of dynamical forecast models and statistical predictions and include predictions of the most likely of five rainfall categories (very wet, wet, average, dry or very dry). Each of these categories has occurred in one-fifth of past years. A long-lead forecast is normally issued in December and a final forecast is issued in February for March to May.
Important
- Long-range forecasts are unlike weather forecasts for the next few days
- Forecasts show the likelihood of a range of possible outcomes
- The most likely outcome in the forecast will not always happen
- Forecasts are for average conditions over a wide region and time period
- For more details on interpretation, see How to use our long-range predictions
Forecast
Our latest forecast for the 2013 north-east Brazil wet season weakly favours below average rainfall over above average rainfall. For detailed information, see
our latest forecast
(PDF, 569 kB)
.
Verification
The final forecast for the 2012 wet season correctly favoured below-average rainfall over the whole region. For more details, see
2012 forecast
(PDF, 1 MB)
.
The table below compares observed outcomes with our past February-issued forecasts for one typical region. Overall, the correlation between the predicted and observed category is 0.63, which is significantly skilful at the 95% level of statistical confidence.
| Year | Forecast category | Observed category |
|---|---|---|
| 1987 | Very Dry | Very Dry |
| 1988 | Very Wet | Wet |
| 1989 | Very Wet | Very Wet |
| 1990 | Dry or Average | Dry |
| 1991 | Wet | Wet |
| 1992 | Dry or Very Dry | Very Dry |
| 1993 | Dry | Very Dry |
| 1994 | Very Wet | Wet |
| 1995 | Wet | Very Wet |
| 1996 | Dry or Average | Wet |
| 1997 | Forecast not issued | Average |
| 1998 | Wet | Very Dry |
| 1999 | Wet | Average |
| 2000 | Wet | Average |
| 2001 | Average | Dry |
| 2002 | Dry | Dry |
| 2003 | Very Dry | Average |
| 2004 | Wet | Very Dry |
| 2005 | Average | Dry |
| 2006 | Average | Average |
| 2007 | Dry or Average | Very Dry |
| 2008 | Average | Wet |
| 2009 | Very Wet | Very Wet |
| 2010 | Dry | Very Dry |
| 2011 | Very Wet | Average |
| 2012 | Very Dry | Very Dry |
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