Weatheroffice
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Monthly and Seasonal Forecasts
As of December 1st 2011, the seasonal forecast system has been upgraded.
The new system is based on 10-member ensembles of predictions made with two coupled atmosphere-ocean-land physical climate models, and produces predictions at all time ranges.
Monthly "30 Days"
Seasonal "3 Months"
- Temperature and Precipitation Deterministic Forecasts
- Temperature and Precipitation Probabilistic Forecasts
- Skill of the Deterministic Forecast System
- Verification of Past Forecasts
- Climatology of Temperature and Precipitation
- Current Sea surface temperature anomalies, snow and ice
- On-line Model Data
- Information on El Niño and La Niña
- Environment Canada climate trends and variations bulletin
Temperature and Precipitation Deterministic Forecasts
| Period | 1-3 month | 2-4 month | 4-6 month | 7-9 month | 10-12 month |
|---|---|---|---|---|---|
| Temperature | Map|List | Map|List | Map|List | Map|List | Map|List |
| Precipitation | Map|List | Map|List | Map|List | Map|List | Map|List |
| Period | 1-3 month | 2-4 month | 4-6 month | 7-9 month | 10-12 month |
|---|---|---|---|---|---|
| Temperature | Map|List | Map|List | Map|List | Map|List | Map|List |
| Precipitation | Map|List | Map|List | Map|List | Map|List | Map|List |
| Period | 1-3 month | 2-4 month | 4-6 month | 7-9 month | 10-12 month |
|---|---|---|---|---|---|
| Temperature | Map|List | Map|List | Map|List | Map|List | Map|List |
| Precipitation | Map|List | Map|List | Map|List | Map|List | Map|List |
What do these maps represent ?
The upper panel shows the seasonal air temperature or precipitation anomaly
forecasts. The forecast are presented in 3 categories: below normal, near normal and above normal. The lower panel illustrates the skill (percent correct) associated to the forecast.The forecast values for
more than 100 locations in Canada are also shown at the "List" links.
Please take into account the skill map (lower panel) when you use the
forecast map (upper panel). To use the forecasts optimally it is strongly recommended to read carefully the user guide.
How are these forecasts produced ?
The forecasts are based on the average of 10-member ensembles of forecasts produced with each of two coupled atmosphere-ocean-land physical climate models. (Before December 1st, 2011 4 atmospheric models forced with persisted sea-surface temperature anomalies were used to produce 1-3 month and 2-4 month forecasts, while at longer forecast times forecasts were produced using a statistical model.)
Temperature and Precipitation Probabilistic Forecasts
| Period | 1-3 month | 2-4 month |
|---|---|---|
| Temperature | Maps| Reliability | Maps|Reliability |
| Precipitation | Maps| Reliability | Maps|Reliability |
| Period | 1-3 month | 2-4 month |
|---|---|---|
| Temperature | Maps| Reliability | Maps|Reliability |
| Precipitation | Maps| Reliability | Maps|Reliability |
| Period | 1-3 month | 2-4 month |
|---|---|---|
| Temperature | Maps| Reliability | Maps|Reliability |
| Precipitation | Maps| Reliability | Maps|Reliability |
What do these maps represent ?
The probability of being below, near or above the normal are shown for the temperature and precipitation. The probabilities are the result of a simple member counting and therefore they are not calibrated. However, a reliability diagram can be used to calibrate the probabilities based on verification of past performance (see the links "Reliability" for temperature and precipitation above).
To use the forecasts optimally it is strongly recommended to read carefully the user guide!
How are these forecasts produced?
The seasonal forecasts are based on a 20-member ensemble of predictions, 10 members from each of two coupled atmosphere-ocean-land physical climate models. The forecast probabilities are estimated by counting the number of individual members in each of the three categories at every location and then dividing by the ensemble size (see computation of probabilistic forecast).
(Before December 1st, 2011, 4 atmospheric models forced with persisted sea-surface temperature anomalies were used to produce 1-3 month and 2-4 month probabilistic forecasts.)
Skill of the Deterministic Forecast System
What do these maps represent ?
By clicking on the above links, you can see the spatial skill distribution
of the forecast system. The colored areas show that the system is
better than pure chance forecast while the grey areas indicate the
areas where the current forecast system has no predictive skill. Please read the page on Long-Range Forecast Skill Maps before doing further interpretation of the maps.
Verification of Past Forecasts
Using this menu, you can see the previous 1-3 month forecast charts produced by Environment Canada since 1996 and the corresponding observed charts. The scores (from the contingency tables) obtained with these forecasts are also available. To see your selection please click the view button.
Climatology of Temperature and Precipitation
What do these maps represent ?
By clicking on the links under "Average" you can see a map of mean observed value of temperature (in degrees Celsius) or precipitation accumulation (in millimetre or mm) for the corresponding season. The Canadian surface stations data used cover the 1981-2010 period for both the temperature and the precipitation.
The links under "Threshold" present maps of the value used as a threshold to classify the observed anomaly in one of the three categories (above, near or below normal). The climatology and threshold values for more than 100 locations in Canada are also shown at the links under "Table". The 1981-2010 climatology is now the reference climatology. Before 1 December 2011 a 1971-2000 climatology was used.
Composite analysis of Continental Snow Coverage, Sea Ice Coverage, and Sea Surface Temperature Anomalies
Static Images : daily and the 30-Day average
Animations (JavaScript Required)
One-year animation of SST Anomalies, Snow Coverage, and Sea Ice Coverage (Pacific Ocean and the Americas). This animation is well suited to observing the ENSO SST Anomaly phenomenon during El-Niño/La Niña years. It also displays the yearly cycle of snow coverage over the northern landmasses.
30-day animation of SST anomalies, Snow Coverage, and Sea Ice Coverage (North America). One can observe the progression or retreat of the snow coverage over North America during the past month.
The climate of Canada is mainly influenced by the sea surface temperature and the sea ice extent of the surrounding seas as well as by the snow cover. Using the above links, you can have access to maps of the current state of these fields as analysed by the CMC. You can also look at some animations to follow the evolution of the conditions during the last months.
On-line Model Data
The fields forecast by the coupled prediction models are available in real time (first day of each month) on the web site of the Canadian Center for Climate Modeling and Analysis. On this site you can also find historical forecasts for 1979-2010 produced by the coupled prediction models for phase 2 of the Coupled Historical Forecasting Project (CHFP2). The model climatologies used to calculate the forecast anomalies and to draw the skill maps are obtained from the 1981-2010 CHFP2 historical forecasts.
Environment Canada El Niño and La Niña pages
The ENSO phenomenon (El Niño and La Niña) is one of the major factors influencing the year to year fluctuations of seasonal temperature and precipitation anomalies in Canada. You can learn more about the worldwide and regional effects of the phenomena as well as follow its evolution by going to the Environment Canada web pages listed above.
Environment Canada Climate Trends and Variations Bulletin
For a review of past conditions of temperature and précipitation, you are invited to look at official trends and variations bulletin of Environment Canada.
Global long range forecast products for WMO
To view the list of global products provided by MSC to World Meteorological Organisation (WMO) users or for any information related to these products you are invited to look at the GPC Montreal web page.