Weather forecasts, particularly medium-range forecasts, have recently become more accurate. The improvements are a result of changes implemented on November 16, 2011 by the Canadian Meteorological Centre to the global data assimilation system that provides the analyses needed for launching global numerical weather predictions, with lead times of up to 10 days. The largest improvements have been seen for the southern hemisphere but have been noted over Canada as well. A significant improvement in predicting jet-level winds was also noted for almost all forecast times.

The changes to the system, which resulted from many years of research, included adding a large quantity of satellite-based observations. The quantity of observations used has increased from about two million to four million per 24-hour time period, and are incorporated from an infrared hyperspectral instrument on board a European operational meteorological satellite. Preliminary tests run prior to November 16, 2011 showed that incorporating the new satellite data tended to modify the analyses mostly in areas over the oceans where there is less conventional data. A new analysis of sea surface temperature with a finer degree-resolution (on a grid of 0.2 degrees) was also added to the system.

Contacts: Godelieve Deblonde, 514-421-4774, Godelieve.Deblonde@ec.gc.ca, Meteorological Research Division | Gilles Verner, 514-421-4624, Gilles.Verner@ec.gc.ca , Prediction Development Division