November 2003 - With the recent events of drought in the Annapolis Valley of Nova Scotia, heavy precipitation events in Newfoundland-Labrador and a major landfall hurricane in Nova Scotia and PEI, extreme weather has been "top-of-mind" for most Atlantic Canadians over the past several years.

The most frequent question from the general public regarding these events is… "Is extreme weather becoming more frequent?". There are indications from several sources of weather and climate information that such is the case. Insurance firms such as Re-Munich track extreme events world-wide and have analyzed an upward trend in weather-related disasters. Usually the very next question that is posed is, "Is this climate change?". From the climate data available and utilizing sophisticated climate system models, we can determine that extreme events such as frequent drought and local severe storms are increasing and are projected to increase throughout the next century. This does not mean, however, that an individual event can be identified as uniquely triggered by climate change/global warming.

Since climate has a contributing natural variability that adds to intensification of storms such as Hurricane Juan, we cannot say, with scientific certainty, that Hurricane Juan was a unique "climate change" storm.

Nonetheless, future tropical events are projected to be more intense with climate change. In the case of Hurricane Juan the ocean temperatures south of Nova Scotia were much warmer than normal. We believe that such an energy source maintained Hurricane Juan's strength, causing it to impact Halifax to a much more severe degree than normal. Projections of global warming include a warming ocean and hence indicate that such a source of energy will continue to intensify tropical features such as Hurricane Juan far beyond a level that has been seen historically.

El Nino - La Nina Update

Equatorial surface and subsurface temperatures were warmer than average throughout most of the Pacific during the month of October. SST anomalies greater than +0.5°C (~1°F) were observed in most areas along the equator between Indonesia and the South American coast. However there is no current indication in the ocean models that a trend toward El Nino formation is occurring. Thus, it is likely that borderline El Niño/ La Nina (neutral) conditions will continue to persist in the equatorial Pacific through the Northern Hemisphere winter of 2003-04.

Typically this means that winter temperatures may be slightly above normal in the western half of the continent while slightly above normal precipitation may occur over northern portions of the west coast during the winter season.