Northeast cities from Baltimore to New York could be in for a snowy winter, according to AccuWeather forecasters.
The weather service's winter 2012-2013 forecast calls for cold weather and large systems of moisture to converge, dumping above-average snow totals along the East Coast. The timing is expected to be in January and February.
El Nino, the global climate pattern expected to develop by the end of September, could contribute heavily, according to the forecast. It typically causes a strong southern branch of the jet stream across the country, which can often phase together with cold air and the northern branch of the jet stream around the mid-Atlantic, causing major winter storms.
If the right blocking occurs, when areas of high pressure settle over Canada or Greenland, forcing cold air down to the U.S., that can also contribute to a snowy winter. Moist systems need plenty of cold air to produce snow and not rain.