NOAA Says Winter Severity Depends On A Wild Card Factor
New Jersey's winter may be influenced by, "La Nina" in the Pacific. But a "wild card" may trump La Nina, according to the winter outlook from the National Oceanic and Atmospheric Administration.
Here's how it may roll this winter...'La Nina' usually helps the jet stream keep colder air up in Canada and away from Jersey. But NOAA's Mike Halpert says another factor, air pressure variations from north to south, may change La Nina's effect. He says that is really going to be dependent on what he terms, "our favorite wild card", "Arctic oscilation".
Dave Robinson, the State Climatologist at Rutgers, says that oscilation is an atmospheric phenomenon that is unpredictable this far ahead. He says they cannot tell you what that atmospheric signal is going to be in December, January and February.
The Arctic Oscillation is always present and fluctuates between positive and negative phases. The negative phase of the Arctic Oscillation pushes cold air into the U.S. from Canada. The Arctic Oscillation went strongly negative at times the last two winters, causing outbreaks of cold and snowy conditions in the U.S. such as the "Snowmaggedon" storm of 2009. Strong Arctic Oscillation episodes typically last a few weeks and are difficult to predict more than one to two weeks in advance.
So if that Arctic oscilation works against "El Nina" this winter, all bets are off for less snow and cold.
In delivering their winter outlook, NOAA also cautions the seasonal outlook does not project where and when snowstorms may hit or provide total seasonal snowfall accumulations. Snow forecasts are dependent upon winter storms, which are generally not predictable more than a week in advance.