We are launching SWCT/NY for the upcoming 2015-2016 winter season, officially activating the site. The delayed release is due primarily to a lack of winter weather conditions across the region, something that is expected to continue for the next few weeks. Premium subscribers received most of the below winter forecast on November 2nd, which prepared them for the conditions that have occurred thus far through the winter. The forecast has been slightly tweaked to account for the latest trends, but generally it remains the same as it has verified very well thus far and remains on track moving through December. For those interested in subscribing for our Premium membership, which includes email updates daily or every other day detailing forecasts and the latest weather expectations across the SWCT/NY region along with school closure/delay percentages during storms and live updates during major weather events, you may subscribe here.
Winter Total Snowfall Expectations for SWCT/NY
Chances of Snowfall <25% of Average: 10%
Chances of Snowfall <50% of Average: 30%
Chances of Snowfall <75% of Average: 50%
Chances of Snowfall <100% of Average: 60%
Changes of Snowfall <150% of Average: 80%
Chances of Snowfall <200% of Average: 90%
Chances of Snowfall >200% of Average: 10%
Winter Average Temperature Expectations
Chances November-March temperatures more than 1 degree above average: 50%
Chances of November-March temperature within 1 degree of average: 35%
Chances of November-March temperatures more than 1 degree below average: 15%
Winter Forecast Summary: A dominant El Nino pattern should ensure that winter weather threats will be more sloppy than white for the SWCT/NY region to start the year. In years with strong El Ninos we tend to see a positive Pacific North American Pattern combine with a strong positive Arctic Oscillation to allow some storm tracks to move near the East Coast but have relatively limited colder air. This means that precipitation is generally near to above average, but so is temperature, limiting overall snowfall but potentially increasing the amount of impacts brought by winter weather.
For this reason, the forecast is for the number of snow days and delays at schools and public institutions to be around to slightly above average. Impacts are more likely inland, where cold air damming and higher latitude should allow for more mixed precipitation in sloppy storms. However, even down to the coast freezing rain/sleet events could allow for more widespread impacts later in the winter season even if snowfall totals are not all that impressive.
November (issued November 2nd, verified well)
All indications are that November is likely to be warmer than average, as a strong southeastern ridge allows warmer air to flow up across the East Coast. There are no signs of any major winter weather threats or major troughs swinging through. As the month comes to an end, we may see some light snow threats with any weak Alberta Clippers inland, but I would be surprised to see any winter weather impacts before Thanksgiving.
December (issued November 2nd)
All indications are that December this winter is likely to be similar to December last year. The El Nino looks to be peaking in strength in the coming month, allowing it to dominate the pattern through December. This should put a strong upper level low south of Alaska, driving moisture into Southern California and keeping much of the US relatively mild. Through the month, there may be a few winter weather threats, but they will generally be few and far between, with rain being relatively more consistent. It is my expectation that there are some sleet/freezing rain concerns inland, and maybe even snow, but that is more likely later in the month, with the first half of the month having only one winter weather threat if really anything at all.
January (updated December 8th)
El Nino conditions are likely to be raging at the beginning of the month, but there are questions around how quickly the El Nino decays moving through the winter, and whether the positive Pacific Decadal Oscillation and Quasi Biennial Oscillation will counteract some of the pattern drivers typically instituted by a positive ENSO cycle. Recent indications are that the El Nino peaked late in December, opening up the potential for the El Nino-driven pattern to break down late in January. This could lead to colder weather and more winter weather threats through the month. The expectation is this is the month that could hold the most sloppy weather events, and potentially the most lasting winter weather impacts (school/road closures, etc.). Ice storms tend to bring larger impacts than snow storms, though figuring out exactly what/where the impacts will be can be the most difficult. Confidence is lowest in this month, as even though snowfall is likely to be below average school closures/delays could be around to above average. Temperatures will likely be around to slightly above average.
February (updated December 8th)
As was the case last year, this is the month that I am seeing the most chance to hold larger snow events. The El Nino should allow the Gulf Stream to remain active and quite warm, and the entire western Atlantic should be poised with more energy than normal. Similarly, as the El Nino breaks down, the positive PDO/QBO could work to amplify the flow and increase the chances of more sizable cold outbreaks across the East. Temperatures are likely to be around to slightly below average, though they could deviate further below average depending on how quickly the El Nino breaks down and what other pattern drivers are looking to be dominating at that time of year. All analogs point to this as the month that should hold the most snowfall and sustained colder weather.
March (updated December 8th)
This month will be the largest wildcard of the winter, and again will come down to how much the El Nino has broken down, if it looks like a La Nina may be coming on late in the summer into the following fall/winter, etc. This month is almost always a wildcard, being notoriously difficult to forecast, but the bias here would also be towards more winter weather. Indications are that the El Nino is finally decaying, as if it did not this month could be mild primarily with rain threats (especially along the coast). However, with the El Nino finally beginning to weaken we could again see that sloppy freezing rain/sleet/snow storm threat lingering into the month, with some of the cold from February maybe carrying over into march. This is the month that may make or break the seasonal numbers; a very snowy or active March could allow total snowfall to get to or slightly above seasonal averages, though a mild or wet March could keep us at above average temperatures and/or below average snowfall through the season. El Ninos typically result in winter arriving late but sticking around a little longer assuming they decay in line with expectations, and accordingly we would expect at least some level of winter weather to linger through March.
Conclusion: This winter forecast will continue to be evaluated through the coming weeks as fresh data comes in and new trends are observed. Public notes and blogs will be posted as necessary, though more consistent updates to the long-range forecast and overall winter expectations will be posted for Premium members alongside their consistent email updates. The release of this public forecast does signify the activation of the Free site, however, and accordingly you may expect more consistent updates on any winter weather threats and daily updates to the 5-day forecast on this site alongside consistent Twitter updates. Please be sure to stay tuned for the latest.