Rain is on the way for the last day of 2018. Partial sunshine this morning will give way to clouds and rain by later this afternoon. The rain could be heavy by the time the ball drops. As far as temperatures go, we will be all over the place the next 48 hours. This morning the thermometer is sitting in the 20s and 30s. By this afternoon it will reach the low and mid 40s, and then approach 50° by midnight – quite the opposite of last years record cold ball drop! This rain storm is bringing up milder air from the south, and we will tap into that as a warm front lifts north into tonight. Tomorrow morning we will see our daily high temperatures, rather than the normal low temperatures at that time. The day will start off well into the 50s, before falling into the 40s by afternoon and 30s by evening.

We do remain dry for the first few days of the new year. Our next chance for any precip will come on Friday in the form of some chilly rain. The models are in a fairly good agreement of this, though a few have tried to keep the system to the south.

Speaking of the models, they have not been good so far this season. I wanted to go a little bit into why that is. To make a long story short, things are a little out of whack in the atmosphere. The stratosphere is undergoing a major warming trend, and thus the polar vortex has been split in three. This is throwing things off.

Take the Madden–Julian Oscillation. MJO is the largest element of the intraseasonal (30–90 days) variability in the tropical atmosphere. It is a large-scale coupling between atmospheric circulation and tropical deep convection. Rather than being a standing pattern like El Nino, it is a traveling pattern, propagating eastwards through the atmosphere above the warm parts of the Indian and Pacific oceans. This overall circulation pattern manifests itself in various ways, most clearly as anomalous rainfall. Look at how different the MJO forecast is between the ECMF (European) and the GEFS (Global Ensemble Forecast System) models:

This is going to make long range forecasting much more difficult over the rest of the winter. Something else that will make this more difficult? The government shutdown. This is what you get when you try to access the current teleconnections:

Unfortunately, this has been deemed a “non-essential” part of NOAA and will be unavailable as long as the shutdown lasts. With that being said, I will refer back to the last time we were able to access these.

While the NAO was forecast to be rather neutral, PNA was heading highly positive while WPO and EPO trend in the opposite direction by late in the first week of January. This would lead you to believe we may have a shot at something into the second week of 2019. For the first week, aside from an occasional cold day, temperatures look to be mainly above average. And for you powder lovers that were disappointed by a quiet December, keep in mind that December is typically a very quiet snow-wise.

According to Josh Timlin, this is the third time Islip has been blanked in December in the last 9 years. The other two years were 2011 and 2015. Snow totals for those seasons? 2011-12: 4.7″ 2015-16: 41.4″.
Another way to look at this is there have only been 5 December days in the past 9 years where more than 1″ of snow fell, so perhaps those who are disappointed this early in the season are expecting too much from December? While I still believe we will come on strong and finish above normal, this goes to show you that December is not exactly a tell-tale sign of what the rest of the winter has in store. –Geoff


2018 was warm and wet. After coming up 2.68″ short of normal in 2017, this year was a whopping 16.79″ above normal. And we aren’t done yet! We may pickup another inch or so tonight before the clock strikes midnight. The all-time wettest year on record for Islip is 64.57″ in 1989. Right now, we have 62.91″ for the year. If we can get 1.67″ before the day is through, we will set a new record! The monthly mean temperatures were cumulatively 17.6° above normal.

From all of us here at Weather Long Island, I would like to wish you and yours a very happy, healthy, and safe New Year. Thank you for following us throughout the year. We hope that our insightful and [usually] accurate forecasts have been useful. Let’s make 2019 great!

Make sure to follow Meteorologists Geoff Bansen and Joe Cioffi on social media!
Geoff: Facebook Twitter Instagram                        Joe: Facebook Twitter Instagram

And don’t forget to bookmark weatherlongisland.com!