Winter 2015-2016 Forecast


The time has come to issue the forecast for the winter of 2015-2016 ! It is now mid November and there going to be a lot of moving parts as we head into the winter months, between a moderate to strong El Nino, above normal snow pack to our north and along with many other things

ENSO: El Nino Phase

Going to start with the El Nino that began developing later last winter and has now peaked at rather strong levels, this strong El Nino with the warmest anomalies focused towards regions 1+2 lead to a very warm , humid and drier than normal summer, the El Nino peaked a few weeks ago and its effects are lingering leading to a much warmer than normal November.

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If the warmest waters were staying in place, in regions 1+2 the winter forecast would be a rather simple one as it would likely be the main driver of the pattern with continued warmth in the east but just perhaps with increased storminess and wet weather for the region

However the warmest anomalies are shifting westward towards the Central and Western Regions, which changes the ball game completely, especially with slow and eventually steady weakening expected as well

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There is strong agreement of steady weakening of the El Nino to more moderate levels by the 2nd half of winter, a shift westward of the warmest waters towards regions 3.4 and 4 will likely amp up the sub tropical jet stream, which has begun over the past few weeks bringing frequent storms to the southern US, this trend will likely continue over the coming weeks and months and it is likely the eastern US including Midwest and Great Lakes will experience a very stormy and active winter, an active Sub tropical jet stream especially when interaction with the polar jet occurs will lead to stronger storms and moisture loaded storms, something that lacked the past few winters as they were cold and snowy but snow came in more moderate bursts rather than big storms, this is more supportive of big storms like Noreasters and just strong storms in general, likely tracking between the Great Lakes and the coast.

However the El Nino is still strong and still mostly east based and I expect the effects to linger for at least several more weeks to as much as a month and a half before these shifts have ay true effect on the weather pattern , as this will likely overwhelm the weather pattern and shut out many other factors for a while to come

Northern Hemisphere Snow Pack

One big factor that may also hinder the effects of the El Nino is snowpack over the Northern Hemisphere

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Snow pack is running above normal over the northern hemisphere, and specifically towards Siberia and NW Canada, above normal autumn snow pack in these regions has strong correlation of bringing cold winter the Central and Eastern US as very strong arctic air masses are able to develop and drop southward, the snow pack is at similar levels to the past 2 winters but maybe just a tad less

Pacific/Eastern Pacific Oscillation

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Warmer than normal waters prevail over the North and east Pacific, this was a big factor that drove the past few winters and looks to be a factor that drives this winter as well, this warmer than normal water usually lead to ridging in the East Pacific and Western US , and also a trough near the Aleutian islands, an alignment like this will typically lead to a trough and thus dominant Northwest flow over the eastern US , which is why the snow pack up north is so important because this alignment can lead to those arctic air masses that develop due to above normal snowpack to be transported southeastward towards the Central and East US

These effects I believe will have much more impact towards the second half of winter once the el Nino shifts west and weakens

Atlantic Influence

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Here are current global SST anomalies, there are 2 important factors in the Atlantic, the very warm waters along the eastern seaboard and the split of colder than normal waters and warmer than normal waters around Greenland

The anomalies around Greenland along with the influences from the North Pacific lead to increased chances of blocking and a negative NAO , and the warmer than normal waters up and down the east coast could support rapidly developing storm systems that track up the coast, a negative NAO block would essentially block storms from exiting quickly but instead linger and have more time to intensify and impact the area for prolonged periods, both factors would also lead to increased chances of strong and moisture loaded storm systems impacting the area this winter, the warm waters especially in January and when storms hug the coast could lead to warm air flooding the coastal plain with more sloppy and mixed storms depending on exact storm track

Winter 2015-2016 Summary

This forecast will cover the period from December 1st through March 22nd

December 2015

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I expect the month of December for the most part to be dominantly influenced by the lingering effects of the strong El Nino, increased storminess will prevail over the eastern US but I expect a dominant storm track towards between the Appalachians and the Great Lakes, which will mostly bring warmth and rainy conditions to the area, transient cold shots and troughs could lead to chances for coastal systems but these will be few and far between and most wintry precipitation will be focused over the interior Northeast, the enhanced sub tropical jet will bring frequent storms to the south and eastern half of the nation with the center of this months cold and snow towards the Rockies and portions of the mid West

January 2016

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January I expect to be the transition month, this is when El Nino’s weakening and west shift will begin to truly impact the pattern, leading to a -EPO , ridging out west and a trough shifting eastward, the month could stsrt warm and wet in the east then turn colder and more wintry by the 2nd half, the shift in the pattern may lead to warmer than normal and drier than normal conditions taking over parts of the western US although a continued active sub tropical jet should bring storminess to the southwest, I expect the dominant storm track to shift eastward and track from the Southern Plains or Gulf coast up the eastern seaboard, the warmer than normal waters could lead to sloppy storms for much of the area, especially those systems that hug the coast, I expect that the bulk of the snow this month will be focused over the interior while its more sloppy yet still wintry along the coastal plain, some big snowfalls are possible especially towards the interior northeast. Cold and stormy conditions over the Southern Plains could lead to above normal wintry precipitation and above normal rainfall over the Southeast

February 2016

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I expect the bulk of our winter to come in February, a deep trough in the east, ridging out west and a continued active sub tropical jet stream, the dominant storm track from the Gulf coast up the eastern seaboard and frequent arctic cold shots, this will be the best month to see big noreasters and coastal storms, along with the best shot to see big snowfalls for the east coast, warm and dry conditions previal towards the West except for the southwest. Cold and stormy conditions also continue over the Southern Plains and Southeast where above normal wintry precipitation is expected

March 2016

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The pattern in March will naturally begin to moderate, but I still expect a colder than normal and stormy month for the south and east and portions of the Midwest with above normal precipitation and above normal snowfall, the west will continue to be warm and things will begin to dry out over the Southwest as El Nino reaches weak levels

Winter 2015-2016 Summary For Our Region

Since my forecast area is specifically for NY, NJ, PA CT, DE and MD , here is a summary for the whole winter for our area

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