2015-16 Winter Forecast

in Breaking News, General, Winter Weather

Early 2015-16 Winter Forecast: A Regional Breakdown

Each July, I release an early winter forecast that is based off of the research that I have done over the previous few months. When reading this forecast, you need to keep a few things in mind. First, it’s July, so things can and likely will change between now and this winter. Also keep in mind that you may not experience the same weather conditions for three months non-stop. It’s not uncommon to experience a month of warmer conditions but the overall winter be cold or vice versa. This previous winter is a great example of that. The weather is constantly changing, and my goal in this early forecast is to give you a look at the big, overall picture. I’ll be getting into the specifics of each individual month in my final winter forecast in November.

I am changing things up a bit this year to accommodate to two groups, those who simply want to know WHAT is going to happen this winter and those who want to know the WHY behind the forecast. In this post, I simply want to provide you with a region-by-region breakdown of what I believe could occur this winter, and while I’ll be getting into some of the research behind the forecast, I’m going to save most of that for next Sunday, July 26th. I have expressed on social media and in my newsletter why this winter is going to be more difficult to nail down than the last two, and I will eventually be expounding upon that. By putting out the forecast in two parts, I will be making more of my research available to those who are interested in breaking it down further.

Firsthand Weather’s Early 2015-16 Winter Forecast:

2015-16 Winter Forecast

Early 2015-16 Winter Forecast Discussion:

An El Niño continues to develop across the central and eastern Pacific and is expected to strengthen through the fall and remain in place through the winter months. An El Niño can have major effects on the overall pattern during the United States winter and often brings cooler and wetter conditions from California to Texas into the Southeast/along parts of the East Coast, while the northern half of the country gets warmer conditions with less precipitation and snow. However, I strongly feel that despite the strength of this El Nino that is already breaking modern records, the future state of the warm pool in the northeast Pacific over the Gulf of Alaska is going to have to be taken into consideration, unless it weakens significantly between now and this winter.

Our previous two winters have been driven by the anomalously warmer waters over the northeast Pacific, which caused ridging to strengthen over the western U.S., bringing with it record warmth and dry weather. In response, this forced a trough to dig into the eastern half of the U.S, bringing with it record cold and snow/ice. If you look at the past two winters, the 2014-15 winter was a near repeat of the 2013-14, except the ridge was farther east last winter, which in return shifted the trough farther east.

Despite the strength of this El Niño, it will likely begin to weaken some through the winter, especially since it began to develop/strengthen much earlier than most other El Niños typically do. That doesn’t mean that it won’t be moderate to strong this winter, but it’s a point that must be noted. Also, it’s worth pointing out that the northeast Pacific warm pool does have the capability to override about any climate signal that may influence the overall pattern in the U.S., even El Nino to an extent. It’s very common to have neutral to warmer waters in the northeastern Pacific and along the West Coast horseshoe around cooler waters just to the west during an El Nino winter, but the extent of the warmth currently across the Pacific basin is unprecedented.

As this El Niño continues to evolve, the northeast Pacific warm pool will likely break down some from the west. While I currently believe that El Niño conditions will have a profound effect on sensible weather across the United States this winter, the current projections for the strength of this El Niño are likely way overdone, although it could eventually get close to or maybe even reach the strength that the 1982-83 and 1997-98 El Niños reached.

Again, I’ll get into the detailed meteorology behind this forecast next Sunday and provide you with all of my research. I’m trying to keep things much simpler in this initial release.

A Region-By-Region Breakdown:

The official early winter forecast map is divided into regions and includes a number for each zone. Simply find the number on the map for your area, and go to your region below.

Region 1) This zone is looking at another dry and warmer than average winter, although wetter conditions could creep up farther north along the coast early on in the winter. During El Niño winters, the more active Pacific jet stream typically stays a bit farther to the south, but there are definitely exceptions to that rule.

Much of Idaho into western Montana should remain particularly dry and warmer. Overall snowfall amounts will likely be below average, especially the farther east one goes in this zone.

Region 2) Finally, California and parts of the Southwest may get some beneficial rain this winter, but let me warn you that I am skeptical at this point. This strengthening El Niño is very impressive so far but so is the warmer waters that currently extend northward along the West Coast into the Gulf of Alaska. One may initially suspect that that could enhance the amount of moisture reaching the coast, and while that may be the case this winter, it also must be noted that the extension of the Pacific jet stream farther east is what brings an increased number of systems into California. If the temperature difference between the warmer, equatorial Pacific waters and the cooler waters farther north is less, then this may shift the jet stream farther north or not extend it as far east.

Right now, I feel that much of this area will receive beneficial rains, but there are uncertainties. I’m predicting slightly above average temperatures for this zone, despite an increased chance of precipitation. As I continue to watch everything over these next few months, I’ll adjust temperatures as needed in my final winter forecast.

Region 3) This zone should get average to slightly above average precipitation with temperatures that will probably be a little bit above average. Even with above average temperatures, snow should be at or above average by the end of the winter, particularly in the mountainous regions.

The area that could end up with closer to average temperatures will be into parts of New Mexico and Arizona, although that is a bit of a wildcard at this point.

Region 4) This zone should end up with well-above temperatures and less snow overall. Let me remind you that this forecast covers a 3-month period, so that does not mean that there won’t be any Arctic intrusions at all in this region. During many El Niño years, the northern jet stream usually stays north of this region, keeping most of the truly Arctic air farther north. Even though I do expect the overall pattern not be nearly as zonal (a west to east flow) as some of the stronger El Niño years in the past, it seems that most of the Arctic intrusions will occur east of this zone.

Some bigger Arctic intrusions could occur later in the winter, especially closer to Great Lakes region. The bigger cities such as Chicago and the Twin Cities should end up with lower than average snowfall.

Region 5) Somebody always ends up in what I refer to as the “in-between” zone, and this year, that region happens to extend from parts of the Plains/Mississippi Valley and into the Great Lakes. Generally, I expect most of this region to have above average temperatures earlier in the winter, but later in the winter could be a different story.

The part of this zone that will likely have the highest chance of getting average to above average snowfall will be across parts of Kansas and Missouri. The rest of this zone may end up with drier than average conditions throughout much of the winter; therefore snowfall could be below average.

Region 6) If you’re familiar at all with what a lot of strong El Niño winters usually look like, you may be wondering why I have this entire region as being cold with typical snow. As I explained above, the very warm waters in the northeast Pacific have not dissipated, and even though we have plenty of time for it to break down from the west, it still could be there in some form by this winter. These warmer waters do have the ability to affect the overall long-wave pattern in the U.S., and as we saw the last two winters, it can create a wavy and amplified jet stream, pushing Arctic air south into this region.

While it’s difficult to say just how cold this region will be at this point, I do believe that several intrusions of Arctic air are possible. I don’t expect snowfall to be nearly as high as last year in places like Boston but decent snowfall totals should occur for many of these regions. Conditions should be drier overall in the Ohio Valley, but the amount of snowfall that the area gets this winter is still a bit of a wildcard. I should have a lot more information in the fall for this region as there are still some fairly sizable uncertainties.

Region 7) This is the zone that you’re going to want to be under if you prefer a variety of wintry weather, however there are some uncertainties that I’ll need to explain. During the majority of most moderate to strong El Niños, the southern jet stream (the sub-tropical jet) becomes much more active and transports more moisture into Texas and eastward into the Southeast/along parts of the East Coast. The big wildcard usually becomes how much cold, Arctic air will be available.

With that said, some of the most remarkable winter events in this zone have occurred when the temperatures overall for the entire winter were just marginal. I’m really leaning towards this being a colder than average winter across much of this zone with those chances increasing the farther east one is. El Niños usually bring about cooler than average conditions across this area during the winter because of more precipitation and clouds, but I do believe some major intrusions of Arctic air could push into this area, especially later in the winter. I will further expound upon my reasoning next Sunday, but the overview discussion at the beginning of this article give you a basic idea of my reasoning.

The ice storm threat will be greater for the southern regions in this zone including places like Atlanta and Birmingham, and almost all of these areas have a decent shot at getting above average snowfall. In fact, some locations in this zone (not all) could end up with well above average snowfall. As always, not everyone in this zone will get the snow they want, but the chances are once again higher than average for a more active winter.

Region 8) This zone has a pretty good shot at getting above average precipitation due to an active and more southern storm track (jet stream) that will likely set up, bringing storm systems and moisture into the region. Due to this likely increase in storminess and cloud-cover, temperatures will probably be below average overall.

The big question becomes whether or not temperatures will be sufficiently cold enough for some of the more northern areas of this zone to get a shot at a winter storm. The chances could be higher for that to occur this winter but far from guaranteed. The 2009-10 El Nino winter was pretty great for some of these areas due to the high amount of blocking that built over the Arctic and Greenland, which displaced Arctic air into the Deep South. Some of you saw snow for the first time in years as a result!

Florida and areas along the Gulf Coast beach could have a heightened threat of severe weather throughout the winter, and the highest impact zones will depend on the dominant storm track this winter.

Concluding Thoughts:

I do expect the El Niño to continue to strengthen through the fall, although not as much as what the forecast models are currently projecting. I also believe that the warmer waters in the northeast Pacific and along the West Coast need to continue to be monitored closely, as that could have a major influence on the pattern this winter across the U.S. For those that are interested in further study, I encourage you to look at the El Niño winters that actually had cooler waters in the northeast Pacific and along the West Coast (a -PDO), which is the exact opposite of what is likely going to be in place this upcoming winter. A cold PDO during an El Nino winter is actually quite rare, but it shows you how the waters in that region can have a big influence on the U.S. pattern, despite an El Nino being in place. I have always found it helpful to study the opposite scenario in order to make good comparisons.

December could end up being warmer for most of the United States with a flip to a much colder pattern in January and February in the eastern U.S. Even with a warmer December, that doesn’t mean an inactive pattern with very little snow or ice for that month, but the most notable part of winter will likely be in January and February. Of course, that’s subject to change.

I didn’t really discuss what’s currently going on in the Atlantic and how that could influence this upcoming winter, but I will next Sunday. Predicting if there will be blocking over Greenland (a -NAO) is difficult, if not impossible, this far in advance. I will try to show you what could happen though.

It has been more difficult this year to find previous winters that are similar to what could occur this upcoming winter. I have particularly been studying the 1957-58, 1986-87, and 2002-03 winters, but be careful not to just combine all of those together and expect that to be what happens next winter. I usually talk about a lot of the research that I do in my newsletter, which I encourage you to sign up for by clicking here. I also update Facebook and Twitter daily.

Thanks for taking the time to read this early winter forecast, and don’t forget to check out the very in-depth discussion on this winter that will be coming out next Sunday (July 26th). It will be a pretty heavy read, but nothing that you can’t handle! See you there.