At a Glance

A developing El Niño could have some notable impacts in 2019.It might be one factor influencing the rest of winter, tornadoes this spring and the Atlantic hurricane season.

2018 was a year of disastrous tropical cyclones, flooding, heat, drought and winter storms.

(2018 RECAPS: Top Weather, Climate EventsStrangest Things We Saw)

Now that we've entered the new year, you might be wondering if there's anything we can say about 2019.

While we can't forecast key details such as how many hurricanes will make a U.S. landfall, there are some broad indicators we'll have our eye on as 2019 unfolds that could influence, for instance, how many tropical storms and hurricanes form.

Let's walk through five of the key weather questions of 2019 and explain what some outlooks and recent research suggest might happen.

1. Will the Heart of Winter Be Cold and Stormy in the East?

The coldest, snowiest months of the year are January and February in much of the United States, based on long-term climatological averages.

(MORE: Snow Winners and Losers So Far)

While November and early December brought bitterly cold temperatures to many areas east of the Rockies, the persistent chill , and there are no strong signals of arctic air spilling into the U.S. through at least mid-January.

All of the Lower 48 states are forecast to be near- or above-average during the , according to NOAA’s 8- to 14-day temperature outlook issued Thursday.

Later in January or in February, however, there's a chance colder weather could return.

The latest outlook from The Weather Company, an Business, predicts the second half of winter to be colder and stormier in the

Three-month temperature outlook for January through March 2019 from The Weather Company, an Business.

(MORE: January-March 2019 Outlook)

"Everything is still on track for a notably cold, stormy late-winter period in the eastern and southern U.S., especially in February," said , chief meteorologist with The Weather Company.

A event may also help to increase probabilities of the high-latitude blocking that would favor a colder late-winter look. The is a about 6 to 30 miles above the ground – above the troposphere, where most of the weather with which you're familiar occurs.

An SSW is when the stratosphere warms sharply – , in just a few days – miles above the Earth's surface.

An SSW appeared to be during the last few days of 2018 into early January. It can take for an SSW to produce high-latitude blocking and weather impacts near the ground.

(MORE: The Polar Vortex Might Weaken Soon)

Need more convincing that it could turn colder and snowier in the heart of winter?

Major Northeast snowstorms such as nor'easters and other coastal storms have a distinct peak in , according to NOAA's National Centers for Environmental Information.

(MORE: Major Northeast Snowstorms Have a Distinct Seasonal Peak)

2. Will 2018's Tornado Lull Continue?

In one of 2018's good weather stories, no violent tornadoes – those with an EF4 or EF5 rating – were documented in the U.S. the entire year, the first year in modern records dating to 1950 that had happened.

The number of F/EF4 or stronger tornadoes by year in the U.S. since 1950. 2018 was the first year in modern records without a single such intense tornado anywhere in the U.S.

(NOAA/SPC)

Due in part to the lack of these high-end tornadoes, only 10 U.S. deaths were attributed to tornadoes in 2018, a dating to 1875.

(MORE: 2018's an Odd Year For U.S. Tornadoes)

For the most part, the jet-stream pattern was not conducive for tornado outbreaks during the typically volatile spring months, particularly in , when persistent cold dominated the central and eastern U.S.

As of mid-December, NOAA's Climate Prediction Center said , with a 60 percent chance it would persist into the spring.

When sea-surface temperatures are warmer than average in the eastern and central equatorial Pacific Ocean by at least 0.5 degrees Celsius (0.9 degrees Fahrenheit) for at least three consecutive months, along with consistent atmospheric indications, an El Niño is considered to be in place.

(HOW EL NIÑO INFLUENCES: Winter TemperaturesSeasonal Snowfall)

A number of studies have found El Niño's effect on the jet stream can influence tornadoes in parts of the U.S.

A 2015 led by John Allen from Columbia University found spring tornado activity can be suppressed in parts of the Plains during an El Niño. A 2017 by Ashton Robinson Cook from the University of Oklahoma also found a southward displacement of winter and spring tornadoes during El Niños tied to displaced jet streams and instability.

Tornadoes, and tornado outbreaks, can be highly variable year-to-year, and El Niño is just one factor in the large-scale weather pattern that could produce tornado-spawning severe thunderstorms.

So, it remains to be seen whether spring 2019 will also give parts of the typically tornado-prone U.S. another breather.

3. Will El Niño Impact the Hurricane Season?

The typical jet-stream pattern during hurricane season with an El Niño features stronger westerly high-level winds that, combined with the typical easterly winds in the tropics, lead to higher wind shear, suppressing tropical development.

Assuming an El Niño develops as forecast, one interesting facet suggested by some numerical models is the potential for the El Niño to linger not simply through spring, but possibly into the summer.

If that happens, it could have some impact on the 2019 Atlantic hurricane season.

In general, wind shear – the change in wind direction and/or speed with height – is . All other factors equal, this shear tends to in a given season.

This sounds like great news, given the back-to-back destructive and hurricane seasons.

But there are several important caveats.

Stronger-than-average wind shear was present in the Caribbean Sea in without an official El Niño, which suppressed development there, but not elsewhere in the Atlantic.Even if you get an El Niño, it matters where the warming occurs. In this case, the warming might be more in the central Pacific, south of Hawaii, rather than in the eastern equatorial Pacific. Known as , these can actually lead to less wind shear over the Atlantic Basin, and a less hostile environment for tropical storms and hurricanes.El Niño is only one of several influences on the atmospheric circulation.The number of landfalls is not correlated to the number of named storms and hurricanes. Even inactive seasons during El Niños can feature a destructive landfall; 1983's Hurricane Alicia in Texas is one example.

We'll keep our fingers crossed that this El Niño will have some suppressing influence. As always, though, you should prepare every hurricane season in case one unfortunate landfall happens.

4. Will It Be Another Terrible Wildfire Year in California?

The short answer: it's too early to know.

"Unfortunately, it is nearly impossible so far in advance to gauge how severe the 2019 fire season will be," said , regional climatologist at the Western Regional Climate Center and assistant research professor of climatology at the Desert Research Institute.

California's wet season, which runs from Nov. 1 to April 30, is one factor that can influence wildfires during the state's dry season.

"A wet winter and spring would reduce the chance of an early start to the fire season but would allow more vegetation to grow, which will actually increase fire danger later in summer and fall due to available fuel," said McEvoy.

A business burns as the so-called Camp Fire destroys the town of Paradise, California, on Nov. 8, 2018.

(Justin Sullivan/Getty Images)

(MORE: Why California's Wildfires Are Most Destructive in Fall)

It is often perceived that California experiences increased rainfall during El Niño years, but that isn't always the case, McEvoy cautioned.

"If El Niño does develop, it is not likely to be strong or even moderate in strength," he said. "A weak El Niño gives very little predictability "

This idea is summed up succinctly by , a Bay Area-based certified consulting meteorologist at Golden Gate Weather Services.

"The bottom line is that California can get wet during El Niño, but (precipitation) is ," Null wrote on ggweather.com. "As a matter of fact, the California drought in the 1976-77 winter was during a weak El Niño."

He noted that a drier winter historically, but only generally, leads to more acreage burned in California. However, even if this winter is wetter than average, many forests still have dead or diseased trees from the four-year drought from 2012 to 2015, he added.

"This, coupled with generally warmer summers, means the trendline for fires in California is tilted upward," Null said.

5. Will 2019 Set Another Global Temperature Record?

Let's end with a more certain forecast.

(NOAA)

While data from 2018 is yet to be released, NOAA's November global climate report calculated that on record for the planet dating to 1880.

Earth's five warmest years in this database have all occurred in the past five years, and nine of the top-10 warmest years have happened since 2005.

In its November 2018 report – not available at the time of this article due to the – NOAA estimated 2019 had about an 86 percent chance of being among the top-five warmest years.

(MORE: Top Climate-Related Stories of 2018)

The two warmest years occurred as a record-tying El Niño peaked in 2016 and while that El Niño intensified in 2015.

So it only stands to reason that if the El Niño develops and persists, the warmth in that stretch of the equatorial Pacific, when added to warm anomalies around the rest of the globe, may vault 2019 ahead of 2017 and 2018, during which either a La Niña or neutral conditions were in play over that stretch of ocean.

The overall long-term trend, rather than whether or not a given year is a fraction of a degree warmer or cooler, is ultimately most important for monitoring global climate change. That has been climbing upward since the late 1970s.