A person walks through heavy snow in downtown Rochester, Minn., on Dec. 1, 2018. (Andrew Link/The Rochester Post-Bulletin via AP)

Winter seemed to start earlier than normal this year, and from the Mountain West to the Mid-Atlantic, Americans have already faced multiple snow and ice threats.

Social media has become the dominant platform for tracking winter storms but, to put it gently, all of the information flowing through the torrent of online streams isn’t always credible.

To help you navigate what’s reliable, trustworthy information, here are seven things you should know:

1) Be skeptical of storm threats advertised more than a week out

On social media, some forecasters take pride in being the first to talk up the possibility of a snowstorm at long ranges, sometimes even 10 days to two weeks into the future.

The limit of how far out we can reasonably predict weather systems is around seven to nine days. Occasionally, we can identify patterns favorable for snow up to two weeks or so in advance, but it’s rare.

While there can be value in communicating the possibility of an upcoming stormy period in very broad strokes one to two weeks ahead of time, it’s also true that many long-range threats fail to materialize.

Anytime you hear about a winter storm threat more than a week into the future, treat it with a healthy dose of skepticism.

2) Ignore the noise. There is such a thing as too much information

Social media feeds that post every run of every model aren’t doing their audience a great service. Models are very jumpy more than a few days into the future, sometimes alternating from one extreme solution to the next. A slow and steady approach to sharing model information, focused on the tendency of forecasts and what models agree and disagree on, is better.

3) Reliable snow amount forecasts generally cannot be made more than two or three days into the future

Sometimes we’ll have a good idea a storm is coming a week ahead of time, but snow amounts are very hard to predict, even within 24 to 48 hours of a storm. They can vary by large amounts over small distances and two to three degrees can be the difference between a lot of snow and bare ground. A small change in the storm’s track can also greatly alter amounts.

The maps generated by computer models simply do not offer a reasonably accurate snowfall forecast more than a few days into the future in most cases. If someone posts one of these maps, the farther into the future it is, the more skeptically you should view it. If it’s a map for a storm more than three days into the future, don’t bother sharing it.

These maps offer little of value and are frequently misleading. Weather providers can communicate the risk of possible storminess several days into the future without resorting to these clickbait maps.

3) Your mobile app snowfall forecast more than three days into the future is likely wrong

Many mobile apps try to spit out predicted snowfall amounts at times ranges into the future it’s just not possible to do so accurately, as just explained. Furthermore, they are mostly computer-generated (a few have manual override) so they lack human input and experience which is critical for snow forecasts.

Importantly, they do not communicate uncertainty in the storm track or take into account how deviations could increase or decrease snow amounts.

4) Human-drawn snowfall maps are generally better than computer model snowfall maps

Even once we’re within two or three days of a storm, snowfall maps prepared by hand will generally be superior to those created by a computer model.

Meteorologists who prepare their own snow maps correct for model biases and wrong assumptions (like an inch of rain always equates to 10 inches of snow) and blend the best models together. Plus, they impart their own local knowledge of how snow is most likely play out in the region they serve.

5) Seek information beyond snow amounts

Some forecasters place disproportionate attention on how much snow will fall but there is so much more to the impact of a winter storm than its snow amount. For most storms, there is little difference between five inches and eight inches in terms of how it affects you.

Follow social media feeds that also provide information about the storm timing, when precipitation will be heaviest, what temperatures will be like, when and where frozen precipitation will stick to pavement, and so forth.

6) Disregard social media amounts you don’t recognize

If you’ve never heard of a source sending out a weather message that seems extreme or questionable, disregard it and/or check information sources you trust for a second opinion before sharing. Signs that the source may not be a credible source of information include:

  • It’s full of spelling/grammatical errors;
  • Updates are infrequent, erratic;
  • It includes hyperbolic or sensational language as well as requests to “please share”;
  • No one else you know is following it.

7) Read this fantastic list “10 Things Everyone Should Know About Winter Weather Forecasts” from Rick Smith, warning coordination meteorologist, at the National Weather Service forecast office in Norman, Okla.

(Rick Smith)