Experts share mixed winter weather predictions

Old Man Winter seems to finally be knocking on Oakland’s door.

Though this November has… Old Man Winter seems to finally be knocking on Oakland’s door.

Though this November has seemed to be a rather mild one, with daily highs reaching nearly 70 degrees on multiple occasions, meteorologists maintain that this month’s weather is just as it should be — actually a bit colder.

This month’s average daily high temperature has hovered around 52 degrees, just 2 degrees more than the all-time high. The month’s average daily low also measures close to the overall average, sinking 2 degrees lower than November’s usual 34-degree mark.

Despite the normal fall weather, WTAE TV Pittsburgh’s chief meteorologist Stephen Cropper warned that this winter could be “a bit harsher than usual for Southwest Pennsylvania.”

Still, Pittsburghers should not expect a repeat of last year’s freak snow storms and precipitation rate that proved to be nearly double the yearly average — no meteorologist predicted a repeat of last year’s Snowpocalypse.

While on the topic, Cropper said that last year’s winter, on the whole, was in fact not as harsh as the snow storms led many people to believe. February was statistically the only bad month last winter, Cropper said.

Forty-eight inches of snow fell in February alone last year. Pittsburgh’s average precipitation for an entire winter is just around 40 inches.

Not all meteorologists shared Cropper’s prediction of a slightly harsher winter.

Meteorologist Alicia Smith with the National Weather Service in Pittsburgh predicted that Southwest Pennsylvania will have a slightly milder winter than usual this year, whereas Northwest and Eastern Pennsylvania’s winters will be comparably normal.

These predictions are from the National Weather Service’s most recent three-month outlook, which covers from December to February — the period considered to be the heart of Pittsburgh’s winter.

Smith did agree with Cropper that last year’s Snowpocalypse was a rare kind of storm and said that the region likely won’t experience another within the next few months.

Smith based her prediction for a milder winter largely on seasonal ocean currents.

Right now the region is amid La Nina, one of two main ocean current patterns, the other being  its more famous counterpart, El Nino.

The ocean currents affect wind patterns, which in turn affect temperature and precipitation for North America, Smith said.

During La Nina, the surface temperature of ocean water in the Pacific cools. This cool water increases trade winds over the Pacific, which blow inland and increase precipitation on the West Coast and in the Midwest of the United States.

Accordingly, El Nino refers to a period of warming of Pacific Ocean surface temperatures and the formation of high pressure fronts blowing over the United States from the West.

These currents are some of the trends and patterns meteorologists look at to help forecast full winters at a time, as opposed to forecasting on a daily or weekly basis.

Cropper said that when forecasting on a long-term basis, it is more important to look at past trends and occurrences than current ones.

In other words, when trying to predict the weather patterns for this winter, meteorologists don’t concern themselves as much with how this October and November’s weather has played out as they do with how last October and November’s weather played out.

Along with La Nina and El Nino, meteorologists also consider the influence of jet streams, hurricanes, tropical storms and solar energy on temperature and precipitation rates before telling us all how to dress for the day and how much we should expect to be shoveling once winter does hit.

Cropper said the main aspect of predicting weather on a seasonal basis, and of meteorology in general, is making educated guesses. This leads to there being an inherent imperfection in the science — no one can guess correctly all the time.

“It’s a career of guesswork,” he said.