From Where Comes Our Air?

Winter air masses in Cincinnati tell the meteorologist a great deal about coming weather.  If I can identify the air mass that will arrive in the Tri-state I can describe the weather and give you a good idea of what it will be like and how it will impact your day without forecasting specifics.

In winter air masses arrive from the north.  They are either maritime polar, continental polar or the "Bringer of Below Zero" air mass we call arctic air.

Occasionally, actually rarely air arrives from the central Pacific and we have a nice mild spell. But in most cases we get mP (maritime Polar) air from the north Pacific, cP (continental Polar) from central and northern Canada or cA (continental Arctic) air from Siberia, the North Pole and the northern fringe of Canada.

The jet stream comes into play by being the steering current that guides the air masses from the various source regions.  A major arctic air outbreak like January 1977, December 1989 or January 1994  we need the "Arctic Express" an over-the-pole jet stream flow which brings air from the interior of Siberia, the coldest region of the northern hemisphere, right over the pole and into the Ohio River Valley.

Continental Polar air is "normal" cold air and we get typical winter temperatures from its arrival.

When the jet stream is from the Pacific Northwest our air is cool to chilly and near or just above normal.

The air this winter should predominately be from the north Pacific meaning close to normal temperatures and the potential for a large amount of precipitation.