Northern lights in Pittsburgh: tonight’s chance

A city of hills and grey skies

Pittsburgh is built where the Allegheny and the Monongahela meet to form the Ohio, and its neighborhoods climb steep hillsides above the rivers. That topography is the first thing to plan around. An aurora at the city's threshold, Kp 7.1, rises only a few degrees above the true northern horizon, and from most of the city a hill, a ridge or a row of houses stands higher than that. The second thing is the weather: the Ohio valley sits under the track of many winter systems and in the reach of lake-effect clouds from Lake Erie, and long grey spells are common from November to March.

The answer is to go north and up. The plateau north of the city rises gently toward the Allegheny National Forest, with farms, woods and small towns. Within an hour, an open hilltop in Butler County gives a far better view than anything inside the city, and within two or three hours the north tier offers some of the darkest skies in the state.

Strong storms only

A threshold of Kp 7.1 means waiting for SWPC watches of G3 or more. NOAA counts about 200 G3 storms per eleven-year cycle, concentrated in the active years, and fewer each year as the solar cycle declines. Many of those storms peak during daylight in Pennsylvania or under cloud. That makes each clear storm night worth acting on quickly: when the hour strip of the tool shows a run of hours with Kp at the threshold and a clear sky, the time to leave is at the start of the run, not at its end.

What to expect

From the Pittsburgh area, a storm aurora usually appears as a red or pink glow over the northern horizon, with pale vertical rays at its brightest moments. The eye sees it faintly; a phone records it far better. For the rest of the state see the Pennsylvania page, and for the city across the state, the Philadelphia page.