Northern Lights Could Be Visible This Week In PA: When To Watch

PENNSYLVANIA — There is a slight chance of seeing the northern lights in Pennsylvania on Monday night, as a minor geomagnetic storm could make conditions right for a display of green and purple hues in the night sky. A much greater chance of seeing the beautiful lights exists Thursday as well, according to forecasters.

The Geophysical Institute in Alaska forecasts the Kp index — the measure of auroral strength — will be about 3 on a 9-point scale Monday.

The University of Alaska Fairbanks Geophysical Institute also predicts aurora activity will be high(+) Thursday, July 13, in parts of Canada and the United States.

The best chances to see the northern lights are in far north U.S. locations such as Alaska, northern Michigan and Maine, but they could be visible as as far south as Pennsylvania, according to a geomagnetic storm watch issued by the National Oceanic and Atmospheric Space Weather Prediction Center.

The Kp index will be around 6 on a 9-point scale on Thursday, according to the Geophysical Institute. In general, the chances of seeing the northern lights are best with a Kp index of at least 5.

Aurora forecasts are notoriously tricky and can quickly change. The Space Weather Prediction Center, which updates its aurora forecasts every 30 minutes, is expected to release its own forecast as July 13 gets closer.

Forecasting exactly when and where the auroras can be seen isn’t an exact science. For the best chances, head to a dark sky and be patient. Normally, the best times to see the northern lights is between 10 p.m. and 2 a.m. local time, according to the Space Weather Center. It also depends on the strength of solar winds.

A waning crescent moon at less than 50 percent illumination will help aurora hunters on Thursday.

This is a particularly active time for the solar storms that produce the northern lights. We’re approaching the expected 2025 peak — called “solar maximum” — of an 11-year solar cycle in which the sun’s magnetic fields flip polarity.

Until 2025, the auroral oval — the area on Earth where the lights are visible — will continue to widen, increasing the chances that the northern lights will dance at lower altitudes.

Last April, people who don’t often see the auroras were surprised by jaw-dropping northern lights displays in more than two dozen states, some as far south as Florida.

Related:

• Why Aurora Displays Are Becoming More Frequent
• Understanding Kp Indices And More Tips For Aurora Hunters
• Perseids And Other Meteor Showers Tune Up In July