Thursday, July 13 – Enthusiasts eagerly awaiting the captivating display of the northern lights may be disappointed, as the highly anticipated phenomenon is expected to be visible in fewer locations than initially forecasted. The Geophysical Institute at the University of Alaska, which initially predicted high activity, now describes the aurora borealis on these days as “active.”
Weather conditions permitting, select areas in Alaska, South Dakota, Wisconsin, Michigan, Maine, and parts of Canada are likely to bear witness to the breathtaking spectacle on Thursday. These same states were previously expected to experience the northern lights on Wednesday as well.
The institute’s projection from just a week ago had indicated that the dazzling display would grace 17 states during the two-day period. The list included Washington, Iowa, Illinois, Ohio, and Massachusetts on July 12, followed by Alaska, Montana, Minnesota, Wisconsin, Michigan, Oregon, Idaho, Wyoming, Nebraska, Indiana, Vermont, and Maryland on July 13.
A representative from the institute informed CBS News via email that the initial forecast was based on the expectation of a moderate solar storm, which typically triggers such activity. However, recent observations have revealed that the solar features responsible for the previous surge of activity have waned over the past month. Consequently, the likelihood of the initially projected high levels of activity has significantly decreased.
NOAA (National Oceanic and Atmospheric Administration) also initially anticipated heightened activity for this week but subsequently revised their forecast. According to NASA, the captivating display of the northern lights is a result of solar wind from coronal holes in the sun interacting magnetically with the Earth.
Bryan Brasher, a project manager at NOAA’s Space Weather Prediction Center, explained via email to CBS News that one specific coronal hole had previously exhibited heightened activity, leading forecasters to expect a similar pattern. However, upon the hole’s return into view, it became apparent that its activity had diminished. As a result, the forecast was adjusted accordingly.
The intensity of geomagnetic storms, which give rise to the northern lights, is measured on the G scale, ranging from G1 (minor storm) to G5 (extreme storm). The original forecast that garnered significant attention was categorized as a G2 event, but NOAA later downgraded it to a G1. Ultimately, it was revised below the G scale.
Brasher clarified that for mid-latitude states to have the opportunity to witness the northern lights, a G3 or G4 storm would be required. He pointed out that in late March and late April, G4 storms occurred, causing the aurora to be visible as far south as Arizona and Oklahoma.
To optimize viewing conditions, it is advisable to observe the lights when the sky is clear and dark. The institute suggests that the lights are most visible closest to the equinox, which occurs during the spring and fall when the days are longest. Auroras are a result of solar storms.
The National Oceanic and Atmospheric Administration provides an animated forecast that showcases the movement of the lights. It indicates that the best time to witness the phenomenon is within an hour or two of midnight, typically between 10 p.m. and 2 a.m. local time.
During periods of average activity, the northern lights are usually visible in Alaska, Canada, and Scandinavian countries like Greenland and Iceland. Late February to early April is typically considered the prime time to experience the spectacle in Alaska.