As the sun went down in Southcentral Alaska Friday, the skies above were crackling with activity, which brought some brilliant northern lights to much of the state despite previously lukewarm forecasts for aurora potential over the weekend.
The University of Alaska Fairbanks Geophysical Institute's aurora forecast was calling for "quiet" aurora on Friday, but the short-term forecast at about 5:30 p.m. was listed as "active," meaning there was a potential to spot aurora from Barrow on the North Slope all the way to Anchorage and Juneau.
A Friday afternoon alert from the National Weather Service's Space Weather Prediction Center (SWPC) in Colorado indicated that the K-index -- a measure of disturbance in the Earth's magnetic field, and subsequently, the potential for northern lights -- had reached a level of four. Anything three or above indicates a heightened prospect for aurora activity. Shortly after 1 p.m. Friday, a forecast indicated a Kp level of three or higher for much of the next two days, which means eager skygazers could catch a glimpse of the elusive northern lights.
The possibilities for aurora viewing on Saturday night were also looking good, as the SWPC reported on Saturday morning that a "solar wind stream" originating from a surface anomaly on the sun was interacting with the Earth's magnetosphere, "bringing unsettled to active geomagnetic conditions."
The activity looked as though it may only get more promising as the day wore on, too.
"The perturbed conditions may be aggravated further as a shock from a 23 January CME (plasma blob) brushes past earth later today or tomorrow," the SWPC reported on its Facebook page.
Helping the odds of spotting aurora are expected clear skies in much of the southern portion of the state as a chilly air mass moves in, according to the National Weather Service. A blizzard warning Friday morning in the Interior dissipated into a forecast of clear skies by Friday evening. Some areas, however, will continue to see low visibility and blowing snow.
"Very cold air is moving into southern Alaska from the interior portions of the state," the NWS reports. "This cold air will accelerate as it flows through gaps in the mountain ranges across the area. Dangerous wind chills will develop over the northern Susitna Valley while strong winds will pick up loose snow and generate blizzard conditions through Thompson Pass and the Copper River Basin."
So if you do decide to go chasing aurora, be sure to dress warm. And don't forget to send us your photos if you happen to catch the celestial show -- we may add them to our reader-submitted gallery. You can submit photos to info(at)alaskadispatch.com.