Aurora Viewing in Southcentral Alaska

The aurora forecast is updated for January 25. Keep an eye out for our daily weather forecast update below and tour status as noted on the Anchorage Aurora Quest page. The Kp estimate is for the maximum levels forecasted for the time between 10:00 p.m. and 4:00 a.m. Alaska time. 

TUE JAN 25 – Planetary K-Index [predicted]: Kp 2-3

WED JAN 26 – Planetary K-Index [predicted]: Kp 2-3

THU JAN 27 – Planetary K-Index [predicted]: Kp 1

Additional Information Affecting Aurora Viewing

Moon: The moon will rise at 3:56 a.m. (Jan. 26) as a 39.23% waning crescent. It will not interfere with viewing a quiet aurora.

Twilight: Twilight will not be a factor in aurora viewing.

Solar Winds: Solar wind parameters are expected to remain enhanced through 26 Jan with continuing Coronal Mass Ejection(CME) influence and positive polarity Coronal Hole High Speed Stream (CH HSS) effects. Other possible weak enhancements from the periphery of CMEs that left the Sun on 22 Jan are possible, in addition to additional positive polarity CH HSS influence. Waning influence is forecast on 27 and 28 Jan.

Geomagnetic Field: The geomagnetic field is expected to range from quiet to active levels on 26 Jan due to a combination of weak glancing influence from the 21 Jan CME and additional positive polarity CH HSS influence. Quiet to unsettled levels are expected by 27 Jan. Quiet conditions are expected on 28 Jan.

Planetary K-Index provides an estimate as to how wide the auroral oval may extend. It does not indicate whether the aurora borealis will appear. The most important factors for aurora viewing are the solar winds and geomagnetic field – so note the information above on those. The Planetary K-Index is measured on a scale of 0-9. Anchorage is within the Kp3 zone (aurora visible overhead), but auroras are often seen here on the horizon as low as Kp1 (except for the early and late season, where a higher Kp is needed.) A fairly accurate Kp index can be determined up to 3-days in advance. For the Kp index indicated in the Anchorage northern lights forecast, that is the maximum Kp predicted during the prime aurora viewing time in the Anchorage area (generally between 9:00 p.m. and 4:00 a.m.). We do not provide the Kp level for a forecast period outside of nominal viewing times (i.e., local daytime).

Last Night’s Aurora

• The maximum level for the Planetary K-Index was a Kp3 at prime viewing time for Southcentral Alaska.
• The maximum hemispheric power achieved last night was 39.0 GW at 2:27 a.m.
• A disturbance was observed in the solar wind which very well could be a reflection of the CME from 21 Jan. Total field peaked at 13 nT and the Bz component underwent several brief southward excursions exceeding -5 nT. Wind speed increased from around 300 km/s to near 380 km/s by the end of the period. The phi angle suggested a fair amount of rotation between positive and negative solar sectors, supporting CME influence.
• The geomagnetic field was quiet to unsettled.

Current Aurora Ovation

Hemispheric Power is a measure of auroral activity that helps determine how bright and active auroras might be. It measures the rate of deposition of charged particles (mainly electrons and protons) into the atmosphere, where they collide with upper atmosphere particles and eventually stop. This process transfers their kinetic energy to the upper atmosphere. The higher the number, the more charged particles are depositing in the upper atmosphere. It’s measured on a scale of 5-150 GW [Gigawatts]. A power level of 20 or more is usually adequate to produce auroras visible to the naked eye. Hemispheric Power fluctuates and is a short range forecast that can be determined only up to around 30-90 minutes in advance with relative accuracy.

The forecast is updated for the night of January 25.

Anchorage

Mostly cloudy, with a low around 12. North wind 5 to 10 mph. Estimated cloud cover is 6% (10:00 p.m.) to 92% (4:00 a.m.) (fully cloudy by 1:00 a.m.).

Girdwood

A 20 percent chance of snow. Mostly cloudy, with a low around 18. Calm wind. Estimated cloud cover is 99% (10:00 p.m.) to 99% (4:00 a.m.).

Butte/Knik River

Mostly cloudy, with a low around 10. Calm wind. Estimated cloud cover is 7% (10:00 p.m.) to 99% (4:00 a.m.).

Palmer (includes Hatcher Pass)

Chickaloon

Mostly cloudy, with a low around 13. Calm wind becoming east around 5 mph. Estimated cloud cover is 56% (10:00 p.m.) to 93% (4:00 a.m.).

Glacier View

Mostly cloudy, with a low around 6. West wind 5 to 10 mph becoming light after midnight. Estimated cloud cover at Lion Head is 94% (10:00 p.m.) to 84% (4:00 a.m.).

Wasilla

Willow

Talkeetna