Can I see the northern lights tonight in Grand Junction?
Unlikely tonight.
NOAA's forecast peaks at Kp 3 during Grand Junction's dark hours tonight (6:10 pm to 5:50 am), strongest from about 11:00 pm. From Grand Junction the aurora usually needs about Kp 8 to show low on the northern horizon, and is overhead only in the most extreme storms. The Moon is 16% lit and up for 21% of the dark hours.
The next three nights
Peak Kp 3 in the dark, 6:10 pm–5:50 am. Moon 16% lit.
Peak Kp 2.33 in the dark, 6:10 pm–5:50 am. Moon 9% lit.
Peak Kp 5 (G1) in the dark, 6:10 pm–5:50 am. Moon 4% lit.
Kp forecast for Grand Junction
NOAA planetary K-index: the past day observed, the next three days forecast, in Grand Junction local time. Lines: the Kp at which the aurora usually reaches Grand Junction's northern horizon, and overhead. The peak value is NOAA's estimated Kp for the 3-hour block starting 11:00 pm.
It is dark in Grand Junction now. Little aurora activity near you right now.
Seeing the aurora from Grand Junction
Grand Junction is at 39.1°N, which is magnetic latitude 47.0°: the aurora follows the magnetic pole, not the geographic one, which is why it reaches further south over North America than over Europe. In a quiet night the auroral oval stays far to the north. When a solar storm arrives the oval widens and slides south; at about Kp 8 it usually reaches low over Grand Junction's northern horizon.
Kp forecasts more than a day ahead are uncertain: the timing and strength of a solar storm are often only clear an hour or so before it hits, when it passes the spacecraft upstream of Earth. So a "possible" night can fizzle, and a quiet forecast can surprise. This page updates every 30 minutes. The full week's aurora forecast · What the Kp index means.
Questions
Can I see the northern lights tonight in Grand Junction?
Unlikely. NOAA's forecast peaks at Kp 3 during Grand Junction's dark hours tonight (6:10 pm to 5:50 am), strongest from about 11:00 pm. From Grand Junction the aurora usually needs about Kp 8 to show low on the northern horizon, and is overhead only in the most extreme storms. The Moon is 16% lit and up for 21% of the dark hours. You also need clear skies to the north, which we do not forecast.
What Kp do you need to see the northern lights in Grand Junction?
About Kp 8 to see the aurora low on the northern horizon, and only in the most extreme storms for it to be overhead Grand Junction is at magnetic latitude 47.0°; the southern edge of the auroral oval sits near 66.5° at Kp 0 and moves about 2° south per Kp step.
What time is best to see the aurora?
Usually within a couple of hours of midnight local time, when your part of the Earth faces the night side of the auroral oval. During a storm it can show any time it is dark, so watch the live Kp and go out when it jumps.
Where should I look?
North. From Grand Junction the aurora usually appears as a green or grey glow low over the northern horizon, rising higher only in strong storms. Get away from street lights and let your eyes adjust for 15 minutes. A phone camera on night mode often shows colour the eye cannot.
Northern lights nearby
All of Colorado →Also over Grand Junction
Data: NOAA Space Weather Prediction Center (planetary K-index forecast, 3-day forecast, 27-day outlook, OVATION aurora model). Magnetic latitudes: AACGM-v2. Darkness and Moon computed with Skyfield and JPL DE440. We do not forecast clouds: you need a clear view to the north. How the verdict is made.