Halloween Aurora Watch: NOAA Predicts a G1 Storm for Oct 31 and Nov 1

Halloween weekend comes with a space-weather appointment. On Thursday, October 29, NOAA's Space Weather Prediction Center updated its geomagnetic storm watch (product WATA20, issue #1134, at 19:10 UTC), extending the predicted G1 (minor) storming to cover both Saturday, October 31 and Sunday, November 1. A watch issued the day before had covered October 31 only; Thursday's update added November 1, and it supersedes all prior watches in effect for the period.

No storm conditions are predicted for Friday, October 30 itself. The driver is a recurrent coronal hole high speed stream — a fast flow of solar wind pouring from a hole in the Sun's corona — expected to arrive late on October 30 and continue into October 31. SWPC's three-day forecast puts the greatest expected Kp index at 5.00, exactly the G1 threshold, with G1 storming likely on both October 31 and November 1.

G1 is the lowest rung of NOAA's geomagnetic storm scale — a minor storm, and honest expectations matter. The watch's stated impacts are modest and mostly high-latitude: weak power-grid fluctuations can occur, minor effects on satellite operations are possible, and the area of impact sits primarily poleward of 60 degrees geomagnetic latitude. This is not an infrastructure story. It is a sky story.

At Kp 5, the aurora brightens across the high latitudes and, on the better periods, reaches into the northern tier of the United States — coverage of the watch names northern Michigan and Maine as the kind of places with a chance to see it, and dark-sky watchers along the northern border states work from the same forecast. How far the display pushes depends on the stream's strength hour by hour, which is why NOAA issues a watch and not a promise.

The practical upgrade in Thursday's update is the second night. Storming is expected to build from late October 30 as the stream arrives, with the strongest predicted three-hour period early on October 31 (UTC) and further G1-level periods recurring into November 1. That puts the nights of Friday October 30 into Halloween, and Halloween night itself, both in play — two dark windows instead of one.

Aurora watching rewards patience over precision: pick a dark spot with a clear northern horizon on both nights, give your eyes a full twenty minutes to adapt, and keep checking after full dark rather than calling it at dusk. Substorms — the sudden brightenings that turn a faint arc into dancing curtains — arrive in bursts that no forecast times to the minute.

You do not need to live under the auroral oval to follow this one. WorldEye's aurora webcams page pairs a live Kp index with tonight's northern cameras, so the number and the sky sit in the same place: when Kp climbs toward 5, the high-latitude feeds are where a substorm shows first, in real time, whatever your own horizon is doing.

For the full circuit — which cameras to favour, what the colours mean, and how to read a forecast before driving anywhere — our guide to watching the northern lights on live webcams is the companion piece. And if this stream underperforms, as streams do, the same pages are the ones to keep: a recurrent coronal hole rotates back around, and the next watch is rarely far behind.