[UPDATE, midnight New York time: the cloud of particles from the solar flare arrived a few hours ago, but it didn’t impact the earth’s magnetic field quite as hard as the best-guess forecast. (Remember the probability of a geomagnetic storm was only 60%; i.e. the probability of no storm was 40%.) Right now, the auroras are likely visible in Canada but probably not in the US. This could change, but don’t get your hopes up too high; we may have to wait for the next solar flare.]
I’ve been sidelined with computer troubles and non-science activities, so first, a belated thanks to everyone who left a thoughtful comment after Monday’s post and question about communicating science to the public. I appreciate hearing your views, especially from readers with a diversity of backgrounds!
Now, many of you may have heard that there is a forecast of northern (and southern) lights, also known as auroras, tonight. What you’ve heard is correct: today’s NOAA space-weather forecast, from http://www.swpc.noaa.gov/forecast.html, says
VI. Geomagnetic Activity Probabilities 13 Apr-15 Apr A. Middle Latitudes Active 30/30/15 Minor Storm 35/45/05 Major-severe storm 10/15/01 B. High Latitudes Active 10/15/15 Minor Storm 20/25/20 Major-severe storm 60/35/20
i.e. it shows that even in mid-latitudes (meaning northern US and southern Canada, and northern Europe, along perhaps with parts of Australia and New Zealand [?]) they are estimating a 35%-45% probability of a minor `geomagnetic storm’ tonight, with a 10-15% probability of a major storm… and a geomagnetic storm, which literally means a lot of activity in the earth’s magnetic field, generally leads to auroras further away from the north and south pole than usual. (more…)