If you missed it the last time, the Aurora Borealis is coming into view again in Wisconsin. While this is typically a Northern occurrence, sometimes the aurora is particularly strong and can be seen in more southern latitudes.
Included in those latitudes is Wisconsin. The 3-day forecast for January 22 -24 indicates a high probability that the greatest expected strength of the geomagnetic storm may reach 6.00 Kp.
The Kp index is a scale used to measure global geomagnetic activity and is closely associated with the visibility of the aurora borealis (Northern Lights) and aurora australis (Southern Lights). It’s an excellent tool for aurora watchers to gauge the likelihood of auroral displays. Here’s a brief overview:
- Scale Range: The Kp index ranges from 0 to 9, with 0 being very little geomagnetic activity and 9 being a major geomagnetic storm.
- Calculation: The Kp index is based on data from ground-based magnetometers worldwide. These magnetometers measure the disturbances in the Earth’s magnetic field.
- Aurora Visibility: A higher Kp index means a greater likelihood of seeing the aurora. For instance, a Kp index of 1-2 is considered low, and the aurora will likely only be visible at high latitudes near the poles. The aurora can be seen at lower latitudes as the Kp index increases.
-
- Kp 0-2: Very weak; aurora is generally visible only near the poles.
- Kp 3-4: Weak to moderate; visible at higher latitudes, possibly seen as far south as Scotland or the northern U.S. states like Michigan or Maine.
- Kp 5-6: Strong; aurora may be seen in more southern latitudes, such as the northern parts of the UK, northern Germany, or the northern U.S. states.
- Kp 7-9: Very strong to severe; visible at much lower latitudes, potentially as far south as the central U.S.