The Aurora (Northern Lights) and when they can be viewed locally
WHAT TO LOOK FOR
Space weather prediction is incredibly challenging. Forecasting space weather is very different from forecasting surface weather. So there are many more challenges and it is much more difficult which can lead to disappointment especially with borderline solar storms. Here is the main page of the NOAA Space Weather Prediction site. At the top of the site it will list current geomagnetic storm conditions and the forecast.
- You’re looking for a G3 or stronger.
- You also want to look at the Kp index forecast. You’re looking for a Kp of 7 or stronger forecast in the next several hours but it has to correlate with night, meaning the skies must be dark while the storm is strong enough
To produce a strong aurora, you need a strong geomagnetic storm. When a G3 storm is forecast by NOAA, that may produce a very faint aurora along the horizon for parts of Virginia and West Virginia. At times, this may only be seen with a camera and possibly not even with the naked eye.
We did have a severe solar storm recently, back on the night of March 23rd. This photo below from Peter Forister was taken during that severe solar storm.
Ideally, to see the northern lights in our area you would want a G4 or a G5 solar storm, and these types of storms are very rare. These are not weather types of storms, these are solar storms. The stronger the solar storm, the more likely radio blackouts or GPS issues.
On the night of April 23, 2023 a rare G4 storm produced northern lights seen as far south as Arkansas. Here’s a local photo from that night.
If you look at the chart below, the Aurora with a G4 storm can be seen as far south as Alabama and with a G5 storm, the aurora can be seen as far south as Texas and Florida. So you know that seeing the Aurora that far south is rare, and that’s how rare a solar storm of this magnitude is.
The Kp index is something you can use to gauge if the aurora will be visible in the mid-latitudes. While a G3 solar storm, or Kp index of 6 can at times produce a faint glow of the northern lights on the horizon, you would really be looking for a Kp index of 7+ for better viewing in Virginia and West Virginia. The image below shows the map of the Kp index lines.
If you click the image that will take you to the current Kp index with past data for 3 days. If you want the Kp index forecast, the text data is accessible by clicking here:
Subscribe to solar storm forecasts
You can get an alert when a powerful solar storm is forecast. After you sign up you can click on the Geomagnetic Storm subscription option and then select a K-index of 8 or 9. Aurora viewing is possible locally with a K-index of 7 in the mid latitudes but it would be very faint and on the horizon.
Ideally you’re looking for a G3 solar storm and stronger
LINKS AND RESOURCES
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