There was a forecast for possible Northern Lights this past Saturday night. But they didn't pan out. There were no widespread Northern Lights observed across North America.
I've been told how much data the Space Weather Prediction Center has on an accurate Northern Lights forecast.
Rob Steenburgh, acting at the Space Weather Forecast Office at Boulder, Colo., Enlightened at the process of a Northern Lights forecast.
Northern Lights are produced when a Coronal Mass Ejection (CME) is shot out of the sun. The energy eventually hits Earth's magnetosphere, and the interaction produces Northern Lights. The plasma and energy were shot toward Earth if the CME is pointed to the Earth at the time of the eruption. The CME travels toward Earth at around 1 million miles per hour.
The shortfall of updated Northern Lights forecast is that only two data points are available to make the forecast. The CME is caught in an image right when it's sun-exposed, 93 million miles from Earth. Once the CME is out of the camera's eye, there is no other way to monitor the travel and strength of the CME for about 92 million miles. So there is no way to monitor the movement and configuration of the CME for about 99 percent of the track toward Earth.
The next time the CME can be measured and evaluated is when the CME is about 1 million miles away. At that point the CME is only 45 minutes from the Earth's magnetosphere
There are two spacecraft, Advanced Composition Explorer (ACE) and the other called Discovr, with instruments to measure the CME's strength. These spacecraft hover about 1 million miles out in space.
So let's look back at this past week. A CME shot off the sun on March 20th. Based on an estimated speed of the CME from just the very short time the CME was in the imagery, an arrival time was forecast. We were all looking for updates Friday and Saturday. There were no new data to make updates. Only when the CME is less than an hour away would be a significant update possible
Think about if you had visitors driving from New York to visiting you in Los Angeles. They're texting when they're pulled out of their New York driveway. Then you didn 't hear from them until they were just outside of Los Angeles.
So I think we better consider a Northern Lights forecast just a rough estimate of when Northern Lights are possible. That's what makes the Northern Lights a very elusive event.