There is a space weather forecasting center of the National Weather Service Degraded Expected strength of a geomagnetic storm from “strong” (Level 3) to “Minor” (Level 1) from Friday.
Read “Storm Strikes.” Title at SpaceWeather.com, An online hub for space weather information. Thursday “Mid-latitude auroras unlikely”.
When the sun erupted on Monday, the so-called coronal mass ejection (CME) or plasma cloud was released. The impact that preceded it had already passed the earth. On Wednesday night there was a brief reaction in the planet’s geomagnetic field atmosphere, but not to the extent predicted. There is little chance that the solar wind on the route will cause a more powerful storm, but the chances are slim.
So what happened? With more observations and better physics-based models, why is it difficult to bring these events to the nail? Here is a short list of dangers that seem to apologize to the world’s space weather forecasters.
First, the sun is far away. Think of it as about 93 million miles away. If you measure the sun to the size of a basketball, the earth is about the size of a bb, and they sit on the opposite end of an NBA-sized basketball court. Also, the intervening space is dynamic and almost invisible.
Second, simple ballistics are an important factor in predicting the impact of coronal mass ejection. That is, does the plasma cloud hit directly or does it stare? Position, position, position.
Third, what you cannot see kills you. Not only is the speed and trajectory of the CME important, but the embedded magnetic field – invisible in the construction of the CME – is a major factor in the strength of the earth’s magnetic field response. Observations taken over 1 million miles above will only be known to the prophets when they pass through the CME. Think spin on a baseball; It’s important to have a curveball or a two – seam fastball.
Finally, while the auroras, also known as the Northern Lights, are effective, you need clear skies to see them, and this allows the moon to stay as dark as possible.
Considering the degraded geomagnetic storm, Sky Watchers in North America may choose to sit on it. At higher latitudes (Northern Canada, Alaska, Northern Europe), the unfinished solar wind will still give us a slight shock, auroras are likely, and a faint moon can be seen.
The event is expected to be one of the first salvos in the near future as the new Solar Cycle 25 is captured, although the chance to see the auroras on Thursday night in mid-latitudes is likely to be missed.