An impulsive solar flare registered as M5.1 erupted from Active Region 3977 at 14:04 UTC on February 2, 2025. The event started at 13:58 and ended at 14:08 UTC.
While there were no radio signatures indicating that a coronal mass ejection was produced, this region is currently positioned at the center of the solar disk, increasing the likelihood of Earth-directed solar flares in the coming days.
Radio signatures were forecast to be most affected over South America and the South Pacific Ocean at the time of the flare.
This event follows M3.0 from region 3981 at 10:12 UTC. Associated with this event was a Type II Radio Emission with an estimated velocity of 664 km/s, suggesting a CME was produced. Subsequent coronagraph imagery showed the CME heading away from Earth.
This region has exhibited rapid growth in its intermediate and trailer spots over the past 24 hours and is now moving toward the center of the solar disk.
Other notable activity over the past 24 hours included a Type II Radio Emission with an estimated velocity of 736 km/s, beginning at 05:40 UTC. This was associated with a halo CME originating on the Sun’s far side.
Solar activity is likely to remain at minor to moderate levels over the next two days, with 55% of M- and 15% of X-class solar flares, primarily due to potential from an active region cluster in the NE quadrant.
The greater than 2 MeV electron flux remained at moderate levels over the past 24 hours, while the greater than 10 MeV proton flux remained at background levels.
A positive polarity coronal hole high-speed stream (CH HSS) on February 2 and 3 is expected to increase the chances of the 2 MeV electron flux reaching high levels through February 4. The greater than 10 MeV proton levels have a slight chance of reaching S1 – Minor storm levels between February 2 and 4.
Solar wind conditions remained influenced by a positive polarity CH HSS during the same period. The total magnetic field strength decreased from a peak of 14 nT to approximately 5 nT by 22:40 UTC on February 1.
Solar wind speeds, as reported by the ACE spacecraft, briefly peaked at just over 700 km/s before declining to around 600 km/s later in the period. The phi angle remained predominantly in the positive sector.
Enhancements in solar wind parameters are expected to continue through February 4 due to persistent, though gradually weakening, positive polarity CH HSS influence. Additionally, interaction with the CME from January 31 could impact Earth’s magnetosphere on February 4.
The geomagnetic field ranged from quiet to active levels under the influence of the positive polarity CH HSS. Active geomagnetic conditions are expected on February 2, with a chance of isolated G1 – Minor storm conditions.
Conditions are likely to drop to an unsettled level by February 3 as the CH HSS influence diminishes. Late on February 4, active conditions may return if the CME from January 31 interacts with Earth’s magnetic field.
References:
1 Forecast Discussion – NOAA/SWPC – Issued at 12:30 UTC on February 2, 2025