Space Weather Forecast - Discussion

Issued: 2025 Apr 16 0030 UTC
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center and processed by SpaceWeatherLive.com

Solar activity

24 h Summary

Solar activity has been at moderate levels due to multiple M-class (R1-Minor) flares. The location of the M1.5 at 15/1020 UTC is difficult to deduce as two flares, of what look like similar magnitude, occur at the same time on the eastern and western limbs. The flare on the east limb around N09 seems to peak at 10/1020 while the west limb flare associated with departing Region 4055 (N07, Lo=237) peaked at 10/1029. The GOES X-ray sensor only observed one peak during this window. The second largest flare of the period was an M1.3 flare at 15/1813 UTC from Region 4055. Region 4060 (N08W03, Dai/beta-gamma) experienced minor growth in its trailer but has been stable otherwise. Region 4062 (S02E61, Dao/beta) continues to come into better view but the magnetic field is still obscured by foreshortening to be confident in its classification beyond beta. There was a CME observed in LASCO/SOHO imagery around 15/1500 UTC. But based on its source location being beyond the eastern limb impacts are not expected.

Forecast

With 4055 now beyond the western limb, probabilities for M-Class (R1-R2, Minor-Moderate) radio blackouts will decrease from 75% to 50% into 18 Apr. However, probabilities may increase if the region beyond the eastern limb around N09 remains active. All four numbered regions on the disk are fairly simple in their magnetic complexity keeping the chances for X-class (Strong) flare activity very low (5%).

Energetic Particles

24 h Summary

The geoeffective positioning of the high speed stream (HSS) associated with the negative polarity coronal hole (CH) in the southern hemisphere has maintained high electron flux at geostationary orbit for multiple days. The greater than 2 MeV electron flux at the GOES-19 satellite position saw a peak flux of 2380 pfu at 15/1620 UTC with the GOES-18 peaking to 5120 pfu at 15/1750 UTC. The greater than 10 MeV proton flux has been at background.

Forecast

HSS influence from the southerly CH will diminish into 16 Apr with potential reconnection with the HSS from the northerly CH 17 Apr. This will increase chances for the greater than 2 MeV electron flux to remain high during the diurnal maxima through 18 Apr. Barring any significant flares from Region 4055 which will remain in a favorable position into 16 Apr, the greater than 10 MeV proton flux is expected to remain at background levels.

Solar Wind

24 h Summary

Solar wind parameters became enhanced at 15/1637 UTC following the arrival of the shock arrival with the CME that left the Sun on 13 Apr. The total interplanetary magnetic field (Bt) reached a maximum of 28.2 nT around 15/1820 UTC, the north-south component (Bz) dropped to a minimum of -20.3 nT at 15/1815 UTC. Wind speeds increased from 400 km/s prior to CME arrival to 554 km/s as of this writing. The phi angle has been variable with the southerly Bz magnetic field embedded in the negative (towards the Sun) flow. Both ACE and DSCOVR have been capturing the event well. A switch was made between the primary satellites around 1830 UTC from DSCOVR to ACE, producing a discontinuity in the density field.

Forecast

Solar wind parameters will remain enhanced 16 Apr due to ongoing influences from the current CME. Effects will wane 17 Apr but parameters will continue to be elevated as the equatorial negative polarity CH becomes geoeffective 17 Apr.

Geospace

24 h Summary

The geomagnetic field was at quiet to unsettled levels for most of the UTC day. CME arrival at 15/1637 UTC enhanced the geomagnetic field to G1 (Minor) storming levels during the 15-18 synoptic period and G2 (Moderate) storming levels in the 18-21 period.

Forecast

Geomagnetic storming is expected to continue through much 16 Apr with G3 (Strong) levels likely. CME influences will wane with G1 (Minor) levels likely to continue on 17 Apr. Expect active to unsettled conditions thereafter. -Bri