Space Weather Forecast - Discussion

Issued: 2026 Jul 20 1230 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 remained at low levels, where the largest flare of the period was a C2.1/sf at 20/0746 UTC from newly numbered Region 4493 (N05E10, Dai/beta-gamma), which produced the majority of the periods flares and exhibited rapid flux emergence. Region 4492 (N15E59, Dac/beta-gamma) evolved greater magnetic complexity in its eastern area. The remaining regions were largely stable and quiet. A slow moving CME off the western limb was first noted in LASCO C2 coronagraph imagery at approximately 19/0430 UTC. Source location was difficult to determine. Large scale reconnection was observed in multiple SUVI wavelengths, starting around 19/0230Z near S11W33, however no prominent filament was identified. Initial analysis of this event indicated a miss ahead of Earth. However, additional modeling will be needed when STEREO data becomes available.

Forecast

Solar activity is likely to be at low levels on 20-22 Jul, with a chance for M-class flare activity.

Energetic Particles

24 h Summary

The greater than 2 MeV electron flux reached high levels this period with a peak flux of 1,174 pfu at 19/1830 UTC. The greater than 10 MeV proton flux was steady at background levels.

Forecast

The greater than 2 MeV electron flux is expected to reach high levels on 20 Jul, then return to normal to moderate levels on 21-22 Jul. The greater than 10 MeV proton flux is expected to continue at background levels through 22 Jul.

Solar Wind

24 h Summary

Solar wind parameters continued at background levels. Total magnetic field strength averaged 4 nT, the Bz component ranged between +/- 4 nT, and solar wind speeds were largely below 300 km/s. Phi was predominantly in a positive orientation.

Forecast

Background solar wind conditions are expected to prevail on 20 Jul through early 21 Jul. Late on 21 Jul, a CIR ahead of a negative polarity CH HSS is likely to move into a geoeffective position, bringing enhancements to the solar wind environment. Further enhancements are likely on 22 Jul as the CIR passes with the onset of the HSS.

Geospace

24 h Summary

The geomagnetic field was quiet under an ambient solar wind environment.

Forecast

The geomagnetic field is expected to persist at quiet levels on 20 Jul and most of 21 Jul. By late on 21 Jul, unsettled to active conditions are likely, with a chance for G1 (Minor) levels near the end of the period. By 22 Jul, unsettled to active periods are expected, with G1 (Minor) storm levels likely as the negative CH HSS moves into a geoeffective position.