\n<\/p>\n
Solar activity has been at low levels this past week with most of the C-level activity originating from Region 4465, including the largest flare of the week, a C2.6 observed on June 10. There are currently 7 numbered sunspot regions on the disk with Region 4467 decaying to plage. \u00a0<\/p>\n
There was a Type-II radio sweep detected by the Radio Solar Telescope Network (RSTN) on June 10. That radio emission was associated with a coronal mass ejection (CME) first observed at the NE quadrant by ground-based coronagraph imagery from HAO\/MLSO coronagraph late June 10, and later by space-based coronagraph LASCO\/C2. Modeling indicates there is no Earth-directed component. \u00a0<\/p>\n
Other CME activity was observed in the coronagraph imagery later in the period, but preliminary analysis indicated no Earth-directed component. \u00a0 Solar activity is expected to remain at low levels, with a chance for M-class flares and a slight chance for X-class flares. NOAA\u2019s SOLAR-1 satellite became operational early on June 11, becoming the Space Weather Prediction Center\u2019s primary source of solar wind data.<\/p>\n
Solar wind speeds continued to decrease after the passage of a weak transient, reaching 374 km\/s at the end of the period. Background solar wind conditions are expected through midday June 11 when a coronal hole high speed stream (CH HSS) is anticipated to become geoeffective through June 13. \u00a0<\/p>\n
Weekly Commentary on the Sun, the Magnetosphere, and the Earth’s Ionosphere, June 11, 2026, by F. K. Janda, OK1HH: \u00a0<\/p>\n
Overall solar activity is rather low, while is expected to continue declining through mid-June. Most active regions are relatively small, typically with a simple magnetic configuration. Nevertheless, class C flares are occasionally observed, sometimes accompanied by CMEs. \u00a0<\/p>\n
Currently, CMEs from June 9 and 11 are expected to arrive, leading to an increase in geomagnetic activity from June 12 to 14. A period of several days of calm activity is predicted to begin on June 16. \u00a0 Shortwave propagation has begun to be significantly affected by the sporadic E layer, while its increased activity can be expected to continue over the next few days. \u00a0<\/p>\n
The Predicted Planetary A Index for June 13 to June 19 is 6, 6, 8, 8, 5, 5, and 5 with a mean of 6.1. The Predicted Planetary K Index is 2, 2, 3, 3, 2, 2, and 2 with a mean of 2.3. 10.7 centimeter flux is 128, 120, 118, 120, 122, 122, and 125 with a mean of 122.1.<\/p>\n
For more information concerning shortwave radio propagation, see<\/span>
<\/span>and the ARRL Technical Information<\/span>
Service web page at, <\/span><\/span>http:\/\/arrl.org\/propagation-of-rf-signals. For<\/span>
an explanation of numbers used in this bulletin, see<\/span>
<\/span>. Information and<\/span>
tutorials on propagation can be found at, <\/span><\/span> <\/span>.<\/span><\/p>\n