SB PROP @ ARL $ARLP019 ARLP019 Propagation Forecast ZCZC AP19 QST de W1AW Propagation Forecast Bulletin 19 ARLP019 From ARRL Headquarters Newington, CT May 8, 2026 To all radio amateurs SB PROP ARL ARLP019 ARLP019 The ARRL Solar Report Solar activity was at low levels this past week with occasional B-class and isolated low-level C-class flares. The largest event of the period was a C1.4/Sf flare from Region 4429 on May 5. There are currently six numbered regions on the visible disk as 4434 decayed to plage and Region 4428 rotated beyond the western limb as an E-type group. The remaining regions mostly showed signs of decay. Region 4425 appeared stable, though full characterization is difficult due to extreme limb proximity. Region 4429 showed continued submergence and decay, decreasing in both area and length along with a total loss of penumbra. Region 4431 showed some minor new development, with a few small spots emerging in both polarities following recent decay. Region 4432 had minor emergence in its intermediate spots, despite an overall gradual decrease in extent. The remaining regions were mostly stable. No Earth-directed CMEs were observed in available coronagraph. Flare probabilities increase beginning May 8 as up to two active regions rotate into view from beyond the eastern limb. Considering the size of these regions and recent far-side eruptions seen in coronagraph imagery, solar activity is expected to increase May 8 - 9 with a chance for M-class (R1-R2/minor-moderate) flares and a slight chance for X-class (R3/strong or greater) flares. Solar wind parameters returned to near background levels as transient coronal mass ejection (CME) influences waned. Solar wind speeds averaged around 375 km/s. The phi angle was predominantly in a positive (away) orientation for the majority of the period with a few short-lived oscillations into a negative (toward) orientation during the period. Spaceweather.com reports a big and active sunspot hiding behind the sun's northeastern limb is about to reveal itself, rotating into view this weekend. A dramatic M2-class solar flare on May 7th confirmed its approach. The unnamed sunspot has produced at least 5 CMEs in recent days. If this production continues, Earth could soon be in line for a solar storm. Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere, May 7, 2026, by F. K. Janda, OK1HH: Overall solar activity declined slowly but steadily in late April and early May. Eruptive activity was low, with active regions mostly and featuring a simple magnetic field configuration. Geomagnetic activity increased significantly only on May 4, after which the polarity of the longitudinal component of the interplanetary magnetic field returned to positive values. The ionosphere returned to a state favorable for shortwave propagation since May 6. Solar activity is likely to remain at current levels, while should decline shortly and slightly in mid-May. Geomagnetically quiet days can be expected starting May 10 again. Prior to that, there will be a slight increase in activity, likely on May 8. No other significant fluctuations are likely. The latest solar report from Dr. Tamitha Skov, WX6SWW, can be found on YouTube at https://www.youtube.com/watch?v=lNcaoB7be-k The Predicted Planetary A Index for May 9 to May 15 is 10, 6, 5, 5, 5, 5, and 25 with a mean of 8.7. The Predicted Planetary K Index is 3, 2, 2, 2, 2, 2, and 5 with a mean of 2.6. 10.7 centimeter flux is 130, 130, 125, 125, 120, 115, and 120 with a mean of 123.6. For more information concerning shortwave radio propagation, see www.arrl.org/propagation and the ARRL Technical Information Service web page at www.arrl.org/propagation-of-rf-signals. For an explanation of numbers used in this bulletin, see www.arrl.org/the-sun-the-earth-the-ionosphere. Information and tutorials on propagation can be found at http://k9la.us. Also, check this: "Understanding Solar Indices" from September 2002, QST. https://bit.ly/3Rc8Njt NNNN /EX | 
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