= NOW 18 WPM transition file follows = Solar activity plunged this reporting week, although there was great the excitement when the solar flux on February 17 was reported as a record breaking 343.1. Because it was the noon reading, it is still reported by NOAA as the solar flux, but this was a false reading when the observatory at Penticton, British Columbia was swamped by energy from a solar flare. So, in this report, I have chosen the 1800 UTC flux value, which was 165. Average daily sunspot number plunged from 182.4 to 107, while average solar flux dropped from 196.4 to 162.4. If I had not changed the 343.1 to 165, solar flux average would have been 187.9, more than 25 points higher than what we report here. Six new sunspots emerged over the week, one on February 16, one each on February 18 and 19, and three more on February 20, then one day after the end of the reporting week, on February 23, two more sunspot groups appeared. The solar flux prediction for the next month shows a peak value of 180 for March 7 to 13. Predicted values are 148 on February 24, 146 on February 25 to 27, 142 on February 28, 140 on March 1 and 2, 145, 150, 155, and 165 on March 3 to 6, 180 on March 7 to 13, then 175 and 170 on March 14 and 15, 160 on March 16 and 17, then 155, 160, 150, 140 and 135 on March 18 to 22, 125 on March 23 and 24, 130 on March 25, then 140 on March 26 to 28, 145 on March 29 and 30, then 150, 155 and 165 on March 31 through April 2. Beginning on April 3, predicted flux values are back to 180, continuing into the following week. Predicted planetary A index is 10 on February 24 and 25, then 12, 18, 20, 16 and 10 on February 26 through March 2, 5 on March 3 and 4, then 15, 18, 15 and 8 on March 5 to 8, 5 on March 9 to 14, 15 on March 15, 8 on March 16 and 17, 5 on March 18 to 20, 10 on March 21 to 23, 5 on March 24 and 25, and 8 on March 26 and 27, then 5, 8, 5, 5, 15, 18, 15 and 8 on March 28 through April 4. A week ago, on February 17, we vainly awaited the arrival of a CME, and at least a weak G1 class geomagnetic storm. Instead, on February 17 at 2016 UTC, we were treated to a strong X2.2 class solar flare in the newly emerging sunspot group AR3229. X ray and UV radiation as well triggered the Dellinger Effect over the Americas. The Dellinger Effect is a Sudden Ionospheric Disturbance. Frequencies up to 30 MHz were attenuated for more than an hour after the flare. The arrival of the CME affected the Earths magnetic field at 1039 UTC on February 20. However, most of the particle cloud passed outside the Earth, therefore there was no geomagnetic storm, but only an increase in geomagnetic activity. The new AR3234 produced M class flares in the following days. Dellinger events could only affect radio wave propagation up to 20 MHz, as long as we had the Sun overhead, of course. Thereafter no significant flares were observed, so no CMEs were directed toward us. But that may change when AR3234 turns toward Earth. In other words, when the Suns rotation moves it to the central meridian, which will happen by the end of the week. Primarily, the overall activity of the Sun and most likely the Earths magnetic field will depend on its activity. The latest report from Dr. Tamitha Skov, WX6SWW, can be found on //youtu.be/ . If you would like to make a comment or have a tip for our readers, please email the author at, k7ra at arrl.net. When reporting observations, dont forget to tell us which mode you were operating. For more information concerning radio propagation, see the ARRL Technical Information Service web page. A detailed explanation of the numbers used in this bulletin is also available on this site. An archive of past propagation bulletins is also available. Sunspot numbers were 101, 86, 109, 112, 135, 106, and 100, with a mean of 107. 10.7 cm flux was 163.2, 165, 167.2, 169, 159.8, 160.9, and 151.9, with a mean of 162.4. Estimated planetary A indices were 24, 6, 6, 7, 8, 17, and 6, with a mean of 10.6. Middle latitude A index was 21, 4, 5, 4, 6, 15, and 4, with a mean of 8.4. = END OF 18 WPM transition file <