This weekend is ARRL Field Day. Good conditions are expected, but on Thursday prior to this weekend there were no sunspots visible. But the forecast is for a rising solar flux over the weekend with no geomagnetic upsets expected.

Last week changes in averages of daily sunspot numbers and solar flux were mixed, not illustrating any particular trend.

Average daily sunspot numbers went from 29.1 to 33.6, and average daily solar flux decreased from 88.3 to 83.8, compared to the previous seven days.

Geomagnetic indices quieted, with the average daily planetary A index dropping from 11.1 to 7 and average mid-latitude A index going from 10.6 to 6.9.

The forecast from USAF and NOAA has predicted solar flux at 80 on June 24, 85 on June 25-30, 80 on July 1-5, 85 on July 6-7, 88 on July 8, 90 on July 9-14, 85 on July 15-18, 80 on July 19, 75 on July 20-23, 80 on July 24, and 85 on July 25-28.

They also predict planetary A index at 8, 12, and 8 on June 24-26, 5 on June 27-30, then 8, 25, 20 and 8 on July 1-4, 5 on July 5-6, 8 on July 7, 10 on July 8-9, then 8, 20, 15 and 5 on July 10-13, 8 on July 14-15, 5 on July 16-19, then 8, 12, 8, 12 and 10 on July 20-24, then 5 on July 25-28 and 25, 20 and 8 on July 29-31.

From F.K. Janda, OK1HH:

Geomagnetic activity forecast for the period June 24-19, 2016.

Geomagnetic field will be:
Quiet on June 29-30, July 1, 16-17
Mostly quiet on June 28, July 6, 10, 13-15,
Quiet to unsettled on June 25-27, July 2, 5, 18
Quiet to active on June 24, July 4, 7-9, 12, 19
Active to disturbed on July 3, 11, 19

Increased solar wind from coronal holes are expected on July 2-3, 6-7, and 16.


Dick Ferry, K2KA, of Westford, Massachusetts sent this in last week on June 17, in an e-mail titled “The Magic Band”:

“On June 13 from 1300Z to 1640Z I worked over 50 contacts with EU and 7 new countries. Signals were amazing over the entire time.

“I have a very modest setup, 200 W to 5-element M2 beam on an 18 foot boom.

“I counted over 10 more countries that I did not work. If only I had a bigger antenna, higher and more power.

“In my 6-meter experience, this was an epic opening, which I think was shared by other hams in the Northeast and across the Midwest and South. Since then the band has been pretty inactive. But on the 13th the band was truly ‘Magic’.”



For more information concerning radio propagation, see the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals. For an explanation of the numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere. An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation. More good information and tutorials on propagation are at http://k9la.us/.

Monthly propagation charts between four USA regions and twelve overseas locations are at http://arrl.org/propagation.

Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins.

Sunspot numbers for June 16 through 22 were 26, 36, 46, 48, 35, 22, and 22, with a mean of 33.6. 10.7 cm flux was 88.2, 86.6, 83.6, 85.2, 84.3, 80.2, and 78.3, with a mean of 83.8. Estimated planetary A indices were 6, 8, 8, 5, 4, 4, and 14, with a mean of 7. Estimated mid-latitude A indices were 5, 7, 10, 5, 4, 3, and 14 with a mean of 6.9.