Solar activity did a rebound this week, back to more active levels.

Average daily sunspot number increased from 36.6 to 65.4.

Average daily 10.7 cm solar flux rose from 95.7 to 111.9.

Solar wind caused geomagnetic numbers to rise, with average planetary A index going from 7.7 to 14.4, and middle latitude numbers from 8.6 to 12.1.

An improved outlook shows solar flux over the next month peaking at 116 on September 2 to 4.  The forecast from USAF/NOAA on Thursday evening was improved from Wednesday.

A look at ARLP032 from 2021 gives a perspective on solar cycle progress.  A year ago, average sunspot number was 6 and average solar flux was just 74.8.  Quite a difference from 65.4 and 111.9 during the past week.

Predicted flux values are 115 on August 12 to 14, 110 on August 15 to 18, 108 on August 19, 104 on August 20 and 21, then 98, 100, 102, 100, 102, and 100 on August 22 to 27, then 102 on August 28 to 30, then 108 and 114 on August 31 and September 1, 116 on September 2 to 4, 112 on September 5 to 7.  110 on September 8 and 9, then 108 on September 10 to 12, 106 on September 13, then 104 on September 14 to 16, 102 on September 17 and 98 on September 18.

Predicted planetary A index is 12 on August 12, 5 on August 13 to 16 then 10, 12 and 15 on August 17 to 19, 8 on August 20 and 21, 5 on August 22 to 26, 12 on August 27, 8 on August 28 to 30, 5 on August 31 through September 2, then 14, 18, 14, 10 and 8 on September 3 to 7, and 5 on September 8 to 12, then 22 on September 13, 15 on September 14 and 15, 8 on September 16, and 5 on September 17 to 22.

OK1HH commented:

"A geomagnetic disturbance rarely comes completely unexpectedly. And even more so in a situation where its source cannot be located (or selected from several locations).  Moreover, lasting five days. All this happened between August 7th and 11th.

At higher latitudes, the 'STEVE' phenomenon was sighted on August 7 (Strong Thermal Emission Velocity Enhancement).  STEVE is a recent discovery.  It looks like an aurora, but it's not.

https://en.wikipedia.org/wiki/STEVE

It all started with a positive phase of disturbance in the ionosphere, when shortwave propagation improved.  The development continued with a deterioration of propagation in the negative phase on August 8, followed by generally below average conditions in the following days.  With a strong influence of sporadic layer E, whose activity usually increases as the Perseids meteor shower approaches maximum (expected on 12 and 13 August).  They are also called the 'Tears of St. Lawrence'.

Starting August 12 onward, we expect a longer mostly quiet period."

NASA expects increasing activity:

https://bit.ly/3QjOLk5

Always appreciate The Sun Now page from the Solar Dynamics Observatory:

https://sdo.gsfc.nasa.gov/

Yet another cycle prediction method:

https://bit.ly/3SKm29J

Tamitha Skov, WX6SWW has a 200 minute part 2 of a course on ground effects:

https://youtu.be/cOom5LQ_LBY

Send your tips, reports, observations, questions and comments to k7ra@arrl.net.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation and the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals. For an explanation of 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/

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

Sunspot numbers for August 4 through 10, 2022 were 52, 69, 69, 87, 63, 58, and 60, with a mean of 65.4.  10.7 cm flux was 108.8, 112.2, 116.3, 116.1, 113, 109.4, and 107.6, with a mean of 111.9.  Estimated planetary A indices were 6, 6, 4, 24, 31, 19, and 11, with a mean of 14.4.  Middle latitude A index was 7, 7, 5, 20, 21, 15, and 10, with a mean of 12.1.