At 2335 UTC on June 2, the Australian Space Forecast Centre issued a geomagnetic warning.
"A solar filament recently erupted from the southwest quadrant of the solar disk. Event modeling suggests a minor impact to the Earth's magnetosphere on late 05 June to early 06 June."
All our measures of solar activity declined in a big way from the last reporting week to the current period, May 26 through June 1.
Average daily sunspot number plummeted from 124.7 to 52.9, and average daily 10.7 cm solar flux receded from 158.8 to 104.3. These are dramatic shifts, although well within expected variations at this point in solar cycle 25.
Predicted solar flux for the next month is 100 on June 3 to 5, 98 on June 6, 95 on June 7 and 8, then 90, 130, 135, and 140 on June 9 to 12, then 145, 150 and 145 on June 13 to 15, 140 on June 16 to 18, then 130, 125, 120 and 110 on June 19 to 22, 100 on June 23 to 29, 98 on June 30 through July 3, then 110, 112, 125, 130, 135, and 140 on July 4 to 9.
Predicted planetary A index is 5 on June 3 and 4, 15 and 12 on June 5 and 6, 5 on June 7 to 9, 8 and 12 on June 10 and 11, 14 on June 12 and 13, then 8 and 12 on June 14 and 15, 14 on June 16 and 17, 12 on June 18, 5 on June 19 to 22, then 16, 22, 12, 10 and 8 on June 23 to 27, and 5 on June 28 to July 6, then 8 and 12 on July 7 and 8, and 14 on July 9 and 10.
OK1HH wrote:
"Last weekly commentary mentioned the possibility that the current 25th solar cycle could resemble the nineteenth, which peaked in 1958. However, it should be recalled that this was before the beginning of the satellite era, so compared to cycles 20 to 24 in fact, we know very little and comparison is difficult. Today's predictions of solar activity, without satellite measurements and observations, cannot even be imagined. The possibility of reaching such a high maximum as we experienced in 1958 applies under the conditions 'if the growth of activity continues with the current speed' and it is not the only condition.
After large active areas sank a week ago, solar activity dropped significantly. No major eruptions were observed.
The surprise was the G1-class geomagnetic storm on May 27th, related to the solar flare on the evening of May 25th. According to most predictions, the CME should have missed the Earth. In the shortwave propagation, we recorded an afternoon improvement on the 27th, followed by a significant degradation in the following days.
The second surprise was the occurrence of reversed magnetic polarity sunspot (AR3027) on June 1st. We commonly encounter this phenomenon around the minimum of the eleven-year cycle, later only exceptionally. The return of higher solar activity can be expected as early as next week. A more significant improvement in shortwave propagation awaits us around mid-June."
Thanks to David Moore, about how the current cycle progress is not exceptional, and definitely not another Cycle 19.
https://bit.ly/3M7YOFS
Interesting.
https://www.sidc.be/silso/predikfcm
https://www.sidc.be/silso/ssngraphics
N0JK wrote on May 31:
"There was great propagation to South America from the Midwest for the CQ WPX CW contest last weekend. Both Saturday and Sunday 10 meters was open to Argentina, Brazil, Uruguay and other countries. I operated 'fixed mobile' with 10 watts and a quarter wave whip. Made 16 contacts.
I suspect the higher solar flux from Solar Cycle 25 picking up helped with TEP ionization. And sporadic-E set up links to TEP."
KA3JAW reports:
"On Wednesday, June 1, 2022, between 1819 and 1833 UTC I received WM2XEJ in EM83 calling CQ using FT8 on the experimental 8-meter (40 MHz) band via short-haul sporadic-E. Distance 670 miles, azimuth 220 deg.
The 8-meter experimental band is within the worldwide Industrial-Scientific-Medical (ISM) segment between 40.660 to 40.700 MHz with a 40 kHz bandwidth, center frequency on 40.680.
WM2XEJ is an FCC Part 5 Experimental Radio Service station operated by Tom Mills, WB4JWM in Eatonton, Georgia.
Tom is authorized to operate at 400 watts ERP using CW, SSB, FT4, FT8, WSPR, and Q65.
Tom uses an Icom IC-9100 rig into a vertical loop antenna at 300 watts ERP.
This was the second time I received WM2XEJ via sporadic-E. The first time was on Saturday, April 30, 2022, between 1607 and 1632 UTC.
Here is an update to the 8-meter experimental band which happened today, Thursday, June 2, 2022.
Sporadic-E started at 1521 til 1917 UTC.
1521 to 1917 UTC WM2XEJ EM83 3RD time received via FT8, 670 miles, azimuth 220 deg.
1704 to 1718 UTC WM2XAN EN74 1ST time received via FT8, 547 miles, azimuth 298 deg."
More on 8 meter experimental stations:
https://bit.ly/3tcsPhb
Nice images:
https://bit.ly/3NQ6LRs
Correction: In last week's bulletin change IL4LZH to Gianluca Mazzini's actual call sign, IK4LZH.
Another important and timely report from Dr. Tamitha Mulligan Skov, WX6SWW.
https://youtu.be/JggsnMpwnrA
Check out her recently updated listing at QRZ.com.
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 May 26 through June 1, 2022 were 87, 69, 34, 42, 40, 39, and 59, with a mean of 52.9. 10.7 cm flux was 122.7, 113.6, 101.8, 98.4, 100.6, 98, and 104.2, with a mean of 104.3. Estimated planetary A indices were 4, 17, 24, 15, 9, 9, and 6, with a mean of 12. Middle latitude A index was 6, 14, 19, 14, 8, 8, and 8, with a mean of 11. (arrl.org)
