ARRL Propagation Report
SB PROP @ ARL $ARLP020
ARLP020 Propagation de K7RA
QST de W1AW
Propagation Forecast Bulletin 20 ARLP020 From Tad Cook, K7RA Seattle, WA May 20, 2022 To all radio amateurs
SB PROP ARL ARLP020
ARLP020 Propagation de K7RA
Solar activity was up, up, up this week, with average daily sunspot numbers increasing from 74.4 to 134.1, and average daily solar flux from 120.3 to 157.3.
To get some perspective, I averaged the weekly averages for sunspot number and solar flux from this bulletin and the previous three, then compared them to the bulletins from one year earlier.
A year ago, the averages for 2021 Propagation Forecast Bulletins
ARLP017 through ARLP020 were 28.9 for sunspot numbers and 75.9 for solar flux. A year later, the averages are 96.6 for sunspot numbers and 138.4 for solar flux.
This documents a substantial increase in solar activity and is another illustration of how this cycle is progressing faster than the official cycle prediction by the experts.
Geomagnetic indicators were higher this week. Average daily planetary A index went from 5 to 9, while middle latitude A index increased from 4.6 to 9.6, compared to the previous reporting period, which always runs from Thursday through the following Wednesday.
Spaceweather.com reported on Wednesday that big sunspot AR3014 doubled in size, and presented this movie from NASA, showing 24 hours of activity:
On Thursday, Spaceweather.com presented this movie of a massive jet of plasma projecting from our Sun's southwestern limb:
Predicted solar flux in Thursday's prediction begins about 8 points lower than the Wednesday forecast, at 172 on May 20, 170 on May 21-24, then a decline from 168, 166, 150, 136, and 138 on May 25-29, then the predicted values revert back to the Wednesday forecast at
140 on May 30-31, 143 on June 1-3, 140 and 136 on June 4-5, 138 on June 6-7, then 140 and 150 on June 8-9, 154 on June 10-12, 152 on June 13-14, then 150 and 148 on June 15-16, 140 on June 17-18, 145 on June 19, 142 on June 20-21, then 138 on June 22 and 136 on June 23-24.
Predicted planetary A index is 12 on May 20, 8 on May 21-22, 5 on May 23-26, 15 and 8 on May 27-28, 5 on May 29 through June 9, 8 on June 10, 14 on June 11-12, 8 and 5 on June 13-14, 8 on June 15-16, 5 on June 17-19, 18 on June 20, then 15 on June 21-23, 8 on June 24, and 5 for at least the following ten days.
The above predictions are from Housseal and Levine of the 557th USAF Weather wing.
The Sun busts out a trio of flares:
"In the last seven days, solar activity has risen monotonously."
(I thought F.K. Janda's use of the word "monotonously" must be a mistranslation, but now I am not so sure. I thought perhaps he meant "monstrously." -K7RA)
"Moderate flares have been observed almost daily. Highest level X-rays belonged to an X1.5 class eruption, start 1350 UTC, peak 1355 UTC, end time 1359 UTC on May 10th from NOAA AR 3006 in the southwest quadrant, classified as magnetic type beta-gamma-delta.
"During the daytime, moderate flares often caused a Short-Wave Fadeout. AR 3007 and AR 3014 also evolved into the beta-gamma-delta magnetic configuration.
"No fibrous eruption was observed in any of the fibers on the solar disc. Observed coronal holes were relatively small, for this reason too, the geomagnetic activity was mostly low. The expected arrival of a CME, related to the flares of classes X1.5 and C4.7 on 10 May did not arrive on Earth.
"The decrease in geomagnetic activity together with the increase in the intensity of solar X-rays contributed to the fact that the critical frequencies of the ionospheric layer F2 were above average, increased further since 15 May."
"Here is the Solar activity forecast for the period May 20-26, 2022:
"Activity level: mostly moderate
X-ray background flux (1.0-8.0 A): in the range C1.4-C2.6 Radio flux (10.7 cm): a fluctuation in the range 145-195
Events: class C (1-10/day), class M (1-8/period), class X (0-3/period), proton (0-1/period) Relative sunspot number (Ri): in the range 140-230
"Jana Hrabalova, RWC Prague Astronomical Institute."
"Geomagnetic activity forecast for the period May 20-26, 2022:
"Quiet: May 21-23
Unsettled: May 19-20, 24-26
Active: May 19, 24
Minor storm: possible May 24
Major storm: 0
Severe storm: 0
"Geomagnetic activity summary:
"Today (Thursday, May 19), unsettled to active conditions are expected. On Friday, May 20, we expect at most unsettled conditions until Saturday, May 21. From this day to Tuesday, May 24, quiet to unsettled conditions are expected.
"About Tuesday, May 24, and Wednesday, May 25, the return of the unsettled conditions may be accompanied by a further active event."
"Tomas Bayer, RWC Prague, Institute of Geophysics, Department of Geomagnetism, Budkov observatory."
KB1AWM wrote on Sunday, May 15:
"Had a nice short opening to VK6OZ on 12m from Charleston, SC at
0330 UTC tonight. The mode was FT8. What was most amazing was given that late night propagation is usually not conducive to 12m, I switched on the amp and received a +17 dB signal report. If you take out the 7 dB from the amp, that still leaves +10 dB barefoot. I'm enjoying these 10 and 12 meter openings!"
I replied: "I've been seeing interesting stuff on 12 meters as well.
Frequently during the day on FT8 I will see my signal from here in Seattle on pskreporter ONLY being received in Florida. Weird!"
On Tuesday, May 17 on 12 meter FT8 starting at 2130 UTC I was only heard by CX6VM in Uruguay (6,945 miles), WH6S on Kauai (2,723 miles) and 3D2EZ Fiji (5,834 miles).
This persisted until 2145 UTC when I was heard by WQ6Q in California
On Thursday, May 19 I used FT8 to observe propagation on 10 meters using pskreporter.info from 1530-1600 UTC. Local sunrise was 1231 UTC. During that half hour I was receiving no signals at all, but my low power signal was being received by many stations, only in the Western United States, all between 700-1200 miles away, with one odd exception, a mysterious WLO in EM50vo, 2149 miles from me in Alabama.
WLO turned out to be the callsign of an old Coastal Maritime station in Mobile, Alabama. This doesn't mean that they are on the 10 meter band with that callsign, but instead have a receiver monitoring the band and forwarding received info via WSJT-X.
Check out this web site:
Interesting web site - the Solar Influences Data Center:
The Solar Terrestrial Centre of Excellence:
Here is a site that talks about 17 flares:
Here is an article titled "Solar flares: What are they and how do they affect Earth?" with nice graphics:
If you would like to make a comment or have a tip for our readers, please email the author at, email@example.com.
For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation and the ARRL Technical Information Service web page 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 12 through 18, 2022 were 112, 120, 105, 129, 173, 153, and 147, with a mean of 134.1. 10.7 cm flux was 133, 149.5, 152.7, 153.6, 161.7, 170.8, and 179.9, with a mean of 157.3.
Estimated planetary A indices were 8, 7, 7, 12, 10, 12, and 7, with a mean of 9. Middle latitude A index was 8, 7, 9, 10, 11, 15, and 7, with a mean of 9.6.