SB PROP @ ARL $ARLP014
ARLP014 Propagation de K7RA
QST de W1AW
Propagation Forecast Bulletin 14 ARLP014
From Tad Cook, K7RA
Seattle, WA April 4, 2020
To all radio amateurs
SB PROP ARL ARLP014
ARLP014 Propagation de K7RA
A new sunspot appeared on the last day in March and the first days
of April, with daily sunspot numbers of 12, 13 and 12. Total
sunspot area increased on each day from 10 to 20 to 30 millionths of
a solar hemisphere.
Fortunately this was a cycle 25 spot, according to the magnetic
Prior to this no sunspots were seen since earlier in March, when
daily sunspot numbers were 13 and 12 on March 8 and 9.
Average daily solar flux this week (March 26 through April 1)
declined from 71.1 to 69.4. Average daily geomagnetic indicators
were identical to the previous week, with planetary A index at 7.7
and middle latitude A index at 5.9.
Predicted solar flux for the next 45 days is 70 on April 3 to 22,
then 68 on April 23 to May 7, and 70 on May 8 to 17.
Predicted planetary A index is 8 on April 3, 5 on April 4 to 14, 10
on April 15, 8 on April 16 to 19, 5 on April 20 to 25, 12 on April
26 and 27, 8 on April 28 and 29, 5 on April 30 through May 11, 10 on
May 12, 8 on May 13 to 16 and 5 on May 17.
Geomagnetic activity forecast for the period April 3 to 29, 2020
"Geomagnetic field will be
Quiet on: April 6 and 7, 10, 20 and 21
Quiet to unsettled on: April 3 to 5, 11 to 13, 24, 28 and 29
Quiet to active on: April (8 and 9, 25)
Unsettled to active on: (April 14 to 19, 22 and 23,) 26 and 27
Active to disturbed: none predicted
Solar wind will intensify on: April 9, 12 and 13, (15 and 16,) 17 to
19, (20,) 26 to 28
- Parenthesis means lower probability of activity enhancement.
- The predictability of changes remains lower as there are no
Chip, K7JA reports, "The late afternoon of March 31st, 2020 brought
a 6-meter opening to the southern half of California, as well as
states to the east. Here in DM03, south of Los Angeles, I worked
Dale, CE2SV on FT8 at 2325 UTC, followed by CE3BN, XQ3MCC, and
XQ3SK/4. Worked CE2SV on CW at 0002 UTC (1 April), and several other
CE and LU stations were heard but not worked, along with HC2GR.
"Flags" from PSKReporter indicate that I was heard by a total of
seven CE stations, plus LU9FVS.
Because we are so far north (geomagnetically), I suspect this may
well have been an E-to-TEP path. Stations as far north as the San
Francisco Bay area got in on the opening, as well.
Nothing on the afternoon of April 1st, but you can bet the entire
West Coast is watching.
I run about 180 Watts from a TS-990 to a 7-element LFA (Loop Fed
Array) about 72 feet high."
Jon Jones, N0JK commented. "Remarkable results with a solar flux of
N0JK also reported, "Sporadic-E propagation appeared on 50 MHz the
afternoon of March 28 from Kansas to Florida. I worked N0RW in grid
EL87 on 6 Meter FT8 at 2242z. I decoded WB4JPG (EM71) but no
KF0M in Wichita, KS EM17 also made several 6 Meter Es contacts with
Florida stations including K3VN. He copied W5LDA (EM15) working
CO3JR (EL83) at 2355z on FT8.
Sporadic-E is rare in March. The month of March has the lowest
occurrence of sporadic-E of any month for the northern hemisphere."
WB5AGZ reported from Stillwater, Oklahoma:
"I have been hearing what I believe to be Sporadic E almost every
afternoon since about last Sunday, March 29.
It is weak but certainly present with long slow fades.
The first evidence was a few seconds during the afternoon of March
29 with a repeater system in North Carolina. The opening was never
long enough to pick out a complete call sign but one could hear
parts of the repeater's voice ID.
The exact time is not known because this is a recording made over
many hours from a scanner connected to a computer running software
that makes a VOX-style sound recording without individual time
It is now Thursday April 2 and a playback from Wednesday picked up a
long QSO between two amateurs using the KQ2H system in the New York
Signals were just strong enough to mostly copy with very long
periods in which it sounded like a system in a town almost out of
range coming via ground wave propagation and then there would be a
fade and then it came back.
A recorded female voice announced the time as 7:15 which is as close
to a time stamp as I have. In the Central Daylight time zone, this
would have been 18:15 or 23:15 UTC. The antenna is a discone about
50 FT above ground feeding a Uniden BCD996XT scanner tuning 6 and 10
Hopefully, we will get much better Es in days and weeks to come."
Space.com offers a solar cycle observation:
Ken, N4SO reports from Alabama, "This late night propagation is now
setting a pattern.
Mode: FT8, Frequency 21.074 MHZ
March 31 12:27 AM local start time, ending 12:30 AM local (the four
digits on the left are UTC)
The stations are located in Australia and New Zealand
052730 -14 0.2 1196 ~ VR2XYL ZM3SSB RE66
052800 -16 0.2 1196 ~ VR2XYL ZM3SSB RE66
052830 -16 0.2 1195 ~ VR2XYL ZM3SSB RE66
053000 -16 0.2 1196 ~ VR2XYL ZM3SSB RE66
The radio is often left on to monitor the frequency 21.074 MHZ."
You can use pskreporter to see what Ken is currently hearing.
Go to https://www.pskreporter.info/pskmap.html and select 15m and
signals received by N4SO using FT8.
KA3JAW monitors 11 meters. "On Tuesday, March 31, 2020, eleven days
after the passing of the spring equinox (March 20), unexpected
visitors waved their hands on the 11 meter band for attention for
six straight hours.
At 4:37 pm local (ET) Mid-Atlantic states noticed sporadic-e signals
originating from the southeastern states of LA, MS, AL, FL, GA.
One hour later, states of TN, AR, then the furthest Gulf of Mexico
state of TX along the northeastern corner borders of AR and LA that
ranged out to 1,200 average air miles near the city of Tyler.
During the 9 pm hour, sporadic-e was slowly degenerating.
At 10:28 pm it had dispersed into The Twilight Zone.
The last time an event like this took place, with half its time was
way back on Monday, February 24th from 9:58 am to 12:49 pm local
Thanks to Don Wright, AA2F for catching an error in the earlier
version of this bulletin in the ARRL Letter, in which I neglected to
update the solar flux and sunspot number averages from last week's
numbers. One thing that contributed to the confusion was the fact
that the averages for the geomagnetic indices were exactly the same
as the previous week's data.
If you would like to make a comment or have a tip for our readers,
email the author at, email@example.com.
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
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 March 26 through April 1, 2020 were 0, 0, 0, 0,
0, 12, and 13, with a mean of 3.6. 10.7 cm flux was 70.2, 69.4,
69.2, 68.8, 69.3, 69.9, and 69.2, with a mean of 69.4. Estimated
planetary A indices were 5, 5, 5, 7, 11, 15, and 6, with a mean of
7.7. Middle latitude A index was 5, 4, 4, 6, 8, 10, and 4, with a
mean of 5.9.