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ARRL Propagation Bulletin ARLP016 (2020)

ARLP016 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 16  ARLP016
From Tad Cook, K7RA
Seattle, WA  April 17, 2020
To all radio amateurs 

ARLP016 Propagation de K7RA

Sunspots are gone again.  We are at the bottom of the solar cycle,
so conditions should only get better.  There is an increase in
on-air activity due to the large number of people staying at home
because of Covid-19, and this week we seem to be overwhelmed with
reports of sporadic E openings.
The last observed sunspot disappeared on April 5, so weekly average
daily sunspot numbers declined from 5.1 last week to zero this
reporting week, April 9 to 15.  Average daily solar flux went from
70.2 to 69.5.
Geomagnetic indicators remain quiet as well, with average daily
estimated planetary A index going from 6.6 to 6.1, and mid-latitude
numbers, sourced from a single magnetometer in Virginia, to 5 from
Predicted solar flux is 69 on April 17 to 24, 70 on April 25 through
May 8, 68 on May 9 to 20, and 70 on May 21 to 31.
Predicted planetary A index is 8 on April 17 and 18, 12 and 8 on
April 19 and 20, 5 on April 21 to 25, 10 on April 26 and 27, 5 on
April 28 and 29, 8 on April 30, 5 on May 1 to 4, then 12, 5, 8 and 8
on May 5 to 8, then 5 on May 9 to 11, 10 on May 12, 8 on May 13 to
16, 5 on May 17 to 22, 10 on May 23 and 24, then 5, 5 and 8 on May
25 to 27, and 5 on May 28 to 31.
Geomagnetic activity forecast for April 17 til May 12, 2020 from F.
K. Janda, OK1HH:
"Geomagnetic field will be  
Quiet on April 20 and 21, May 2 and 3, 6  
Quiet to Unsettled on April 17 and 18, 22 to 24, 28 and 29  
Quiet to Active on (April 25, May 1, 5, 7 to 9, 12)  
Unsettled to active on (April 19, 26 and 27, 30, May 4, 10 and 11)  
Active to Disturbed:  Nothing. 
Solar wind will intensify on April 17 to 19, (20,) 26 to 28, May 4
to 6, 8 to 10
- Parenthesis means lower probability of activity enhancement.  
- The predictability of changes remains lower as there are no
HI8PLE wrote on April 11 from Dominican Republic:
"E's season started very well here, there has been a great activity
on 144 MHz in the Caribbean.  On April 9 2140 UTC worked PJ2BR,
April 11 0027 UTC worked J69DS, at 1936 9Y4D, 9Z4DZ, finally April
12 at 0113 YY5BRB, all QSO using FT8 with 16 ele beam and 150 watts.
I have noticed that the conditions with the Lesser Antilles are
steady and last all day and night, then, at dusk some TEP activity
on 50 MHz with PY, LU, CE and CX.
It seems to me that this will be a good E's season until June-July.
Take care and please stayhome.  73, Edgar"
Danny Miller, KB8W (EN57) wrote:
"Yesterday, April 14, 2020 was the earliest Es/TEP activity that I
have ever experienced here in EN57 (in the far NW corner of
Michigan's Upper Peninsula)."
"I have been active for the past 10 years on 6 meters.  I looked
back in my logs and find that the first Es activity of the spring
season is usually in early May, in 2019 my first contact was on May
10.  But I have never even heard anyone via Es in April of any year
(I have made contacts via meteor scatter in all months of the
"6m opened for me at about 1710Z on April 14 when I copied CM2XM
(EL83) on 50.313 MHz using FT8.  Over the next 10 hours I worked 19
stations in New England, the Gulf coast and Cuba."
"According to PSKReporter, I was heard at 2202Z by TI2CDA (EJ79) and
at 2201Z by HK4GSO (FJ26), those are the first TEP receptions that I
have experienced.  I was still hearing signals when I turned off the
radio and went to bed at about 0400Z April 15."
"For me, a remarkable day as I run only 50 W to a 5 element Yagi."
AA8WH writes from Michigan, "Starting April 14 at about 2246 UTC, 6
meters was open on FT8.  I worked NK4DX, in Ft. Lauderdale.  When 6
died down, I moved down to 12 meters, and worked KN4NN in
Crawfordville FL, W9OO in Harvey, IL.  I then moved up to 10 meters
and worked WZ9B in Noble IL, N4UXP in Atlanta GA, NT4J in Fuquay
Varina NC, AB0S in Beloit KS.
At 0324 UTC, signal strengths were up to s-7 on the peaks, N5LFA in
Potts Camp MS, WB4HMA in Nashville TN, N4JRS in Oakwood GA, J68HZ on
St. Lucia.
10 meters continued to stay open well past 0400 UTC."
Lance Collister, W7JG wrote from Frenchtown, Montana:
"April 15 was the best 6m activity I have ever seen this early in
the season.  Unlike the eastern half of the country, out here in
western Montana we normally are one or two hops away from linking
into any high TEC activity and/or TEP propagation.  Usually it seems
a higher Kp index is required to cause 6m Es openings to the south
from up here.  But perhaps because the Kp index had been up to 3 on
both April 14 and early on April 15 plus the time of year had
something to do with it.  Anyway, the 6m band was open from here in
western Montana to the southeast for 9 hours, and I worked my first
HC (Ecuador) station since I got on 6m 24 years ago.  In addition to
many domestic contacts, these DX stations were all worked on 50.313
using FT8 mode:  XE1KK, XE1K, XE1EE, XE1H, TI2CDA,TG9AJR, TG9ANF,
and CX6DRA."
"Normally up here, we wouldn't think a big Es opening before the end
of May was possible!  I am sure it helped that so many people were
sequestered at home during the pandemic and able to be by their
radios!  This may be a once in a lifetime event, but it sure was
memorable!  Looking forward to the great 6m EME condx at the end of
this month to pick up another ATNO on 6m."
Check out Lance's web page at
Dave Bono, K6OAK of Fremont, California wrote, "We are in the middle
of week 5 of Stay at Home restrictions here in the S.F. Bay Area.  I
thought I would use the opportunity of being home to make some
improvements to my 6BTV ground mounted antenna.  So I checked all my
cable connections and added two 33 foot and a few shorter ground
radials.  Then I went into the shack shortly after 2200Z and fired
up the Kenwood 590SG to see if there was any improvement.  Listening
to FT-8 there were signals on all bands 6 to 40M!  Wow what a
difference.  I worked a bunch on 10M in short order at under 30
watts.  I wish I could say it was the radials, but I'm sure it was
just a coincidence that the bands opened up after being very stingy
for the prior few days and weeks!"
Mike, W9NY operates from the top of a tall building in Chicago.
"To my surprise 10 meters and 6 meters were full of stations coming
in to Chicago the evenings of April 14 and 15.  Using a
non-directional poorly matched antenna (G5RV for 20 meters up 450
feet) with 100 watts on SSB I worked several stations around the USA
on 10 and some on 6 meters including Mexico.  Can't wait for those
WB5AGZ wrote:
There was a whopper of an opening to Oklahoma on Tuesday April 14
from around 16:30 Central Daylight time until it all faded out near
Midnight.  As heard from a discone about 50 FT above the ground,
signals on 10 meters from the East Coast of the US rolled in from
the New York City Area down to North Carolina with lots of different
signals fading in and out over each other which is quintessential
Sporadic E behavior.
It all appears to have started rather suddenly at about 16:45 local
time.  The scanner was hearing business and public safety signals
from local sources and then W4BWW in East Tennessee came in out of
the blue talking to a station in Kansas which was inaudible from
here, here being about 60 miles South of the Oklahoma/Kansas border.
That exchange was probably on 29.6 as it was simplex.  The next
signal was a piece of a repeater ID in North Carolina in which all
one could hear was a female voice saying "North Carolina at the end
of the ID.  In a later fade-in, that turned out to be WB4BVA in
Wilksborough, North Carolina.
After that, it was crazy-town on steroids.  There was a MCW ID for a
repeater in the 3rd or 4th call area that was too mutilated to read
which later turned out to be N3AUY MD PL 4A when it faded in again.
I cheated and replayed the recording several times before I could
copy the CW properly.
I am not used to a PL tone of 4A but that is what it sent.  It's
obviously in Maryland.
One of the signals in for a good portion of the evening was the
WA3PBD repeater in Pitsburg, PA.  It's full MCW ID is WA3PBD/R PGH
and it's signal was present though occasionally blotted out by
temporarily stronger signals from other repeaters before coming back
in.  Another briefly-heard system was the KD2WA repeater whose voice
ID gives the PL tone as 110.9 Hz in a synthesized male voice.
I did possibly hear a Florida station but am not sure if I actually
heard him on simplex or he was hitting one of the repeaters.  The
scanner is set to scan 29.6 through 29.680 in 20 KHZ steps and the
band opening was good enough to make this a very chaotic experience.
Newcomers to amateur radio who heard this opening got to hear what
10 FM was like in previous sunspot maxima even though this is the
bottom of the barrel for solar activity.
Also, what anybody hearing all this chaos may not realize is that
there was once a time in which the 30 to 50 MHZ band was the
work-a-day band for business and public safety communications in the
Americas.  The incredible Sun spot cycle of 1958 meant that hundreds
of cities and small towns alike would jam each other's radio systems
with full-quieting foreign traffic or "skip" as they tried to do
routine business.  The Boston Fire Department was full quieting in
Oklahoma and surrounding states on 33.77 MHZ on just about any
Winter day during Solar peaks.
Those openings spurred the mass moves to the 150 to 174 and up radio
bands where most mobile business and emergency services now live.
This is the kind of thing that can hook people in to amateur radio
for life."
If you would like to make a comment or have a tip for our readers,
email the author at,
For more information concerning radio propagation, see and the ARRL Technical Information
Service at  For an
explanation of numbers used in this bulletin, see
An archive of past propagation bulletins is at  More good
information and tutorials on propagation are at
Monthly propagation charts between four USA regions and twelve
overseas locations are at
Instructions for starting or ending email distribution of ARRL
bulletins are at
Sunspot numbers for April 9 through 15, 2020 were 0, 0, 0, 0, 0, 0,
and 0, with a mean of 0.  10.7 cm flux was 70.3, 69.2, 70.6, 70.8,
70.3, 68.9, and 68.4, with a mean of 69.5.  Estimated planetary A
indices were 5, 5, 6, 7, 5, 8, and 7, with a mean of 6.1. Middle
latitude A index was 5, 4, 4, 5, 4, 7, and 6, with a mean of 5.


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