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ARRL Propagation Bulletin ARLP036 (2016)

ARLP036 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 36  ARLP036
From Tad Cook, K7RA
Seattle, WA  September 2, 2016
To all radio amateurs 

ARLP036 Propagation de K7RA

Over the past week (August 25-31) average daily sunspot numbers rose
from 33.9 to 60.1, and average daily solar flux increased from 79.6
to 87.9, compared to the previous seven days.

In fact, the average daily sunspot number for August was 50.4, the
highest since February, when it was 56.1.

The three month moving averages of sunspot numbers for this year
were 49, 45.3, 43.1, 35.4, 33 and 33.5.

Over the same period average planetary A index declined from 9.7 to
8, and mid-latitude A index went from 8.7 to 6.9. That's a nice
combination, lower geomagnetic activity and higher solar activity.
As solar activity declines overall, there will be brief respites
when sunspots increase, but only temporarily,

Predicted solar flux is 100 on September 2-4, 95 on September 5-8,
85, 78 and 80 on September 9-11, 82 on September 12-16, 80 on
September 17-21, 82 on September 22, 85 on September 23-25, 82 on
September 26-27, 85 on September 28-29, 80 on September 30 and
October 1, 78 on October 2-7, 80 on October 8, and 82 on October

Predicted planetary A index is 15 on September 2, 12 on September
3-4, 15 on September 5-6, 10 on September 7-8, 5 on September 9-12,
then 10 and 8 on September 13-14, 5 on September 15-16, then 8, 5,
15, 12 and 8 on September 17-21, 5 on September 22-24, then 20, 18,
10, 15, 12, 10 and 8 on September 25 through October 1, 15 on
October 2-3, 8 and 10 on October 4-5, and 5 on October 6-9.

Here are a couple of geomagnetic predictions from the Czech

Geomagnetic activity forecast for the period September 2-September 8, 2016:

Quiet: September 6-8
Unsettled: September 2-8
Active: possible September 5-6
Minor storm: 0
Major storm: 0
Severe storm: 0

Geomagnetic activity summary:

After the observed active periods, we expect partial decrease to
unsettled conditions. We expect the unsettled conditions at most for
the whole forecast period. Between September 6 and 8, decrease to quiet
conditions is possible.

Active periods can occur in the first half of forecast week, we
expect only isolated events.

From Tomas Bayer RWC Prague Institute of Geophysics of the ASCR,
Prague Department of Geomagnetism Budkov observatory (BDV).

This is from last week's propagation forecast bulletin. We did not
receive their current forecast, so included a more recent short-term
forecast above:

Geomagnetic activity forecast for the period September 1-21, 2016

Geomagnetic field will be: 

Mostly quiet on September 9-11, 14-16, 18

Quiet to unsettled on September 1-3, 6-8, 12, 17 

Quiet to active on September 4-5, 13, 19-21

Increased solar wind from coronal holes are expected on September
4-5, 12-13, 17, 19-21.

This email from Jeff Hartley in West Virginia was dated August 26,
but did not arrive in time to include in last week's propagation
forecast bulletin:

"I have been on the air a lot this week. There was a very long
lasting Es opening to St. Paul Island, CY9C on Aug 24; I worked them
on 15 SSB, 12, 10, and 6M each both modes! Their 10M SSB operator
said they made over 1000 6M QSOs that day by around 1800Z and the
opening lasted on 10M until just past 2200Z! 10M was open probably
all of the time except a few minutes from 1745-2200Z to them. It
must have started fairly early in the AM and they had a very fast
operator on 6M. I will send more detailed report if time this week.
There were quite a lot of Es before the 24th, but nil the past 2

"The skip zones on 20 and 40 were very long all day today making it
difficult to work National Parks on the air east of WI, but EU was
loud in mid-afternoon until past 2230Z."

Jeff sent another email yesterday, September 1:

"When CY9C on St. Paul Island just north of Nova Scotia started
operating it was easy to work them on all bands 20M and lower even
no problem on 160M. But I had to work them on backscatter on 17M
phone, surprisingly easy, and they were quite weak on 15M CW
backscatter one afternoon but heard me after a few minutes of
calling while they were working southerly W4s who were loud here on
a sporadic E opening. We had quite a bit of sporadic-E as high as
10M into mostly FL, but also the gulf coast states around to TX and
up to OK on the 23rd, but nil to anywhere north. Then some Es magic
occurred to CY9C on the 24th which made many operators happy on many
high bands.

"I turned on the radio at 1756Z and found them loud (worked first
call on 10M phone), then 2 minutes later on 12 M phone. I listened
back on 10M and the CY9C operator mentioned they had worked over
1000 QSOs on 6M that day! So they must have had several wide open Es
hours already by then. My 6M antenna is intermittently shorted, so I
gave it a try with my small Force 12 10-15-20M tribander which had a
low SWR on 6 and worked them right away on 50130 kHz CW, with them
peaking around S5-7 and first call even louder a bit later on SSB. I
checked back once more around 1900Z and they were still coming thru
on 6M. I filled in the remaining slots on 15 phone (first call
running 5W), 12 CW, and 17 CW and on 10 CW at 2020Z with a booming
S9+15-20 dB signal. The Es opening apparently lasted until just past
2200Z. The operators were excellent and worked the high bands as
much as they could that day.

"Since then sporadic-E has been almost nil except for some Saturday
evening which I will mention. The Es MUF tool confirmed
my observations. It estimates Es MUF for each grid square using
cluster spots and several ionospheric sounders operated by the U.S.
government, the nearest to here being in SE Virginia at Wallops

"The 25th was the 100th anniversary of the National Park service, so
I spent the day trying to work National Parks On The Air stations
who were very active through about 1900Z. It was a challenge with
very long skip zones on 20 M and even on 40 with a low solar flux,
but I worked almost all of them (several on backscatter) except for
3 or so in the NE USA and OH. The next day activity was still high
with conditions even a bit worse and my backscatter QSO luck ran out
with many in the east completely in the noise and no Es again.

"Saturday started with making a few QSOs in the Romanian DX test
finding 15M open to all over Europe as far as RK4FD in SE EU, and
Russia, Sweden and Lithuania as well. Most signals were S7 or weaker
with many fading in and out of my low noise floor.

"Then, I worked the Kansas QSO Party finding 20 meters to be nearly
perfect for the whole operating period from 1400Z-0200Z Saturday and
1400Z-1900Z Sunday. I worked 475 KS QSOs mostly on 20 with about 90
on 40 and 104 of the 105 counties which were all active. 40 was very
weak to KS most in the afternoon until about 2200Z, but I caught
some mobiles there. Virtually everyone was very good copy on 20 and
the home stations with yagis were as loud as 30 dB over S9 with
stations using wires over S9 at times. I think some Es saved 20 from
closing to KS around 2400Z as stations in OH appeared on 40M who had
been skipping over in the noise all day working the OH QSO Party.

"15 meters sounded dead Saturday afternoon except to Brazil, even
though the Hawaii QSO Party was also taking place. I did work about
14 HI QSOs while also working KS on 20M including a few who called
me.  Signals were not really loud from there until 0100Z, but quite
workable all day from 1730Z onward. Finally, on Sunday 15 M opened
well to Hawaii which I first noticed at 2000Z. I heard KH6TU work
Spain also hearing the EA3. All of the 4 stations were very easy to
work, the loudest around S 7-9. I think the SFI was slightly higher.
Also of note were loud EU stations until around 2400Z Saturday off
the back corner of my yagi on 20M."

The Autumnal Equinox is less than 3 weeks away. This always means HF
conditions are likely to be better.

This story about a daylight star party in New Jersey mentions K2BOG,
but not by callsign: .

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 the ARRL
Technical Information Service web page at, For an explanation of the
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 August 25 through 31 were 39, 44, 52, 64, 67,
64, and 91, with a mean of 60.1. 10.7 cm flux was 78.7, 81.9, 83.9,
85.4, 87.8, 100.4, and 97.5, with a mean of 87.9. Estimated
planetary A indices were 11, 7, 5, 3, 6, 16, and 8, with a mean of
8. Estimated mid-latitude A indices were 9, 5, 5, 4, 5, 12, and 8,
with a mean of 6.9.


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