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ARRL Propagation Bulletin ARLP043 (2012)

ARLP043 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 43  ARLP043
From Tad Cook, K7RA
Seattle, WA  October 26, 2012
To all radio amateurs 

ARLP043 Propagation de K7RA

Good conditions should prevail for the CQ World Wide SSB DX Contest
this weekend. A chance of solar flares has greatly diminished in the
past few days, and the latest forecast has planetary A index at a
steady and quiet 5 for this weekend and beyond, through the first
week in November.

The average of the daily sunspot number for October 18 through 24
was 95.3, down 1.7 points from the previous seven days. Average
daily solar flux rose 14.7 points to 143.9. Geomagnetic activity was
quieter, with all daily planetary A index measures in the

The current prediction (from October 25) from NOAA and the U.S. Air
Force shows solar flux at 125 on October 26, 120 on October 27, 115
on October 28-29, 110 on October 30-31, 105 on November 1-2, 100 on
November 3, then 105 and 110 on October 4-5, 115 on October 6-7, 120
on November 8-11, 125 on November 12-13, then peaking at 145 on
November 18 and dropping back to 100 on November 29-30. It then
rises to 120 on December 5-8.

This is a substantial downward revision from the previous day's
forecast, (presented in the October 25 ARRL Letter) which showed
solar flux at 135 on October 25-26, 130 on October 27-29, 125 on
October 30 through November 1, and 100 on November 2-3.

Now that I use the spreadsheet I prepared last week for tracking the
USAF/NOAA flux forecast changes, I can see a history of the changing
flux forecast for today. Until October 1 a flux value of 150 was
predicted for October 26, then it changed to 135 on October 1-14,
130 on October 15-17, 125 on October 18-19, 120 on October 20, 130
on October 21, back to 150 this week on Monday, October 22, then 140
on Tuesday, 135 on Wednesday, and yesterday 125 on October 25.

You can check the actual solar flux directly from the Penticton,
British Columbia observatory today some time after 2000 UTC at
Three readings per day are shown at 1700, 2000 and 2300 UTC, and the
local noon (2000 UTC) value becomes the official one for the day.
The way to read it is to scroll all the way to the bottom of the
page, then in the first column is the date (expressed as 20121026)
and the second is the time, 200000 for 2000 UTC. Then for the
observed solar flux, skip over to the fifth column to the right.
You can see that yesterday the three values were 132.2, 130.0 and
129.2, and so 130 became the official flux value for October 25, as
reported by NOAA at

Note the Penticton observatory resolves the number to one more
decimal place than the report from NOAA, which rounds it to the
nearest whole number.

Predicted planetary A index is 5 on October 26 through November 7,
10, 20 and 15 on November 8-10, 5 on November 11-17, 10 on November
18-19, and 5 on November 20 through December 4.

Our regular weekly geomagnetic forecast from F.K. Janda, OK1HH of
the Czech Propagation Interest Group shows quiet conditions today,
October 26, active to disturbed on October 27-28, quiet on October
29, mostly quiet October 30, quiet October 31 and November 1, mostly
quiet November 2-3, quiet to active November 4, active to disturbed
November 5, quiet to active November 6, mostly quiet November 7,
quiet to unsettled November 8-9, quiet to active November 10, active
to disturbed November 11, quiet to unsettled November 12-13, mostly
quiet November 14, and quiet November 15-17.

I received OK1HH's forecast at 1618 UTC on October 25, and I don't
know how long prior to that it was created. Based on the fact that
the likelihood of solar flares dropped dramatically in the past few
days, I think we can discount the dire prediction (active to
disturbed on October 27-28) for the contest weekend.

I received an email from him at 1132 UTC today (October 26) and he
thinks there still could be a disturbance, because a coronal hole is
position right in the center of our view of the Sun.

Sunspot group 1598 emitted a powerful X1 class solar flare on
October 23, and it is rotating into the center of the solar disc
today. But it shrunk in the past couple of days, and now the chance
of flares has declined to just 5%, according to NOAA forecasters
quoted at The shrinking of the formerly
giant sunspot led to declining solar flux predictions and should
ease any worries from the OK1HH prediction about this weekend.

Check this video at
showing sunspot group 1598 and the recent flare. Note the position
of the sunspot projected the flare away from Earth.

Also please ignore the videos previewed on the right side of the
screen, which on my display show nonsense about the end of the
world, grand planetary alignments, phantom rogue planets, the scary
"Planet X," and probably channeling your past lives using crystals.
Old time hams know that crystals are only good for channelizing

Jeff Hartley, N8II of West Virginia writes on October 22, "Regarding
peak signal directions during very disturbed conditions, they tend
to peak farther south in general and seem to divert the most on 20
meters, but I don't have any Yagis below that band. Russian Central
Asians from Zone 18 which normally peak 0 to 10 degrees were peaking
around 330-350 as an event was just starting. The next morning VK6s
which usually peak around 310 were best around 280-290 degrees. JAs
on 20 sometimes peak due north where the true heading is 330 during
low K index periods.

"Don't forget long path; T30PY around 2000Z on the October 21 was
long path on 15 SSB about S3, but not hearing well, later at 2300Z,
they were about the same strength short path and hearing people
better. I also worked A71EM long path on 17 CW around 1400Z. The
Middle East is often better long path in our mornings on 20 than
short path, but they come through well short path from 1900Z,
sometimes all the way through their sunrise.

"Conditions were quite good over the weekend (October 20-21). I had
a solid run of Russian stations on 10 meter CW starting around 1200Z
Saturday October 20 including many UA9s in zone 17, one UN0 also
made it thru with an S3 signal. OH6NT called in with a 25 dB over S9
signal. I was busy with the family Saturday evening, but Sunday
evening and afternoon were definitely above recent normal
conditions, with very late openings to Europe and Africa on all
bands, including 3B9SP on 10 CW at 2030Z. The morning
Asians/Russians were not as good on 10 Sunday, but did log VU2MGS on
10 CW. Sunday evening was quite good working BA7IO on 10 CW about 90
minutes past sunset and JA8CMC was S9 along with a CQ answer from
UA0IT who was S5-7 with only a vertical antenna."

Pat Ryan, KC6VVT of Tonica, Illinois reported on October 20, "10
meters opened yesterday between the US and Europe, and many stations
appeared on 10 as word spread via Facebook. I heard (in grid EN51)
IZ7NLJ running 400 watts into his home brew Yagi antenna, and
CT1DVV, both working the US pileups! I used my 100 watt radio and 10
meter resonant vertical whip antenna on my mobile parked in my
driveway to work Augi from club station 9A1CCB in Croatia (JN85) and
Karel OK1CF in the Czech Republic (JO60) from 1558-1608Z. Later,
around 1742Z from the inside station (using 100 watts into a 5-band
ribbon dipole, 20-10M), I worked Antonio CU3AG in Azores Island

Pete Markavage, WA2CWA of Sayreville, New Jersey reports, "On
October 18 had a great morning on 10 meters AM. Band opened around
9:30 AM into Europe. Worked mostly around 29.01 MHz, included: OR0A,
G3VWH, SM2A, AND ON3KA. AM is alive and well on the upper end of 10
meters.  I was running about 100 watts into an old Wilson System 1
tri-bander up about 40 feet."

Last week's Propagation Forecast Bulletin ARLP042 mentioned Joe
Dawson, K4WLS of Atlanta, Georgia and his Slinky antenna. He wrote
again on October 19 about a Slinky-to-Slinky QSO: "I spoke to a ham
in Italy on 10 meters this morning who is running the same mini
slinky antenna. He tells me that the low take off characteristics of
the antenna make it his DX choice on 10 and 12 meters.

"I got a slinky junior antenna to use on a camping trip. I put it up
to test it as an inverted V on my back deck. It has worked MAGIC on
17, 15, 12 and 10 meters. I would not have believed it since I
thought it would tune to 20 and 40 due to the electrical length.
Well, it does not tune to 20 and 40 but DX contacts galore on the
upper 4 HF bands. I love it!"

Lee Gordy, KJ4KUT of Cartersville, Georgia wrote, "When 'Ten is In,'
then you can load just about anything and make some DX contacts with
low wattage. My uncle W4TIY (SK), former FCC Monitoring Engineer,
was stationed in Texas at the end of World War 2. He had rented a
room at a boarding house. 'Ten was In' so he loaded the metal
bedsprings....literally. Made some really good contacts."

And finally, Don Kalinowski, NJ2E of Cary, North Carolina sent along
this interesting and entertaining video about the NASA Radiation
Belt Storm Probes. Watch it at,
and note that you can expand this all the way to double normal
resolution by clicking on the asterisk-like "Change Quality" control
at the bottom, then click on "Full Screen" all the way to the right.

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 Find more good
information and tutorials on propagation 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 October 18 through 24 were 112, 120, 112, 75,
86, 84, and 78, with a mean of 95.3. 10.7 cm flux was 137.6, 141.4,
151.4, 144.2, 155.6, 141.6, and 135.6, with a mean of 143.9.
Estimated planetary A indices were 5, 4, 3, 3, 3, 7, and 4, with a
mean of 4.1. Estimated mid-latitude A indices were 4, 3, 3, 2, 2, 9,
and 6, with a mean of 3.7.


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