Propagation Forecast Bulletin #02 de K7RA:
W1AW Bulletin via the ARRL
January 11, 2013
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Propagation Forecast Bulletin #02 de K7RA:
QST de W1AW
Propagation Forecast Bulletin 2 ARLP002
>From Tad Cook, K7RA
Seattle, WA January 11, 2013
To all radio amateurs
SB PROP ARL ARLP002
ARLP002 Propagation de K7RA
After last week's somewhat downbeat look at sunspot cycles, current,
past and future, we sure have some great activity to report this
The average daily sunspot number more than doubled in the past week,
rising nearly 93 points to 163.3. Average daily solar flux was up
more than 37 points to 147.7. On top of that, the geomagnetic
conditions were very quiet, which is a wonderful combination, not
often seen in more active solar cycles.
There is a bit of uncertainty regarding the mid-latitude A-index on
January 5-6. Some sort of outage for 24 hours blocked the data (from
Fredericksburg, Virginia) on 8 consecutive 3-hour readings from late
January 5 (UTC) through early January 6. The mid-latitude K-index
tracked closely with the planetary K-index from January 3-9, so if
the data were not missing, the January 5 mid-latitude A-index would
probably have been a little higher, and the January 6 mid-latitude
A-index a little lower than reported. The daily A-index is based
solely upon the eight K-index readings throughout the day.
Currently NOAA and USAF predict solar flux values of 175 on January
11-12, 170 on January 13-14, 165, 150 and 125 on January 15-17, 105
on January 18-19, 110 and 120 on January 20-21, 125 on January
22-24, 130 on January 25-28, 135 on January 29, 140 on January 30
through February 1, then 135, 140, 135 and 130 on February 2-5, and
125 on February 6-7.
A predicted planetary A index is 5 on January 11, 8 on January
12-13, 5 on January 14-19, 8 on January 20-21, 5 in January 22-25,
10 on January 26, 5 on January 27 through February 2, 8 on February
3-5, 5 on February 6-8, and 10 on February 9.
The forecast is from January 10, and the solar flux portion is
identical to the same report on January 9. The A index portion is
only slightly different on a couple of days, otherwise the same as
OK1HH has an updated geomagnetic activity forecast. He says to watch
for quiet to unsettled conditions January 11-12, active to disturbed
January 13, quiet to unsettled January 14, mostly quiet January 15,
quiet to active January 16, quiet on January 17-19, mostly quiet
January 20-21, quiet on January 22-25, mostly quiet January 26,
quiet to active January 27, quiet January 28-29, mostly quiet
January 30-31, and quiet again on February 1-2.
Howard Lester, N7SO of Schuylerville, New York recently saw his wire
antennas go down in a big wind. The former inverted vee is now
suspended two feet above ground at the feedpoint, and 12 feet above
ground at each end. So it is now an actual upright V instead of an
inverted vee. Howard was excited to see what he could work this week
with the fast rising solar flux and sunspot numbers.
He wrote, "Mysteriously, the antenna system still loads with
identical settings on my transmatch. So I decided to try
transmitting, called a guy on SSB in Germany, and he came back to me
with a nice signal report. Then a guy in Greece. And on 17 CW I
broke through a little pileup to Iceland."
This was from January 9-10. On January 10 he wrote, "I made a couple
of contacts on 15 SSB to Poland and to eastern Ukraine, both less
than 1 hour after sunrise. They're all using giant antennas, so no
wonder they hear me. It seems awfully early in the morning this time
of year for 15, let alone 12, to be open, except that the flux is so
high right now.
"I just worked OZ1ADL, Jan, in Galten, Denmark on 12 meter SSB. He
gave me a 59 report, and was especially surprised after I described
my antenna situation. But, HIS antenna is a 13-element log periodic
at 100 feet."
With the fast-rising solar flux this week, it has been fun to
examine the thrice daily readings from the observatory at Penticton,
and look at the first column on the left for date, second column for
time and the fifth column for observed solar flux. Daily readings
are at 1800, 2000 and 2200 UTC, but the 2000 UTC reading (local
noon) is the official solar flux number for the day.
Carl Luetzelschwab, K9LA of Indianapolis, Indiana has some
observations on recent solar activity. Carl wrote, "The New Year
welcomed us with a nice increase in solar activity. In the past
several days I, along with many others, worked A45XR and A65BP (and
others) in the late morning hours on 12m and 10m via long path to
the southwest from here in the Midwest. I even worked VU2XO on 10m
SSB via long path (to the south) at 1638z on Friday January 4 - he
was extremely weak but workable.
"These QSOs are good examples of low probability openings, and they
were aided by the increased aforementioned solar activity. VOACAP
predicts these openings (even at low solar activity), along with
many other low probability paths. You just have to be there when
"Both ends of the path are looking toward the equatorial ionosphere,
with the highest MUFs in the world (even at low solar activity). Our
end of the path is in daylight, which of course is good for these
higher band QSOs. The other end is past sunset, but not far enough
past sunset to have the MUF decrease significantly - thank goodness
the ionosphere recombines much slower after sunset than it ionizes
at sunrise. And more than likely this wasn't conventional multi-hop
- I suspect chordal hops that kept the losses down."
Thank you, Carl.
Several readers had comments about past solar cycles. Lou De Chiaro,
WB2IJT of Lindenwold, New Jersey wrote, "I was fairly active on HF
during the late 1960s when Cycle 20 peaked. At the time, my rig was
a Heath SB-300 receiver and SB-400 transmitter running around 100
watts CW output. My largest HF antenna consisted of a rhombic that
measured around 40 feet in the short dimension and about 300 feet in
the long dimension. The best propagation results happened on 10
meters during the 1969-1970 period, and I both observed 20 dB/S9
signals and received equally glowing reports from several VK and ZL
stations on both CW and SSB. My QTH at the time was in northern NJ.
Since then, I have unfortunately not seen signals of comparable
strength from 'down under,' though one always wants to remain
Ken Bourke, N6UN of San Diego, California wrote, "I was born in 1940
and fit the age group that you talk about and the expectations we
had. I enjoyed the current article about this age group as it moved
thru the 11 year sunspot cycles and it is very accurate and true. No
cycle compares to the 1958 one.
"We old QCWA hams always hope and think we will have another cycle
like that 1958 one, but it never has happened. In 1958 I was 18
years old, in Illinois (W9ZVG, Extra Class), with 1 KW and a quad at
60 feet. But I even got bored working so many DX countries. I did
not know I was experiencing a once in a lifetime event. 15 meters
was also hot. I made a tape recording of the crowded 10 meter band
on old tape at 7.5 ips.
"But I always thought the band would come back like that 1958 event
every 11 years, but it never has come back like 1958. I still keep
hoping and do think some cycle in the future will be even stronger,
with a higher daily 23 cm solar flux than our 110 or 120 today, like
over 150 or 200 daily, solar flux which might occur with a big long
term solar eruption and massive solar wind. I keep waiting for a lot
of long term continuous solar activity."
Fortunately, solar flux this week is actually over 150, rising to
174 on January 10 and predicted at 175 on January 11-12.
Tom Gallagher, N6RA of San Francisco, California wrote, "I was one
of the lucky ones to be on the air and hunting DX in the 50s. I'm
now 70. I was licensed in 1955 as KN4DRO in Miami at the age of 12.
I quickly got into DXing (having been an SWL DXer at the age of 10
and a BC band DXer at the age of 6 when my parents gave me my own
little BC band radio). In 1958 I received DXCC #3698. I had about
210 countries when I went off to college in 1960 (I was actually the
#9 DXer in the state of Florida with my puny station when I went off
to college). I had a very modest station--50 watts on CW and AM (I
had 140 countries on AM phone) with a 2 element quad at 30 feet. My
experience during the various sunspot cycles was very much like you
outlined. I had them all for a while, but missed South Sudan
(haven't sent in the new PJ cards yet).
"6 meters has taken my interest in the last 13 years or so. There
seem to be a lot of geezer HF DXers on 6! I had hopes of making
DXCC on 6, but it's harder than I ever envisioned from the West
Coast and the sunspots don't seem to be cooperating. I do have some
juicy DX on 6 from 2001, such as Z22JE, ZD7, 3W, DU, VR2, etc."
Before closing, check out a couple of interesting articles about
solar activity at
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
http://arrl.org/propagation-of-rf-signals. For an explanation of the
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. Find more good
information and tutorials on propagation at
Monthly propagation charts between four USA regions and twelve
overseas locations are at
Sunspot numbers for January 3 through 9 were 116, 167, 181, 186,
196, 144, and 153, with a mean of 163.3. 10.7 cm flux was 128.8,
143.1, 145.1, 142.2, 149.7, 155.6, and 169.3, with a mean of 147.7.
Estimated planetary A indices were 2, 2, 3, 3, 3, 3, and 3, with a
mean of 2.7. Estimated mid-latitude A indices were 2, 2, 1, 6, 3, 3,
and 3, with a mean of 2.9.
Source: W1AW Bulletin via the ARRL.
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