SB PROP @ ARL $ARLP051
ARLP051 Propagation de K7RA
QST de W1AW
Propagation Forecast Bulletin 51 ARLP051
From Tad Cook, K7RA
Seattle, WA December 19, 2014
To all radio amateurs
SB PROP ARL ARLP051
ARLP051 Propagation de K7RA
Solar activity made a strong comeback this week, with the average
daily sunspot number on December 11-17 rising 57 points to 145.4
from the previous seven days, while average daily solar flux was up
28.1 points to 167.7.
But then toward the end of the week, activity made a large jump,
with solar flux at 213.2 on Thursday.
Predicted solar flux is 220, 225, 220 and 210 on December 19-22,
then 200, 195, 190 and 160 on December 23-26, then 140 on December
27-29, 135 on December 30 through January 1, 140 on January 2-4, 145
on January 5, 155 on January 6-7, 160 on January 8, and 165 on
January 9-12. Flux values then peak at 175 on January 14-15.
Predicted planetary A index is 10, 15, 10 and 8 on December 19-22, 5
on December 23-27, 8 on December 28-30, 10 on December 31 and
January 1, then 12, 25, 15 and 10 on January 2-5, 8 on January 6-7,
10 on January 8-9, and 8 on January 10-12.
OK1MGW graces us with another of his geomagnetic forecasts. He
expects (although is uncertain about) quiet to active conditions on
December 19, mostly quiet December 20-21, quiet on December 22,
mostly quiet December 23-24, quiet on December 25-26, quiet to
unsettled December 27-28, mostly quiet December 29-31, quiet to
unsettled January 1-2, active to disturbed on January 3, quiet to
active January 4-5, quiet to unsettled January 6-7, quiet to active
January 8, quiet to unsettled January 9-10, quiet to active January
11, and mostly quiet January 12-14.
He expects increased solar wind on January 2-5 and 8-11.
Peter Kolman, OK1MGW of the Czech Propagation Interest Group, has
been producing weekly forecasts with OK1HH since 1978.
On December 17 the 10.7 cm receivers at Penticton must have become
overloaded, because NOAA/USAF adjusted the noon reading down from
198.5 to 192, which correlates to the earlier 10:00 AM reading of
191.5, rounded off.
We saw something similar on November 24, but in the opposite
direction. The three flux readings for the day were 170.1, 144.4,
and 168.4 at 10:00 AM, noon and 2:00 PM. It is always a rounded off
noon reading that NOAA reports, but this time it was bumped up from
144.4 to 172, I suppose to be more consistent with the other
readings. I've never noticed this before.
We saw another lowering of the reported flux number on November 5
when the three readings were 135.7, 145.2 and 136.3, but NOAA
reported 135 for the day.
At 0105 UTC on December 18 the Australian Space Forecast Centre
issued a geomagnetic warning. They said to expect a CME impact on
December 19-20, resulting in increased geomagnetic activity. The
warning says to expect unsettled to active geomagnetic conditions on
December 19 and active conditions on December 20.
We received some great reports this week. First Jimmy Mahuron, K9JWJ
of Salem, Indiana wrote "10 meters still going strong" on December
13, and said running 25 watts into an inverted-V he worked about two
dozen stations in Colorado, California, Oregon, Utah, Iowa, Canada
Dennis Condron, K0LGI of Marion, Iowa sent some information on using
distant broadcast television signals to detect meteor trails. He
says Stan Nelson, KB5VL in Roswell, New Mexico also does this, and
has a web site at http://www.roswellmeteor.com/ which displays their
One display at
Dennis's results during the recent Geminid meteor shower. I think we
can assume that all these displays are quiet most of the time, and
that there are no local broadcasters using the same channels.
Also check http://www.spaceweatherradio.com/ .
A couple of reports came in over the past day from people who worked
ZL1RS on 6 meters.
Craig Hill, K3PLV of Erie, Pennsylvania reports, "At 0011Z on
December 15 I worked ZL1RS on 6 meters. He was a true 559 when I
worked him. I did not listen after I worked him so he may have even
gotten stronger later. This is a new one for me on 6. Usually
propagation to New Zealand just does not get this far north and east
on 6. I live in Erie PA and envy the 6 meter propagation the
stations have in the southern part of the US. The solar flux index
was 166. I don't think that's high enough for F2 on 6 and it
wouldn't be transequatorial propagation. So I'm confused how this
happened. I saw no other stations spotted in the Pacific except a
few VKs just to Central and South America. I run 1000 Watts to a 10
element yagi on 6, and ZL1RS uses a homebrew 7 element yagi on a 9.6
meter boom and an amplifier."
I suspect it was a lucky coincidence of two E-skip paths linking up.
And currently we are in the second (and smaller) annual E-skip
season. From the signal report it looks like he was using CW.
We received another report from Bruce Smith, AC4G of Taft, Tennessee
which is just about two miles north of the border with Alabama, and
about 80 miles directly south of Nashville.
"Very excited about my 6 meter CW QSO made on December 14 at 0020Z
on 50.103Mhz with ZL1RS. Signal reports both ways 559. ZL1RS peaked
to S7 just before fading into the noise and gone in about 2 minutes,
never to be heard again. This is the first ZL I have ever heard on
6 meters in EM65 southern Tennessee the blackhole of the US. Just
thought I'd pass this along.
"Worked the ARRL 10 meter contest last weekend running 4.5 watts and
was able to make QSOs to South America, Alaska, Hawaii, and as far
away as Japan Sunday afternoon during 2 hours of operating."
Sounds so great! Thanks, Bruce.
Since the two contacts with the same New Zealand station were about
24 hours apart, I am wondering if instead of occurring on subsequent
days, they were actually just a few minutes apart? Just from my
experience with these sorts of things, I suspect they both occurred
on December 14 in North America time, but K3PLV used the actual UTC
date (the next day) but maybe AC4G reported his local date, while
reading the UTC time off his clock? It happens! I've made the same
mistake in the past. The same confusion often arises when trying to
figure out when the contest begins. If it is 0001 UTC Saturday,
then here on the Left Coast it is 4:01 PM PST Friday.
Don't forget the ARRL CW Rookie Roundup this weekend. If you
received your license in 2012, 2013 or 2014, you are a Rookie and
eligible to compete. The rest of us are encouraged to participate,
work the newcomers, and submit check logs.
has all the details.
Also, remember that SKN is less than two weeks away! Dust off that
old straight key and spend a mellow night operating and welcoming
the New Year. See http://www.arrl.org/straight-key-night for
details. This is another test of your UTC savvy, mentioned above. It
begins on January 1, in the New Year, at 0000 UTC. That is 7:00 PM
EST on New Years Eve, December 31, 2014.
John Parnell, K7HV sent this in from Seattle, after responding to my
query about 10 meters last weekend:
"I did not do the contest seriously. I did note that the fallout
from the CME and resultant high A index knocked out most of the path
to Europe, I only worked Spain and Canary Isle, in a short AM EU
opening from the Pacific NW. The band was open elsewhere but a bit
noisy, more so on Sunday. Decent N-S path to Oceania and S Atlantic,
VP8RAF was very loud, decent openings to E/SE Asia in the
"BTW, I finally figured out a way to load my G5RV on 160 (by
shorting the ant and using an external tuner vs my rig's autotuner -
duh!). I was therefore able to get on the ARRL 160 contest - my
first time on the band in years. With only a few hours of operating
I worked 28 states and 5 VE provinces, ALL over N America...THAT was
"As is traditional for this time of year, I am working VUs on 20.
Looking at my log, I see that I have only worked VU between late Oct
and early January...all long-path."
And another Northwest ham, who wishes to remain anonymous, sent
"Are you kidding? It was GREAT!
"Limited EU of course, with the limited sunlit area on N Hemisphere
in mid December. And I understand there was an unusual opening over
the N pole at our midnight, into EU which almost everyone out here
"ZF2DX in Caymans did great. Kevin N5DX is his call. He is living
there now. Many did very well."
Check out this interesting Scientific American blog post about
applying AI to solar prediction:
Also, this sounds like an interesting book combining art with
I have it on order from my local library.
And further, I am reluctant to pass this on, except that it reflects
the fears and concerns of some people who send me email with
questions, perhaps after doing a web search for "sunspot" or "solar
flare" or "end of the world as we know it."
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
information and tutorials on propagation are at http://k9la.us/.
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 December 11 through 17 were 115, 132, 121, 175,
152, 169, and 154, with a mean of 145.4. 10.7 cm flux was 147.5,
154.2, 159.8, 166.4, 169.3, 184.6, and 192, with a mean of 167.7.
Estimated planetary A indices were 6, 21, 9, 11, 15, 8, and 8, with
a mean of 11.1. Estimated mid-latitude A indices were 4, 15, 7, 9,
11, 7, and 6, with a mean of 8.4.