SB PROP ARL ARLP030
ARLP030 Propagation de K7RA
At 2330 UTC on July 24, Australia's IPS Radio and Space services
issued a geomagnetic disturbance warning. Increased geomagnetic
activity is expected due to a coronal mass ejection. They predict
quiet to unsettled conditions on July 25, active to minor storm on
July 26, and active conditions on July 27.
As this bulletin nears release early Friday morning, the planetary A
index was 4 on four recent readings, followed by 2 on the last one.
But the mid-latitude K index was 4 on three recent readings, then 5
on the last two. Geomagnetic activity is increasing, as expected.
Over the past reporting week, compared to the previous period (July
11 to 17) average daily sunspot numbers decreased by less than four
points to 73.4, while average daily solar flux declined slightly
more than three points to 110.6.
NOAA/USAF predicts Planetary A Index at 18 on July 26, 12 on July
27, 8 on July 28, 5 on July 29 to 31, 8 on August 1, 5 on August 2
to 8, 8 on August 9 to 11, 5 on August 12 and 13, 8 on August 14 and
15, 5 on August 16 and 17, 10 on August 18, 15 on August 19 to 22,
and then 8, 5 and 8 on August 23 to 25.
The outlook for solar flux calls for 105 on July 26 and 27, then
110, 115, 120, 125, 130, 135, 130, 125, 120, 125, 120 and 125 on
July 28 through August 8, 120 on August 9 to 12, 115 on August 13,
120 on August 14 to 17, 125 on August 18, 120 on August 19 and 20,
and 125 on August 21 to 23. The latest projection shows a short
term solar flux peak at 135 on September 4 and 5 after a minimum of
100 on August 27 and 28.
OK1MGW from the Czech Propagation Interest Group sees quiet to
active geomagnetic conditions on July 26 and 27, quiet to unsettled
July 28 and 29, quiet on July 30 and 31, quiet to unsettled August
1, quiet to active August 2, active to disturbed August 3, quiet
August 4, mostly quiet August 5, active to disturbed August 6 and 7,
quiet to unsettled August 8 to 11, quiet August 12 and 13, quiet to
active August 14 and 15, and quiet to unsettled August 16 and 17.
Juan Carlos, CO8TW lives in Santiago de Cuba, about 600 miles
southeast of Havana. He put up a new propagation web site that has
many useful features and an interesting mix of information. Check
it out at http://www.qsl.net/co8tw/pro.htm.
Another interesting propagation page I ran across recently is at
G4CJC has a 10 meter report at
The NOAA/NWS Space Weather Prediction center has a Facebook page at
Note the July 16 article about the K index,and a map of North America showing
how high the planetary K index has to be in order to see aurora borealis from
any location. For my location near Puget Sound, it seems to say a K index at 8
or higher would be good. But for Northern Minnesota and North Dakota a K
index of only 4 seems adequate. Of course on Facebook is the always
timely and useful page from NW7US titled "Space Weather and Radio
Resources at HFRadio.org", at
David Moore sent an interesting article from The Guardian about the
Met Office now offering coverage of space weather. Met originally
was short for meteorological but now is the official name for the
British weather and climate service. Read it at
There also is yet another article about the current solar cycle
being the weakest in the past 100 years, this time from Sky and
Jeff Hartley, N8II of Shepherdstown, West Virginia wrote in response
to the comment last week about the lack of 6 meter openings into
DM04. Jeff is in FM19, and wrote on July 20, "It has not been a
good Es season from here, but we have had several multi-hop openings
since July 1 mostly out into Arizona and New Mexico along with one
to Oregon, Washington, and VE7. Only once did I catch Europe and it
was only to France and Portugal. So, I am not too surprised that
many are disappointed with their 6 meter openings this year. Even
the 20 meter E-skip is much less frequent than normal this year."
"Today, July 20 there was a Russian sponsored contest and in a few
short minutes I heard/worked strong stations from HS, YD, BH8, UN,
and UA9 on 15 meter CW around 1245Z. This was the best shape in
which I have heard 15 in some time."
On July 19, Jon Pollock, K0ZN of De Soto, Kansas wrote, "Even though
sunspot numbers have been modest, I was on last night (July 18)
between about 0130-0330 UTC (on 17 meters) and from my QTH in
Eastern Kansas I worked several stations in the Central Pacific
including E51AND in the Cook Islands and some ZL's, all on CW and
with decent (but not strong) signals. Interestingly, on both ends
of these QSO's we were running high power into basic unity gain
antennas and only netted about S-5 signals, so path loss was
moderately high. But, the bottom line is, 18 MHz was open into the
Pacific from Kansas well into the late evening. I still find that
if 17 meters sounds 'dead' with low noise, it is usually open with
very long skip and the main problem is a lack of activity, not a
lack of propagation."
Good point, Jon. You can also listen for beacons if you suspect a
quiet band is not actually dead (or make some calls.), or get a
trial account at QupNow (see http://q-upnow.com/) and click on HF
Availability. This relies on up-to-the-minute global measurements
of TEC (Total Electron Content in the ionosphere), and allows you to
test propagation on any path, but only for the current time. It
shows the relative signal strength all long that path, from your QTH
to the target location and continuing on out the other side over the
great circle route. Note that it also works on 160 meters. You can
either enter coordinates for both locations, or it may be more
convenient to use the grid square entry method.
Don May, N5DN of Houston, Texas pointed out that on July 25,
Spaceweather.com ran an article about the weak solar cycle titled
"Underwhelming". "Kinda makes a DXer want to cry.", weeps Don, and
we can all certainly empathize. But, there is still room for hope.
The article also said, "Solar physicist Dean Pesnell of the Goddard
Space Flight Center thinks Solar Cycle 24 is double peaked--and the
second peak is yet to come." If you can't find the article and
accompanying graphic, go to http://www.spaceweather.com/ and enter
July 25 in the Archives drop-downs in the upper right.
Chip Margelli, K7JA of Garden Grove, California (DM03) wrote
"Although 6 meters has been terrible this year, I did just work
KH6HME (KH7Y operating) on 144.276.5 MHz on SSB and CW. Fred
started at 5x1 and came up to about 5x5. Time was 1857 UTC on 25
July. Good to hear Fred activating Paul Lieb's memorial callsign."
Chip notes that Fred was running 80 watts and an 8 element Yagi from
Mauna Loa. Chip was running 100 watts using a TS-2000 and an 8
element LFA Yagi ten feet above his roof.
For more information concerning radio propagation, see the ARRL
Technical Information Service 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 July 18 through 24 were 112, 94, 57, 49, 53, 84,
and 65, with a mean of 73.4. 10.7 cm flux was 114.8, 113.6, 112.5,
109.4, 109.9, 106.7, and 107.6, with a mean of 110.6. Estimated
planetary A indices were 15, 14, 6, 5, 6, 5, and 5, with a mean of
8. Estimated mid-latitude A indices were 16, 13, 6, 4, 6, 5, and 6,
with a mean of 8.