ARRL

ARRL Propagation Bulletin ARLP052 (2009)

SB PROP @ ARL $ARLP052
ARLP052 Propagation de K7RA

ZCZC AP52
QST de W1AW  
Propagation Forecast Bulletin 52  ARLP052
From Tad Cook, K7RA
Seattle, WA  December 18, 2009
To all radio amateurs 

SB PROP ARL ARLP052
ARLP052 Propagation de K7RA

Sunspot activity continued this week, with new group 1035 emerging
December 14, following 1034, which appeared December 9.  Daily
sunspot numbers since December 9, through December 17, have been 13,
13, 13, 12, 14, 28, 38, 30 and 24.  Solar flux values have been
above 80 since December 15, with the values from Tuesday through
Thursday of this week at 81.6, 83.2 and 86.9.  The 2000z (local noon
in Penticton) are the official daily number, and on December 17 at
1800z the flux value was 88.1, higher than any flux value in the
past three years.

The last time the 10.7 cm flux was higher was December 15, 2006 at
88.2.  Just three days prior to that on December 12, 2006 it was
104.2.  It wasn't long ago that flux values were in the sixties, but
we haven't seen solar flux below 70 since October 16, 2009 at 69.6.

The latest prediction from NOAA and USAF is for flux values around
88 for December 18-20, then 85, 82, 82 and 80 for December 21-25.
Predicted planetary A index for December 18-24 is 5, 6, 15, 6, 5, 5
and 5, indicating a possible disturbance on Sunday.  Geophysical
Institute Prague predicts quiet conditions December 18-19, unsettled
to active December 20, quiet to unsettled December 21-22, unsettled
December 23, and quiet December 24.

Currently at the NASA STEREO site (http://stereo.gsfc.nasa.gov/) we
can see sunspot group 1035 at a high latitude heading toward the
western (right-hand) side of the solar image, and just passed over
the eastern horizon a bright patch of activity that could emerge as
a sunspot.  There is also some activity in the southern hemisphere
on the far side just emerging from the less than 13.7 percent of the
Sun not visible to STEREO.

At http://www.swpc.noaa.gov/ftpdir/indices/DSD.txt under the column
"Sunspot Area 10E-6 Hemis" you can see the area (in millionths of a
solar hemisphere) covered by sunspots steadily growing all week.

This increased sunspot activity gives us improved chances of
expanded HF propagation.  For instance, doing a projection with a
popular propagation prediction program, with zero sunspots today
from my location in Seattle to Brazil on 12 meters, there is a
chance of propagation from 1800-2000z, but for less than 25 percent
of the time.  But with an average of sunspot number for the past few
days at 30.7, the same path has excellent probability of opening
with strong signals from 1700-2100z.

Mail after the 10 meter contest last weekend indicated that
propagation was disappointing on Saturday and much better on Sunday.
You can also see comments on the Contest Soapbox at
http://www.arrl.org/contests/soapbox/.  Just select "2009 ARRL Ten
Meter Contest" from the drop-down menu.

In contrast to the 10 meter reports, there were a great many
enthusiastic reports on 160 meters propagation this week.  James
French, W8ISS of Lincoln Park, Michigan operated from the Red Cross
communications center in Ann Arbor.  He reports that the 10 meter
contest didn't get interesting until late in the event on Sunday.
He says, "Listened a few times down on 160 meters and heard non-stop
signals across the whole band."

Jan Wise, KA5PRO in Pocahontas, Arkansas was surprised on December
10 at 0407z when he contacted KH7XS in Laupahoehoe, which is on the
northeast side of the Big Island of Hawaii.  Jan was running 100
watts SSB on 1.845 MHz into a simple inverted L antenna at 50 feet.

Dick Bingham, W7WKR of Stehekin, Washington reports that last
Saturday night in the evening local (West Coast) time he was
surprised to work an SM4HCM and FM5CD on 160 meter CW with 100 watts
into a sloping half-square antenna.

Jeff Hartley, N8II of Shepherdstown, West Virginia also reports
great 160 meter conditions last weekend during the 10 meter contest.
He noted great signals from Northern Europe, and 160 was "much
better than during the 160 meter contest!"

Jon Jones, N0JK of Wichita, Kansas said 10 meters was bad Saturday,
but he had great results on Sunday.  He reports, "There was
widespread Es (E-skip) across the southern part of the country. Had
Texas, Louisiana, Mississippi, Florida and Alabama stations in all
afternoon steady and loud. After 2200 UTC the Es spread west to
Arizona, New Mexico and northeast to Ontario, Maryland, Michigan,
etc."

"The Es to the Gulf of Mexico allowed an 'Es link' to form TEP
(trans-equatorial propagation), and on to South America. So despite
a low solar flux, CX, LU, PY stations were very strong around 2300
UTC Dec 13. I was able to work several PYs CXs and LU1HF while
running 5 watts and a CB mag-mount whip on the car on 10M CW. They
were an honest 599 despite a very simple antenna to Kansas. As
strong as during solar Cycle 23 peak."

Randy Shirbroun, ND0C of Worthington, Minnesota reports some great
80 meter conditions last weekend.  He wrote, "I was playing around
off and on in the 10 meter Contest and there was some great Es and
so-so TE on Saturday evening and especially Sunday afternoon.  But
for me the really exciting thing was around midnight (local) on
Friday night on 80 meters."

"I run exclusively QRP so I am definitely a slave to the whims of
the propagation gods.  There wasn't anything going on 10 when I
checked it around 0545 UTC Saturday - not very surprising but I was
hoping for maybe a little MS (meteor scatter) or Es.  So I went to
80 CW and was very pleasantly surprised.  I was able to work 6
central and eastern Europeans (HA, HB, 9A, S5, and DK) in an hour
running 5 watts to a dipole at 45 feet here in SW Minnesota.  It
wasn't easy, but the band was relatively quiet and no big pile-ups
and the guys on the other end were patient and obviously had good
ears.  It was definitely my best hour of 80 meter DXing!  I think
that was a very special opening, but I definitely need to check 80
more often.  (I'll bet it was a great night for the guys on 160 with
decent antennas and a little power.)  Hopefully it is a sign of
things to come this winter on the lower bands, especially with
non-existent sunspots.  Maybe 5BDXCC with QRP is possible!  I have
240 on 10, 270 on 15, 270 on 20, 100 on 40 and now 55 on 80 - we'll
see!"

Randy Crews, W7TJ of Spokane, Washington wrote on December 16, "We
are still in the low portion of the cycle, and I remember in years
past during this time with a quiet Sun and geomagnetic field, low
band propagation is exceptionally good. The higher solar activity
enhances 40 meters, 30 meters and even 80 meters. Last weekend I
worked three new European countries on 160 meters.  80, 40, and 30
meters offer short path European propagation starting an hour before
local sunrise, switching to long path at sunrise, and back to short
path propagation once again about 45 minutes to an hour past
sunrise. Pretty cool!"

Robert Elek, W3HKK of Johnstown, Ohio reported on December 12,
"Hark! Sunspots!  And a big bump up in 40/80/160 DX was noted on Dec
11 and 12. But prior to that, 40 had been relatively quiet for the
past week. However, on 12/6, OX3KQ sounded like a beacon on 7.153,
with signals from S7 to S9 +5 dB for a couple of hours (1900-2100z).
Mid afternoon! My average noise level was S2. OX3KQ was using a
rotary dipole at 70 feet and working pile ups into most of Europe,
plus pockets of JA and stateside stations who could penetrate his
European wall. HA, IZ4, EC, UW5, DJ2, YO, RK0, A41, Z31, UR5, RZ8
were a sample of what he was plucking off, plus a dozen or so US and
a dozen JAs. Non stop DX for him, and it sounded like he was picking
them off the top of the pile. Fascinating to see how the skip would
move around favoring first to his east, then to his west, then to
his north."

"Again, we see that on a quiet or dead band, DX is possible from
almost any point on the globe on 40 meters. Also, E51NAA (North Cook
Islands) was worked again, on both 12/11 and 12/12 between
0400-0500z, around 7.025 MHz with good signals. I've heard him
coming through for over a week now, again, on a quiet band."

"Another Magical Opening on 160: On 12/11 at 0500z I worked TF4M,
plus LA, SM, PA: all with 599 signals, with 100w cw/160m inverted L
with an average height above ground of 10 feet! It seems 1.815-1.840
is a jam packed DX segment especially on Friday and Saturday nights.
And around 1.843, a UM0 (Uzbekistan) was a solid 5x7(3 S-units above
my noise) and looking hard for takers. Amazing! You could hear
nearly all of Europe calling CQ that night, many signals in the 579
to 599 range. On an antenna you could almost jump up and touch!
Amazing.  So it doesn't take a lot to join the fun."

If you would like to make a comment or have a tip for our readers,
email the author at, k7ra@arrl.net.

For more information concerning radio propagation, see the ARRL
Technical Information Service web page at,
http://www.arrl.org/tis/info/propagation.html. For a detailed
explanation of the numbers used in this bulletin, see
http://www.arrl.org/tis/info/k9la-prop.html. An archive of past
propagation bulletins is at http://www.arrl.org/w1aw/prop/.

Monthly propagation charts between four USA regions and twelve
overseas locations are at http://www.arrl.org/qst/propcharts/.

Instructions for starting or ending email distribution of this
bulletin are at http://www.arrl.org/w1aw.html#email.

Sunspot numbers for December 10 through 16 were 13, 13, 12, 14, 28,
38, and 30 with a mean of 21.1. 10.7 cm flux was 73.9, 72.1, 74.5,
75.5, 78.6, 81.6, and 83.2 with a mean of 77.1. Estimated planetary
A indices were 1, 0, 1, 2, 4, 0 and 3 with a mean of 1.6. Estimated
mid-latitude A indices were 1, 0, 2, 1, 4, 0 and 2 with a mean of
1.4.
NNNN
/EX