Register Account

Login Help

ARRL Propagation Bulletin ARLP043 (2011)

ARLP043 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 43  ARLP043
From Tad Cook, K7RA
Seattle, WA  October 28, 2011
To all radio amateurs 

ARLP043 Propagation de K7RA

The day last week's Propagation Forecast Bulletin ARLP042 was
released - Friday, October 21 - the daily sunspot number broke
another record for cycle 24, when it rose to 207. You have to look
back to November 26, 2003 when it was two points higher, 209, to
find a number at least as high.

But average daily sunspot number for the week was off by two points
to 156.6, and average daily solar flux rose nearly 8 points to

How much higher will it go?  Latest prediction shows sunspot
activity peaking between February and July 2013, so there would seem
to be plenty of opportunity for more daily sunspot readings of 207
and higher.

Propagation on HF is quite exciting right now, with 10 meters
opening up world wide daily. Based on recent conditions, working the
CQ World Wide SSB DX Contest this weekend should offer plenty of

The latest predicted solar flux is 130 on October 28-31, 125 on
November 1, 120 on November 2-5, then 125 and 130 for November 6-7
and 135 on November 8-10. Flux values for the near term are expected
to peak at 165 on November 17-18.

Predicted planetary A index is 7, 8, 10 and 10 on October 28-31 and
5 on October 31 through November 3, 8 on November 4-5, 5 on November
6-10 and 8 on November 11-13.

Geophysical Institute Prague predicts quiet to unsettled conditions
October 28, unsettled October 29, quiet to unsettled October 30 and
quiet October 31 through November 3.

A week ago (October 21) we received this update from Jeff Hartley,
N8II of Shepherdstown, West Virginia, and in the first part he was
referring to the sunspot number reaching 195 the day before: "Whoo
hoo! Actually, things sounded a bit better the 2 days prior to last
night. It's fairly commonplace at 2100Z to hear JAs and western EU
at the same time on 12 meters! I had a solid QSO (S5) with BG4AEC
(China) running 100 watts and a vertical on 10 meters SSB around
0015Z on Oct 19, past the peak of propagation. It's hard to get much
done because the radio is too much of a draw! Unfortunately, the
flooding in SE Asia seems to be keeping the rare countries (XV, XU,
XZ) off the air. K3ZO is in Thailand but unable to operate much
because HS0AC is being used for emergency communications. Cars are
being parked on bridges and upper levels of garages to avoid the
flooding! I hear 9M6XRO almost daily on either 12 or 10 meters."

Speaking about the Draconids meteor shower, Jon Jones, N0JK of
Wichita, Kansas wrote: "The Dracs would have been big news a year
ago on VHF, but with all the F2 and TEP being worked on 6M this
fall, it kind of puts the Draconids meteor shower on the back
burner.  One important 'lesson' from it is the astronomer's
predictions of meteor shower outbursts are much better now and more

Check this video of some solar events a few days ago:

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 20 through 26 were 195, 207, 164, 128,
151, 147, and 104, with a mean of 156.6. 10.7 cm flux was 159.1,
167.8, 164.1, 155.5, 145.3, 138.8, and 132.2, with a mean of 151.8.
Estimated planetary A indices were 5, 5, 3, 3, 23, 33, and 3, with a
mean of 10.7. Estimated mid-latitude A indices were 3, 5, 2, 2, 16,
27, and 4 with a mean of 8.4.


Instragram     Facebook     Twitter     YouTube     LinkedIn