ARRL

Secure Site Login

ARRL Propagation Bulletin ARLP001 (2017)

SB PROP @ ARL $ARLP001
ARLP001 Propagation de K7RA

ZCZC AP01
QST de W1AW  
Propagation Forecast Bulletin 1  ARLP001
From Tad Cook, K7RA
Seattle, WA  January 6, 2017
To all radio amateurs 

SB PROP ARL ARLP001
ARLP001 Propagation de K7RA

The Sun was quieter this reporting week compared to the previous
seven days. There were 4 zero-sunspot days, Thursday December 29,
Sunday, Monday, and Wednesday, plus a fifth on the following
Thursday, January 5. Geomagnetic numbers were also lower.

Average daily sunspot number decreased from 7.6 to 4.7, average
daily solar flux declined a half point from 73.6 to 73.1, while
average daily planetary A index went from 17.3 to 9.3. Average
mid-latitude A index went from 11.6 to 6.3.

The latest forecast sees solar flux at 72 on January 6, 71 on
January 7-13, 76 on January 14, 77 on January 15-19, 75 on January
20-24, 74 on January 25-27, 73 on January 28 through February 2, 75
on February 3-7, 76 on February 8-10, and 77 on February 11-15.

The Ap prediction for planetary A index sees 18, 14, 10, 6 and 5 on
January 6-10, then 12 on January 11-12, 8 and 10, on January 13-14,
then 5 on January 15-16, then 25, 20, 25, and 18 on January 17-20,
then 20 on January 21-22, 10 on January 23, and 5 on January 24-26,
then 12, 15, 10, 12 and 18 on January 27-31, then 24, 22, 15 and 8
on February 1-4 and 5 on February 5-9.

F.K. Janda, OK1HH delivered his geomagnetic predictions a day early
this week:

Geomagnetic activity forecast for the period January 6-February 1,
2017.

Geomagnetic field will be: 
Quiet on January 8-10, 16, 24-25, 
Mostly quiet on January 11-12, 15, 26, 30, 
Quiet to unsettled on January 23, 27, 29 
Quiet to active on January 6-7, 13-14, 17-18, 28, 31
Active to disturbed on January 19-20, (21-22,) February 1

Increases in solar wind from coronal holes are expected on January
6-8, 17-20, 25, (27-31,) and February 1.

Parenthesis means lower probability of activity enhancement.

Jon Jones, N0JK wrote:

"Nice activity on 6 meter meteor scatter in the Quadrantids Meteor
Shower Jan. 3, 2017.

"I set up portable on 50 MHz about 8 am this morning west of
Lawrence, Kansas. Very cold and strong wind -- wind chill 10 deg F
here in Lawrence.

"Two contacts in 5 minutes -- W4HLR and WZ8D on 50.145 MHz SSB. I
CQ'd a while longer, got cold and packed up.

"Listened from home on 50.145 and heard a loud 'blue whizzer' on
WZ8D at 1447z - worked John again easily with the attic dipole. Near
as I can tell -- the peak of the Quads was between 1400 - 1530z.

"N8JX EN64 heard me earlier, but weak. I am blocked by a hill to the
northeast to N8JX from home, so back out portable at 1510z. Worked
Terry in 2 minutes on 50.145 MHz at 1513z. I was running 100 W and 2
el yagi. He pegged the meter.

"Lots of meteor scatter activity on 6 meters with the new MSK144
mode. It is very efficient. But nice to see the old school SSB
meteor scatter activity in the Quads."

Jon mentioned MSK144, a new WSPR mode for meteor scatter. Details
here:

https://physics.princeton.edu/pulsar/k1jt/Release_Notice.txt

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://arrl.org/propagation-of-rf-signals. For an explanation of
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. More good
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 29, 2016 through January 4, 2017 were
0, 11, 11, 0, 0, 11, and 0, with a mean of 4.7. 10.7 cm flux was
73.4, 73.6, 73.5, 72.5, 73, 73.4, and 72.4, with a mean of 73.1.
Estimated planetary A indices were 5, 4, 12, 14, 7, 12, and 11, with
a mean of 9.3. Estimated mid-latitude A indices were 2, 2, 10, 9, 5,
8, and 8, with a mean of 6.3.
NNNN
/EX