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ARRL Propagation Bulletin ARLP034 (2014)

SB PROP @ ARL $ARLP034
ARLP034 Propagation de K7RA

ZCZC AP34
QST de W1AW  
Propagation Forecast Bulletin 34  ARLP034
From Tad Cook, K7RA
Seattle, WA  August 22, 2014
To all radio amateurs 

SB PROP ARL ARLP034
ARLP034 Propagation de K7RA

Solar indices and outlook are stronger this week. Average daily
sunspot numbers rose 19.7 points to 114.6, while average daily solar
flux increased 25.7 points to 138.8. Average daily estimated
planetary A index dropped from 7.4 to 4.3. This compares the August
14 to 20 period against the previous seven days.
 
The day with the greatest geomagnetic activity was Tuesday, August
19 when the planetary A index was 17. This was caused by a weak CME,
but according to Spaceweather.com the inner magnetic structure
"contained a region of south pointing magnetism that partially
cancelled Earth's north pointing magnetic field." This opened a
crack in the magnetosphere, and solar wind poured through,
triggering unexpectedly brilliant aurora.
 
The outlook for solar activity has improved. A week ago the average
predicted solar flux for the next ten days, August 22 to 31, was 121.
Now based on the Thursday, August 21 prediction the average solar
flux for the same period has risen to 149.5, a robust increase of
28.5 points.
 
Predicted solar flux is 140 on August 22 to 26, 150 on August 27, 160
on August 28 to 30, and 165 on August 31. Flux values then drop to 125,
130, 125, 120, 115 and 110 on September 1 to 6, 105 on September 7 to 9,
100 on September 10 and 110 on September 11 and 12. It meanders a bit,
and then rises to 140 on September 24 before declining again.
 
Predicted planetary A index is 8 on August 22, 5 on August 23 to 28, 8
on August 29, then 5, 12, 10 and 8 on August 30 through September 2,
5 on September 3 to 5, 8 on September 6 and 7, 10 on September 8, 5 on
September 9 to 14, 12 and 14 on September 15 and 16, then 8 on September
17 and 18, and 5 on September 19 to 23.
 
F. K. Janda, OK1HH predicts the geomagnetic field will be quiet to
unsettled August 22, active to disturbed August 23, quiet to
unsettled August 24, mostly quiet August 25, quiet to active August
26 to 29, active to disturbed August 30, quiet to active August 31,
mostly quiet September 1 and 2, quiet to unsettled September 3, quiet
September 4 and 5, quiet to unsettled September 6, quiet September 7,
mostly quiet September 8 and quiet to unsettled September 9.
 
Jon Jones, N0JK reports a late season e-skip opening on August 16
around 0015 UTC. AA6YQ (FN42) was very loud on 6 meters across the
south and Midwest.
 
Several stations in Washington State heard the VE8WD six meter
beacon on 50.02 MHz from Yellowknife, NW Territories at 0220 to 0249
UTC on August 20. The distance was about 1100 miles.
 
Check out the DX maps at http://n3tuq.com/dxmap.php . You can look
at real time contacts on 10, 6 or 2 meters, giving a picture of
propagation around the world. Right now at 1300 UTC the sun is
rising over the West Coast of North America, and I am looking at a
large number of 6 meter contacts all over Europe. I switched to 10
meters, and I can see contacts between Europe and Ethiopia,
Thailand, Algeria and Saudi Arabia.
 
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
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 August 14 through 20 were 108, 119, 99, 121, 92,
84, and 89, with a mean of 114.6. 10.7 cm flux was 102.7, 113.1,
112, 115.1, 110.6, 111, and 118, with a mean of 138.8.  Estimated
planetary A indices were 4, 5, 3, 7, 5, 17, and 6, with a mean of
4.3. Estimated mid-latitude A indices were 5, 6, 4, 9, 5, 14, and
7, with a mean of 3.7.
NNNN
/EX

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