Subj : ARRL Propagation Bulletin
To : All
From : Daryl Stout
Date : Fri Dec 02 2016 03:11 pm
SB PROP @ ARL $ARLP049
ARLP049 Propagation de K7RA
ZCZC AP49
QST de W1AW
Propagation Forecast Bulletin 49 ARLP049
From Tad Cook, K7RA
Seattle, WA December 2, 2016
To all radio amateurs
SB PROP ARL ARLP049
ARLP049 Propagation de K7RA
SWS Geomagnetic Disturbance Warning 16/53 issued at 2301 UTC/01
December 2016 by the Australian Space Forecast Centre.
A small coronal hole will move into a geoeffective position around 4
Dec. This could result in brief active to minor storm periods from
late 3 Dec or early 4 Dec.
Increased geomagnetic activity expected due to coronal hole high
speed wind stream from 03 to 04 December 2016
GEOMAGNETIC ACTIVITY FORECAST
03 Dec: Quiet, with possible minor storm late in the day.
04 Dec: Active to Minor Storm
Average daily sunspot numbers rose from 28.7 in the previous seven
days to 32.9 in this past reporting week, November 24 to 30.
Average daily solar flux rose from 78.5 to 82.6. Geomagnetic
indicators increased only slightly, with average planetary A index
changing from 12.7 to 13.6, and average mid-latitude A index rising
from 10.1 to 10.3.
Predicted solar flux is 85 on December 2 to 4, 80 on December 5 and
6, 78 on December 7 to 11, 80 on December 12 and 13, 82 on December
14 and 15, 80 on December 16 and 17, 78 on December 18 and 19, 80 on
December 20 to 22, 82 on December 23 and 24, 84 on December 25, 83
on December 26 and 27, 80 on December 28 and 29, 82 on December 30
and 31, 80 on January 1 and 2, 78 on January 3 to 7, 80 on January 8
and 9 and 82 on January 10 and 11.
Predicted planetary A index is 5 on December 2 and 3, then 10, 8 and
5 on December 4 to 6, then 15, 12, 18, 20 and 10 on December 7 to
11, 5 on December 12 to 17, then 8, 12, 16 and 22 on December 18 to
21, then 30, 12 and 10 on December 22 to 24, 8 on December 25 to 27,
5 on December 28 to January 2, then 15, 12, 18, 20 and 10 on January
3 to 7, then 5 on January 8 to 13.
Geomagnetic activity forecast for the period December 2 to 28, 2016
from Petr Kolman, OK1MGW of the Czech Propagation Interest Group.
Geomagnetic field will be:
Quiet on December 2 to 5, 13 to 16, 27 and 28
Mostly quiet on December 6, 12, 17, and 26
Quiet to unsettled on December 11, 18 and 19, 23 to 25
Quiet to active on December 7 to 10, 20
Active to disturbed on December 21 and 22
Increased solar wind from coronal holes are expected on December 7
to 10, 17 to 23.
Reliability of predictions is reduced at present due to higher
sunspot activity.
Here is an interesting chart from England's Daily Mail, comparing
solar cycles:
http://dailym.ai/2gNNtwq
The blue line represents an average of all previous solar cycles,
from cycle 1 to cycle 23. The red line is the current cycle 24, and
the grey line is solar cycle 5, which may be similar to the current
cycle.
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 November 24 through 30 were 12, 12, 13, 31, 44,
43, and 75, with a mean of 32.9. 10.7 cm flux was 79, 80.9, 81.2,
82.6, 85.2, 85.5, and 83.6, with a mean of 82.6. Estimated planetary
A indices were 24, 33, 12, 10, 8, 5, and 3, with a mean of 13.6.
Estimated mid-latitude A indices were 17, 24, 9, 9, 7, 4, and 2,
with a mean of 10.3.
NNNN
/EX
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