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ARRL Propagation Bulletin ARLP007 (2017)

SB PROP @ ARL $ARLP007
ARLP007 Propagation de K7RA

ZCZC AP07
QST de W1AW  
Propagation Forecast Bulletin 7  ARLP007
From Tad Cook, K7RA
Seattle, WA  February 17, 2017
To all radio amateurs 

SB PROP ARL ARLP007
ARLP007 Propagation de K7RA

In the last reporting week (February 9 to 15) average daily sunspot
numbers declined from 21.3 to 17.6, and average daily solar flux
rose from 73.5 to 75.1.  Average planetary A index dropped from 12.9
to 4.7, and mid-latitude A index from 9.9 to 2.9.

Predicted solar flux is 74 on February 17 to 19, then 77, 80, 83, 85
and 80 on February 20 to 24, 78 on February 25 and 26, 76 on
February 27 and 28, 75 on March 1 and 2, 73 on March 3 and 4, 72 on
March 5 to 7, 73 and 74 on March 8 and 9, 75 on March 10 and 11, 78
on March 12 to 15, 80 on March 16 to 18, then 82, 85 and 82 on March
19 to 21, 80 on March 22 and 23, 78 on March 24 and 25, 76 on March
26 and 27, 75 on March 28 and 29 and 73 on March 30 and 31.

Predicted planetary A index is 12, 10 and 8 on February 17 and 19, 5
on February 20 and 21, 8 and 14 on February 22 and 23, 10 on
February 24 and 25, then 5, 25, 30, 25 and 20 on February 26 through
March 2, 15 on March 3 to 5, 8 on March 6, 5 on March 7 to 12, then
8, 12 and 10 on March 13 to 15, 8 on March 16 and 17, 5 on March 18
to 20, then 10 and 15 on March 21 and 22, then 10 on March 23 and 24
and 5, 25, 30, 25 and 20 on March 25 to 29, and 15 on March 30
through April 1.
 
Geomagnetic activity forecast for the period February 17 to March
15, 2017 from F.K. Janda, OK1HH:

Geomagnetic field will be: 
Quiet on February 21, 24, 26, March 8, 11 and 12 
Mostly quiet on February 19 and 20, March 9 and 10 
Quiet to unsettled February 17, March 4, 7, 13 to 15 
Quiet to active on February 18, 25, March 3, 6 
Active to disturbed on February (22 and 23,) 27 and 28, March 1 and
2, 5

Increases in solar wind from coronal holes are expected on February
16 and 17, (18 to 22, 26 and 27,) March 2 to 5
Remark: 
- Parenthesis means lower probability of activity enhancement.
 
The weekly ARRL Newsletter (published every Thursday online) carried
a fascinating and timely article this week about the reactivation of
the HAARP facility in Alaska via Professor Chris Fallen, KL3WX:
http://bit.ly/2kwpB6J

The ARRL Newsletter also runs a weekly preview of this ARRL
Propagation Bulletin.  Here is the latest version of the HAARP blog:
https://sites.google.com/alaska.edu/gakonahaarpoon/operations-news
 
The ARRL International DX CW Contest begins this evening, UTC.
http://www.arrl.org/arrl-dx

Starting tonight is also the Novice Rig Roundup, which is an on-air
activity concentrating on operating old Novice ham transmitters from
the 1950's and 1960's, which was all crystal controlled and 75 watts
or less, CW only (except for AM on 2 meters).  Let's see.  Where is
my old DX-20?
 
Stations using modern rigs are welcome also.  Check it out at
http://novicerigroundup.com/ .
 
Thanks to David Moore for this, concerning a slower spinning Sun:
http://to.pbs.org/2lJmPrX
 
For more information concerning radio propagation, see the ARRL
Technical Information Service 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 February 9 through 15, 2017 were 15, 18, 18, 18,
16, 15, and 23, with a mean of 17.6. 10.7 cm flux was 75.4, 74,
75.7, 76.2, 74.8, 74.5, and 74.8, with a mean of 75.1.  Estimated
planetary A indices were 7, 8, 5, 3, 5, 2, and 3, with a mean of
4.7.  Estimated mid-latitude A indices were 5, 5, 3, 2, 2, 1, and 2,
with a mean of 2.9.
NNNN
/EX

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