QST de W1AW  
Propagation Forecast Bulletin 16  ARLP016
>From Tad Cook, K7RA
Seattle, WA  April 22, 2019
To all radio amateurs 

SB PROP ARL ARLP016
ARLP016 Propagation de K7RA

New sunspot group 2739 appeared on April 17, and the daily sunspot
number rose to 24. The new sunspot has a polarity indicating it is
still part of old Solar Cycle 24, the current sunspot cycle. This
reporting week (April 11-17) the average daily sunspot number rose
from 6.9 to 14, while average daily solar flux increased from 75.4
to 76.4.

Sunspots have been visible on every day since April 7, so as of
April 18 that is 12 continuous days.

Geomagnetic indicators were quieter, with average planetary A index
declining from 10.6 to 6.4.

Predicted solar flux for the next 45 days is 75 on April 19, 70 on
April 20-21, 68 on April 22-25, 69, 70 and 69 on April 26-28, 71 on
April 29-30, 70 on May 1, 72 on May 2-3, 77 on May 4, 79 on May 5-6,
78, 79 and 77 on May 7-9, 78 on May 10-17, 71 on May 18-19, 69 and
68 on May 20-21, 69 on May 22-23, 70 and 69 on May 24-25, 71 on May
26-27, 70 on May 28, 72 on May 29-30, then 77 on May 31 and 79 on
June 1-2.

Predicted planetary A index is 5 on April 19-26, then 10, 8 and 5 on
April 27-29, 10 on April 30 through May 2, then 7, 5 and 13 on May
3-5, then 10, 14 and 7 on May 6-8, 8 on May 9-10, 5 on May 11-20,
then 10, 8 and 5 on May 21-23, 10, 8 and 5 on May 24-26, 10 on May
27-29, then 7, 5, 13 and 10 on May 30 through June 2.

Jon, N0JK reports that summer sporadic-E season began on April 14
when he copied K2PL (Virginia) and KE3QZ (Maryland) from Jon's home
in Kansas on 6 meters.

Geomagnetic activity forecast for the period April 19 to May 15,
2019 from F.K. Janda, OK1HH.

'Geomagnetic field will be:
Quiet on April 19, May (12), 13
Quiet to unsettled on April 20-22, 25, 27, May 3, 8, 10-11
Quiet to active on April 27, May 2, 4
Unsettled to active on April 23, 26, 28-30, May 1, 5-7, 9
Active to disturbed April 24

Solar wind will intensify on April 22-24, (25,) May 1-3, 9-13

Parenthesis means lower probability of activity enhancement.'

Jeff, N8II sent this report last Friday, April 12, too late for
Propagation Forecast Bulletin ARLP015:

'There was not much action on 17 or 15M today. However, I did catch
C5DL on 15 and 17M CW around 2000Z and worked them on both bands
easily. The signal on 15M was peaking S4-5 at a beam heading of 130
degrees (true heading about 70). Then, after 2100Z I managed to work
AM70URE/9 in Ceuta, Africa on 15M SSB beaming to the south Atlantic
on scatter. He was working SA, so his antenna was in the best
position to work the scatter. Signals from south EU were good at
2030Z on 20M; one Italian was S9+20dB and 2 others very loud.
EA3GWK in Spain was S9+15dB.'

I think this is an old video from Dr. Tamitha Skov, WX6SWW about the
solar magnetic field when it reverses:

www.spaceweatherwoman.com/can-the-suns-magnetic-field-flip/ .

Various images of sunspots:

https://earthsky.org/todays-image/photos-sunspot-ar-2738-apr-2019 .

If you would like to make a comment or have a tip for our readers,
email the author at, [email protected].

For more information concerning radio propagation, see the ARRL
Technical Information Service web page at,
arrl.org/propagation-of-rf-signals. For an explanation of
numbers used in this bulletin, see
arrl.org/the-sun-the-earth-the-ionosphere.

An archive of past propagation bulletins is at
arrl.org/w1aw-bulletins-archive-propagation. More good
information and tutorials on propagation are at k9la.us/.

Monthly propagation charts between four USA regions and twelve
overseas locations are at arrl.org/propagation.

Instructions for starting or ending email distribution of ARRL
bulletins are at arrl.org/bulletins.

Sunspot numbers for April 11 through 17, 2019 were 13, 14, 14, 11,
11, 11, and 24, with a mean of 14. 10.7 cm flux was 78.5, 77.3,
77.9, 75.4, 75.4, 74.2, and 76.1, with a mean of 76.4. Estimated
planetary A indices were 7, 9, 8, 4, 8, 6, and 3, with a mean of
6.4. Middle latitude A index was 6, 7, 7, 3, 8, 6, and 3, with a
mean of 5.7.