Register Account

Login Help

ARRL Propagation Bulletin ARLP011 (2019)

ARLP011 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 11  ARLP011
From Tad Cook, K7RA
Seattle, WA  March 15, 2019
To all radio amateurs 

ARLP011 Propagation de K7RA

Sunspots reemerged for 8 days on March 5-12. Average daily sunspot
numbers rose from 4.4 in last week's bulletin to 9.9 this week
(March 7-13). Average daily solar flux barely changed, from 70.6 to
70.9. Average planetary A index declined from 12.6 to 5.1, and
average middle latitude A index from 9.7 to 3.9.

The Vernal Equinox will occur next Wednesday, March 20 when the
southern and northern hemispheres will be bathed in equal amounts of
solar radiation.

Predicted solar flux is 70 on March 15-17, 68 on March 18-22, 69 on
March 23-28, 70 on March 29, 71 on March 30 through April 8, 70 on
April 9, 69 on April 10-24, 70 on April 25 and 71 on April 26-28.

Predicted planetary A index is 12, 8 and 8 on March 15-17, 5 on
March 18-19, 10 on March 20, 5 on March 21-25, then 12, 30, 28, 14
and 8 on March 26-30, 5 on March 31 through April 1, 8 on April 2-3,
5 on April 4-9, then 12, 10 and 8 on April 10-12, 5 on April 13-15,
10 on April 16, 5 on April 17-21, then 10, 26, 24, 12 and 8 on April
22-26 and 5 on April 27-28.

Geomagnetic activity forecast for the period March 15 to April 13,
2019 from F.K. Janda, OK1HH.

"Geomagnetic field will be:
Quiet on March 22-24, 31, April 4-9. 13
Quiet to unsettled on March 16-18, 25, April 1-3, 11-12
Quiet to active on March 19-21, April 10
Unsettled to active on March 15, 26, 29-30
Active to disturbed on March 27-28

"Solar wind will intensify on March (15,) 21-22, 25-28, April 1, (2,

"Parenthesis means lower probability of activity enhancement."

Australia's Space Weather Services issued a geomagnetic disturbance
warning at 0003 UTC on March 15: "Increased geomagnetic activity
expected due to coronal hole high speed wind stream on March 15-16,

"15 March: Unsettled to Active, possible Minor Storm periods for
High latitudes.  16 March: Quiet to Unsettled"

Jim DeYoung, N8OQ sent this interesting question on March 13:

"I have been wondering about the fact the north magnetic pole has
been shifting towards Russia significantly and therefore are there
any expected resultant significant shifts in the auroral oval that
would affect propagation to/from North America or to Asia?

"The reason I ask is I made probably my best QSO of all time a few
weeks ago during the CQ 160m Phone contest.  I always run QRP for
that contest as a good test of my operating skills (ears), noise
levels, rigs, and most importantly my antenna.  I have used for many
years a 93-meter horizontal loop fed with about 24 meters of window
line up generously about 13 meters.  The 'loop' is kind of more like
a trapezoid but actually what is called a scalene.

"For my station I had very good propagation conditions for the CQ
160m Phone contest.  Heard ZF9, ZF2, PJ4 (2x), TO4, C6, HQ9, OK7 and
others I didn't write down. Didn't work any of them as expected at 5
watts QRP phone.

"However, on February 24 at 0417 UTC I worked UA7K with 5 watts on
1.838 LSB!  At his twilight sunrise on the north-east side of the
Black Sea.  Apparently one of those fabled 160m enhancements at a
station sunrise/sunset.  Easy!  Called once not expecting a thing.
A short pause on his end.  I hear N8OQ.  I give RR.  He gives me his
CQ Zone 16.  I report Victor Alpha Virginia.  He gives roger and in
the log he goes.  LOTW QSL received a few days later! WOW!
"The QSO was so easy I soon began to think I must have been hearing
things, got the call sign wrong, something.

"I heard no big guns work him, but I heard at least one other
run-of-the-mill U.S. station work him for the few minutes I paused
to monitor him.  When I checked again about 15 minutes later he was
gone but I then heard a Czech station and a Lithuanian but didn't
get them. Both also near their twilight sunrise line.  My antenna
and low noise floor allow me to hear these stations that few if any
others were calling. The UA7K clearly also had a very low noise
floor but is apparently one of those super contest stations, Russian
Contest Club. My 5 watts not enough to work any others of the good
DX stuff--too bad!  I was tempted several times to turn on the amp
but resisted! This is currently my best of all time QSO.

"Was this QSO assisted by the auroral oval shifting away from the
transatlantic path?"

I didn't have an answer for Jim but wanted to pass this on to

Interesting article about solar activity from Canada's CBC:

Thanks, David Moore, for sending this link concerning massive solar

The latest video from Dr. Tamitha Skov, WX6SWW, can be found at, .

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

For more information concerning radio propagation, see the ARRL
Technical Information Service web page at, For an explanation of
numbers used in this bulletin, see

An archive of past propagation bulletins is at More good
information and tutorials on propagation are at

Monthly propagation charts between four USA regions and twelve
overseas locations are at

Instructions for starting or ending email distribution of ARRL
bulletins are at

Sunspot numbers for March 7 through 13, 2019 were 14, 11, 11, 11,
11, 11, and 0, with a mean of 9.9. 10.7 cm flux was 70.9, 71.8,
70.7, 71.1, 70.4, 70.7, and 70.8, with a mean of 70.9. Estimated
planetary A indices were 8, 5, 5, 4, 3, 7, and 4, with a mean of
5.1. Middle latitude A index was 5, 3, 4, 3, 3, 5, and 4, with a
mean of 3.9.


Instragram     Facebook     Twitter     YouTube     LinkedIn