SB PROP @ ARL $ARLP015
ARLP015 Propagation de K7RA
ZCZC AP15
QST de
W1AW
Propagation Forecast Bulletin 15 ARLP015
From Tad Cook,
K7RA
Seattle, WA April 10, 2020
To all radio amateurs
SB PROP ARL
ARLP015
ARLP015 Propagation de K7RA
After five days of new cycle 25
sunspot activity, sunspots vanished.
Average daily sunspot number rose from
3.6 last week to 5.1 this
time. The average daily sunspot number over the
days they were
visible, March 31 through April 4, was 12.2, but these
observations
straddled two reporting weeks.
Average daily solar flux
rose from 69.4 to 70.2. Geomagnetic
indicators remain quiet, with average
planetary A index declining
from 7.7 to 6.6, and average mid-latitude A index
slipping from 5.9
to 5.3.
Predicted solar flux for the next 45 days
is 70 on April 10 to 13,
68 on April 14 to 23, 70 on April 24 through May 7,
68 on May 8 to
20, and 70 on May 21 to 24.
Predicted planetary A
index is 8 on April 10 and 11, 5 on April 12
to 14, 10 on April 15, 8 on
April 16 to 19, 5 on April 20 to 25, 10
on April 26 and 27, 5 on April 28
through May 6, 8 on May 7 and 8, 5
on May 9 to 11, 10 on May 12, 8 on May 13
and 16, 5 on May 17 to 22
and 10 on May 23.
F. K. Janda, OK1HH
wrote:
"Geomagnetic activity forecast for the period April 9 to May 5,
2020
Geomagnetic field will be
Quiet on: April 10, 20 and 21, May
2 and 3
Quiet to unsettled on: April 11 to 13, 17 and 18, 22 to 24, 28 and
29
Quiet to active on: (April 9, 14, 16, 25, May 1)
Unsettled to
active on: (April 15, 19, 26 and 27, 30, May 4 and 5)
Active to disturbed:
nothing predicted
Solar wind will intensify on: April 9, 12 and 13,
(15 and 16,) 17 to
19, (20,) 26 to 28, May 4 to 6
Remarks:
-
Parenthesis means lower probability of activity enhancement.
- The
predictability of changes remains lower as there are
no
indications."
Tamitha Skov, WX6SWW is excited about signs of cycle
25:
https://youtu.be/UKsPSnSZers
Frank
Donovan, W3LPL sent this out to the Potomac Valley Radio Club
yesterday, and
shared it with us for this bulletin:
"Some of us have noticed a slight
uptick in solar activity since
Christmas Day when when two Cycle 25 spots --
AR 2753 and AR 2754 --
appeared. Only one of the five subsequent sunspots --
AR 2757 --
has been from old Cycle 24. All of the sunspots over the the
last
12 months have been relatively weak and have had little affect
on
propagation.
Although the beginning of Cycle 25 won't be
officially declared
until late this year, its highly likely that it began on
Christmas
Day 2019.
The next important event to look for is a strong
Cycle 25 sunspot,
hopefully that will occur this year."
https://iopscience.iop.org/article/10.3847/2515-5172/ab79a1
https://www.syfy.com/syfywire/welcome-cycle-25-a-new-solar-magnetic-cycle-has-begun
Jon
Jones, N0JK wrote yesterday:
"With the early start to the summer
sporadic-E season, some Es are
linking from North America to South
America.
On April 9, LU9FF and LU9FVS spotted K4CVL on 50.313 MHz FT8
at
2230z. K4TR and NN4X in South Florida spotted stations in
Chile.
Signals were strong enough for SSB with AC4TO EM70 working
CA3SOC
and LU8YD on 50.110 MHz SSB at 2224z.
KN4NN, AA5AU and N0FW
(EM79) Ohio were also making FT8 contacts with
South America on 6
meters."
KA3JAW monitors 11 meters, (That's right, Citizens Band!)
for
interesting propagation events from Easton, PA
(FN20jq):
"Sporadic-E was up on eleven meters on Tuesday, April 7 from
6:45
until 11:00 pm local (ET).
During this event, the Es funnel path
coned me stations only from
the coastal Gulf of Mexico states of Louisiana,
Mississippi,
Alabama.
I find it somewhat strange that Es remains
active up till late
nightly hours during the opening of Spring
season.
I thought Tuesday, March 31 was a good DX day monitoring the
11
meter band with reception of Tyler, Texas at 1,254 miles.
But
today, Saturday, April 4 was way more exciting with reception of
multiple
Puerto Rico stations rolling-in from 6:42 pm local (ET)
until 8:00 pm that
were 374+ miles further in range.
One operator there was making greater
than 1,600 miles contacts from
West Virginia up into Rhode
Island.
Around local sunset at 7:29 pm the baseline background noise
level
environment jumped 30 dB when one particular operator running
high
power would key the microphone.
Puerto Rico operators would
occasionally peak 20 dB over local
operators.
The distance from my
QTH to San Juan, Puerto Rico runs 1,628 miles.
This would be considered to be
at the far end range of a single-hop
sporadic-e path. Perhaps the plasma
cloud was tilted a few degrees
from horizon."
I've been using the FT8
mode with WSJT-X software to observe
marginal propagation modes, in which
communication occurs due to
refraction via whispery ionized clouds. Using
low power and a
deliberately marginal antenna (short piece of wire, thrown
out the
basement window, never more than 4 feet above ground) I
can
immediately see signal reports from many stations via
https://www.pskreporter.info/pskmap.html
. Some of the results on
160 through 10 meters seem quite remarkable,
considering the antenna
and power level.
If you would like to make a
comment or have a tip for our readers,
email the author at, k7ra@arrl.net.
For more information
concerning radio propagation, see
http://www.arrl.org/propagation and
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 April 2 through 8, 2020 were 12, 13, 11, 0, 0,
0, and 0, with a
mean of 5.1. 10.7 cm flux was 69.8, 69.9, 70.1,
71.2, 69.9, 69.9, and 70.4,
with a mean of 70.2. Estimated
planetary A indices were 7, 9, 5, 5, 3, 4,
and 13, with a mean of
6.6. Middle latitude A index was 7, 7, 4, 4, 2, 3,
and 10, with a
mean of 5.3.
NNNN
/EX
