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ARRL Propagation Bulletin ARLP027 (2021)

SB PROP @ ARL $ARLP027
ARLP027 Propagation de K7RA

ZCZC AP27
QST de W1AW  
Propagation Forecast Bulletin 27  ARLP027
From Tad Cook, K7RA
Seattle, WA  July 2, 2021
To all radio amateurs 

SB PROP ARL ARLP027
ARLP027 Propagation de K7RA

Solar activity is strong! Average daily sunspot number rose from 14
to 34.7, and average daily solar flux increased from 79.3 to 86.9.
Both figures represent a dramatic increase in solar activity.  These
averages are for the recent seven day period, Thursday through
Wednesday, and the sunspot number on Thursday was 56, which is above
the average of 34.7, always a good sign.

Planetary A index went from 5.3 to 6.1, while average daily middle
latitude A index was at 6.1, the same as last week.

Predicted solar flux is 94 on July 2 to 6, 90 on July 7 and 8, 85 on
July 9 to 11, 82 on July 12 to 14, 80 on July 15 to 18, 82 on July
19, 85 on July 20 to 24, 88 on July 25, 90 on July 26 to 28, 92 on
July 29 through August 1, 90 on August 2, and 85 on August 3 to 7.

Predicted planetary A index is 8, 12, 8, 10 and 8 on July 2 to 6, 5
on July 7 and 8, 8 on July 9 and 10, then 5, 15 and 12 on July 11 to
13, 5 on July 14 to 20, 8 on July 21, 5 on July 22 to 26, 10 on July
27, 5 on July 28 to 30, 12 on July 31, 5 on August 1 to 4, then 8 on
August 5 and 6, and 5, 15 and 12 on August 7 to 9.

Geomagnetic activity forecast for the period July 2 to 29, 2021 from
F. K. Janda, OK1HH.
 
"Geomagnetic field will be
Quiet on: July 16 and 17, 24 and 25
Quiet to unsettled on: July 2 and 3, 6 and 7, 9 to 11, 18, 23, 29
Quiet to active on: July 4 and 5, 12, 14 and 15, (19 to 22,) 26
Qnsettled to active: July (8,) 13, 27 and 28
Active to disturbed: nothing forecast

Parenthesis means lower probability of activity enhancement."

Jon Jones, N0JK reports from Kansas EM28:

"A sporadic-E opening to Europe on 50 MHz on July 1 to the Heartland
(Midwest USA) the afternoon of July 1.
 
I decoded many Europeans. F6EXV in with a good signal. But difficult
getting takers.  Finally worked G4PLZ at 1933z. He was my only PSK
flag in Europe.

Even area ops who run KW and big Yagis were having trouble raising
Europe, but saw one work F6EXV and I think EI4DQ. K0TPP EM48 to the
east having better luck with Europe.

Here in northeast Kansas decoded EA, EI, F, G, and PA2M. EI3KD,
EI4DQ had good signals."

K4ZOT reported on June 28 from EM73 near Atlanta: 

"I thought you might be interested in this 6M DX which totally caught
me by surprise today.

I have been a 6M enthusiast since I received my license in 1964 when
I operated a Layette HA-460 6M 10W transceiver. In all this time I
have never worked or heard an African 6M station. I have worked JA
several times on 6M and other Pacific locations, but never Africa.
Much to my total surprise today, June 28, at 1926 UTC, 5T5PA
(Mauritania) suddenly popped on the FT8 JTALert 'Callsigns' screen
with an audio alert of new DX. Again, to my utter amazement I worked
him on the first call, a distance of 4241 miles. Not the longest 6M
DX by far, but surprising from Africa at least from this location. 

I believe he worked one or two other stations and then he was gone.
Perhaps only on for 2-3 minutes. A wonderful 6M DX from my station
using a 5 element Yagi at only 32 feet.

6M is indeed the 'Magic Band' as it has been for me for 55 years of
operation.  Best of all - Johannes confirmed the contact in LOTW
just a few minutes after we made contact. Thank you Johannes - a
true Ham in the best spirit of the hobby."

KA3JAW reported:

"On Thursday, July 1, 2021 at 10:15 am EDT, FM-DXer Bryce Foster in
Mashpee, Massachusetts received 87.7 RTP Antena-3 Pico da Barrosa,
Azores via 2x-Es. Station running 30 kW by vertical polarization.
Distance 2379 air miles. Reception lasted up to 35 minutes with
audio identification along with a stream match. This is the first
time I heard of a US to Azores link on the FM broadcast band.

W9NY reported on June 28:

"The propagation on 20 meters between my Dune Acres, Indiana station
and much of Europe and Asiatic Russia beginning last night (6/27/21)
at 11 pm and continuing for about 2 hours was absolutely amazing. It
reminded me of 10 meters at the peak of prior sunspot cycles.

Around 14.208 I called CQ and worked one station after another, from
Finland in the North to Corsica and Greece in the South and all
across Russia to several points in Siberia. Many of the signal
reports given and received were 20 to 30 DB over S9. A couple
nearly pinned the needle on my Icom 7610. In fact, I worked many
stations running 100 watts to simple antennas like a dipole or
vertical that were coming in over S9 and a few stations that were
QRP but still producing S5 to S7 signals. I have not heard an
opening like that in many years and it was certainly a lot of fun. I
probably should have turned on my QRP rig but I never got around to
it!

Perhaps a harbinger of things to come!

I did check out 17, 15, 12, 10 and 6, which were all quiet.

And today there was a fair amount of activity on 10 meters and 6
meters."

Frank, W3LPL wrote:

"Propagation through the auroral ovals and polar regions is likely to
be mostly normal through Sunday. There is a slight possibility that
isolated below normal intervals may briefly degrade propagation
through the auroral ovals and polar regions from midday Saturday
through early Sunday.
 
We are in the quiet geomagnetic activity season, only about half as
many geomagnetically disturbed days occur in June and July compared
to the more geomagnetically active equinox seasons.

Sporadic-E propagation occurs every day during June and July at
mid-latitudes in the northern hemisphere making long distance
propagation up to 15,000 km sporadically available in the 17, 15,
12, 10 and 6 meter bands from sunrise through midnight and
occasionally somewhat later.

The solar flux is likely to be at least 94 through Sunday. Solar
active region 2835 has grown to 770 micro-hemispheres (2.3 billion
square kilometers, four times the surface area of the Earth), almost
as large as the active region that significantly improved HF
propagation during late November 2020. Region 2835 is significantly
improving HF propagation on 30 and 20 meters during late afternoon,
nighttime and early morning hours and 17 and 15 meter propagation
during the day through early evening. Active regions 2836 and 2837
are slowly and quietly decaying and are having no effect on HF
propagation.

https://sdo.gsfc.nasa.gov/assets/img/latest/latest_1024_0171.jpg

160 and 80 meter propagation from North America to VK/ZL and the
South Pacific is likely to be seasonably normal through Sunday.

40 meter short path propagation to south Asia is likely to be mostly
normal at about 0015 UTC through Sunday. 40 meter short path
propagation from North America to east Asia after about 0930 UTC is
likely to be mostly normal with a slight possibility of isolated
below normal intervals on Saturday.

30 meter propagation through the auroral ovals and polar regions is
likely to be mostly normal with a slight possibility of isolated
below normal intervals late Saturday. 30 meter propagation is always
significantly degraded within a few hours of local noon because of
E-region blanketing of long distance F2 propagation.

30 meter night time long distance propagation in the northern
hemisphere is likely to improve due to increased ionizing solar
radiation in the northern high latitude regions caused by increased
sunspot activity, higher solar elevation angles and much shorter
nights with no source of ionizing solar radiation.

20 meter daytime and evening propagation through the auroral ovals
and polar regions is likely to be mostly normal with a slight
possibility of isolated below normal intervals late Saturday.

20 meter northern transpolar propagation within a few hours of
sunrise and sunset is improving with increased solar ionizing
radiation on the northern polar region caused by increased sunspot
activity and high solar elevation angles 24 hours per day during the
midnight sun season. 20 meter long distance propagation is
significantly degraded from mid-morning through late afternoon at
low and mid-latitudes in the northern hemisphere by F1 region midday
blanketing of low angle propagation during the summer.

20 meter late afternoon, nighttime and early morning long distance
propagation in the northern hemisphere is likely to improve due to
increased ionizing solar radiation in the northern high latitude
regions caused by increasing sunspot activity, higher solar
elevation angles and much shorter nights with no source of ionizing
solar radiation.

17 and 15 meter daytime long distance propagation in the northern
hemisphere is likely to improve due to increased ionizing solar
radiation in the northern high latitude regions caused by increasing
sunspot activity, high solar elevation angles and long days.

17, 15, 12, 10 and 6 meter sporadic-E propagation up to 15,000 km is
likely to be sporadically available from sunrise through midnight
and occasionally later through late July.

Geomagnetic disturbances caused by coronal hole high speed stream
effects are likely to remain mostly brief, minor and somewhat less
frequent through at least late 2021. The southward oriented (-Bz)
component of the IMF plays a crucial but unpredictable role in
triggering all geomagnetic storms. Brief minor to moderate
geomagnetic storms may be gradually triggered when the IMF persists
in a southward orientation (-Bz) with enhanced IMF field strength
for several hours coincident with the effects of an Earth directed
coronal hole high speed stream.

More frequent, longer duration, minor to severe geomagnetic storms
may be triggered suddenly and unpredictably when the IMF persists in
a southward orientation (-Bz) with enhanced IMF field strength for
several hours or more coincident with the effects of an Earth
directed fast CME.

There is a slight possibility that Earth-directed effects of a weak
CME and continuing weak coronal hole high speed stream effects may
slightly to moderately enhance IMF field strength, solar wind speed
near Earth and geomagnetic activity. If the weak CME is
geo-effective it may slightly degrade HF propagation through the
auroral ovals from midday Saturday through early Sunday. Geomagnetic
storms are not likely through Sunday. There is a slight possibility
of an M-class solar flare from Friday through Sunday, but its
possible HF propagation effects are likely to be brief and minor.

Mid-latitude northern hemisphere sunset is now 77 minutes later and
daylength is 163 minutes longer than it was on the March 20th.
Daylength and solar elevation angle in the northern polar region are
slowly declining through mid-July due to gradually waning summer
solstice effects."

For more information concerning shortwave 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/.

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

Sunspot numbers for June 24 through 30, 2021 were 11, 25, 16, 32,
50, 56, and 53, with a mean of 34.7. 10.7 cm flux was 80.6, 83.4,
82.4, 87, 88.6, 92.5, and 94.1, with a mean of 86.9.. Estimated
planetary A indices were 5, 7, 4, 4, 4, 5, and 14, with a mean of
6.1. Middle latitude A index was 6, 8, 5, 4, 4, 5, and 11, with a
mean of 6.1.
NNNN
/EX

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