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SB PROP @ ARL $ARLP035
ARLP035 Propagation de K7RA

ZCZC AP35
QST de W1AW
Propagation Forecast Bulletin 35 ARLP035

From Tad Cook, K7RA

Seattle, WA August 27, 2021
To all radio amateurs

SB PROP ARL ARLP035
ARLP035 Propagation de K7RA

Sun watchers saw no days without sunspots this week. Average daily
sunspot numbers rose from 17.7 last week to 21.7 this reporting
week, August 19 through 25.

Average daily solar flux increased from 73.8 to 78.5.

Geomagnetic indicators were quiet, with average daily planetary A
index declining from 6.1 to 4.7, and average daily middle latitude A
index dropping from 7.6 to 5.7.

We are less than one month away from the Northern Hemisphere
autumnal equinox, on Wednesday, September 22, 2021. Both
hemispheres will be bathed in equal measures of solar radiation,
always a positive for HF propagation.

Predicted solar flux is 90 on August 27 to September 2, 85 on
September 3, 73 on September 4 to 11, 74 on September 12 to 15, 76
on September 16 to 18, 77 on September 19 and 20, 76 on September
21, 75 on September 22 to 29 and 73 on September 30 through October
8.

Predicted planetary A index is 16, 12, 10 and 8 on August 27 to 30,
5 on August 31 through September 1, 8 and 12 on September 2 and 3, 5
on September 4 to 10, then 10 and 8 on September 11 and 12, 5 on
September 13 to 18, 8 on September 19 and 20, 15 and 10 on September
21 and 22, 7 on September 23 and 24, 5 on September 25 to 28, then 8
and 12 on September 29 and 30 and 5 through the first week in
October.

I find it encouraging that the above solar flux forecast from USAF
and NOAA was revised upward over the past few days, and that the
sunspot number (47) on Thursday, August 26 was much higher than the
average daily sunspot number (21.7) over the previous seven days.

Geomagnetic activity forecast for the period August 27 til September
21, 2021 from F. K. Janda, OK1HH.

"Geomagnetic field will be
Quiet on September 1, 5, 10, 14 to 18
Quiet to unsettled August 28, 31, September 2 to 4, 6 to 9, 19 and 20
Quiet to active on August 29 and 30, September 11 to 13, 21
Unsettled to active August (27)
Active to disturbed, Nothing predicted

Remarks:
- Parenthesis means lower probability of activity enhancement."

At 0839 UTC on August 26 the Australian Space Forecast Centre issued
a geomagnetic warning. "A weak slow moving CME associated with a
disappearing solar filament on 23 August may have a glancing impact
at Earth late on the UT day of the 26th or into 27th August. Mildly
elevated geomagnetic activity may occur following the impact.
Another weak slow moving CME observed occurring towards the middle
of the UT day on 24 August appears to be primarily eastward,
although there is a chance it may also have a glancing impact at
Earth during the 27th August, potentially resulting in mildly
elevated geomagnetic activity."

Darrell Emerson, AA7FV wrote:

"I have a question about a possible 17m propagation anomaly between
my location (AA7FV in Tucson AZ, DM42pg, 32.3N 110.7 W) and the
NCDXF beacon W6WX (CM97ae). According to QRZ.com, W6WX is at a
bearing of 301 degrees, and a distance of 1158 km from AA7FV.
Sunset at W6WX is 02:49 UTC, and sunset at AA7FV is 01:58 UTC.

I have been using the program 'Faros' to look at the propagation
times from various NCDXF beacons. As I'm sure you know, the NCDXF
beacons are time synchronized using GPS, and so by looking at the
arrival times of transmissions from a given beacon, it is easily
possible to distinguish between short path and long path
propagation. This is what the program Faros does.

As a check, here is data taken at the same time with the same setup
on the beacon ZL6B, which shows no anomaly. You can see that I was
receiving the beacon from about 0h UTC until about 04:30 UTC. The
propagation delays (blue dots) line up precisely with the delay
(about 39 ms) expected for short path propagation, which is marked
by the horizontal dashed line labeled 'SP'. No surprise here. The
expected long path delay would be nearly 100 ms, but there are no
signals observed with that delay, during this time period."

Darrell sent graphics which I am unable to reproduce in this
bulletin, but you could email him via his address on QRZ.com if you
want copies.

I referred his quesion to Carl, K9LA, who responded:

"Thanks for those interesting plots from Faros.

ZL6B sunrise is around 1906 UTC, so I would have expected that you'd
see him again later in the day (a bit after 1906 UTC). But perhaps
the MUF wasn't high enough at that time. Or something else was going
on. Dropping out around 0430 UTC is understandable, as your sunet is
around 0200 UTC and the MUF was slowly dropping until ZL6B (still in
daylight) went away around 0430 UTC.

As for the W6WX results, being only 1158 km from you says a
relatively high elevation angle would be required on the true great
circle path. And that says the MUF over that path would not likely
be high enough for normal refraction at a high elevation angle on 18
MHz (since we're just starting to come out of solar minimum). So
your comment about an unusual ionized cloud (or an enhanced area in
the ionosphere) is a possible explanation.

The 20 msec or so delay suggests an off-great circle path from an
enhanced area of ionization. And my guess is that this area was
south of you and W6WX as that puts it closer to the equatorial
ionosphere, where more interesting short-term events happen than
north of your location. It's too bad that the azimuth arrival angle
isn't measured."

If you're interested in some more Faros results, check out https://k9la.us/Aug17_Long_Path-Short_Path_Switching_on_15-Meters_Part_1.pdf and https://k9la.us/Sep17_Long_Path-Short_Path_Switching_on_15-Meters_Part_2.pdf

By the way, Carl says he accidentally deleted an email from someone
named Edgar in Toronto who had questions about VOACAP, and now he
has no way to respond. If you are Edgar, please contact K9LA.

Ken Brown, N4SO (EM50tk) in Alabama reported hearing the XE1FAS/B
beacon on 28.171 MHz at 0542 UTC (12:42 AM local time) on August 26.
"Just above the noise and then faded out." The path distance was
1,001 miles.

Reader K6HPX has some fascinating antenna photos on his QRZ.com
profile. Check it out.

The latest from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/jJgxa0SMojE

You can always find her new videos here:

https://www.spaceweatherwoman.com/forecasts/

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 August 19 through 25, 2021 were 25, 14, 25, 16,
14, 29, and 29, with a mean of 21.7. 10.7 cm flux was 74.9, 77.7,
77.1, 77.1, 78.1, 80.9, and 83.6, with a mean of 78.5. Estimated
planetary A indices were 4, 5, 3, 3, 4, 5, and 9, with a mean of 4.7
Middle latitude A index was 5, 6, 4, 4, 8, 5, and 8, with a mean of
5.7.
NNNN
/EX

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

XPost: rec.radio.shortwave, rec.radio.info

SB PROP @ ARL $ARLP035
ARLP035 Propagation de K7RA

ZCZC AP35
QST de W1AW
Propagation Forecast Bulletin 35 ARLP035

From Tad Cook, K7RA

Seattle, WA September 2, 2022
To all radio amateurs

SB PROP ARL ARLP035
ARLP035 Propagation de K7RA

The past week saw many interesting events. The DRAO observatory at
Penticton, British Columbia (the source of 10.7 cm solar flux
measurements) was overwhelmed by solar flares, and at 2000 UTC on
August 28 reported a solar flux value of 251.9, and the next day at
1700 UTC, a value of 357.1.

The 2000 UTC local noon numbers are the official solar flux number
for each day, so for the August 28 value I chose to report the 2300
UTC number of 133.5 instead.

I checked with astronomer Andrew Gray at Penticton, and he reported,
"The high values are indeed because of solar activity, both
yesterday and today flares occurred right during our flux
measurements."

Solar activity increased this reporting week (August 25-31) with
average daily sunspot numbers rising from 58.7 to 74.9 and solar
flux from 104.5 to 123.8.

Without that correction for August 28, average daily solar flux
would have been 140.8 instead of 123.8.

I have seen these errors in the past, but they are rare. When they
occur, there is only 1/3 chance they will happen during the daily
2000 UTC reading, which sends them into the official daily solar
flux data.

Note that NOAA did not correct the high false value:

https://services.swpc.noaa.gov/text/daily-solar-indices.txt

Average daily A index was a little lower, the planetary values
shifting from 12.6 to 10.1 and middle latitude from 11 to 9.4.

Three new sunspot groups appeared on August 25 at the beginning of
the reporting week, but none until September 1, with two new sunspot
groups. The daily sunspot number rose from 42 on Wednesday to 67 on
Thursday.

Total sunspot area peaked on August 27.

Predicted solar flux is more optimistic in the Thursday night
version, as opposed to the Wednesday forecast reported in the ARRL
Letter.

Instead of 110 on September 2, the latest forecast is 116, 118 and
118 on September 2-4, 115 on September 5, 110 on September 6-8, then
118, 124, 130 and 128 on September 9-12, then 120, 117, 105 and 102
on September 13-16, then 98 on September 17-18, then 104, 102 and
108 on September 19-21, 118 on September 22-23, 124 and 125 on
September 24-25, 120 on September 26-28, 115 on September 29 to
October 1, then 112 on October 2, 108 on October 3-4, then 115, 120,
124 and 130 on October 5-8.

Flux values may briefly dip below 100 in mid-October.

Predicted planetary A index is 10, 15, 30, 25 and 15 on September
2-6, 10 on September 7-8, 12 and 8 on September 9-10, 5 on September
11-12, then 12, 15 and 10 on September 13-15, 8 on September 16-17,
5 on September 18-23, then 14, 10 and 8 on September 24-26, 5 on
September 27-29, then 30, 38, 20, 15, 18, 10, 12 and 8 on September
30 through October 7, and 5 on October 8-9.

At 0209 UTC on September 2 the Australian Space Weather Forecasting
Centre issued a geomagnetic disturbance warning: "Disturbed
conditions caused by a high speed wind stream in a geoeffective
direction are expected September 3-5."

Frantislav K. Janda, OK1HH shares his weekly commentary:

"The recent rise in solar activity, especially during August 27-30,
was triggered by two sunspot groups, AR3088, which on 29 August fell
behind the western limb of the solar disk, and AR3089, which on 30
August passed through the central meridian, so entered the region of
the so-called present active longitudes.

"Both sunspot groups are in the southern hemisphere of the Sun,
while in both were daily registered flares of moderate magnitude.
CMEs have been registered in four cases. Given the proximity of the
coronal hole, we would expect a significant increase in geomagnetic
activity, but only at first approach.

"However, there was only a slight increase in geomagnetic activity,
confirming the current solar wind path models. We expect it to
intensify and then increase in geomagnetic activity since about
September 4 onwards. A further gradual increase in total solar
activity can be expected a few days later."

I (K7RA) noticed some curious 12 meter propagation, testing the band
using FT8 on https://pskreporter.info/pskmap.html. This way I can
see instantly where my signal is heard, and get accurate, objective
signal reports.

On August 31 at 2038-2116 UTC my calls were heard nowhere in North
America outside my local area, which were stations 4-54 miles away.
But all stations hearing me were in a straight line running through
Mexico and Central America, then down to Brazil.

XE1GLL, XE1EE, and XE1AQY, down to V31MA, LU6FL and PU3MSR. No 12
meter resonant antenna, just a 32 foot end-fed indoor wire fed with
a 4:1 UnUn transformer and automatic antenna tuner.

Other curious 12 meter behavior was on Saturday, August 27 at 2252
UTC when the only stations hearing me (FT8 again) were ZL2OK at
7,120 miles with a strong signal report of +4 dB and WH6FXV at 2,649
miles.

Ten minutes later at 2302 UTC JA1QGI was the only station reporting,
from 4,746 miles away. Four minutes later JN4MIV reported. At 2312
UTC ZL2OK was back, this time reporting -4 dB, 8 dB lower than the
earlier report.

At 2315 UTC I worked JH6RKI and copied several more Japanese
stations.

Newsweek Magazine has been reporting interesting solar news
recently:

https://bit.ly/3q5XACl

And Forbes.

https://bit.ly/3AOWD6G

Is "The Independent" one of the UK Fleet Street tabloids? Perhaps a
RSGB member could inform us.

https://bit.ly/3e5kJlF

Another wonderful report from Dr. Tamitha Skov, WX6SWW, ham radio's
own Space Weather Woman:

https://youtu.be/hh_EPRjMmzY

In the following links, many are presented for your amusement only.
I do not believe that a huge solar flare will ever engulf the Earth.

A canyon of fire: https://bit.ly/3RcWSiy

EarthSky reports (page down): https://bit.ly/3wRStK1

A report four weeks old, but still relevant: https://bit.ly/3KH0yH4

Growing sunspot a threat: https://bit.ly/3cEgFZt

Our angry Sun: https://bit.ly/3cHMiBm

This one is a bit over the top: https://bit.ly/3TzEnqd

From a few days ago: https://bit.ly/3CSJFY3

Radio blackouts: https://bit.ly/3Rwwpwa

Flares and blackouts: https://bit.ly/3KH2jEa

More Flares: https://bit.ly/3e5ninN

Existential threat: https://bit.ly/3Qc3MDE

Flare facing Earth: https://bit.ly/3q5gzgv

Sunspot somehow destroys Earth: https://bit.ly/3cHGSGy

The 61st annual All Asian DX Phone contest is this weekend.
Information can be found here: https://bit.ly/3ALPkwa

Send your tips, reports, observations, questions, and comments to k7ra@arrl.net.

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 August 25 through 31, 2022 were 94, 88, 84, 79,
87, 50, and 42, with a mean of 74.9. 10.7 cm flux was 117.8, 118.6,
127.5, 133.5, 130.6, 125.6, and 113.3, with a mean of 123.8.
Estimated planetary A indices were 5, 5, 14, 7, 14, 13, and 13, with
a mean of 10.1. Middle latitude A index was 5, 5, 11, 7, 13, 13, and
12, with a mean of 9.4.
NNNN
/EX

--- SoupGate-Win32 v1.05
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XPost: rec.radio.shortwave, rec.radio.info

SB PROP @ ARL $ARLP035
ARLP035 Propagation de K7RA

ZCZC AP35
QST de W1AW
Propagation Forecast Bulletin 35 ARLP035

From Tad Cook, K7RA

Seattle, WA September 1, 2023
To all radio amateurs

SB PROP ARL ARLP035
ARLP035 Propagation de K7RA

First, this alert from Australia.

"ASWFC GEOMAGNETIC DISTURBANCE WARNING ISSUED AT 0706UTC/31 AUGUST
2023 BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.

A filament eruption and associated coronal mass ejection (CME) were
observed on UT day 30-Aug. This CME is expected to impact Earth from
1800 UT +/- 12 hours on 02-Sep, with impacts possibly rolling into
UT day 03-Sep. G1-G2 geomagnetic conditions are expected over this
time, with a chance for periods of G3."

Solar activity was down again this week, with average daily sunspot
numbers dropping from 105.9 to 78.7, and average daily solar flux
from 149.4 to 140.9.

Only three sunspot groups appeared, one each on August 25, 28 and
30.

But I have noticed a gradual transition from summer toward fall
conditions, with 10 and 12 meter openings more frequent. The
autumnal equinox is only three weeks from now.

Geomagnetic indicators were a little lower. Average planetary A
index went from 8.4 to 7, and average middle latitude numbers from
10.1 to 8.9.

What is the outlook?

Predicted solar flux shows a peak around 168 on September 18-21.

Forecast values are 140 on September 1, then 150, 150 and 145 on
September 2-4, 150 on September 5-9, 147 on September 10-11, then
145, 150, 155, 150, 155 and 160 on September 12-17, 168 on September
18-21, then 165, 160, and 148 on September 22-24, 150 on September
25-26, then 152, 150, 145,and 140 on September 27-30, then 145 on
October 1, 150 on October 2-3, 152 on October 4, 156 on October 5-6,
150 on October 7. and 148 on October 8-9.

Predicted planetary A index is 10, 12 and 35 on September 1-3, then
15, 10 and 8 on September 4-6, 5 on September 7-13, then 12, 10, 10
and 8 on September 14-17, 5 on September 18-22, then 10, 10 and 8 on
September 23-25, 5 on September 26 to October 2, then 10, 8 and 8 on
October 3-5, and 5 on October 6-10.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere for September 1-7, 2023 from OK1HH.

"On 27 August, we predicted a rise in geomagnetic activity,
triggered by the arrival of particles from the filament solar flares
three days earlier. It did occur, but to a lesser extent than we
expected. No significant solar flare (at least of M-class) was
observed until 25 August, which is somewhat surprising for the
current phase of Cycle 25 development.

We did not see a major flare until August 26 at 2250 UTC, and it was
an M1-class solar flare, hidden behind the Sun's eastern edge, but
it was a long duration eruption (LDE). It was accompanied by a CME,
which of course was not heading toward Earth, but in this case Mars
(which it should hit on September 1).

The coronal mass ejection (CME) was observed on August 29 at about
1748 UTC near the coordinates N05W35. Another major solar flare, C3,
was observed on August 30 with a maximum at 2334 UTC at AR 3413.

Prior to that, a filament of solar plasma disappeared near S18W24 at
2015 UTC.

Still, we expect only a slight increase in Earth's magnetic field
activity in the next few days.

Ionospheric propagation has varied erratically, with partial credit
due to the sporadic E layer that occurred irregularly in Earth's
northern hemisphere late this summer."

India's solar mission: https://bit.ly/3PiPJ1N

Flares: https://bit.ly/47X6gzC

Four hours of Tamitha Skov and extreme space weather events:

https://youtu.be/_Li9wxmmbQs

This weekend is the phone portion of the All Asia DX Contest:

https://bit.ly/43GPrXq

Send your tips, reports, observations, questions and comments to
k7ra@arrl.net. When reporting observations, don't forget to tell
us which mode you were operating.

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 .

Also, check this article from September, 2002 QST:

https://www.arrl.org/files/file/Technology/tis/info/pdf/0209038.pdf

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 August 24 through 30, 2023 were 86, 77, 75, 69,
68, 82, and 94, with a mean of 78.7. 10.7 cm flux was 144.1, 138.9,
139.3, 141.5, 141.7, 142.2, and 138.6, with a mean of 140.9.
Estimated planetary A indices were 9, 5, 7, 11, 6, 5, and 6, with a
mean of 7. Middle latitude A index was 9, 7, 9, 13, 8, 7, and 9,
with a mean of 8.9.
NNNN
/EX

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