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


--- MBSE BBS v1.0.8.4 (Linux-x86_64)
* Origin: American Radio Relay League (3:633/280.2@fidonet)

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 13, 2024
To all radio amateurs

SB PROP ARL ARLP035
ARLP035 Propagation de K7RA

With sunspot numbers up and solar flux decreasing, we saw ten new sunspot groups this week; two on September 6, three on September 7, two on September
8, one on September 9, and two on September 11.


Average daily sunspot numbers increased from 155.3 to 178.4, while average daily solar flux declined from 230.3 to 223.7.


Geomagnetic indicators were quiet, with average daily planetary A index dropping from 14 to 7.9 and middle latitude numbers from 12.7 to 11.7.


The solar flux forecast calls for 10.7 cm numbers at 210 on September 13-14, 205 on September 15-20, then 225 and 220 on September 21-22, then 225 on September 23-24, then 230, 235, 230 and 225 on September 25-28, and 240 on September 29-30, then 240, 245 and 230 on October 1-3, 220 on October 4-5,
225 on October 6-7, 220 on October 8-9, 225 on October 10-11, 220 and 215 on October 12-13, 210 on October 14-15, then back up to 240 at the end of the month.


Predicted planetary A index is 35 and 25 on September 13-14, then 15 on September 15-16, then 12, 15, 12 and 12 on September 17-20, 5 on September 21-25, then 25, 25, 15 and 10 on September 26-29, then 5 on September 30 through October 4, 10 on October 5-6, then 30, 22 and 8 on October 7-9, 5 on October 10-13, 8 on October 14-15, and 5 on October 16-22, then 25 on October 23-24.


Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere - September 11, 2024 from OK1HH.


"The solar wind speed, as measured in geostationary orbit, increased in two jumps on 12 September - first shortly after midnight UTC from 360 km/s to 430 km/s, then to 520 km/s after 0818 UTC. Meanwhile, the polarity of the longitudinal (north-south) component of the IMF (Bz) was negative. The consequence was a significant deterioration of shortwave propagation conditions.


"The development continued on 12 September as the X1.3 solar flare was
detected at 0943 UTC. The source was a new AR turning into view off the southeast limb (former AR 3792, whose high activity during the parade on the Sun's far side was well known thanks to helioseismological observations).


"However, the strong (G3) Geomagnetic Storm followed, while threshold was reached at 14:43 UTC. Values of critical frequencies f0F2 in the
mid-latitudes of the northern hemisphere of the earth were 2 MHz lower
compared to the previous days. Now it can be expected geomagnetic disturbance around September 14 (possible arrival of particles from the September 11
CME). We may wait until September 18 for quiet days."


WP3GW wrote:
"After a 4 month hiatus, just began again on FT8. I have noted that the SFI
has been more than 200, and have worked European stations at about 2200 UTC, three hours after propagation normally closes to the Caribbean.


"And have seen signals late night and in mornings before the Sun comes up in
10 meters, making it a twenty plus hours open band. Have made 7 new countries on FT8 in almost 3 weeks.


"Hope these conditions keep good for this contest season.

"Cheers, Angel Santana WP3GW."

Jeff, N8II wrote:
"There have been somewhat limited openings to Europe on 10 meters for about 2 weeks. On Monday September 2 I worked several Southern EU and several UK stations, some with good signals. Today, the 8th was exceptionally good. Not only was the 10 meter band open to all but possibly NE Europe, but stations
in the Middle East were S9 to S9+20 dB. On SSB I worked A42K, Oman, and
4K6FO, Azerbaijan. Also, UA9CTT, Asiatic Russia was S9+20 dB and UN4L, Kazakhstan was peaking S8 all of them working the All Asia Contest. I called
CQ with the majority of my callers from the UK all with good signals, many
over S9. The only somewhat weak Brit was a mobile running 5W who was peaking S5. OH6TS, Finland answered my CQ, and I heard SM5CAK, Sweden over S9. I was also called by Hungary and Romania. It was like the middle of October on a
good day, very surprising 2 weeks before the equinox. All of my QSOs were between 1400-1520Z. I also worked JE6RFM on 15M SSB during that time and
heard a JA5 about S7. T

here was an Indonesian also on 15M working the Asian contest who was S9+.

"The Summer has been frustrating with very limited activity except in
contests above 20M. 20M was open through most of the night to Europe
throughout the June-August period.


"The sporadic-E was poor this year, fewer openings and mostly single hop.
Every day 10M was open to Central and South America. Around the middle of August, we started getting daily openings to the West Coast. Since then, most days were open to AF and OC. Hawaii has been loud on several occasions including the NAQP Phone test 2nd weekend of August and was also briefly loud during the Hawaii QP last weekend of August.


"Today September 12 there was a good F2 opening to EU; I worked two R4s (next to Asia), several SP, DL, I, HB9, F. YL3BF called and was about S4-6. The UK was not part of the opening. One of the Germans was running 15W to a 5M long indoor wire and was peaking S9!"


The latest from Dr. Tamitha Skov, WX6SWW, Space Weather Woman: https://youtu.be/RHphr4iloHs [ https://youtu.be/RHphr4iloHs ]


Impressive sunspots: https://bit.ly/3zjgI8o [ https://bit.ly/3zjgI8o ]

Send your tips, reports, observations, questions and comments to
k7ra@arrl.net [ mailto: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 [ http://www.arrl.org/propagation ] and the ARRL Technical Information Service web page at: http://arrl.org/propagation-of-rf-signals [ 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 [ http://arrl.org/the-sun-the-earth-the-ionosphere ] .


An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation [ http://arrl.org/w1aw-bulletins-archive-propagation ] .


More good information and tutorials on propagation are at http://k9la.us [ http://k9la.us ] .


Also, check this: "Understanding Solar Indices" from September 2002 QST. https://bit.ly/3Rc8Njt [ https://bit.ly/3Rc8Njt ]

Instructions for starting or ending email subscriptions to ARRL bulletins are at http://arrl.org/bulletins [ http://arrl.org/bulletins ] .


Sunspot numbers for September 5 through 11 2024 were 167, 188, 179, 176, 213, 147, and 179, with a mean of 178.4. 10.7 cm flux was 240.7, 248.9, 221.7, 227.6, 214.8, 205.2, and 207, with a mean of 223.7. Estimated planetary A indices were 7, 8, 7, 9, 9, 7, and 8, with a mean of 7.9. Middle latitude A Index was 8, 8, 9, 19, 9, 7, and 18, with a mean of 11.1.

NNNN
/EX

ARRL The National Association for Amateur Radio®
Unsubscribe [ https://home.arrl.org/action/My-Account/Opt-In-Out ]


--- MBSE BBS v1.0.8.4 (Linux-x86_64)
* Origin: American Radio Relay League (3:633/280.2@fidonet)