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

SB PROP @ ARL $ARLP025
ARLP025 Propagation de K7RA

ZCZC AP25
QST de W1AW
Propagation Forecast Bulletin 25 ARLP025

From Tad Cook, K7RA

Seattle, WA June 24, 2022
To all radio amateurs

SB PROP ARL ARLP025
ARLP025 Propagation de K7RA

This past reporting week (June 16-22) began with a bang, when the
daily sunspot number was 159. But sunspot numbers declined every day
to finally reach 80 on June 22.

One new sunspot group emerged on June 15, another on June 16, one
more on June 18, and another on June 21.

Average daily sunspot number over the week was 124.6, up
substantially from 74.3 the previous seven days.

Average daily solar flux rose from 123.9 to 140.5.

Average daily planetary A index rose from 9.7 to 11.4, and the
middle latitude numbers increased one point to 11.9

It was great to see the Sun covered with spots on Spaceweather.com.
Use the Archives feature toward the upper right, and you can see the
daily solar images on the left side of the page for any date in the
past. I particularly appreciated the image of June 17, our Sun
blanketed with sunspots!

Unfortunately, a California wildfire cut off power to the Solar
Dynamics Observatory Data Center at Stanford University, so solar
images are not being provided, according to Spaceweather.com.

ARRL Field Day is this weekend. What is the outlook?

The latest from US Air Force forecasters Housseal and King at the
USAF 557th Weather Wing shows predicted solar flux at 120, 115 and
110 on June 24-26, and Planetary A index of 8, 12 and 15. Field Day
is actually on June 25-26, but it is useful to see the prediction
for Friday. The planetary A index shoes a moderate but increasing
geomagnetic instability.

Newsweek reported a recent sunspot:

https://bit.ly/3xNdZiB

The latest (Thursday night) forecast from USAF shows solar flux at
120 and 115 on June 24-25, 110 on June 26-27, 100 on June 28-29, 105
on June 30, 100 on July 1-2, then 105, 110, 115, 120 and 125 on July
3-7, 130 on July 8-9, 135 on July 10, 140 on July 11-16, then 138,
134, 125 and 121 on July 17-20, then 114, 118 and 105 on July 21-23,
100 on July 24-29, then 105, 110, 115 and 120 on July 30 through
August 2.

The planetary A index prediction is 8, 12, and 15 on June 24-26, 5
on June 27 to July 7, then 8, 8, 12 and 8 on July 8-11, 5 on July 12-13,
12 on July 14-16, 10 on July 17, 5 on July 18-19, then 12, 18, 12 and 10
on July 20-23, then 5 on July 24 through August 3, and 8 on August 4-5.

F.K. Janda, OK1HH wrote:

"The distribution of active areas on the Sun according to
heliographic latitudes has changed relatively little during the last
three solar rotations, therefore the predictions of the overall
solar activity level were quite reliable.

"The parameters of the solar wind, measured around the Earth, and
the activity of the geomagnetic field had a similar course.

"The highest usable frequencies of the ionospheric layer F2 (MUF)
were increased on June 19-20. The sporadic E layer played the most
important role in the shortwave propagation on June 16-19."

The latest space weather video from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/whjz9b0kLhY

A story about how "We can't reliably predict solar cycles" can be
found at:

https://bit.ly/3NiMbbx

I have no idea what prompted an incredible series of news stories
late Thursday. Was it a slow news day? Perhaps an indication of a
respite from national tragedies?

The following websites contain stories about our Sun, and the
emergence of a big spot. Interesting because on Thursday the sunspot
number declined to 69 from 80 the day before, and much lower
compared to the 124.6 average for the previous seven days:

https://bit.ly/3zZ30VU

https://bit.ly/3ODJiTP

https://bit.ly/3OEDgCA

https://bit.ly/3bdRWtI

https://bit.ly/39R3SBu

https://bit.ly/3nf1B6c

https://bit.ly/3NieXsZ

https://bit.ly/3nf1QhC

https://youtu.be/EJj_zseYqQs

https://bit.ly/3HOJOMC

https://bit.ly/3yfrIA8

https://bit.ly/3Ngyiun

https://bit.ly/3QMSw1O

https://bit.ly/3OjuY38

https://bit.ly/3yiUY9q

https://bit.ly/3HNMMAO

https://bit.ly/3tXVlDo

https://bit.ly/3HOhvhe

https://inhabitat.com/massive-sunspot-glares-at-the-earth/

https://bit.ly/3Ngzyh5

https://bit.ly/3yhj2cH

https://bit.ly/3QKwcGb

If you would like to make a comment or have a tip for our readers,
please email the author at, k7ra (at) arrl.net .

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation and the ARRL Technical Information
Service web page 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 16 through 22, 2022 were 159, 152, 145,
120, 112, 104, and 80, with a mean of 124.6. 10.7 cm flux was 146.7,
148.9, 140.2, 143.6, 136.5, 138.8, and 128.7, with a mean of 140.5.
Estimated planetary A indices were 12, 13, 14, 12, 10, 8, and 11,
with a mean of 11.4. Middle latitude A index was 14, 14, 15, 10, 10,
10, and 10, with a mean of 11.9.
NNNN
/EX

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

SB PROP @ ARL $ARLP025
ARLP025 Propagation de K7RA

ZCZC AP25
QST de W1AW
Propagation Forecast Bulletin 25 ARLP025

From Tad Cook, K7RA

Seattle, WA June 23, 2023
To all radio amateurs

SB PROP ARL ARLP025
ARLP025 Propagation de K7RA

Sunspot numbers and solar flux rose this week. There were two new
sunspot groups on June 15, another on June 17 and one more on June
18, three more on June 19, two more on June 20 and another on June
21.

Average daily sunspot number increased from 122 to 143, and average
daily solar flux rose from 154.8 to 165.4.

Average daily planetary A index jumped from 5.7 to 15.4, while the
middle latitude numbers increased from 6.7 to 13.1.

Predicted solar flux is 180 on June 23-24, 185 on June 25-27, 180 on
June 28, 175 on June 29 through July 1, 180 on July 2-3, 175 on July
4-5, 170 on July 6-10, then 165 on July 11, 160 on July 12-13, 165
on July 14-15, 160 and 155 on July 16-17, 160 on July 18-19, 165 on
July 20-24, 170 on July 25, 175 on July 26-28, and 180 on July
29-30.

Predicted planetary A index is 14, 10 and 8 on June 23-25, then 5,
5, and 12 on June 26-28, then 5, 5, and 12 again on June 29 through
July 1, 8 on July 2, 5 on July 3-7, 12 on July 8, 5 on July 9-11,
then a dramatic increase to 20 and 30 on July 12-13, 8 on July
14-15, and 12 on July 16-17, 10 on July 18, 5 on July 19-23, 12 on
July 24-25, 5 on July 26-27, 12 and 8 on July 28-29, and 5 on July
30 through August 3.

These predictions are from forecasters Liming and Dethlefsen of the
US Air Force 557th Weather Wing at Offutt AFB.

See https://bit.ly/3qRNJnr

So, what does this forecast show for ARRL Field Day, which is this
weekend?

Geomagnetic numbers are a bit more unsettled than what was shown in
last week's bulletin, which had an A index of 5 for Friday through
Sunday. The latest shows 14, 10 and 8. Predicted solar flux looks
excellent, at 180, 180 and 185.

Of course, Field Day does not begin until Saturday, but here we also
include data for the day prior.

X1.1 solar flare:

https://bit.ly/3CI0OCA

Another report from South Asia regarding solar flares as some sort
of existential threat. Don't worry. Nothing terrifying about what
they report, but there is a nice description of what the SOHO
observatory does.

https://bit.ly/444VhSk

https://soho.nascom.nasa.gov

Reader David Moore shared this video:

https://www.space.com/earth-sunlight-dance-solstice-video

Don't know why, but no weekly report from OK1HH this time around.

On Thursday I attended an online event, the "Space Weather
Enterprise Forum," thanks to a tip from K6PFA.

Most of the sessions concerned threats from solar flares, but there
was great commentary from Bill Murtaugh of NOAA's Space Weather
Prediction Center.

He noted that the current solar cycle should peak in summer 2024
instead of 2025 and will peak much stronger than the consensus
forecast from earlier in the cycle. He also noted that increased
flare activity always occurs in the years following a sunspot cycle
peak.

John Dudley, Managing Director of Flight Operations at American
Airlines gave an interesting presentation about how space weather
affects routing of international flights.

He mentioned their expert on space weather at the airline, and I
looked him up. Yes, a ham, KC1ENP. Could not find an email address
for him, so I sent a QSL card to make contact.

Thanks to https://spaceweather.com/ for this fascinating article about
setting up a personal space weather station. It is under the
heading, "A New Way To Detect Solar Flares":

https://essd.copernicus.org/articles/15/1403/2023/

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 June 15 through 21, 2023 were 112, 120, 110,
133, 181, 155, and 190, with a mean of 143. 10.7 cm flux was 153.1,
157.2, 158.1, 164.1, 168.8, 180.1, and 176.4, with a mean of 165.4.
Estimated planetary A indices were 24, 38, 8, 10, 10, 10, and 8,
with a mean of 15.4. Middle latitude A index was 17, 24, 8, 12, 9,
13, and 9, with a mean of 13.1.
NNNN
/EX

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

SB PROP @ ARL $ARLP025
ARLP025 Propagation de K7RA

ZCZC AP25
QST de W1AW
Propagation Forecast Bulletin 25 ARLP025

From Tad Cook, K7RA

Seattle, WA July 5, 2024
To all radio amateurs

SB PROP ARL ARLP025
ARLP025 Propagation de K7RA

Solar activity increased this week, with average daily sunspot numbers rising from 149.6 to 181.6. For some reason average daily solar flux decreased from 178 to 175.

Seven new sunspot groups emerged this week, one on June 27, two on June 28, three on June 29, and one more on July 3.

Average daily planetary index rose from 10.3 to 15.6 while average middle latitude A index rose from 10.1 to 11.6.

On Friday, June 28, a CME caused a severe G4 class geomagnetic storm. Middle latitude A index was 32 and planetary A index was 59, much higher than Alaska's college A index (36).

Predicted solar flux is 175, 172 and 168 on July 5 to 7, 160 on July 8 and 9, 155 on July 10 and 11, 170 on July 12 and 13, 180 on July 14, 175 on July 15 to 17, 180 on July 18 to 21, 185 on July 22, 180 on July 23 to 29, 175 on July 30, 170 on July 31
through August 9 and 180 on August 10.

Predicted planetary A index is 8, 5, 5, 12 and 10 on July 5 to 9, 5 on July 10 to 13, then 10, 10 and 8 on July 14 to 16, 5 on July 17 to 19, then 10 and 8 on July 20 and 21, and 5 on July 22 through August 9, and 10 on August 10 and 11.

"Geomagnetic activity forecast for July 5 to 11, 2024
Quiet: July 5 to 7, 9 and 10
Unsettled: July 7 and 8, 11
Active: possible July 8, 11
Minor storm: 0
Major storm: 0
Severe storm: 0

"Next week, we expect at most quiet to unsettled conditions. More unsettled conditions with possible isolated active event are possible about July 7 and 8, and also at the end of the current forecast period, about Thursday, July 11." Tomas Bayer RWC
Prague
Institute of Geophysics of the ASCR Department of Geomagnetism Budkov Observatory

2023 NOAA updates:
www.weather.gov/news/102523-solar-cycle-25-update [ https://www.weather.gov/news/102523-solar-cycle-25-update ]

https://bit.ly/3XRnufb [ https://bit.ly/3XRnufb ]

https://bit.ly/3VT7net [ https://bit.ly/3VT7net ]

Latest from Tamitha Skov, KX6SWW: https://youtu.be/kGUb15uWzBw [ https://youtu.be/kGUb15uWzBw ]

Blackout: https://bit.ly/45R9PqD [ https://bit.ly/45R9PqD ]

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 www.arrl.org/propagation [ http://www.arrl.org/propagation ] and the ARRL Technical Information Service web page at, www.arrl.org/propagation-of-rf-signals [ http://arrl.org/propagation-of-
rf-signals ] .

For an explanation of numbers used in this bulletin, see wwww.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 www.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: https://bit.ly/3Rc8Njt [ https://bit.ly/3Rc8Njt ]

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

Sunspot numbers for June 27 through July 3 2024 were 146, 162, 205, 192, 192, 192, and 182, with a mean of 181.6. 10.7 cm flux was 182.5, 180.7, 186.4, 173.8, 170.6, 163.8, and 167.4, with a mean of 175. Estimated planetary A indices were 9, 59, 14, 11,
6, 5, and 5,
with a mean of 15.6. Middle latitude A index was 11, 32, 11, 10, 5, 6, and 6, with a mean of 11.6.
NNNN
/EX

ARRL The National Association for Amateur Radio®
Unsubscribe [ http://arrl.informz.net/arrl/pages/Copy_of_Copy_of_Unsubscribe_Test_GF?_zs=KTqxl&_zmi=34lF ]

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