SB PROP @ ARL $ARLP007
ARLP007 Propagation de K7RA

ZCZC AP07
QST de W1AW
Propagation Forecast Bulletin 7 ARLP007

From Tad Cook, K7RA

Seattle, WA February 17, 2023
To all radio amateurs

SB PROP ARL ARLP007
ARLP007 Propagation de K7RA

At 0725 UTC on February 15 the Australian Space Weather Forecasting
Centre issued a geomagnetic disturbance warning: "A CME impact
occurred around 2200 UTC on February 14. Bz has been southward for
the majority of time since impact and there is a chance of G1
geomagnetic conditions."

Bz is the north-south direction of the Interplanetary Magnetic Field
(IMF).

They predicted a disturbance for February 15-16.

They issued a new warning on February 17 at 0206 UTC:

"A partial halo CME observed on 15-Feb is due to impact Earth's
magnetosphere late on 17-Feb or early 18-Feb UTC. G1 geomagnetic
conditions are expected on 18-Feb, with a slight chance of G2.

"INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS
EJECTION FROM 17-19 FEBRUARY 2023."

For the latest geomagnetic conditions, I prefer this source:

https://www.swpc.noaa.gov/products/planetary-k-index

More on the IMF:

https://bit.ly/3E6IZ15

Many sunspots appeared over this reporting week (February 9-15) with
three new sunspot groups on February 9, one more on February 10, two
more on February 11, another on February 12 and three more on
February 13. Finally, there was one more yesterday, Thursday,
February 16.

Recent sunspot images:

https://www.spaceweather.com/images2023/12feb23/hmi1898.gif

That one is for February 12. To see February 13, just change the
12feb23 string to 13feb23, and so on, for any other date.

Average daily sunspot numbers increased from 95.1 to 182.4, and
average daily solar flux from 155.9 to 196.4.

Geomagnetic activity also rose, with average daily planetary A index
going from 11.7 to 13.7, and middle latitude numbers from 7.6 to
10.7.

The most active days were at the beginning and end of the week, with
planetary A index at 21 on February 9 and 29 on February 15. On
those two days the college A index at Fairbanks, Alaska was 33 and
46. The quietest day was Monday, February 13 when the planetary A
index was 4.

The outlook for the next month seems modest, with predicted solar
flux at 155, 160, 155, 145 and 135 on February 17-21, 125 on
February 22-23, 130 on February 24-26, 140 on February 27 to March
1, 145 on March 2-3, then 150, 155 and 165 on March 4-6, 180 on
March 7-13, 170 on March 14-15, 160 on March 16-18, and 150 on March
19, 140 on March 20-21, and 135 on March 22-25.

Predicted planetary A index is 22, 30, 12, 8 and 12 on February
17-21, 10 on February 22-24, then 5, 5 and 8 on February 25-27,
another 5, 5, and 8 on February 28 through March 2, then 5, 5 and 16
on March 3-5, then 18, 15 and 8 on March 6-8, and 5 on March 9-20,
then 10 on March 21-23, and 5, 5 and 8 on March 24-26, and another
5, 5 and 8 on March 27-29.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - February 16, 2023, from F.K. Janda, OK1HH.

"On February 11, we observed a seemingly dangerous sunspot group
AR3217, whose magnetic field had a beta-gamma-delta configuration,
in which large flares are often observed, up to X-class flares
accompanied by CMEs. This is what we saw at 1548 UTC, while extreme
UV radiation ionized the upper part of the Earth's atmosphere.
Direct result was the Dellinger effect, which disrupted shortwave communications over all of South America.

"But this particular eruption did not create a CME. Another
explosion did. Five hours before the X eruption, a magnetic filament
appeared in the northern hemisphere of the Sun, which spewed a CME
into space. Thereafter we were expecting an Earth impact on
Valentine's Day, February 14. This was a fairly accurate prediction
because the Earth's intervention occurred just one day later, on
February 15. It was not a direct hit, only a weak G1 class
geomagnetic storm developed.

"On February 15 a magnetic filament eruption near the solar equator
and another CME heading towards Earth was observed. We can expect an
arrival on February 17-18, again as a weak G1 class geomagnetic
storm, perhaps intensifying to a mild G2 class storm on February 18.
Further we can expect to see more M-class solar flares in the next
few days. Also, an X-class flare is not out of the question. In
addition, the AR3226 sunspot group with an unstable magnetic field,
is directly facing the Earth."

Impossible but dramatic solar image:

https://bit.ly/3Ib3eMp

Spaceweather.com warns:

"GEOMAGNETIC STORM WATCH: Photographers, warm up your cameras. A CME
is heading for Earth, and it could spark an unusually good display
of Northern Lights when it arrives on Feb. 17-18. NOAA forecasters
say that moderate G2-class geomagnetic storms are possible. During
such storms, auroras have been seen in the USA as far south as,
e.g., New York and Idaho."

From the Western Washington DX Club email list:

WT8P posted at 1855 UTC on February 16:

"6M FT8 open to central and SA At 1845 UTC, LU9AEA (Argentina) and
TG9AJR (Guatemala) on FT8, 50.313 MHz."

W7YED posted at 1939 UTC, February 16:

"I was able to pick up 5 new ones on 6m in the space of about 20
minutes. Nice opening!

"TI, CX, CE, LU, TG were all between +3 and -18."

A story about "vicious solar storms":

https://bit.ly/3S8g7uV

Aurora on Valentine's Day:

https://bit.ly/3YUvsSb

A video last week from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/Igfp_EK73Xk

This weekend is the CW portion of the ARRL International DX Contest.
For details see: https://www.arrl.org/arrl-dx .

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 .

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 February 9 through 15, 2023 were 150, 190, 209,
197, 185, 206, and 140, with a mean of 182.4. 10.7 cm flux was
214.9, 207.8, 209.5, 199.7, 189.2, 179.7, and 173.7, with a mean of
196.4. Estimated planetary A indices were 21, 16, 11, 7, 4, 8, and
29, with a mean of 13.7. Middle latitude A index was 16, 12, 10, 5,
3, 6, and 23, with a mean of 10.7.
NNNN
/EX


--- MBSE BBS v1.0.8 (Linux-x86_64)
* Origin: American Radio Relay League (3:633/280.2@fidonet)

SB PROP @ ARL $ARLP007
ARLP007 Propagation de K7RA

ZCZC AP07
QST de W1AW
Propagation Forecast Bulletin 7 ARLP007

From Tad Cook, K7RA

Seattle, WA February 16, 2024
To all radio amateurs

SB PROP ARL ARLP007
ARLP007 Propagation de K7RA

Seven new sunspot groups appeared over the past week, February 8-14,
two on February 8, three on February 10, and two more on February 13
and 14.

Then on February 15 three more sunspots emerged.

Now this is a personal opinion, but from recent numbers I suspect
that we may at the peak of Solar Cycle 25 or just prior to the peak.
We won't know when the actual peak occurred until six months after.

Average daily sunspot number declined from 142.3 to 134.6, but
average daily solar flux increased from 165.5 to 190.

I don't know why the solar numbers were so seemingly out of whack,
but average daily sunspot number declined as average daily solar
flux rose, by a lot.

Average daily planetary A index rose from 5.1 to 7.4, while middle
latitude numbers from 4.4 to 6.1.

The most active day was February 11 with planetary A index rising to
15, but that is hardly stormy. This was caused by an unexpected CME
impact at 0211 UTC according to Spaceweather.com.

So, what is the outlook for the next few weeks?

Concerning solar flux, it seems we are currently in the midst of a
peak over the next few days at 185 and 182 on February 15-16, then
another short term peak at 170 on March 3-10.

On February 17-23 the forecast sees the flux at 175, 172, 170, 165,
175, 165 and 160, then 150 on February 24-28, then 155, 160 and 165
on February 29 through March 2, then 170 on March 3-10, 165 on March
11-3, 170 on March 14, 160 on March 15-19, then 162, 165 and 160 on
March 20-22.

Predicted planetary A index is 5 on February 16-18, 8 on February
19, 5 on February 20-25, then 8 and 7 on February 26-27, then 5 on
February 28 through March 23.

This is the same data that appeared in the ARRL Letter on Thursday,
which was the report from February 14.

Unfortunately, NOAA did not post the updated forecast on Thursday.
Thursday evening, I phoned the NOAA forecast desk, and they didn't
have the data from US Air Force. I then phoned the 557 Weather Wing
at Offutt Air Force Base and was told they had a major network
outage Thursday afternoon, and the data may be lost.

Fortunately, the phone numbers at both locations are answered 24-7.

If you need an updated forecast, check:

https://services.swpc.noaa.gov/text/45-day-ap-forecast.txt

It is normally updated every day after 2200 UTC.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - February 15, 2024 from OK1HH:

"Over the past week, we saw the transition of two large active
regions with complex magnetic configurations on the solar disk:
AR3575 followed by AR3576, which will be at the western limb of the
disk on February 16.

"More massive flares, including proton flares accompanied by CME
were observed in both regions. Protons from the flares bombarded the
Earth's atmosphere for most of the days. CMEs, however, hit the
Earth with little or no impact. This included a strong X3.4 class
solar flare followed by a S2 class radiation storm on 9th February.
Energetic solar protons impacted the upper layers of the Earth's
atmosphere and caused mainly polar cap absorption (PCA). This
significantly increased the attenuation of radio signals at high
latitudes.

"We could also guess whether the CMEs were just delayed since the
eruptions of 9 and 10 February and would not arrive until 13
February, or whether they would miss the Earth. NASA guessed that
they would arrive. But the correct answer was they missed, which was
confirmed by the more or less calm development on 14 February.

"After the sunset of the two large active regions AR3575 and AR3576,
solar activity will decrease. However, helioseismological
observations indicate the presence of active regions on the far side
of the Sun. After their ascent to the solar disk, solar activity
will increase again since early March. Solar activity should be
highest between March 3 and 10. Meanwhile, geomagnetic activity
should continue to be low. Therefore, we expect an improvement in
shortwave propagation conditions.

"F.K. Janda, A.R.S. OK1HH, http://ok1hh.nagano.cz/ "

This weekend is the CW portion of the ARRL International DX contest.
Details can be found at:

https://www.arrl.org/arrl-dx


Two articles about a CME and flares:

https://bit.ly/3OHvtpZ

https://bit.ly/49zgoia


Three days of sunspots:

https://bit.ly/3SJhbGi


Multiple pictures of Sunspot region 13585:

https://bit.ly/3UFVhGQ


Bob, KB1DK, from Connecticut wrote:

"During the last two weeks, activity on 10 meter SSB was bustling,
and included many POTA, SOTA, and mobile stations in Europe. In
fact, I heard Europeans on 12 meters saying they moved to that band
because 10 became so busy. Propagation on 10 has been very good from
southern New England, resulting in multiple QSOs with India and New
Zealand. QSOs with the middle east are almost routine now.

"My occasional fixed mobile operating has been extremely productive
and satisfying. I strongly recommend taking advantage of these great
conditions on 10 meters while we have them."

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 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/ .

Also, check this QST article about Solar Indices:

https://bit.ly/3Rc8Njt

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

Sunspot numbers for February 8 through 14 2024 were 149, 105, 146,
144, 153, 122, and 123, with a mean of 134.6. 10.7 cm flux was 185,
183.4, 193.8, 180.4, 208.3, 194.8, and 184.1, with a mean of 190.
Estimated planetary A indices were 5, 6, 5, 15, 4, 10, and 7, with a
mean of 7.4. Middle latitude A index was 5, 4, 4, 12, 4, 8, and 6,
with a mean of 6.1.
NNNN
/EX


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