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ARRL Propagation Bulletin ARLP003 (2023)

ARLP003 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 3  ARLP003
From Tad Cook, K7RA
Seattle, WA  January 20, 2023
To all radio amateurs 

ARLP003 Propagation de K7RA

Last week's Propagation Forecast Bulletin ARLP002 opened with "Wow!"
I don't know what to say about this week, except it is beyond wow.

This actually has me thinking about Solar Cycle 19.

Lately we have seen solar flux at the same levels we saw at the peak
of Solar Cycle 23. If we are about 30 months away from the peak of
this Solar Cycle 25, could this get us to the 1957-59 levels last
seen in Solar Cycle 19? Stories from that time tell of worldwide
coverage 24x7 on 10 meter AM from low power mobile stations.

Average daily sunspot numbers rose from 135.9 to 173.4, while
average solar flux went to 221.8 from 181.2. Yesterday the thrice
daily solar flux reported from the Penticton, British Columbia
observatory indicated rising solar flux at 224.6, 226.1 and 230.1.
These are recorded at 1800, 2000 and 2200 UTC. It is the middle
number, at local noon, that is recorded as the official number for
the day.

From "If sunspot production continues apace for
the rest of January, the monthly sunspot number will reach a 20-year

Average planetary A index increased from 6.7 to 13.9,

On January 15 the planetary A index reached a peak of 30, a very
high value indicating a geomagnetic storm. Conditions were stormy
throughout the week, due to flares and CMEs. On that day in
Fairbanks, Alaska the college A index was 53, a very high number.
There was a large polar cap absorption event.

Nine new sunspot groups appeared during this reporting week, January
12-18. One on January 12, four on January 13, two more on January
15, and two more, one each on January 17 and 18.

Predicted solar flux is 220 on January 20-21, 215 on January 22-23,
210 on January 24-25, 215 on January 26-27, 185 on January 28-29,
190 on January 30 through February 2, 195 and 200 on February 3-4,
205 on February 5-6, 210 on February 7-11, then a big jump to 235
and 230 on February 12-13, 225 on February 14-16, 220 on February
17, then 215 on February 18-19, 210 and 200 on February 20-21, 190
on February 22-23, and 185 on February 24-25. Solar flux is expected
to rise above 200 again in the first week of March.

Predicted planetary A index is 15, 12 and 8 on January 20-22, 5 on
January 23-24, then 12, 10, 12 and 8 on January 25-28, 5 on January
29 through 31, then 12 and 8 on February 1-2, 5 on February 3-6,
then 12, 12, 15 and 12 on February 7-10, 5 on February 11-13, then
8, 15, 10 and 7 on February 14-17, 5 on February 18-20, then 7, 18,
10 and 7 on February 21-24, 5 on February 25-26, then 7, 18, 12 and
8 on February 27 through March 2.

OK1HH wrote:

"Large sunspot groups on the Sun's far side, detected by
helioseismology at the beginning of this year, showed the region of
active heliographic longitude gradually approached the eastern limb
of the solar disk. Solar activity increased after their arrival.

"Solar flux rose from 146 on January 2 to 195 on January 11. Yet one
solar revolution back (December 15) it was only 166 and two turns
back (November 18) only 116.

"The January 6 prediction of increasing activity was brilliantly
confirmed, especially by a large X-class flare in AR3182 with a
maximum at 0057 UTC.

"Surprisingly, it did not produce a CME - the ejected particles
never left the Sun.

"In the following days, the activity of AR3182 was joined by the
newly erupted AR3184, again in the southeast of the solar disk. An
X-class flare was observed there as well (X1.9 on January 9 1850
UTC). Most of the large flares in the last few days occurred during
nighttime in Europe. Blackouts up to 30 MHz were recorded,
especially by stations in and around the Pacific. It was not until
the eruption on January 9 that a shortwave blackout was seen in the
western Atlantic, including the East Coast of the U.S. On January
10, the Sun produced another X-class eruption, from new sunspot
group AR3186.

"As active regions approached the central meridian, the probability
of Earth being hit by particles from possible CMEs increases, or
more importantly the Earth's magnetic field activity increases, MUF
levels decrease, and the evolution of shortwave propagation
gradually worsens, especially during disturbances that are difficult
to predict accurately."

Sam, KY8R commented on 30 meter propagation:

"Reading your report it looks good, but I have to tell you 30M is
like a dead horse in the Sonoran Desert."

I replied:

"On FT8 and I make many contacts on 30 meters, but it seems to be
best around sunrise or sunset, before and after.

"I just did a prediction with W6ELprop and it shows 30 meters from
my location (CN87) open during daylight hours to the East Coast, and
to Texas 24x7 with brief dropouts at 7am local here (1500 UTC) and
10:30 PM (0630 UTC).

"From your location, it looks different. To Texas it fades starting
at 0200 UTC and stays dead until 1400 UTC and is strongest at 1500
and 2330 UTC.

"To Atlanta from DM33 (you) it is weakest from 1700-2100 UTC. Of
course, these are statistical approximations."

Mike Schaffer, KA3JAW in Easton, Pennsylvania FN20jq is having fun
on 10 meter FM.

"Today (January 19) I made a 2-way QSO with John, AL7ID in Fairbanks
for five minutes from 2028-2033 UTC on the 29.6 MHz national calling
frequency, then QSY 29.5 FM.

"I just barely heard him mention the QSY to 29.5.

"Initially he was 2x2 QSB, then minutes later 3x4 QSB.

"The FM signal was spreading apart due to F2 propagation and made it
difficult at times.

"He was my first Alaska 10-meter FM simplex contact!"

Mike has a YouTube video of both his Alaska QSO, and another with

Earlier, Mike reported:

"On Tuesday, January 17th, 29.6 MHz FM went active with multi-hop
sporadic-E or F2 propagation into France, United Kingdom, Mexico,
Alaska, and Argentina into the northeast USA.

"Readability ranged from unreadable to practically no difficulty,
Strength ranged from faint - signals barely perceptible to fair
signals. All the signals had light QSB.

"UTC:    Callsign:     Grid:
1544     F5SDD         JN23qf
1617     G4RIE         IO83rn
1803     XE2LVM        DL92dp
2040     AL7ID         BP64ku 
2040     LU1HJS        FF79XX"

Jon Jones, N0JK reported:

"Some interesting 6 meter propagation on January 16.

"First, there appeared to be a 6 meter F2 opening between Puerto
Rico and Colorado that morning. K0RI in DM78 and NO0T/P in DN70
spotted KP4AJ in FK68 around 1550 UTC on 6 meter FT8. No
intermediate stations spotted. The 10.7 cm solar flux was reported
to be 234. [Jon had probably not seen the updated flux for that day
yet. It was actually 228.1 and 234.3 the day before.]

"Later there was sporadic-E from Kansas to Mexico. I logged XE2JS in
DL68 at 1605 UTC. He was very strong.

"That afternoon the TN8K DXpedition to the Congo Republic worked
PJ4MM, V26OC, and FG8OJ on 6 meter FT8 via F-layer propagation around
2230 UTC.

"The ARRL January VHF contest is this weekend. There is a
possibility of sporadic-E and even some F2 on 6 meters in this

Later Jon reported a 6 meter contact with Mexico.

Sunspots in the news:

Sky & Telescope with an article on giant sunspot group AR3190:

An article on 11 year, 100 year, and 2300 year cycles:

Here is the latest report from Dr. Tamitha Skov, WX6SWW:

Send your tips, reports, observations, questions and comments to

For more information concerning shortwave radio propagation, see and the ARRL Technical Information
Service at . For an
explanation of numbers used in this bulletin, see .

An archive of past propagation bulletins is at . More good
information and tutorials on propagation are at .

Instructions for starting or ending email distribution of ARRL
bulletins are at .

Sunspot numbers January 12 through 18, 2023 were 151, 181, 170, 177,
186, 185, and 164, with a mean of 173.4. 10.7 cm flux was 211.6,
208.5, 227.8, 234.3, 228.1, 221.7, and 220.3, with a mean of 221.8.
Estimated planetary A indices were 9, 12, 11, 30, 14, 6, and 15,
with a mean of 13.9. Middle latitude A index was 8, 10, 9, 17, 10,
5, and 11, with a mean of 10.


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