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ARRL Propagation Bulletin ARLP047 (2020)

ARLP047 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 47  ARLP047
From Tad Cook, K7RA
Seattle, WA  November 20, 2020
To all radio amateurs 

ARLP047 Propagation de K7RA

As solar flux declined over the past week, I noticed less long
distance propagation on 10 meters reported on from
my local grid square CN87.

Propagation on 12 meters though was quite strong. After 0100 UTC on
Nov 15 trans-equatorial propagation was evident between East Asia
and Australia on 10 meters.

Further down in this bulletin is a 12 meter report from NN4X.

Solar activity declined dramatically over the past week, with
average daily sunspot numbers going from 31.3 to 12. On November 15
and 16 there were no sunspots at all, which greatly affected the
decline in this week's average.

Solar flux weakened from a weekly average last week of 90, to 79.8
this week.

Predicted solar flux over the next 45 days until the start of 2021
is also relatively weak, although the short term prediction improved
from November 18 to November 19. The November 19 prediction is 75 on
November 20 to December 8, 72 on December 9-10, 70 on December
11-12, 75, 72 and 72 on December 13-15, 70 on December 16-22, 72 on
December 23-24, and 75 on December 25 through January 3, 2021.

Predicted planetary A index is 5, 8, 12 and 8 on November 20-23,
then 5 on November 24 through December 2, 8 on December 3-4, 5 on
December 5-17, then 8, 12, 8, 10 and 12 on December 18-22, 5 on
December 23-29, 8 on December 30-31, and 5 on January 1-3, 2021.

Geomagnetic activity forecast for the period November 20 to December
16, 2020 from F.K. Janda, OK1HH.

"Geomagnetic field will be:
quiet on: December 1, 6-8, 12-14, (15-16)
quiet to unsettled on: November 28-30, December 2, 4, 10-11
quiet to active on: November 26-27, December 3, 5, 9
unsettled to active: November (20,) 21-22, (23-25)
active to disturbed: - None predicted
"Solar wind will intensify on: November (20,) 21-25, (30,) December
(2,) 3-5, (9).

- Parenthesis means lower probability of activity enhancement.
- The predictability of changes remains lower because there are
  few unambiguous indications."

This bulletin has mentioned the paper by McIntosh, et. al.,
"Overlapping Magnetic Activity Cycles and the Sunspot Number:
Predicting Sunspot Cycle 25 Amplitude."

This week a reference appeared in the ARRL Letter, and is a link to that paper.

My favorite passage: "Our method predicts that SC25 could be among
the strongest sunspot cycles ever observed, and that it will almost
certainly be stronger than present SC24 (sunspot number of 116) and
most likely stronger than the previous SC23 (sunspot number of 180).
This is in stark contrast to the consensus of the SC25PP, sunspot
number maximum between 95 and 130, i.e., similar to that of SC24."

SC25PP is the Solar Cycle 25 Prediction Panel, which met in
September 2020.

The new prediction is very exciting, and suggests a cycle that may
rival Cycle 19, which peaked in March, 1958. The effects on
shortwave radio propagation were remarkable, and included daily
worldwide propagation on 10 and even 6 meters, and not just during
daylight hours.

I was about to turn six years old at the time, and we lived in
Reedley, a small fruit packing town in California's San Joaquin
Valley, where my father worked supplying agricultural chemicals to
farmers. He drove a company car which contained a low-band VHF FM
radio (probably 30-40 MHz, judging from my memory of the bumper
mounted antenna), and I recall him describing being unable to
contact the base station in Fresno, about 25 miles away, while
getting QRM from other users in Texas.

I've heard from many hams who were new Novice licensees at the time,
and assumed conditions would always be like they were then. They
have been waiting a long time.

I would love to see daily sunspot numbers above 200.

An article about sunspot activity in 1958:

NN4X reported from Florida on 12 meter FT8 activity on November 14:

"12M was in great shape!
------------------------------------ 12m
134500   1  0.1 1225  ~  DL1EZ TZ1CE -14
134500   3 -0.5 1596  ~  OQ4U KM8AM R-07
134500  20  0.5 1786  ~  PY2GG EA8TH R+12
134500  13  0.3 2058  ~  SM7DLK WA8NLX EM92
134500   9  0.2 1976  ~  CQ OZ7PBI JO45
134500   2 -0.4 1712  ~  SV2DFK V51LZ RR73
134500   0  0.0 2107  ~  CQ EA1DR IN82
134500  -9  0.1  629  ~  9J2BS EA4CYQ IM78
134500 -20 -0.2 1393  ~  9J2BS YB9WIC R-13
134500 -18  0.0  994  ~  CQ S79VU LI75
------------------------------------ 12m
134530  20  0.5 1786  ~  PY2GG EA8TH R+12
134530  28  0.1  862  ~  EA8AAH W4AFB EL98
134530  -5 -0.4 1712  ~  4Z4DX V51LZ R+01
134530 -13  0.1 1225  ~  DL1EZ TZ1CE -14"

Mike Schaffer, KA3JAW (FN20jq) wrote:

"Yikes, October out-of-season single-hop sporadic-E is active on the
6 meter band along the east coast!

"On Saturday, October 17, 2100-2300 UTC, it is 25 days past the
Autumnal Equinox.

"Once again, the unexpected happens during the early recovery out of
a Solar Minimum.

"I was monitoring the 6M FT-8 mode on 50.313 MHz for Es to show-up
along the Gulf of Mexico coastal region.

"Then it happened, the first direct decodes in monitor receiving

"215700  3 -0.4 1527  ~  WA2FZW W4KBX EL98
220345  -2 -0.4 2178  ~  KK2DOG W4KBX EL98
220545  -1 -0.4 2177  ~  KC3PIB W4KBX EL98
220845  -9 -0.5 1566  ~  CQ K2IL EL97

"Grid Squares:
EL98 - central Florida, around Orlando
EL97 - south central, north of Lake Okeechobee

"Now that the band is open with the Es expanding further south, I
decided to try for any contacts down on the SSB calling frequency on
50.125 MHz.
"When I rolled down there, several operators were already having
conversations about how pleasant that the band came back to life
since the summer months.

"At 2252 UTC I put out the first CQ call, AG4N, Bill from West Point,
Georgia, very close to the Alabama state line replied.

"From my QTH to AG4N, azimuth 230 deg, distance 771 air miles.

"I gave Bill a 4x7 signal report with QSB.

"The Es was being funneled as far away as Mobile, Alabama (996 miles)
and Biloxi, Mississippi (1,045 miles).

"By 2335 UTC the band started to collapse with signal reports sliding
down to 2x2.

"No double-hop Es from Puerto Rico, Dominican Republic or other
northern Caribbean Sea islands was heard.

"Even if the band conditions sound dead, I urge everyone to continue
monitoring the 6M SSB calling frequency, 50.125 MHz, then take it
one step further and make that CQ call. You might be pleasantly
rewarded even if you are running 10 watts into a 6M horizontal 1/2
wave dipole that is below eight feet off the ground."

Here is a forecast from November 14 from Dr. Tamitha Skov, WX6SWW:

This weekend is the ARRL SSB Sweepstakes Contest, see .

If you would like to make a comment or have a tip for our readers,
email the author at,

For more information concerning radio propagation, see and the ARRL Technical Information
Service web page 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 for November 12 through 18, 2020 were 27, 24, 11, 0,
0, 11, and 11, with a mean of 12. 10.7 cm flux was 85.1, 81.9, 80.2,
78.7, 76.6, 79.1, and 77.3, with a mean of 79.8. Estimated planetary
A indices were 3, 3, 3, 4, 2, 3, and 4, with a mean of 3.1. Middle
latitude A index was 3, 2, 2, 2, 0, 3, and 3, with a mean of 2.1.


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