QST de W1AW  
Propagation Forecast Bulletin 25  ARLP025
>From Tad Cook, K7RA
Seattle, WA  June 21, 2019
To all radio amateurs 

SB PROP ARL ARLP025
ARLP025 Propagation de K7RA

The quiet Sun continues, with still another week passing with zero
sunspots. For 33 days in a row, no sunspot activity, as of Thursday,
June 20. So far this year 62% of the days are without sunspots,
really the same as all of last year, which was 61%.

Average daily solar flux over the past week was 67.1, down from 69
last week and 69.5 the week before.

Predicted solar flux over the next 45 days is 67 on June 21-28, 69
on June 29 through July 4, 68 on July 5-6, 69 on July 7-9, 68 on
July 10-11, 67 and 66 on July 12-13, 67 on July 14-20, 68 on July
21-24, 69 on July 25-31, 68 on August 1-2, and 69 on August 3-4.

Predicted planetary A index is 5 on June 21-23, 10 and 8 on June
24-25, 5 on June 26 through July 5, 8 on July 6, 5 on July 7-9, 8 on
July 10-11, 5 and 8 on July 12-13, 12 on July 14-17, 10, 8, 5, 8, 12
and 8 on July 18-23, and 5 on July 24 through August 1, then 8, 5
and 5 on August 2-4.

The Summer Solstice occurs at 11:54 AM EDT on Friday, June 21. And
of course, the next day is ARRL Field Day. The low predicted
planetary A index over Field Day weekend is a welcome sign, with
little chance of any geomagnetic disturbance.

Geomagnetic activity forecast for the period June 21 to July 17,
2019 from F.K. Janda, OK1HH, who sees slightly more active
geomagnetic conditions on Field Day weekend.

'Geomagnetic field will be:
Quiet on June 27, 30, July 9
Quiet to unsettled on June 22, 28-29, July 3, 8, 10-11, 13-17
Quiet to active on June 21, 23, 26, July 1-2, 4-5, 12
Unsettled to active on June 24-25, July (6- ) 7
No disturbed days predicted.

'Solar wind will intensify on June (23) 24-27, (28,) July 5-7,
(8-9,) 10-11.

'Parenthesis means lower probability of activity enhancement.'

Martin McCormick, WB5AGZ commented that he doesn't think the solar
flux has ever been below 66, where it was a few days ago, so we must
be at solar minimum. But I pointed out that if you look at page 11
in this Preliminary Report and Forecast, it shows predicted flux
values going even lower:

ftp://ftp.swpc.noaa.gov/pub/warehouse/2019/WeeklyPDF/prf2283.pdf

But I don't believe those numbers. I don't see how it is possible
that solar flux will go below 60 in 2021 and 2022. I keep checking
at the beginning of every month, waiting for this prediction to be
corrected, but so far haven't seen it.

Rich Zwirko, K1HTV and Steve, NN4X reported a transatlantic 2 meter
contact by D41CV:

https://bit.ly/2RstTcP

An article about Europe's L5 project, and what it means for space
weather forecasting:

https://bit.ly/2L4thc7

Dr. Tamitha Skov's most recent video can be found at:

https://youtu.be/F5Wa6bXGy_I

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

For more information concerning radio propagation, see the ARRL
Technical Information Service web page at,
arrl.org/propagation-of-rf-signals. For an explanation of
numbers used in this bulletin, see arrl.org/the-sun
-the-earth-the-ionosphere.

An archive of past propagation bulletins is at
arrl.org/w1aw-bulletins-archive-propagation. More good
information and tutorials on propagation are at k9la.us/.

Monthly propagation charts between four USA regions and twelve
overseas locations are at arrl.org/propagation.

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

Sunspot numbers for June 13 through 19, 2019 were 0, 0, 0, 0, 0, 0,
and 0, with a mean of 0. 10.7 cm flux was 67.5, 68, 66.7, 65.9,
66.3, 67, and 68, with a mean of 67.1. Estimated planetary A indices
were 10, 8, 4, 4, 3, 4, and 4, with a mean of 5.3. Middle latitude A
index was 12, 13, 6, 6, 5, 3, and 4, with a mean of 7.