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ARRL Propagation Bulletin ARLP004 (2019)

SB PROP @ ARL $ARLP004
ARLP004 Propagation de K7RA

ZCZC AP04
QST de W1AW  
Propagation Forecast Bulletin 4  ARLP004
From Tad Cook, K7RA
Seattle, WA  January 25, 2019
To all radio amateurs 

SB PROP ARL ARLP004
ARLP004 Propagation de K7RA

Sunspot group 2733 appeared on Tuesday with a sunspot number of 18,
and on Wednesday it increased in size with a sunspot number of 19,
which was also the sunspot number on Thursday, January 24.

See images of this sunspot group at,
http://www.solarham.net/regions/2733.htm

2733 is a remnant of old Solar Cycle 24. Average daily sunspot
numbers increased to 5.3, from 0 the previous week. Average daily
solar flux increased slightly from 69.4 to 69.8.

Average daily planetary A index increased from 4.9 to 5.9, while
mid-latitude A index was unchanged at 4.

Predicted solar flux is 72 on January 25-29, 70 on January 30
through February 4, 69 on February 5-16, 71 on February 17-28, 70 on
March 1-3, and 69 on March 4-10.

Planetary A index is predicted at 18, 10 and 3 on January 25-27, 5
on January 28-30, 8 on January 31, then 15, 12 and 8 on February
1-3, 5 on February 4-18, then 18, 25, 18 and 10 on February 19-22, 5
on February 23-26, then 10 and 15 on February 27-28, 12 and 8 on
March 1-2, and 5 on March 3-10.

Tomas Bayer of the Institute of Geophysics of ASCR, Department of
Geomagnetism, Budkov Observatory sends this geomagnetic activity
forecast for January 25-31, 2019:

"Quiet: Jan 27-30
Unsettled: Jan 25-26, 31
Active: Jan 31
Minor storm: 0
Major storm: 0
Severe storm: 0

"Geomagnetic activity summary:

"After the last active event (January 23, local K-index has reached
4) we expect geomagnetic activity to decrease to quiet to unsettled
level. We expect the most unsettled episode about January 25 and 26,
and, additionally, at the end of forecast period, January 31.
Between these events, January 27-30, we expect quiet conditions."

Next week we will return to geomagnetic forecasts from Frantisek
Janda, OK1HH. He is on Facebook at https://www.facebook.com/OK1HH .

Dr. Tamitha Skov's latest report, although by now several days old:

https://www.youtube.com/watch?v=AlLjlHjffzYz

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

For more information concerning radio propagation, see 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/.

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

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

Sunspot numbers for January 17 through 23, 2019 were 0, 0, 0, 0, 0,
18, and 19, with a mean of 5.3. 10.7 cm flux was 68.6, 68.8, 69.7,
69.2, 69.9, 70.7, and 71.5, with a mean of 69.8. Estimated planetary
A indices were 7, 6, 4, 4, 4, 3, and 13, with a mean of 5.9.
Estimated mid-latitude A indices were 5, 5, 2, 2, 2, 2, and 10, with
a mean of 4.
NNNN
/EX

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