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The K7RA Solar Update

06/28/2019

A new sunspot group emerged on June 24, but don’t count on it persisting much longer. It emerged already far along the western limb and is about to rotate off the visible solar disc. Sunspot numbers on June 24-27 were 24, 12, 11 and 11.

Average daily sunspot number increased from 0 to 6.7 over the week of June 20-26, while average daily solar flux increased from 67.1 to 67.4.

Average daily planetary A index decreased from 5.3 to 5, and average daily middle latitude A index decreased from 7 to 5.7.

Predicted solar flux is 67 on June 28 through July 5, 68 on July 6, 69 on July 7-9, 68 on July 10-11, 67 on July 12-27, 68 on July 28, 69 on July 29-31, 68 on August 1-2, 69 on August 3-5, 68 on August 6-7, and 67 on August 8-11.

Predicted planetary A index is 5 on June 28-30, 8 on July 1, 5 on July 2-5, 8 on July 6, 5 on July 7-9, 8 on July 10-11, 5 on July 12-20, then 8, 12 and 10 on July 21-23, 5 on July 24 through August 1, 8 on August 2, 5 on August 3-5, 8 on August 6-7, and 5 on August 8-11.

You can see daily updates of these predictions, usually sometime after 2100 UTC at ftp://ftp.swpc.noaa.gov/pub/forecasts/45DF/ .

Geomagnetic activity forecast for June 28 until July 24, 2019 from F.K. Janda, OK1HH, who has been compiling this weekly geomagnetic forecast since January 1978.

Geomagnetic field will be:
Quiet on June 28, 30, July 9, 14-16, 21
Quiet to unsettled on June 29, July 3, 8, 10-11, 13, 17, 20
Quiet to active on June July 1 (- 2), 4-6, 12, 18, 24
Unsettled to active on July 7, 19, 22-23
No disturbed conditions predicted.

Solar wind will intensify on June (28,) July 5-7, (8-9,) 10-11, (17-19, 22-24). Parenthesis means lower probability of activity enhancement.

On Tuesday, June 25, Steve Sacco, NN4X, reported from Florida: “Amazing over-the-pole conditions on 17 meters this morning. Decoded dozens of Japanese stations on FT8 between 1200Z and 1245Z and worked a few. UA0BA was logged at 1512Z, and I worked HS0ZIV at 1519Z. I was called by BH4QYX immediately afterwards but did not complete that contact.”

The latest video from Dr. Skov, WX6SWW: https://youtu.be/XzX1Ea7pqz4

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 June 20 through 26, 2019 were 0, 0, 0, 0, 24, 12, and 11, with a mean of 6.7. 10.7 cm flux was 67.7, 66.5, 66.4, 67.2, 67.9, 67.9, and 68, with a mean of 67.4. Estimated planetary A indices were 7, 6, 4, 3, 5, 4, and 6, with a mean of 5. Middle latitude A index was 8, 8, 5, 4, 5, 5, and 5, with a mean of 5.7.

 



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