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The K7RA Solar Update


Solar activity increased last week (January 21-27), compared to the previous seven days. Average daily sunspot numbers increased from 46 to 57.3, and average daily solar flux went from 100.7 to 106. Geomagnetic indices were also higher, with planetary A index going from 9 to 11.6.

Predicted solar flux for the short term is 110 and 108 on January 29-30, 105 on January 31 through February 1, 108 on February 2-4, 100 on February 5-6, 105 on February 7-11, 110 on February 12-13, 105 on February 14-15, 100 on February 16-20, 105 on February 21 and 108 on February 22-24.

Predicted planetary A index is 12, 8 and 5 on January 29-31, then 8, 15, 12 and 8 on February 1-4, 5 on February 5-6. 12 on February 7-8, 10 on February 9, 8 on February 10, 5 on February 11-16, then 10, 15, 10, 12 and 15 on February 17-21 and 12, 10, 8, 10 and 15 on February 22-26.

F.K. Janda, OK1HH, predicts the geomagnetic field will be quiet to unsettled on January 29-30, mostly quiet on January 31, quiet to unsettled on February 1, quiet to active February 2, quiet to unsettled February 3, quiet on February 4-5, quiet to unsettled February 6, quiet to active February 7-8, quiet to unsettled February 9, quiet on February 10, mostly quiet February 11-12, quiet to unsettled February 13, quiet to active February 14, mostly quiet February 15, active to disturbed February 16-17, quiet to active February 18-21, and mostly quiet on February 22-24.

OK1HH expects an increase in solar wind on February 2-3, 5-7, 15-16 and 20-21. He feels less certain about the solar wind forecast for February 2-3.

This report from Jeff Hartley, N8II, of Shepherdstown, West Virginia on January 24: “It was a bit tough working VP8STI (South Sandwich) on 30 and 40 meters. Europe often seemed to have a big edge. Ten meters was also tough, especially for K5P (Palmyra). Twenty meters continues to close pretty early to Europe and in all directions in the PM. Higher K index values of 3-4 continue to not matter that much most of the time. Ten meters to the western USA is improving, with loud signals from Arizona and California most days from 1600-2100Z. We also had Es to Texas and Arkansas one day.”

We also heard from Jon Jones, N0JK on January 26: “The K5P DXpedition to Palmyra encountered low F2 MUFs to North America for the first part of their operation. There were only short, weak openings to Palmyra on 10 and 12 meters for many in North America. 15 and 20 meters were their workhorse bands.

“On January 20, a CME impact sparked a geomagnetic storm that afternoon and the K index peaked at 6. Geomagnetic storms can shut down high latitude polar paths, but can enhance propagation towards and across the geomagnetic equator. K5P had a booming signal on both 10 and 12 meters around 2000z, allowing many to work the rare country on these bands. On 10 and 12 meters they peaked over S-9 on my mobile vertical. I logged K5P on 12 meter CW, but couldn't get through the boiling cauldron on 10. I checked for their 6-meter beacon on 50.106, but no copy.”

That Kp-index value of 6 was at the 0600 UTC reading on January 21, which was late in the evening on January 20 for most of North America, 10:00 PM PST here on the West Coast. The planetary A index on January 20-21 was 25 and 32.

Earlier on January 26 Jon reported on six meter activity: “A second "peak" of sporadic E for the 2015/2016 winter Es season on 6.

“Friday afternoon January 22 I worked KZ4RR EM90 and K1TO EL87 on 6 meters at about 2000z via Es while mobile between Lawrence and Topeka, Kansas. Sunday January 24 at 2125z I had a nice chat with VE2XK FN07, again while I was mobile in Lawrence.

N0JK/M        16/01/24 2127Z  50130.0 FN07 ES EM28 Tks Jon            VE2XK

K1TO EL87 heard the XE2HWB/b DL44 via double hop Es on Jan. 23 at 0034z.

 - Jon N0JK EM28 KS”

And finally, David Moore sent this link: On Jan. 26th, 2016, NASA's Solar Dynamics Observatory captured imagery at several different wavelengths of superheated plasma exploding away from the Sun in a Coronal Mass Ejection event. The blast was not Earth-directed.

For more information concerning radio propagation, see the ARRL Technical Information Service at For an explanation of the numbers used in this bulletin, see An archive of past propagation bulletins is at More good information and tutorials on propagation are at

My own archives of the NOAA/USAF daily 45 day forecast for solar flux and planetary A index are in downloadable spreadsheet format at and .

Click on “Download this file” to download the archive, and ignore the security warning about file format. Pop-up blockers may suppress the download.

Monthly propagation charts between four USA regions and twelve overseas locations are at

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

Sunspot numbers for January 21 through 27 were 56, 50, 54, 47, 58, 61, and 75, with a mean of 57.3. 10.7 cm flux was 104, 100.5, 98.9, 103.8, 107.6, 114.8, and 112.7, with a mean of 106. Estimated planetary A indices were 32, 14, 12, 11, 3, 4, and 5, with a mean of 11.6. Estimated mid-latitude A indices were 15, 10, 10, 9, 3, 3, and 3, with a mean of 7.6.




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