The K7RA Solar Update


Only one day (March 2) showed any sunspot activity over the past reporting week, with a daily sunspot number of 11 so average daily sunspot activity declined from 6 to 1.6. Average daily solar flux went from 68.3 to 67.6.


No sunspots have been seen since March 2.


Geomagnetic indicators were quiet, with average planetary A index dropping from 10.4 to 5.1, and mid-latitude A index from 7.4 to 4.6.


Predicted solar flux is 68 on March 9-15, 70 on March 16, 72 on March 17-29, 70 on March 30, 68 on March 31 through April 11, 70 on April 12, and 72 on April 13-22.


Predicted planetary A index is 12 and 10 on March 9-10, 5 on March 11-16, then 15 and 18 on March 17-18, 5 on March 19-20, then 12, 18, 10, 5, 8 and 20 on March 21-26, 5 on March 27-29, 8 on March 30-31, then 5 on April 1-3, 8 on April 4-5, 5 on April 6-9, then 10, 12, 12, 15 and 18 on April 10-14, 5 on April 15-16, then 12, 18, 10, 8, 5 and 20 on April 17-22.


Geomagnetic activity forecast for the period March 9 to April 3, 2018 from F.K. Janda, OK1HH.

“Geomagnetic field will be:

Quiet on March 12-13, 20, 29, April 1-2

Mostly quiet on March 9, 19, 24, 28, 30-31, April 3

Quiet to unsettled on March 10-11, 14-15, 19, 23, 25, 27

Quiet to active on March 16, 21-22

Active to disturbed on March 17-18, 26

Amplifications of the solar wind from coronal holes cannot be predicted for the period before March 10, but I do not expect any significant upsurge.

Then solar wind will intensify on March (10,) 16-18, (19-20, 25-26, April 3).


- Parenthesis means lower probability of activity enhancement.

- With regard to ongoing changes, current forecasts remain less reliable especially in the first half of March.”



Regular contributor David Moore shared this Science Daily article with us concerning how magnetic waves heat the Sun’s atmosphere and propel solar wind:


From Jon Jones, N0JK: "I went out fixed/mobile on 10 meters early Sunday afternoon around 1900z March 4 in the ARRL DX SSB from eastern Kansas. I used a 1/4 wave whip antenna with 5 watts. I didn't expect much on 10 meters with the SFI of only 68, but was pleasantly surprised with good conditions on 10.


“Sometimes the solar flux numbers don't correlate well to the actual ionization. As it turned out, there was both TEP to deep South America and one-hop F2 skip to the Caribbean and northern South America. PJ4G, FM5AN and 8P5A were up to an honest 40 dB over S-9! Skip zones were very evident with others closer or further away much weaker. 


“I saw Hawaii spotted to the west coast, but no copy here. K6IJ in northern California said the Hawaiian stations were very loud. The shortest F2 heard was C6. Kudos to PZ5K for pulling my weak signal out of the noise. I ended up with 14 contacts in 11 countries."


Jon sent this on March 8: “Along with improved conditions on 10 meters March 4 in the ARRL DX SSB contest, on March 8 six meters opened for afternoon TEP across the geomagnetic equator between the Caribbean, Central America to deep South America starting around 2200z. Contacts were made using CW, SSB and the new FT8 digital mode. The SFI was 67, SSN = 0, K = 1.


“Some 6-meter DX cluster spots on March 8:

TI5/N5BEK    2256Z  50313.0 9 dB FT8                         CX9AU     

HI8PLE       2249Z  50313.0 FT8 -03 in GF05rk               LW2DAF    

ZF1EJ        2248Z  50313.0 FT8 -01 in GF05rk               LW2DAF    

HH2AA        2248Z  50130.0 Now in SSB calling           CX9AU     

NP2Q         2248Z  50313.0 FT8 -12 IN GF05rk               LW2DAF    

KP4S         2247Z  50110.0                                 LU4EFC    

HH2AA        2246Z  50313.0 -10db in GF05rk                 LW2DAF    

WP4CQ        2244Z  50110.0 Gracias x QSO!                  LU4EFC    

HH2AA        2241Z  50103.0 tnx fer QSO..! 73               LU5DF     

WP4CQ        2241Z  50101.0 tnx fer qso and 579 73          CX9AU       

HH2AA        2232Z  50101.0 Now go to cw 50101              CX9AU     

YS1AG/B      2227Z  50022.0 529                             LU5DF     

HH2AA        2226Z  50313.0 tnx 73 Dan                      CX9AU     

WP4CQ        2222Z  50110.0 55 IN GF05rk                    LW2DAF    

OA4B/B       2218Z  50036.3 539                             LU5DF     

HH2AA        2217Z  50313.0 FT8                             LU1DKC    

HI8PLE       2215Z  50125.0 59 gracias Edgar                CX9AU       

HI8PLE       2214Z  50125.0 S8 in GF05rk                    LW2DAF    

HI8PLE       2212Z  50110.0 Gracias x QSO!                  LU4EFC    

NP4BM        2211Z  50115.0 S8 in GF05rk                    LW2DAF    

LU4EFC       2210Z  50110.0                                 HI8PLE         

NP4BM        2208Z  50115.0 Gracias Victor 59 tambien       CX9AU        

NP4BM        2204Z  50110.0 55 Gracias Victor, 73           LU5DF         

NP4BM        2202Z  50110.0 CQ 59                           LW3EX”



This week I am not sure what Dr. Skov means by “solar storms.” At least I don’t see any geomagnetic effects, since January 27:


A message from Dr. Skov: "This week finds me knee-deep leading the Space Weather Certification Committee for the American Meteorological Society. We've made some real headway this week and I wanted to share the good news. The committee has decided to focus its efforts on establishing a broadcast certification for getting information out to the public, instead of going for a science-related, but more technical consulting certification for industry. This means we put YOU first! 


“I couldn't be more thrilled with this decision. We are now free to concentrate on finding ways to train meteorologists and give them the tools they need to bring Space Weather into our living rooms. I have you to thank for keeping me honest and inspired as we continue building the future. We still have a long way to go, but today it feels like we are one step closer to the Sun.


“This week's forecast finds Amateur Radio operators disappointed at the dimming of old region 2699. We had hoped it would stay bright and boost the solar flux, but instead it has retreated underneath the surface of the Sun. This means HF radio propagation remains poor. As a consolation, the Sun has launched several solar storms, including one that is Earth-directed. 


“Along with some fast wind we are expecting over the next few days, this could bump us up to storm levels and bring us some more aurora, especially at high latitudes.


Cheers, Tamitha"


See Dr. Skov’s latest video here:



 For more information concerning radio propagation, see the ARRL Technical Information Service 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


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 March 1 through 7, 2018 were 0, 11, 0, 0, 0, 0, and 0, with a mean of 1.6. 10.7 cm flux was 67.2, 67.8, 67.8, 67.5, 67.6, 67.6, and 67.8, with a mean of 67.6. Estimated planetary A indices were 6, 4, 6, 6, 5, 5, and 4, with a mean of 5.1. Estimated mid-latitude A indices were 5, 3, 5, 7, 5, 4, and 3, with a mean of 4.6.





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