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ARRL Propagation Bulletin ARLP010 (2018)

ARLP010 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 10  ARLP010
From Tad Cook, K7RA
Seattle, WA  March 9, 2018
To all radio amateurs 

ARLP010 Propagation de K7RA

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 remains 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. 1/4 wave whip
with 5 watts. Didn't expect much on 10 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. Both TEP to deep South America and one hop F2 skip to
the Caribbean and northern South America was in. PJ4G, FM5AN and
8P5A were up to an honest 40 dB over S9. They were loud!

"Skip zones were very evident with others closer or further away
much weaker.

"Saw Hawaii spotted to the west coast, no copy here. K6IJ in
northern California said the Hawaiian stations were very loud.
Shortest F2 heard was C6. Kudos to PZ5K for pulling my weak signal
out of the noise. 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, 6 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.  SFI 67, SSN = 0, K = 1."

And on March 8:

"Jon N0JK -- some 6 meter spots March 8:

"TI5/N5BEK    2256Z  50313.0 9db 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. Tamitha Skov means by "solar
storms." I don't see any geomagnetic effects, at least since January

The latest 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 back
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!"

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

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


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