QST de W1AW
Propagation Forecast Bulletin 5 ARLP005
From Tad Cook, K7RA
Seattle, WA January 29, 2016
To all radio amateurs
SB PROP ARL ARLP005
ARLP005 Propagation de K7RA
Solar activity increased last week (January 21-27), compared to theÂ previous seven days.
Average daily sunspot numbers increased from 46 to 57.3, and averageÂ daily solar flux went from 100.7 to 106. Geomagnetic indices wereÂ also higher, with planetary A index going from 9 to 11.6.
Predicted solar flux for the short term is 110 and 108 on JanuaryÂ 29-30, 105 on January 31 through February 1, 108 on February 2-4,Â 100 on February 5-6, 105 on February 7-11, 110 on February 12-13,Â 105 on February 14-15, 100 on February 16-20, 105 on February 21 andÂ 108 on February 22-24.
Predicted planetary A index is 12, 8 and 5 on January 29-31, then 8,Â 15, 12 and 8 on February 1-4, 5 on February 5-6. 12 on February 7-8,Â 10 on February 9, 8 on February 10, 5 on February 11-16, then 10,Â 15, 10, 12 and 15 on February 17-21 and 12, 10, 8, 10 and 15 onÂ February 22-26.
F.K. Janda, OK1HH predicts the geomagnetic field will be quiet toÂ unsettled on January 29-30, mostly quiet on January 31, quiet toÂ unsettled on February 1, quiet to active February 2, quiet toÂ unsettled February 3, quiet on February 4-5, quiet to unsettledÂ February 6, quiet to active February 7-8, quiet to unsettledÂ February 9, quiet on February 10, mostly quiet February 11-12, quietÂ to unsettled February 13, quiet to active February 14, mostly quiet
February 15, active to disturbed February 16-17, quiet to activeÂ February 18-21, and mostly quiet on February 22-24.
OK1HH expects an increase in solar wind on February 2-3, 5-7, 15-16Â and 20-21. He feels less certain about the solar wind forecast forÂ February 2-3.
This report from Jeff Hartley, N8II of Shepherdstown, West VirginiaÂ on January 24:
“It was a bit tough working VP8STI (South Sandwich) on 30 and 40Â meters. Europe often seemed to have a big edge.” 10 meters was also tough, especially for K5P (Palmyra).”20 meters continues to close pretty early to Europe and in allÂ directions in the PM. Higher K index values of 3-4 continue to notÂ matter that much most of the time.
“10 meters to the western USA is improving, with loud signals fromÂ Arizona and California most days from 1600-2100Z. We also had Es toÂ 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 NorthÂ America for the first part of their operation. There were onlyÂ short, weak openings to Palmyra on 10 and 12 meters for many inÂ North America. 15 and 20 meters were their workhorse bands.
“On January 20 a CME impact sparked a geomagnetic storm thatÂ afternoon and the K index peaked at 6. Â Geomagnetic storms can shutÂ down high latitude polar paths, but can enhance propagation towardsÂ and across the geomagnetic equator. K5P had a booming signal on bothÂ 10 and 12 meters around 2000z, allowing many to work the rareÂ country on these bands. On 10 and 12 meters they peaked over S-9 onÂ my mobile vertical. I logged K5P on 12 meter CW, but couldn’t getÂ through the boiling cauldron on 10. I checked for their 6-meterÂ beacon on 50.106, but no copy.”
That Kp-index value of 6 was at the 0600 UTC reading on January 21,Â which was late in the evening on January 20 for most of NorthÂ America, 10:00 PM PST here on the West Coast. The planetary A indexÂ on January 20-21 was 25 and 32.
Earlier on January 26 Jon reported on 6 meter activity:
“A second ‘peak’ of sporadic-E for the 2015/2016 winter Es season onÂ 6.
“Friday afternoon January 22 I worked KZ4RR EM90 and K1TO EL87 on 6Â meters about 2000z via Es while mobile between Lawrence and Topeka,Â Kansas. Sunday January 24 at 2125z I had a nice chat with VE2XKÂ FN07, again while I was mobile in Lawrence.
“N0JK/M 16/01/24 2127Z 50130.0 FN07 ES EM28 Tks Jon VE2XKÂ “K1TO EL87 heard the XE2HWB/b DL44 via double hop Es on Jan. 23 atÂ 0034z.”
And finally, David Moore sent this link: https://shar.es/1hKeAN
On Jan. 26th, 2016, NASA’s Solar Dynamics Observatory capturedÂ imagery at several different wavelengths of superheated plasmaÂ exploding away from the Sun in a Coronal Mass Ejection event. TheÂ blast was not Earth-directed.
If you would like to make a comment or have a tip for our readers,Â email the author at firstname.lastname@example.org.
- For more information concerning radio propagation, see the ARRLÂ Technical Information Service web page at,
- For an explanation of theÂ numbers used in this bulletin, seeÂ http://arrl.org/the-sun-the-earth-the-ionosphere.
- An archive of pastÂ propagation bulletins is atÂ http://arrl.org/w1aw-bulletins-archive-propagation.
- More goodÂ information and tutorials on propagation are at http://k9la.us/.
My own archives of the NOAA/USAF daily 45 day forecast for solarÂ flux and planetary A index are in downloadable spreadsheet format atÂ http://bit.ly/1VOqf9B and http://bit.ly/1DcpaC5 .
Click on “Download this file” to download the archive, and ignoreÂ the security warning about file format. Pop-up blockers may suppressÂ the download.
Monthly propagation charts between four USA regions and twelveÂ overseas locations are at http://arrl.org/propagation.
Instructions for starting or ending email distribution of ARRLÂ bulletins are at http://arrl.org/bulletins.
Sunspot numbers for January 21 through 27 were 56, 50, 54, 47, 58,Â 61, and 75, with a mean of 57.3. 10.7 cm flux was 104, 100.5, 98.9,Â 103.8, 107.6, 114.8, and 112.7, with a mean of 106. EstimatedÂ planetary A indices were 32, 14, 12, 11, 3, 4, and 5, with a mean ofÂ 11.6. Estimated mid-latitude A indices were 15, 10, 10, 9, 3, 3, andÂ 3, with a mean of 7.6.