[SFDXA] ARLP014 Propagation de K7RA

Fri Apr 8 11:06:31 EDT 2022

> SB PROP @ ARL $ARLP014
> ARLP014 Propagation de K7RA
> 
> ZCZC AP14
> QST de W1AW  
> Propagation Forecast Bulletin 14  ARLP014
> From Tad Cook, K7RA
> Seattle, WA  April 8, 2022
> To all radio amateurs 
> 
> SB PROP ARL ARLP014
> ARLP014 Propagation de K7RA
> 
> Lots of solar activity livened up HF conditions over the past
> reporting week, March 31 to April 6. Average daily sunspot number
> rose from 90.1 to 94.6, and daily solar flux from 132.7 to 135.3.
> 
> It looks like solar flux may peak this month at 140 on April 24-28.
> 
> Since March 18 we were unable to get daily solar flux from the
> observatory in Penticton, British Columbia, so for a couple of weeks
> we relied on secondary sources which were all in whole numbers,
> instead of resolving to 0.1. Multiple inquiries to the observatory
> led nowhere, but now the data is back online at,
> https://bit.ly/3LDlgqC .
> 
> I had to fudge the flux value for March 31, because the value of
> 239.5 was obviously an error, probably due to a CME overwhelming the
> 10.7 cm receiver at the observatory, so I averaged the morning and
> afternoon readings to 149.3. The official daily flux value is always
> from the 2000 UTC local noon reading.
> 
> Geomagnetic conditions were quite active on March 31 through April
> 2. Average daily planetary A index for the week increased from 10 to
> 14.4, and middle latitude A index from 8.1 to 10.9.
> 
> Spaceweather.com reported 146 solar flares over the month of March
> and predicts even more for April. They also report that Solar Cycle
> 25 is progressing faster and stronger than earlier predictions.
> 
> A new sunspot group appeared on March 31, two more on April 1,
> another on April 2 and one more on April 3, and one more on April 5.
> 
> Predicted solar flux is 108 on April 8-9, 105 on April 10-11, 100 on
> April 12-14, then 110, 115 and 120 on April 15-17, 125 on April
> 18-19, 130 on April 20-23, 140 on April 24-28, 135 on April 29-30,
> 130 on May 1, 120 on May 2-3, 125 on May 4-5, 120 on May 6, 115 on
> May 7-8, 110 on May 8-9, 115 on May 11, and 120 on May 12-14.
> 
> Predicted planetary A index is 12, 15, 10 and 8 on April 8-11, 5 on
> April 12-19, 10 on April 20-21, then 5, 15, 10 and 8 on April 22-25,
> 5 on April 26-28, then 18, 12, 10 and 8 on April 29 through May 2, 5
> on May 3-7, then 12 and 10 on May 8-9, and 5 on May 10-16.
> 
> Solar wind in the news:
> 
> https://bit.ly/3rdXycD
> 
> F.K. Janda, OK1HH reports:
> 
> "Total solar activity has been declining. Recent CMEs generated by
> solar flares have usually not been headed to Earth. In particular,
> on April 6, the solar wind was expected to intensify from a CME
> generated by a filament eruption on April 3rd, but only a small
> portion of the solar plasma cloud reached Earth.
> 
> "The Earth's magnetic field was unsettled to active until April 2
> and partly on April 4 and 7. The increased geomagnetic activity on
> the night of April 3 to 4 worsened diurnal short wave propagation
> conditions on April 4. Thereafter, despite the continuing decline in
> solar activity, shortwave propagation conditions improved.
> 
> "In further development, we first expect a decline in solar
> activity. Its growth in the second half of the month will again
> cause an improvement of shortwave propagation. However, the
> development will be slightly irregular."
> 
> Another great video forecast from Dr. Tamitha Skov, WX6SWW, the
> Space Weather Woman:
> 
> https://youtu.be/SxU6Lv30DuQ
> 
> WB8VLC reports from Oregon:
> 
> "Another great week on 10 meters but only SSB/CW and not much FM
> activity, but the activity was very strong with signals to South
> Africa, Taiwan, Philippines, Norfolk Island, and Australia.
> 
> "Interesting that I have not heard any European stations during any
> morning or afternoon openings to the east, just South Africa."
> 
> A small portion of his log:
> 
> "April 3 it was ZS in the morning and VK at night then China and
> Philippines:
> 
> "2344 UTC N7ET/DU7  28.014  CW 599 Philippines
> 2340 UTC  BV1EL     28.010  CW 599 Taiwan
> 2311 UTC  VK3NX     28.015  CW 599 Australia
> 1900 UTC  ZS3Y      28.373  SSB 55 South Africa"
> 
> K5JRN reports on 6 meters from Austin, Texas:
> 
> "Interesting conditions observed here on April 4 and 6. On 6 meters
> on 4/4/22, I worked HK3X (FJ24) in Columbia and HC1MD/2 (EI97) in
> Ecuador while running 30 watts to an indoor dipole wrapped around a
> couple of bamboo tomato stakes glued end to end. [I will assume FT8
> was the mode. - K7RA]
> 
> "That same combo helped me snag HC2DR (FI07) in Ecuador today (4/6).
> My signals were not strong, ranging from -13 to -24 in Colombia and
> Ecuador. I've also been heard in Argentina and have copied several
> Argentinian hams, including LU9AEA (GF05), but have not yet worked
> an LU on 6.
> 
> "Today, I've also been heard in Uruguay by CX7CO (GF15) but have not
> heard any CX stations yet. Indeed, I'm not receiving anyone else on
> 6 meters except a few locals and those South American stations. The
> north-south paths seem like narrow pipelines."
> 
> Speaking of "narrow pipelines," I often see this on 10 and 12 meters
> using FT8. Monitoring pskreporter.info, on April 7 at 1630 UTC on 12
> meters my signal was only reported by stations on the East Coast
> over a narrow band, all from 2296-2359 miles from me, at first only
> by many stations in Virginia and North Carolina, but not South
> Carolina.
> 
> Later at 1645 UTC coverage expanded to Florida and Georgia, but
> still within that narrow mileage limit. Later by 1720 UTC reports
> had spread to New York, Georgia and  Florida, and the mileage range
> expanded slightly to 2119-2489 miles. But there was one major
> exception, HK3A in Bogota, Colombia at 4091 miles.
> 
> The night before (local time) at 0220 UTC on 17 meters I was copied
> only into a specific area about 2300 miles away in Ohio, Virginia,
> Pennsylvania, and Maryland, then suddenly at 0232 UTC the coverage
> expanded to California, Oregon, Texas, Alabama, and Florida.  All of
> this with low power and a crude end-fed indoor antenna, fed with an
> UnUn and autotuner.
> 
> Thanks to KA7F for the following:
> 
> https://bit.ly/3rbkUj8
> 
> Information on Solar Cycle 25 increasing:
> 
> https://bit.ly/3x9cv3p
> 
> And more from the Southgate Amateur Radio Club:
> 
> https://bit.ly/38BbEOW
> 
> More solar phenomena:
> 
> https://bit.ly/3ra65NV
> 
> And more:
> 
> https://earthsky.org/sun/sun-activity-week-of-march-28-to-april-3/
> 
> N0JK reports:
> 
> "On Saturday April 2, 2022 N0LL (EM09) copied LU5VV, CE2SV, LU1WFU
> and PV8DX on 50.313 MHz FT8 TEP. I copied CE2SV on TEP and K0SIX
> (EN35) calling PY5CC on 50.313 MHz Es at 2109 UTC."
> 
> If you would like to make a comment or have a tip for our readers,
> please email the author at, k7ra at arrl.net.
> 
> For more information concerning shortwave radio propagation, see
> http://www.arrl.org/propagation and the ARRL Technical Information
> Service web page 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/.
> 
> Instructions for starting or ending email distribution of ARRL
> bulletins are at http://arrl.org/bulletins .
> 
> Sunspot numbers for March 31 through April 6, 2022 were 84, 109,
> 118, 129, 86, 75, and 61, with a mean of 94.6. 10.7 cm flux was
> 149,3, 146.6, 143.3, 140.2, 128, 122.4, and 117, with a mean of
> 135.3. Estimated planetary A indices were 27, 17, 22, 10, 11, 6, and
> 8, with a mean of 14.4. Middle latitude A index was 18, 12, 19, 7,
> 8, 6, and 6, with a mean of 10.9.
> NNNN
> /EX