[SFDXA] ARLP047 Propagation de K7RA

Fri Nov 20 17:19:05 EST 2020

> SB PROP @ ARL $ARLP047
> ARLP047 Propagation de K7RA
> 
> ZCZC AP47
> QST de W1AW  
> Propagation Forecast Bulletin 47  ARLP047
> From Tad Cook, K7RA
> Seattle, WA  November 20, 2020
> To all radio amateurs 
> 
> SB PROP ARL ARLP047
> ARLP047 Propagation de K7RA
> 
> As solar flux declined over the past week, I noticed less long
> distance propagation on 10 meters reported on pskreporter.info from
> my local grid square CN87.
> 
> Propagation on 12 meters though was quite strong. After 0100 UTC on
> Nov 15 trans-equatorial propagation was evident between East Asia
> and Australia on 10 meters.
> 
> Further down in this bulletin is a 12 meter report from NN4X.
> 
> Solar activity declined dramatically over the past week, with
> average daily sunspot numbers going from 31.3 to 12. On November 15
> and 16 there were no sunspots at all, which greatly affected the
> decline in this week's average.
> 
> Solar flux weakened from a weekly average last week of 90, to 79.8
> this week.
> 
> Predicted solar flux over the next 45 days until the start of 2021
> is also relatively weak, although the short term prediction improved
> from November 18 to November 19. The November 19 prediction is 75 on
> November 20 to December 8, 72 on December 9-10, 70 on December
> 11-12, 75, 72 and 72 on December 13-15, 70 on December 16-22, 72 on
> December 23-24, and 75 on December 25 through January 3, 2021.
> 
> Predicted planetary A index is 5, 8, 12 and 8 on November 20-23,
> then 5 on November 24 through December 2, 8 on December 3-4, 5 on
> December 5-17, then 8, 12, 8, 10 and 12 on December 18-22, 5 on
> December 23-29, 8 on December 30-31, and 5 on January 1-3, 2021.
> 
> Geomagnetic activity forecast for the period November 20 to December
> 16, 2020 from F.K. Janda, OK1HH.
> 
> "Geomagnetic field will be:
> quiet on: December 1, 6-8, 12-14, (15-16)
> quiet to unsettled on: November 28-30, December 2, 4, 10-11
> quiet to active on: November 26-27, December 3, 5, 9
> unsettled to active: November (20,) 21-22, (23-25)
> active to disturbed: - None predicted
> 
> "Solar wind will intensify on: November (20,) 21-25, (30,) December
> (2,) 3-5, (9).
> 
> "Remarks:
> - Parenthesis means lower probability of activity enhancement.
> - The predictability of changes remains lower because there are
>  few unambiguous indications."
> 
> This bulletin has mentioned the paper by McIntosh, et. al.,
> "Overlapping Magnetic Activity Cycles and the Sunspot Number:
> Predicting Sunspot Cycle 25 Amplitude."
> 
> This week a reference appeared in the ARRL Letter, and
> https://bit.ly/36Pb0J7 is a link to that paper.
> 
> My favorite passage: "Our method predicts that SC25 could be among
> the strongest sunspot cycles ever observed, and that it will almost
> certainly be stronger than present SC24 (sunspot number of 116) and
> most likely stronger than the previous SC23 (sunspot number of 180).
> This is in stark contrast to the consensus of the SC25PP, sunspot
> number maximum between 95 and 130, i.e., similar to that of SC24."
> 
> SC25PP is the Solar Cycle 25 Prediction Panel, which met in
> September 2020.
> 
> The new prediction is very exciting, and suggests a cycle that may
> rival Cycle 19, which peaked in March, 1958. The effects on
> shortwave radio propagation were remarkable, and included daily
> worldwide propagation on 10 and even 6 meters, and not just during
> daylight hours.
> 
> I was about to turn six years old at the time, and we lived in
> Reedley, a small fruit packing town in California's San Joaquin
> Valley, where my father worked supplying agricultural chemicals to
> farmers. He drove a company car which contained a low-band VHF FM
> radio (probably 30-40 MHz, judging from my memory of the bumper
> mounted antenna), and I recall him describing being unable to
> contact the base station in Fresno, about 25 miles away, while
> getting QRM from other users in Texas.
> 
> I've heard from many hams who were new Novice licensees at the time,
> and assumed conditions would always be like they were then. They
> have been waiting a long time.
> 
> I would love to see daily sunspot numbers above 200.
> 
> An article about sunspot activity in 1958:
> 
> https://bit.ly/3pOtbHE
> 
> NN4X reported from Florida on 12 meter FT8 activity on November 14:
> 
> "12M was in great shape!
> ------------------------------------ 12m
> 134500   1  0.1 1225  ~  DL1EZ TZ1CE -14
> 134500   3 -0.5 1596  ~  OQ4U KM8AM R-07
> 134500  20  0.5 1786  ~  PY2GG EA8TH R+12
> 134500  13  0.3 2058  ~  SM7DLK WA8NLX EM92
> 134500   9  0.2 1976  ~  CQ OZ7PBI JO45
> 134500   2 -0.4 1712  ~  SV2DFK V51LZ RR73
> 134500   0  0.0 2107  ~  CQ EA1DR IN82
> 134500  -9  0.1  629  ~  9J2BS EA4CYQ IM78
> 134500 -20 -0.2 1393  ~  9J2BS YB9WIC R-13
> 134500 -18  0.0  994  ~  CQ S79VU LI75
> ------------------------------------ 12m
> 134530  20  0.5 1786  ~  PY2GG EA8TH R+12
> 134530  28  0.1  862  ~  EA8AAH W4AFB EL98
> 134530  -5 -0.4 1712  ~  4Z4DX V51LZ R+01
> 134530 -13  0.1 1225  ~  DL1EZ TZ1CE -14"
> 
> Mike Schaffer, KA3JAW (FN20jq) wrote:
> 
> "Yikes, October out-of-season single-hop sporadic-E is active on the
> 6 meter band along the east coast!
> 
> "On Saturday, October 17, 2100-2300 UTC, it is 25 days past the
> Autumnal Equinox.
> 
> "Once again, the unexpected happens during the early recovery out of
> a Solar Minimum.
> 
> "I was monitoring the 6M FT-8 mode on 50.313 MHz for Es to show-up
> along the Gulf of Mexico coastal region.
> 
> "Then it happened, the first direct decodes in monitor receiving
> mode:
> 
> "215700  3 -0.4 1527  ~  WA2FZW W4KBX EL98
> 220345  -2 -0.4 2178  ~  KK2DOG W4KBX EL98
> 220545  -1 -0.4 2177  ~  KC3PIB W4KBX EL98
> 220845  -9 -0.5 1566  ~  CQ K2IL EL97
> 
> "Grid Squares:
> EL98 - central Florida, around Orlando
> EL97 - south central, north of Lake Okeechobee
> 
> "Now that the band is open with the Es expanding further south, I
> decided to try for any contacts down on the SSB calling frequency on
> 50.125 MHz.
> 
> "When I rolled down there, several operators were already having
> conversations about how pleasant that the band came back to life
> since the summer months.
> 
> "At 2252 UTC I put out the first CQ call, AG4N, Bill from West Point,
> Georgia, very close to the Alabama state line replied.
> 
> "From my QTH to AG4N, azimuth 230 deg, distance 771 air miles.
> 
> "I gave Bill a 4x7 signal report with QSB.
> 
> "The Es was being funneled as far away as Mobile, Alabama (996 miles)
> and Biloxi, Mississippi (1,045 miles).
> 
> "By 2335 UTC the band started to collapse with signal reports sliding
> down to 2x2.
> 
> "No double-hop Es from Puerto Rico, Dominican Republic or other
> northern Caribbean Sea islands was heard.
> 
> "Even if the band conditions sound dead, I urge everyone to continue
> monitoring the 6M SSB calling frequency, 50.125 MHz, then take it
> one step further and make that CQ call. You might be pleasantly
> rewarded even if you are running 10 watts into a 6M horizontal 1/2
> wave dipole that is below eight feet off the ground."
> 
> Here is a forecast from November 14 from Dr. Tamitha Skov, WX6SWW:
> 
> https://youtu.be/HCBth8nS79w
> 
> This weekend is the ARRL SSB Sweepstakes Contest, see
> http://www.arrl.org/sweepstakes .
> 
> If you would like to make a comment or have a tip for our readers,
> email the author at, k7ra at arrl.net.
> 
> For more information concerning 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 November 12 through 18, 2020 were 27, 24, 11, 0,
> 0, 11, and 11, with a mean of 12. 10.7 cm flux was 85.1, 81.9, 80.2,
> 78.7, 76.6, 79.1, and 77.3, with a mean of 79.8. Estimated planetary
> A indices were 3, 3, 3, 4, 2, 3, and 4, with a mean of 3.1. Middle
> latitude A index was 3, 2, 2, 2, 0, 3, and 3, with a mean of 2.1.
> NNNN
> /EX