sabato 19 dicembre 2015

Propagation de K7RA


Propagation Forecast Bulletin 51  ARLP051
From Tad Cook, K7RA
Seattle, WA  December 18, 2015
To all radio amateurs

Australia's Space Weather Services issued a geomagnetic disturbance warning at 2224 UTC on December 17. It read in part, "Two coronal mass ejections observed Dec 16 are expected to impact the Earth in sequence late Dec 18 to early Dec 19. Brief minor to major geomagnetic storm con ditions may result."

For December 18 they predicted quiet to active conditions, and on December 19 active to minor storm.

Solar activity increased over the past week, compared to the previous seven days. Average daily sunspot number on December 10-16 was 74.3, up from 48 over the previous seven days, December 3-9.

Average daily solar flux increased from 102.2 to 118.6.

Geomagnetic indices were also higher, with planetary A index going from 9.9 to 15.6, and mid-latitude A index from 6.6 to 11.3.

The latest prediction from USAF/NOAA forecasters shows predicted daily solar flux at 120 on December 18, 125 on December 19-21, 120 on December 22-23, then 115, 110, 105 and 98 on December 24-27, 95 on December 28-29, 98 on December 30-31, 100 on January 1-2, 105 on January 3, 110 on January 4-6, 115 on January 7-9, and then peaking at 130 on January 11-13 before dropping back below 100 after January 22.