‰ Now 18 WPM transition file follows ‰

Average daily sunspot numbers over the past week were less than half
the value for the previous week, dropping nearly 73 points to 56.4.
Average daily solar flux declined as well, nearly 47 points to
110.7. Average geomagnetic indices were up about fifty percent, but
still very quiet. The higher average was due to events on January
17, when the planetary A index was 13, higher than recent measures,
but still moderate. The cause of the mild disturbance was the
arrival of a CME, or Coronal Mass Ejection.  Predicted solar flux
from the January 24 forecast from NOAA and USAF has 10.7 cm flux
values at 100 on January 25 and 26, 95 on January 27 to 30, 100 on
January 31 through February 1, 110 on February 2, 120 on February 3
and 4, 125 on February 5 to 8, 120 on February 9 to 14, 115 and 110
on February 15 and 16, and 105 on February 17 and 18.  It doesnt
look like a return to solar flux values around 170, where it was on
January 9 to 12, is expected any time soon. But those high levels
earlier in the month werent predicted either.  Looking back, a flux
reading of 135 was predicted for January 9 in the November 25
through December 9 daily forecasts, then downgraded to 110 on
December 10 to 16, then increased to 115 on December 17 to 30,
downgraded to 105 on December 31 through January 2, increased to 115
on January 3, 135 on January 4, 130 on January 5 and 6, 145 on
January 7, and 150 on January 8. The final result? 169.3 on January
9, far above any predictions over the previous 45 days, which were
revised eight times.  The forecasts are issued daily, usually after
2100 UTC and posted at
//www.swpc.noaa.gov/ftpmenu/forecasts/45DF.html.  The predicted
planetary A index from the same January 24 forecast is 8, 15, 20 and
12 on January 25 to 28, 5 on January 29 through February 8, 8 on
February 9 and 10, 5 on February 11 to 18 and 8 on February 19. The
January 25 to 28 levels are higher then predicted a day earlier, on
January 23. In that earlier forecast, planetary A index for those
same four days was 8, 8, 5 and 5.  F.K. Janda, OK1HH of the Czech
Republic expects the geomagnetic field will be quiet to unsettled on
January 25 and 26, quiet January 27 and 28, mostly quiet January 29,
quiet on January 30 and 31, mostly quiet February 1 and 2, and quiet
on February 3.  Mostly quiet February 4, quiet on February 5 and 6,
quiet to unsettled February 7 and 8, quiet to active February 9 and
10, mostly quiet February 11 and 12, quiet to active February 13 and
14, active to disturbed on February 15, and quiet to unsettled
February 16.  For more information concerning radio propagation, see
the ARRL Technical Information Service web page.  A detailed
explanation of the numbers used in this bulletin is also available
on this site.  An archive of past propagation bulletins is also
available.  Sunspot numbers were 74, 56, 46, 48, 50, 53, and 68,
with a mean of 56.4. 10.7 cm flux was 122.7, 115.2, 106.7, 106.6,
108.3, 110.3, and 104.9, with a mean of 110.7.  Estimated planetary
A indices were 13, 9, 7, 9, 4, 1, and 1, with a mean of 6.3.
Estimated mid latitude A indices were 12, 7, 9, 8, 4, 1, and 1, with
a mean of 6.

‰ End of 18 WPM transition file ‰