[net.ham-radio] ARRL PROPOGATION FORECAST

wheatley@inuxi.UUCP (Steven Wheatley) (01/31/86)

qst de k9eui
hr propagation forecast bulletin nr 4  from arrl headquarters
newington ct  january 27, 1986
to all radio amateurs  bt

through the 26th, solar flux numbers for january are lower than
those  for  the same days in the previous solar rotation on all
but 6 days.  on 3 of these 6, the figures were the same as  the
last  time  around.   unless  something unexpected happens this
week, january will be about 1 unit per day lower than december.
this  is not unexpected, in what could be the last full year of
this solar cycle, but it does not necessarily follow  that  the
rest  of  this  cycle  will  show  a steady decline.  the final
months of the 3 other cycles for which accurate  flux  readings
are  available  do  not  show  a consistent daily dropping off,
except on a long term, smoothed  basis.   from  the  middle  of
august  to the middle of october 1985, the flux was never above
73, and much of the time is was in  the  high  60s.   september
averaged  only  69.5.   but since the middle of october we have
had 4 days in the 90s, and 54 days of 75 or higher.

the importance of these statistics is that  for  the  fall  and
early  winter dx season in the northern hemisphere, the sun was
active enough for fairly good coverage on all bands  except  28
mhz  for nearly half of the days.  on at least one third of the
days we could have done fairly well, even  on  28  mhz.   solar
activity  does  not  rise  and  fall  in  smooth or symmetrical
curves.  it is likely that, except in the  few  weeks  when  we
move from cycle 21 into cycle 22, we will not see dx conditions
generally very different from those we have lived with over the
past year or so.

for the forecast week, we will be operating with the solar flux
and sunspot numbers very close to the minimum quiet sun levels.
this means that our nightime dx work will be done mostly on  10
mhz  and  lower  frequencies.  the 14 mhz band, always crowded,
will tend to be even more jammed in daytime hours.   how  early
it  opens,  and  how  late  it stays open, will depend upon the
solar flux numbers, and they will  never  be  much  worse  than
during this week.

we are in a geomagnetically disturbed period as  this  bulletin
is  being prepared.  this should be over about january 29.  the
solar flux will be rising by the end of this  week.   the  next
major  geomagnetic  disturbance is expected about february 3 to
4.

there were no visible sunspots for the week january  16  to  22
ar