[net.ham-radio] arrl propagation forecast bulletin nr 42

rjr@mgweed.UUCP (Bob Roehrig) (10/16/84)

qst de k9eui
hr propagation forecast nr 42  from arrl headquarters
newington ct  october 15, 1984
to all radio amateurs  bt

the solar flux has been below predicted levels  for  more  than
four months, and it has run close to minimum values since early
september.  currently, flux numbers are  more  than  20  points
below  the  96  used  for the prediction charts in october qst.
thus, when 21 and 28 mhz are normally at their best, 28 mhz  is
useful only on transequatorial or other low latitude paths, and
21 mhz is behaving more like 28 mhz was expected to be.  unless
solar  activity  increases markedly, the rest of this year will
be very different  from  the  printed  predictions,  which  are
prepared far in advance of their appearance in qst.

as for the week ahead, geomagnetic activity was headed downward
at  bulletin  time.   dx conditions were fair to good, and will
continue so through about the 16th.  higher  geomagnetic  field
activity is expected most of the time through the 25th, but the
months end should be the best of the entire autumn  dx  season,
especially  on high latitude paths.  if sunspot activity rises,
the effects on dx in late october could be very favorable.   if
current flux levels continue, 14 mhz and lower frequencies will
be the dx mainstays for october and early november in  all  but
the southern tier of states.

american sunspot numbers for october 4 through 10 were  between
0 and 15 with a mean of 5.9  ar

rjr@mgweed.UUCP (Bob Roehrig) (10/22/85)

qst de k9eui
hr propagation forecast bulletin nr 42  from arrl headquarters
newington ct  october 21, 1985
to all radio amateurs bt

in a special midweek bulletin we reported  a  solar  flux  rise
that  began october 13.  from 67 it rose to 80 by the 20th, the
highest flux reading since early july.  the  21  mhz  band  has
been  open  over much of the world in the past few days, and 10
meter beacons z21and and zs6pw have been heard in northern  usa
for  the first time in more than a year.  over the past weekend
10 meter occupancy was the highest in many months.

as of sunday night we were coming out of a  week  of  generally
poor  conditions, the result of above average geomagnetic field
activity.  things should improve october  21  through  23,  but
absorption  and  fading  will  be  bad  again october 26 to 30.
another major disturbance is expected early in november.

the main source of the higher solar flux is a fairly large spot
area  that came around the east limb october 15.  its influence
will decline as it moves westward this week, and the flux  will
slide  downward if, as seems likely, no major new areas replace
it. the main propagation factor for the next few  days  however
will be magnetic field activity.  the a index is low as this is
written and it is dropping lower,  but  not  for  long.   there
should  be  a  longer  favorable  period later this week, but a
major disturbance will be with us by november 1.  we are in the
best  weeks  of the entire year for propagation in the northern
hemisphere, in any case, and with enough solar activity to keep
things interesting through this week.

american sunspot numbers for october 10 to 16  were  between  0
and 17 with a mean of 4.3  ar