[net.ham-radio] Propagation bulletin 50

ad7i (12/14/82)

qst de ad7i
hr propagation forecast bulletin nr 50	from arrl headquartere
newington ct  december 13, 1982
to all radio amateurs  bt

the solar flux rise that began at 171 on december 2 peaked at 279 on
the 19th, the highest reading since february 1.  for two days the
flux was more than 100 points above the corresponding day in the
previous solar rotation, an unlikely event so far past the peak of
this solar cycle.  this activity pattern will be reversed, probably
before the 19th, as the decline that began on the 11th is expected to
be a steep one.

the high solar flux in recent days did not bring much improvement in
dx conditions, because it was associated with numerous and intense
solar flares.  the increased geomagnetic activity resulting from
these caused high absorption on all amateur frequencies.  still the
50 mhz band was open marginally across the atlantic on at least three
days.

the down side of the flux peak should bring generally good
propagation but with the loss of 50 mhz dx, probably by the 17th.
the earths magnetic field will be more stable through the forecast
week, resulting in better conditions on all dx frequencies, a trend
that will be reversed again about the 19th.

american sunspot numbers were between 119 and 181 last week, for a
mean of 147.  they have peaked and will be much lower before next
weeks bulletin	ar

ad7i@houxp.UUCP (12/15/83)

qst de ad7i
hr propagatin forecast bulletin nr 50  from arrl headquarters
newington ct  december 12, 1983
to all radio amateurs  bt

during the last half of november, solar activity was very low and
there were days when no sunspots could be seen.  after december 2,
the sun began to look more as it should for this point in the solar
cycle.  the solar flux had been as low as 80, but it peaked at 112 on
the 9th, just in time for the arrl 10 meter contest on the 10th and
11th.  there was worldwide contest activity and the many impressive
scores will show that this is no time to be writing off 28 mhz for
the rest of the solar cycle.  an outbreak of new sunspots is nearly
always followed by an increase in geomagnetic activity and generally
poor propagation in the higher latitudes of the northern hemisphere.
we were close to auroral conditions as this bulletin was being
prepared, and high absorption and severe fading are likely to be with
us most of the time through the 15th.  conditions will improve the
next two days and remain quite good through the 21st.  the balance of
the month will be erratic, until the 30th, bit generally gmod
propagation will close out the old year and usher in the new.

american sunspot numbers for december 1 through 7 were between 3 and
42 with a mean of 18.3  ar