ARRL

ARRL Propagation Bulletin ARLP025 (1997)

SB PROP @ ARL $ARLP025
ARLP025 Propagation de K7VVV

ZCZC AP25
QST de W1AW
Propagation Forecast Bulletin 25  ARLP025
From Tad Cook, K7VVV
Seattle, WA  June 20, 1997
To all radio amateurs

SB PROP ARL ARLP025
ARLP025 Propagation de K7VVV

Solar activity is still low.  Although average sunspot numbers were
up from 18.3 to 30.1 from last week to the current one, average
solar flux was down to 70.6 from a low average of 73.1 the week
before.  Solar flux was below the 90 day average of 74 on every day
over the past week.

The projection for this month shows the solar flux staying in the
mid to low seventies.  No geomagnetic disturbances are forecast.

Now that we are moving into the summertime propagation period,
expect Sporadic-E layer openings on 10 meters through August.
Because fewer people are using 10 meters now than at the peak of the
solar cycle, many 10 meter openings may go unnoticed.  While solar
flux remains far too low to sustain reliable activity on 10,
Sporadic-E skip does provide some interesting short and medium path
length openings, with single hop propagation out to about 1,300
miles and multiple hop propagation to about twice that distance.

Sunspot Numbers for June 12 through 18 were 26, 27, 31, 29, 38, 31
and 29 with a mean of 30.1.  10.7 cm flux was 69.6, 70.1, 70.6,
70.7, 72.1, 69.6 and 71.2, with a mean of 70.6, and estimated
planetary A indices were 6, 3, 3, 6, 5, 5, and 4, with a mean of
4.6.
NNNN
/EX