ARRL

ARRL Propagation Bulletin ARLP047 (2000)

SB PROP @ ARL $ARLP047
ARLP047 Propagation de K7VVV

ZCZC AP47
QST de W1AW  
Propagation Forecast Bulletin 47  ARLP047
From Tad Cook, K7VVV
Seattle, WA  November 22, 2000
To all radio amateurs 

SB PROP ARL ARLP047
ARLP047 Propagation de K7VVV

This bulletin is written a day and a half earlier than usual because
of the Thanksgiving holiday.  For that reason, the projected solar
flux and A indices expected for this weekend will not be quite as up
to date as usual.  Also, it is too early to include the sunspot
number for Wednesday, the end of our normal reporting week, so next
week's bulletin will have two week's worth of solar flux, sunspot
numbers and planetary A indices.

Geomagnetic indices have been very quiet this week, with both the
planetary and Boulder A indices in the single digits.  The quietest
day was Thursday, November 16, when the Boulder A index was one, and
the Boulder K index was zero for most of the day.  This indicates a
very stable geomagnetic environment.  The planetary A index was four
on that day and on the next.

Solar flux has been rising after reaching a near term minimum on
November 14.  It was 173.7 on Monday, 185.4 on Tuesday, and today on
Wednesday, the three daily readings were 192.4, 194.9 and 203.5.
The noon reading of 194.9 is the official number.

The current projection has the 10.7 cm flux rising above 200 on
Thanksgiving, peaking at 210 on Friday, then 205 on Saturday and 200
on Sunday through next Thursday.  This looks good for the big DX
contest this weekend, although generally the Maximum Usable
Frequency is more dependent upon the average solar flux for the
previous week or ten days rather than a value on the day of
interest.  The predicted planetary A index also looks good, which
currently is projected to be ten for Thursday through Saturday, and
twelve for Sunday and Monday.

There was a full-halo coronal mass ejection last week on November
16, but it was on the back side of the sun, projecting the energy
away from earth.  It was only partially seen.  The region that
produced that activity will be rotating into view sometime soon, but
not soon enough to affect the contest weekend.

N0AX pointed out that last week's bulletin mention's something
called a solar ''flair''.  Of course, your author was only
demonstrating a flair for erroneous homonyms.  That thing coming out
of the sun is still a flare, no matter what is written here.  After
re-reading the above three lines, your author realized that he
actually referred to himself as your ''other'', so that homonym
problem is only getting worse with age.  Your author still thinks of
himself as a young ham, but that is because he was first licensed at
age 12.  Never mind that this was over 35 years ago.  Senior moments
seem to be increasing weekly.  Happy Thanksgiving to all.
NNNN
/EX