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ARRL Propagation Bulletin ARLP049 (2003)

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SB PROP @ ARL $ARLP049
ARLP049 Propagation de K7RA

ZCZC AP49
QST de W1AW =20
Propagation Forecast Bulletin 49  ARLP049
From Tad Cook, K7RA
Seattle, WA  December 1, 2003
To all radio amateurs=20

SB PROP ARL ARLP049
ARLP049 Propagation de K7RA

At the end of this bulletin are the numbers for last week, as
promised in Propagation Forecast ARLP048, issued on November 26.
This reporting period (through last Wednesday, November 26) had
average daily sunspot numbers over twice the value for the previous
week, and average daily solar flux nearly 60 points higher.

The big upset during the last reporting period was the planetary A
index of 117 on November 20. This happened when the energy from a
coronal mass ejection swept over earth while the interplanetary
magnetic field pointed south, leaving the earth's magnetic field
vulnerable. The coronal mass ejection causing all the havoc was from
sunspot 484, and occurred on November 18 around 0800z.

The recent recurrence of large sunspots has subsided with sunspots
484, 486 and 488 rotating off the visible solar disk. The sunspot
number remains relatively high due to a number of smaller sunspots
scattered across the solar surface. Solar flux should decline over
the next few days to 145, 130, 130, 125 and 120 for Monday through
Friday, December 1-5. Solar flux and sunspot numbers may reach a
minimum for the short term around December 8 before rising again to
current levels after the middle of the month.

This last weekend's CQ Worldwide CW DX Contest experienced some nice
conditions. Geomagnetic indices were very quiet, with the
mid-latitude A index at 4 and 7, and K indices as low as 1, and even
0 on the two days prior. Geomagnetic conditions should remain
moderate through this week, but could rise again around December
7-15.

Average daily solar flux and sunspot numbers for November were a bit
lower than October, but October's numbers were higher than recent
months. Average daily sunspot numbers for November 2002 through
November 2003 were 159.8, 144.8, 150.0, 87.9, 119.7, 114.3, 89.6,
118.4, 132.8, 114.3, 82.6, 118.9 and 103. Average daily solar flux
values for the same months were 168.7, 157.2, 144, 124.5, 133.5,
126.8, 116.6, 129.4, 127.7, 122.1, 112.2, 155.5, and 140.8.

For more information about propagation and an explanation of the
numbers used in this bulletin see the Propagation page on the ARRL
Web site at http://www.arrl.org/tis/info/propagation.html.

Sunspot numbers for November 20 through 26 were 118, 131, 123, 158,
149, 202 and 209 with a mean of 155.7. 10.7 cm flux was 175.2, 177,
176.2, 178.2, 177.3, 170.7 and 170.9, with a mean of 175.1.
Estimated planetary A indices were 117, 39, 22, 21, 12, 13 and 9,
with a mean of 33.3.
NNNN
/EX


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<P><FONT SIZE=3D2>SB PROP @ ARL $ARLP049</FONT>

<BR><FONT SIZE=3D2>ARLP049 Propagation de K7RA</FONT>
</P>

<P><FONT SIZE=3D2>ZCZC AP49</FONT>

<BR><FONT SIZE=3D2>QST de W1AW&nbsp; </FONT>

<BR><FONT SIZE=3D2>Propagation Forecast Bulletin 49&nbsp; ARLP049</FONT>

<BR><FONT SIZE=3D2>From Tad Cook, K7RA</FONT>

<BR><FONT SIZE=3D2>Seattle, WA&nbsp; December 1, 2003</FONT>

<BR><FONT SIZE=3D2>To all radio amateurs </FONT>
</P>

<P><FONT SIZE=3D2>SB PROP ARL ARLP049</FONT>

<BR><FONT SIZE=3D2>ARLP049 Propagation de K7RA</FONT>
</P>

<P><FONT SIZE=3D2>At the end of this bulletin are the numbers for last =
week, as</FONT>

<BR><FONT SIZE=3D2>promised in Propagation Forecast ARLP048, issued on =
November 26.</FONT>

<BR><FONT SIZE=3D2>This reporting period (through last Wednesday, =
November 26) had</FONT>

<BR><FONT SIZE=3D2>average daily sunspot numbers over twice the value =
for the previous</FONT>

<BR><FONT SIZE=3D2>week, and average daily solar flux nearly 60 points =
higher.</FONT>
</P>

<P><FONT SIZE=3D2>The big upset during the last reporting period was the =
planetary A</FONT>

<BR><FONT SIZE=3D2>index of 117 on November 20. This happened when the =
energy from a</FONT>

<BR><FONT SIZE=3D2>coronal mass ejection swept over earth while the =
interplanetary</FONT>

<BR><FONT SIZE=3D2>magnetic field pointed south, leaving the earth's =
magnetic field</FONT>

<BR><FONT SIZE=3D2>vulnerable. The coronal mass ejection causing all the =
havoc was from</FONT>

<BR><FONT SIZE=3D2>sunspot 484, and occurred on November 18 around =
0800z.</FONT>
</P>

<P><FONT SIZE=3D2>The recent recurrence of large sunspots has subsided =
with sunspots</FONT>

<BR><FONT SIZE=3D2>484, 486 and 488 rotating off the visible solar disk. =
The sunspot</FONT>

<BR><FONT SIZE=3D2>number remains relatively high due to a number of =
smaller sunspots</FONT>

<BR><FONT SIZE=3D2>scattered across the solar surface. Solar flux should =
decline over</FONT>

<BR><FONT SIZE=3D2>the next few days to 145, 130, 130, 125 and 120 for =
Monday through</FONT>

<BR><FONT SIZE=3D2>Friday, December 1-5. Solar flux and sunspot numbers =
may reach a</FONT>

<BR><FONT SIZE=3D2>minimum for the short term around December 8 before =
rising again to</FONT>

<BR><FONT SIZE=3D2>current levels after the middle of the month.</FONT>
</P>

<P><FONT SIZE=3D2>This last weekend's CQ Worldwide CW DX Contest =
experienced some nice</FONT>

<BR><FONT SIZE=3D2>conditions. Geomagnetic indices were very quiet, with =
the</FONT>

<BR><FONT SIZE=3D2>mid-latitude A index at 4 and 7, and K indices as low =
as 1, and even</FONT>

<BR><FONT SIZE=3D2>0 on the two days prior. Geomagnetic conditions =
should remain</FONT>

<BR><FONT SIZE=3D2>moderate through this week, but could rise again =
around December</FONT>

<BR><FONT SIZE=3D2>7-15.</FONT>
</P>

<P><FONT SIZE=3D2>Average daily solar flux and sunspot numbers for =
November were a bit</FONT>

<BR><FONT SIZE=3D2>lower than October, but October's numbers were higher =
than recent</FONT>

<BR><FONT SIZE=3D2>months. Average daily sunspot numbers for November =
2002 through</FONT>

<BR><FONT SIZE=3D2>November 2003 were 159.8, 144.8, 150.0, 87.9, 119.7, =
114.3, 89.6,</FONT>

<BR><FONT SIZE=3D2>118.4, 132.8, 114.3, 82.6, 118.9 and 103. Average =
daily solar flux</FONT>

<BR><FONT SIZE=3D2>values for the same months were 168.7, 157.2, 144, =
124.5, 133.5,</FONT>

<BR><FONT SIZE=3D2>126.8, 116.6, 129.4, 127.7, 122.1, 112.2, 155.5, and =
140.8.</FONT>
</P>

<P><FONT SIZE=3D2>For more information about propagation and an =
explanation of the</FONT>

<BR><FONT SIZE=3D2>numbers used in this bulletin see the Propagation =
page on the ARRL</FONT>

<BR><FONT SIZE=3D2>Web site at <A =
HREF=3D"http://www.arrl.org/tis/info/propagation.html">http://www.arrl.or=/
g/tis/info/propagation.html</A>.</FONT>
</P>

<P><FONT SIZE=3D2>Sunspot numbers for November 20 through 26 were 118, =
131, 123, 158,</FONT>

<BR><FONT SIZE=3D2>149, 202 and 209 with a mean of 155.7. 10.7 cm flux =
was 175.2, 177,</FONT>

<BR><FONT SIZE=3D2>176.2, 178.2, 177.3, 170.7 and 170.9, with a mean of =
175.1.</FONT>

<BR><FONT SIZE=3D2>Estimated planetary A indices were 117, 39, 22, 21, =
12, 13 and 9,</FONT>

<BR><FONT SIZE=3D2>with a mean of 33.3.</FONT>

<BR><FONT SIZE=3D2>NNNN</FONT>

<BR><FONT SIZE=3D2>/EX</FONT>
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