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ARRL Propagation Bulletin ARLP020 (2019)

SB PROP @ ARL $ARLP020
ARLP020 Propagation de K7RA

ZCZC AP20
QST de W1AW  
Propagation Forecast Bulletin 20  ARLP020
From Tad Cook, K7RA
Seattle, WA  May 17, 2019
To all radio amateurs 

SB PROP ARL ARLP020
ARLP020 Propagation de K7RA

Sunspot activity continues, and this reporting week, the average
daily sunspot number rose from 16.1 to 22.7, while average daily
solar flux went from 73.5 to 75.7. The two sunspot groups that
appeared on May 3 and May 6 are fading fast and rotating off the
visible solar disc. Two geomagnetically active days occurred on May
11 and 14, when the planetary A index reached 25 and 36.

Predicted solar flux is 72 on May 16-18, 70 on May 19, 68 on May
20-22, 67 on May 23-29, 70, 72, 74, and 76 on May 30-June 2, 77 on
June 3-11, 75 on June 12, 72 on June 13-14, 70 on June 15, 69 on
June 16-17, 68 on June 18, 67 on June 19-25, and 70, 72, 74, and 76
on June 26-29.

Predicted planetary A index is 28, 20, and 8 on May 16-18, 5 on May
19-27, 10, 12, 8, and 10 on May 28-31, 5 on June 1-15, 8 on June 16,
5 on June 17-23, 10, 12, 8, and 10 on June 24-27, and 5 on June
28-29.

On May 10 Jeff, N8II in West Virginia reported a sporadic E opening
on 10 meters.

"Even a couple of QRP stations with small antenna were loud.
Starting around 1600-1900 UTC, I worked a mobile in South Carolina,
several in north Florida, Louisiana, a couple of Tennessee,
heard/worked all over Texas from Houston to Oklahoma border to west
Texas, Missouri, several Illinois, several Indiana, Wisconsin, two
Iowa, Nebraska," he said.

"I also worked W2SDR in Salem County, New Jersey, apparently on Es
backscatter; when I turned antenna from west to New Jersey, his
signal did not improve (it was slightly weaker). All were 10-meter
SSB, most were S9 or better."

Also on May 10, Jon, N0JK, reported 6 meter sporadic-E openings from
Kansas.

"Here in the Midwest, the band was open to W1, W2, W3, and W4. It
was probably the most widespread opening so far this season," he
reported. "I worked AA2UK FM29 at 1908 UTC on 6 meters. Saw PV8DX
Brazil spotted to W1, W3, and W4."

If you would like to make a comment or have a tip for our readers,
email me, Tad Cook, K7RA, at k7ra@arrl.net.

For more information concerning radio propagation, see the ARRL
Technical Information Service web page at,
http://arrl.org/propagation-of-rf-signals. For an explanation of
numbers used in this bulletin, see
http://arrl.org/the-sun-the-earth-the-ionosphere.

Sunspot numbers for May 9-15 were 25, 24, 26, 24, 23, 24, and 13,
with a mean of 22.7. The 10.7-centimeter flux was 76.2, 76.3, 78,
76, 74.7, 74.4, and 74, with a mean of 75.7. Estimated planetary A
indices were 7, 7, 25, 4, 6, 36, and 6, with a mean of 13. Middle
latitude A index was 8, 7, 19, 5, 5, 23, and 8, with a mean of 10.7.
NNNN
/EX