SB PROP @ ARL $ARLP026
ARLP026 Propagation de K7RA
ZCZC AP26
QST de W1AW
Propagation Forecast Bulletin 26 Â ARLP026
From Tad Cook, K7RA
Seattle, WA Â June 24, 2005
To all radio amateurs
SB PROP ARL ARLP026
ARLP026 Propagation de K7RA
First the outlook for ARRL Field Day, which is this weekend, June 25-26.
A projection from early Thursday from Geophysical Institute Prague, Geomagnetic Department, shows active geomagnetic conditions on Friday, June 24, followed by unsettled to active on June 25-26. This is from an early Thursday morning prediction.
Thursday afternoon Air Force Space Weather Operations predicted a planetary geomagnetic A index of 20 for each of those same three days. They’ve predicted a planetary A index of 20 for Saturday and Sunday since June 7. Prior to that they predicted values of 18 for Saturday and 20 for Sunday. These aren’t great conditions for HF, but are not at the level of a geomagnetic storm like we had on Thursday June 23 when the planetary K index went all the way to 7, and the planetary A index was 48. Sunspot numbers and solar flux are expected to remain low, with solar flux around 85.
This operating event gives no multipliers for DX or the number of states or sections worked, so it isn’t like a DX contest in which poor conditions leading to no opening to Europe or Asia becomes a bad thing. Given the low sunspot numbers, 20 and 40 meters are going to be the best bands for working cross country, with 80 meters open after dark. 40 and 80 should be the best bands for working stations less than 1000 miles away, day or night.
To review the past week, sunspots and solar flux numbers were lower. Average daily sunspot numbers dropped nearly 28 points from the previous week to 51.1. Average daily solar flux was off over 15 points to 87.7. The big geomagnetic activity of note was one day following our Thursday through Wednesday reporting period, on Thursday, June 23, when the mid-latitude A index was 30 and planetary A index was 48.
Markus Hansen, VE7CA in North Vancouver wrote with some propagation observations on the longest day of the year, June 20. He notes that southern West Coast stations (I assume California) were working East Coast on 6 meters, but he heard nothing in British Columbia until 8-9 PM that evening, when he worked California on 6 meters. He called CQ beaming West and Northwest to try to work KH6 or KH7, but had no luck. He reports that on 10 meters the KH6WO beacon “was pounding in at S9+10-20 db.”
Markus says, “Just after midnight I returned to have another listen and there was no 6-meter activity, but 20 meters was wide open to Europe and the South Pacific with many stations across the band. On 20 meters the OH2B beacon was a steady S9+20 dB and no arctic flutter. Pointing to the Pacific, the W6WO, KH6WO, ZL6B, VK6RBP, JA2IGY and VR2B beacons were all readable, some very strong. On 15 meters the KH6WO and ZL6B were still all readable both over S9 and on 10 meters I was hearing KH6WO at between S5 - S2.”
He continues, “I called CQ on both 15 and 10 meters but no answers.
Amazing. The longest day of the year sure can produce some very interesting propagation.”
Check out VE7CA’s personal web page at, http://www.shelbrook.com/~ve7ca/.
Matthew Chambers, KC0QEV in Macon, Missouri reports nice 2 meter tropospheric openings on June 21. With 10 watts PEP into a 7 element antenna only 4 feet above the ground he worked Northern Michigan and Arkansas from EM39. The stations he worked were in EN82 and EM36. A neighbor of his running 300 watts on 2 meters into a pair of big Yagis at 100 feet worked into Southern Texas and could hear stations in Mexico. Matthew reminds us not to forget VHF for Field Day this weekend.
Roger Bonuchi, AC9Y from the Chicago area mentioned great 6 and 10 meter openings on June 17-18. He heard East Coast stations on both bands when mobile at S9 and above, and worked a number of stations on 10 meters. When he returned home, he used an attic mounted horizontal loop on 6 meters to work many stations on CW and SSB. His best was VE6TA in Edmonton via CW, where he received a 559 report. This was about 1500 miles from his QTH on Chicago’s South Side.
He also passes on an interesting resource, which he referred to as “Hepburn’s Tropo page.” This is a tool for predicting tropospheric ducting based on weather patterns. Check it out at, http://home.cogeco.ca/~dxinfo/tropo.html.
Bob Sluder, N0IS wrote about a fantastic opening to Hawaii on 6 meters from the Midwest. He’s in Imperial, Missouri, and said the opening to KH6 did not last long that evening, but he heard many beacons from the west, and could still hear them Thursday morning at 7:00 AM.
One last note about Field Day propagation. As I’m finishing this after 0800z on Friday, I noticed that the IMF (Interplanetary Magnetic Field) is now pointing south, which is not what we would like. Earlier it was pointing north, which better protects Earth from solar wind. Perhaps it will change direction again before Saturday.
If you would like to comment or have a tip, email the author at, k7ra@arrl.net.
For more information concerning radio propagation and an explanation of the numbers used in this bulletin see the ARRL Technical Information Service propagation page at, http://www.arrl.org/tis/info/propagation.html. An archive of past bulletins is found at, http://www.arrl.org/w1aw/prop/.
Sunspot numbers for June 16 through 22 were 67, 59, 50, 43, 47, 53 and 39 with a mean of 51.1. 10.7 cm flux was 98.1, 90.8, 90, 86.9, 86.1, 82.8 and 79.5, with a mean of 87.7. Estimated planetary A indices were 26, 14, 7, 7, 5, 4 and 7 with a mean of 10. Estimated mid-latitude A indices were 19, 9, 5, 3, 2, 1 and 6, with a mean of 6.4.
NNNN
/EX
