ZCZC AP13
QST de W1AW
Propagation Forecast Bulletin 13 ARLP013
From Tad Cook, K7VVV
Seattle, WA March 26, 1999
To all radio amateurs
SB PROP ARL ARLP013
ARLP013 Propagation de K7VVV
Solar activity dropped again last week, with average solar flux off over 21 points and average sunspot numbers down by over 19 points. There was some saving grace for HF operators though. One was the relatively low geomagnetic activity, with A indices in the single digits only, and the other was the arrival of the vernal equinox, when daylight is equal in the southern and northern hemispheres.
Note that the highest solar flux for the current cycle was on February 14, when the noon reading was 204.6 and the afternoon reading was actually slightly higher at 208.2. Yet the noon reading on Wednesday of this week was 100 points lower, and the morning reading was 106.8.
Don't expect a big jump in solar activity for the CQ Worldwide WPX Phone Contest this weekend. Predicted solar flux for Friday through Sunday is 105, 105 and 110, and the planetary A index is somewhat unsettled at 12 for all three days.
Beyond the weekend expect the solar flux to rise to 130 by the end of the month, then go to 135 around April 5 and 140 two days later. It is expected to reach 150 around April 10-14. Look for recurring coronal holes to bring back unsettled to active conditions around March 28 through April 4, and possibly another week beyond that. There is also a possibility of increased solar flare activity over the same period until April 3.
N2XRM sent along a nice reference to a URL of aurora web links from the University of Alaska's Poker Flat Research Range at http://www.pfrr.alaska.edu/~pfrr/AURORA/LINKS.HTM
N4VHF sent a list of 6 meter DX he has worked this month from North Florida. His best was LU8WAT who was using only 6 watts and a 5 element beam, but was S7 and 5,340 miles away.
N1UAI has been having a ball on 10 meter FM, and told about working stations around the northeast via a repeater in Dallas. He hears this repeater on 29.66 MHz almost every day since last fall.
WA5IYX in San Antonio reported some unexpected and unseasonable E-skip on 6 meters on Tuesday and Wednesday this week, including stations in Mexico and South America.
Sunspot Numbers for March 18 through 24 were 127, 157, 119, 97, 101, 33 and 52 with a mean of 98. 10.7 cm flux was 148.1, 139.3, 132.7, 124, 115.9, 112.9 and 108.2, with a mean of 125.9, and estimated planetary A indices were 7, 6, 6, 6, 3, 5 and 4, with a mean of 5.3.
Here are some path projections for this weekend from Chicago, Illinois: