|Posted by Wooden sign Photos's on June 28, 2012 at 10:45 PM|
Tad "The Sun came up this morning like a burning red balloon"Cook, K7RA, reports: Sunspot activity continued to drop until early thisweek: The average daily sunspot numbers were 26.3, down more than 58 pointsfrom last week's numbers, while the average daily solar flux declined to 92.8,down over 33 points from last week's average. The weekly sunspot numberaverage has declined since the May 31-June 6 period, when it was 130.4,followed by 116.1 the next week, 84.6 the next and 26.3 this week. In last week's ARRL Letter, we reported theaverage daily sunspot number as 87, but it was really 84.6. This is because wereported what may have been a preliminary sunspot number of 46 for June20, but the sunspot number for that date was 29. Geomagnetic conditions overthe past week were quiet. The average planetary A index was 5.7, down from12.6 last week, 9 the week before and 13.4 the week before that. The quietplanetary A index for this week was exactly as it was on the week of May24-30 -- 5.7 -- which also happened to be the mid-latitude A index for thatperiod. The latest prediction from USAF/NOAA shows geomagnetic activitypeaking on June 29-July 4, probably from a coronal hole spewing solar wind. Thepredicted planetary A index for June 28-30 is 7, 10 and 18, followed by 15on July 1-3, 10 and 8 on July 4-5, 5 on July 6-7, 8 on July 8-9, 5 on July10-25, and then 10, 18, 15, 15, 15 and 8 on July 26-31. This is an echo ofthe activity this week, based on the 27.5 day rotation of our Sun,relative to Earth. The predicted solar flux is 110, 115 and 115 on June 28-30, 120and 125 on July 1-2, 130 on July 3-5, 135 and 140 on July 6-7, 135 on July8-9, 130 on July 10-11, 125 on July 12-13, then 120, 115, 110 and 105 onJuly 14-17. Solar flux may dip below 100 around July 19-28. Look for more onthe ARRL website on Friday, June 29. For more information concerning radiopropagation, visit the ARRL Technical Information Service Propagation page. This week's"Tad Cookism" is brought to you by Eurythmics' You HurtMe.