The K7RA Solar Update

The K7RA Solar Update

Tad Cook, K7RA, Seattle, reports: At 2311 UTC on June 14 the Australian Space Weather Forecast Centre issued a geomagnetic disturbance warning, predicting geomagnetic activity to reach active levels — with isolated minor storming possible — on June 16. A very fast-moving stream of solar wind from a coronal hole is expected to arrive on June 16, possibly sparking G1-class geomagnetic storms as well as auroral displays at high latitudes.

We saw four zero-sunspot days over the past week, so the average daily sunspot number declined from 19.3 to 4.9 from the previous 7 days. Average daily solar flux for the June 8-14 reporting week dipped from 77.1 to 74.4.

Average daily planetary A index increased from 5.6 to 7.3 and average mid-latitude A index went from 5.6 to 6.9. Over the June 1-7 reporting week, the mid-latitude and planetary A indices were both 5.6.

Predicted solar flux is 74 on June 15-21; 72 on June 22-24; 70 on June 25; 75 on June 26-July 7; 78 on July 8; 78, 77, 78, 76, and 74 on July 8-12; 72 on July 13-21; 70 on July 22-23, and 75 on July 24 and beyond.

Predicted planetary A index is 15, 25, 15, 12, and 10 on June 15-19; 5 on June 20-July 8; 15, 12, 8, 15, 25, and 15 on July 9-14; 12 on July 15-16, and 5 on July 17 and beyond.

Sunspot numbers for June 8 through 14, 2017 were 12, 0, 0, 0, 0, 11, and 11, with a mean of 4.9. The 10.7-centimeter flux was 74, 73.7, 74.7, 74.3, 75.2, 74.9, and 74.1, with a mean of 74.4. Estimated planetary A indices were 4, 5, 4, 17, 8, 8, and 5, with a mean of 7.3. Estimated mid-latitude A indices were 5, 6, 5, 14, 6, 6, and 6, with a mean of 6.9.