Solar activity picked up this week, with average daily sunspot numbers for August 15-21 up nearly 42 points (forty-nine percent) to 126.9, when compared to the previous seven days. Likewise, average daily solar flux increased from 111.7 to 126.3.
The latest prediction from USAF/NOAA has solar flux at 130, 125, 120, and 115 on August 23-26, 110 on August 27-29, 105 on August 30, 95 on August 31 t…
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Again this week, solar activity was unchanged, with average daily sunspot numbers slipping from 85.4 to 85, and average daily solar flux increasing 4.4 points to 111.7. Geomagnetic conditions were stable.
The latest solar flux prediction from USAF/NOAA has flux values of 125 on August 16, 130 on August 17-18, 120 on August 19-20, 110 on August 21-23, 105 on August 24, 110 on August 25-26, 115 on…
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Solar indicators barely moved this week, with average daily sunspot numbers up 5.8 points to 85.4, and average daily solar flux down 2.4 points to 107.3.
Predicted solar flux for the next week is low, with the predicted average for Thursday August 8 through Wednesday August 14 at 104.9, a little lower than the 107.3 average for this past week.
Solar flux is predicted at 105 on August 9-16, 110 on…
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At 2330 UTC on July 24, Australia’s IPS Radio and Space services issued a geomagnetic disturbance warning. Increased geomagnetic activity is expected due to a coronal mass ejection. They predict quiet to unsettled conditions on July 25, active to minor storm on July 26, and active conditions on July 27.
As this bulletin nears release early Friday morning, the planetary A index was 4 on four rece…
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Unsettled geomagnetic conditions continued this week, punctuated by periods of relative quiet. The most active days were July 14-15. The planetary A index was 20 and 25, and the mid-latitude A index was 15 and 33 on those dates. Of course Alaska’s College A index was higher, at 58 and 34.
The A index is a daily value, and it is calculated from eight measurements per day (once every three hours) …
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Average daily sunspot numbers over the past week rose over 23 points to 109.4, compared to the previous reporting week. Average daily solar flux was up nearly 21 points to 127.9. Two days, July 6 and July 10, had the most geomagnetic activity, with a planetary A index of 25 on July 10. Planetary A index of July 6 was 21.
The forecast issued on July 7 had a predicted solar flux of 145 on July 11-…
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The average daily sunspot numbers sank nearly 50 points this week to 94.3, while the average daily solar flux was down more than 16 points to 117.8. The geomagnetic indices were quite high, due to a solar wind storm. Sunspot numbers for May 23-29 were 117, 99, 107, 92, 87, 75 and 83, with a mean of 94.3. The 10.7 centimeter flux was 134.5, 127.3, 121.3, 120, 110.1, 104.8 and 106.9, with a mean …
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Solar activity remains quiet, but on May 16 the daily sunspot number reached 212. I had to keep searching further and further back in the records to find a higher sunspot number. One year, six months and one week earlier — November 9, 2011 — the sunspot number was almost that high, at 208. Going back seven years, 10 months and 12 days to July 4, 2005, it was 192. To find activity beating the …
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Since we are now at (or close to) the peak of Solar Cycle 24, it is no surprise that the solar indices are up. The latest forecast predicts Solar Cycle 24 to peak this fall, but that will be determined after the fact, and it will be based on a long running average of sunspot numbers. This past week, the average daily sunspot numbers increased by more than 34 points, rising to 156.1, while the a…
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This week, the average daily sunspot numbers remained about the same, with the number nudging up from 120.9 to 121.7, while the average daily solar flux numbers went from 136.5 to 137.5. For the past two weeks, the average planetary A index has been the same as the mid-latitude A index. Last week they were both 9.9; this week, both values were 8.
Sunspot numbers for May 2-8 were 102, 139, 156, 1…
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Solar activity made a healthy jump over the past week, with the average daily sunspot numbers up more than 30 points to 120.9, while the average daily solar flux increased more than 27 points to 136.5. The most active day for geomagnetic indices was May 1, when the planetary A index reached 21 and the high-latitude College A index (measured near Fairbanks, Alaska) was a whopping 57. That number…
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Solar activity was quiet this week: The average daily sunspot number declined nearly 23 points to 90.6, while the average daily solar flux values were down nearly 13 points to 109.1. The most active day was April 24, with a planetary A index of 19 and mid-latitude A index of 15. The average daily mid-latitude A index was the same this week as last, 4.9. Sunspot numbers for April 18-24 were 86, …
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While solar activity weakened this past week, geomagnetic conditions were stable. The geomagnetic storm predicted for last weekend did not happen, and both the planetary and mid-latitude A index only rose to 10 on April 14 in response to a glancing blow from a coronal mass ejection (CME). The average daily sunspot numbers declined nearly 25 points to 113.3, while the average daily solar flux wa…
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Both the average daily sunspot numbers and the solar flux were up this week, with the sunspot numbers rising nearly 57 points to 138.1, and the average daily solar flux up more than 25 points to 138.8. Paired with the average daily planetary A index dropping from 9.4 to 4.1, this is great news for HF propagation. On April 8, the daily sunspot number reached 162; two days later, it was at 163. T…
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Solar activity increased over this past week, with the average daily sunspot numbers up 32 points to 81.6, while the average daily solar flux increased more than 16 points to 113.4. The geomagnetic field was active on March 29 due to solar wind. Sunspot numbers for March 28-April 3 were 49, 73, 70, 83, 84, 103 and 109, with a mean of 81.6. The 10.7 centimeter flux was 98.7, 105.1, 108.4, 113.3,…
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Solar activity was down this week, with the average daily sunspot number at 49.6, less than half last week’s figure. The average daily solar flux dropped 22 points to 97, and geomagnetic activity was quiet also. Sunspot numbers for March 21-27 were 60, 54, 56, 45, 56, 41 and 35, with a mean of 49.6. The 10.7 centimeter flux was 106.1, 100.9, 98.2, 96, 92.6, 92.4 and 93, with a mean of 97. The e…
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This past week, the average daily sunspot numbers were up 16.2 points to 101.1, while the average daily solar flux remained about the same, rising from 118.5 to 119. An eruption on March 15 caused a coronal mass ejection (CME) that hit Earth on March 17, causing the planetary A index to jump to 46. Sunspot numbers for March 14-20 were 133, 105, 90, 126, 116, 68 and 70, with a mean of 101.1. The…
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Solar indicators were mixed this week, with the average daily sunspot number down 8.4 points to 84.9, while the average daily solar flux rose 5.9 points to 118.5. Geomagnetic indices were much quieter, with the average planetary A index down 4.7 points to 4.4 and the average mid-latitude A index down 5 points to 3.9. Sunspot numbers for March 7-13 were 80, 59, 63, 89, 105, 95 and 103, with a me…
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Both the averages of daily sunspot numbers and solar flux rose, with the sunspot numbers up nearly 36 points to 93.3, and the solar flux up nearly 12 points to 112.6. The most active geomagnetic day was Friday, March 1, when the planetary A index was 27 and the mid-latitude A index was 23; Alaska’s high latitude College A index was a whopping 64.
Sunspot numbers for February 28-March 6 were 63, …
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This past week, there was a decline in the solar and geomagnetic indices: The average daily sunspot number dropped nearly 21 points to 57.7, while the average daily solar flux softened by 4.7 points to 100.9 and the average daily planetary A index declined 6.4 points to 5.1. This isn’t much of a change, but geomagnetic activity was low already, and this is even lower.
Sunspot numbers for Februar…
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There was a modest rise in the average daily sunspot numbers over the past seven days, rising 27 points to 78.3, while the average daily solar flux was up marginally, only 1.6 points to 105.6. The geomagnetic indices also went up, with the planetary A index rising from 5.6 to 6.4, and the middle latitude A index rising from 5.1 to 6. There was a more substantial rise in both the solar flux and …
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Solar activity continues at the low levels that we have seen in the past few weeks. The sunspot numbers have been remarkably consistent, with the average daily numbers for the weeks since January 17 at 56.4, 55.7, 50.7 and finally 51.3 for this past week. As you can see, the average daily sunspot number rose less than 1 point from the previous week to the past week, while the average daily sola…
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The average daily sunspot numbers hardly changed from last week and the week prior, but the average daily solar flux bounced back to about the level it was from two weeks ago: The average daily sunspot numbers were down 5 points to 50.7, while the average daily solar flux was up 7.7 points to 106.4. Sunspot numbers for January 31-February 6 were 47, 65, 54, 79, 30, 41 and 39, with a mean of 50….
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The average daily sunspot numbers this past week dropped nearly 73 points to 56.4, while the average daily solar flux declined nearly 47 points to 110.7. The average geomagnetic indices were up about 50 percent, but it was still very quiet. The difference was mostly due to events on January 17 when the planetary A index was 13 — higher than in recent weeks, but still moderate. The cause of the…
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After last week’s somewhat downbeat look at sunspot cycles — current, past and future — we sure have some great activity to report this week: The average daily sunspot number more than doubled in the past week, rising nearly 93 points to 163.3, while the average daily solar flux was up more than 37 points to 147.7. On top of that, the geomagnetic conditions were very quiet, which is a wonderf…
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It is Friday, and the world did not end. To herald this non-event, NASA even produced a wonderful video that explained how the whole thing was a misconception. The Mayan calendar is like an odometer, and when it gets to 999,999, it just roles over to 0 and begins anew. As expected, Phil Plait of Bad Astronomy also provided a nonsense-free assessment, where he referred to the non-event as the “M…
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The average daily sunspot numbers fell 13.5 points this week, from 61.1 to 47.6, while the average daily solar flux was about the same this week as last, rising 1.1 points to 102.7. Geomagnetic indices were even quieter this week than last. Sunspot numbers for December 6-12 were 49, 23, 35, 40, 49, 55 and 82, with a mean of 47.6. The 10.7 centimeter flux was 97.4, 97.1, 101.1, 103.7, 104, 103.7…
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Solar activity declined again this week, with the average daily sunspot numbers dropping 17.8 points, from 78.9 to 61.1, while the average daily solar flux declined 19.4 points, from 121 to 101.6. Sunspot numbers for November 29-December 5 were 89, 67, 49, 43, 44, 58 and 78, with a mean of 61.1. The 10.7 centimeter flux was 113.1, 110.6, 101.7, 97.7, 96.6, 96.2 and 95.5, with a mean of 101.6. T…
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The average daily sunspot number for the week was down nearly 38 percent to 78.9, compared to last week’s average of 126.9. The average daily solar flux dropped nearly 13 percent, to 121 from 138.9. The seven-day reporting period for these data ran from November 22-28. Sunspot numbers for November 22-28 were 93, 85, 87, 64, 81, 76 and 66, with a mean of 78.9. The 10.7 centimeter flux was 127.7,…
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In November 16 edition of the Solar Update, we reported that the average daily sunspot number on November 8-14 was 104.9. In the next seven day reporting period — November 15-21 — the average was 126.9, making for a nice increase; with solar flux, the average over the previous period was 129.5. In the most recent period, the average daily sunspot number increased to 138.9. In the four days si…
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There has been an exciting and dramatic rise in sunspot activity this week. The daily sunspot number was 188 on Monday, November 12 — higher than it has been in more than a year. The last time the daily sunspot number was as high was on November 9, 2011, when it was 208. Prior to last November, we have to go back nine years — November 26, 2003 — into the previous solar cycle to find a number…
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Solar activity retreated again this week, with the average daily sunspot numbers declining 8.7 points to 49.7, while the average daily solar flux was down nearly 20 points to 97.2. Sunspot numbers for November 1-7 were 48, 34, 35, 46, 47, 61 and 77, with a mean of 49.7. The 10.7 cm flux was 98.4, 96.5, 93.3, 95, 96.6, 98.7 and 101.7, with a mean of 97.2. The estimated planetary A indices were 1…
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Solar activity quieted this week, with the average daily sunspot numbers down nearly 37 points to 58.4 and the average daily solar flux declining 27 points to 116.9. Sunspot numbers for October 25-31 were 58, 71, 59, 55, 75, 56 and 35, with a mean of 58.4. The 10.7 cm flux was 130, 130.7, 121.7, 117, 108.4, 106.3 and 104.2, with a mean of 116.9. The estimated planetary A indices were 4, 4, 4, 3…
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Good conditions should prevail for the CQ World Wide SSB DX Contest this weekend. A chance for solar flares has greatly diminished in the past few days, and the latest forecast has the planetary A index at a steady and quiet 5 for this weekend and beyond, through the first week in November.
The average daily sunspot numbers for October 18-24 were down 1.7 points from the previous seven days, to …
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Sunspot activity rose this week, with the average daily sunspot numbers up more than 45 points to 97, while the average daily solar flux rose more than 24 points to 129.2. Sunspot numbers for October 11-17 were 82, 89, 85, 97, 119, 107 and 100, with a mean of 97. The 10.7 cm flux was 116.6, 121.9, 124.9, 132.1, 136.8, 137 and 135, with a mean of 129.2. The estimated planetary A indices were 6, …
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There was another decline in sunspot activity this week, but based on activity over the past few days, combined with the projected solar flux values, it is making a steady recovery. The sunspot numbers for October 4-10 were 56, 55, 39, 37, 41, 63 and 71, with a mean of 51.7. The 10.7 cm flux was 109.5, 106.2, 98.8, 98.1, 103.4, 106.2 and 112, with a mean of 104.9. The estimated planetary A indi…
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A coronal mass ejection (CME) hit the Earth on September 30, triggering a jump in geomagnetic indices. The planetary A index on October 1 was 31, and the K index jumped to 7, making aurora visible across the northern tier of the United States. The northern latitude college A index was 23 (near Fairbanks, Alaska), about the same as the mid-latitude index — which was 21 — in Fredericksburg, Vir…
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The average daily sunspot numbers rose this week from 56 to 81.3, while the average daily solar flux increased from 101.4 to 129.7. Sunspot numbers for September 20-26 were 68, 74, 46, 57, 90, 121 and 113, with a mean of 81.3. The 10.7 cm flux was 117.4, 116.9, 124.5, 133.6, 136.6, 139.8 and 139.2, with a mean of 129.7. The estimated planetary A indices were 9, 5, 4, 2, 2, 2 and 6, with a mean …
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The average daily sunspot numbers dropped this week, from 83.1 to 56, while the average daily solar flux declined from 118.9 to 101.4. Sunspot numbers for September 13-19 were 44, 44, 53, 77, 51, 61 and 62, with a mean of 56. The 10.7 cm flux was 99.1, 100.5, 97.5, 97.3, 101.5, 104.3 and 109.8, with a mean of 101.4. The estimated planetary A indices were 6, 5, 6, 7, 6, 8 and 14, with a mean of …
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Solar activity retreated this week, with the average daily sunspot numbers off nearly 46 points — about 35 percent — to 83.1, while the average daily solar flux declined 18 points to 118.9. Sunspot numbers for September 6-12 were 112, 110, 70, 87, 62, 73 and 68, with a mean of 83.1. The 10.7 cm flux was 128, 133.4, 128.6, 123, 111.3, 105.1 and 102.6, with a mean of 118.9. The estimated planet…
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There was a surprising jump in solar activity occurred this week: The average daily sunspot numbers rose nearly 55 points (that’s almost 74 percent) to 128.7, while the average daily solar flux values were up more than 28 points to 136.9. Sunspot numbers for August 30-September 5 were 118, 144, 120, 108, 156, 150 and 105, with a mean of 128.7. The 10.7 cm flux was 127.8, 130.5, 145.6, 142.3, 14…
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Although solar activity is quite low, there was an increase in sunspot numbers and in the solar flux over the past week. The average daily sunspot numbers were up nearly 20 points — about 36 percent — to 74.1, while the average daily solar flux increased nearly 13 points to 108.7. Sunspot numbers for August 23-29 were 49, 69, 70, 78, 85, 73 and 95, with a mean of 74.1. The 10.7 cm flux was 96…
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The weak solar activity continues: The average daily sunspot numbers for the seven days of August 16-22 were down 23 points — 30 percent — to 54.6, while the average daily solar flux dropped a little over 16 percent — 18.7 points — to 96. These figures offer a comparison between August 9-15 and the latest reporting period of August 16-22. Sunspot numbers for August 16-22 were 34, 42, 56, 69…
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There was a big drop in solar activity over the past week, with the average daily sunspot numbers declining nearly 42 points to 77.6, and the average daily solar flux down 20 points to 114.7. Sunspot numbers for August 9-15 were 124, 105, 98, 76, 62, 46 and 32, with a mean of 77.6. The 10.7 cm flux was 131.2, 125.4, 119.7, 112.3, 108.1, 105.8 and 100.7, with a mean of 114.7. The estimated plane…
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The average daily sunspot numbers rose more than 20 points this week — about 20 percent — to 119.4, while the average daily solar flux was up 3 points to 134.7. Sunspot numbers for August 2-8 were 126, 160, 140, 107, 108, 96 and 99, with a mean of 119.4. The 10.7 cm flux was 134.6, 139.7, 138.7, 134, 134.1, 128.5 and 133.3, with a mean of 134.7. The estimated planetary A indices were 16, 7, 7…
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The average daily sunspot numbers this week were up more than 47 points to 99.3, while the average daily solar flux rose nearly 35 points to 131.7. Sunspot numbers for July 26-August 1 were 77, 91, 108, 79, 106, 116 and 118, with a mean of 99.3. The 10.7 cm flux was 114.7, 123.3, 126.6, 131.4, 136, 139.8 and 150.1, with a mean of 131.7. The estimated planetary A indices were 4, 5, 11, 6, 13, 6 …
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In last week’s Solar Update, we reported a blast of energy from a solar flare headed our way, predicted to arrive on Saturday, July 14. The CME hit at 1800 UTC, and it had a huge effect on propagation and geomagnetic indices. The next day, the planetary A index was 60, the mid latitude A index was 39 and the high latitude college A index was 88. Conditions haven’t been that upset since March 9,…
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Solar activity rose moderately this week, with the average daily sunspot numbers up nearly 3 points to 120.9, and the average daily solar flux rising more than 28 points to 166.8. There was quite a bit of geomagnetic activity — the most happening on July 9 — when the mid-latitude A index reached 29, the planetary A index was 30 and Alaska’s college A index was 60. Sunspot numbers for July 5-1…
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Solar activity jumped way up this week, with the average daily sunspot numbers increasing by nearly 92 points to 118.1, while the average daily solar flux rose to 138.5 from 92.8 the week before. One new sunspot group appeared on June 29, another on July 1 and two more on July 4. Sunspot numbers for June 28-July 4 were 73, 97, 90, 137, 165, 136 and 129, with a mean of 118.1. The 10.7 cm flux wa…
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Sunspot activity continued to drop until early this week: The average daily sunspot numbers were 26.3, down more than 58 points from 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 number average 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…
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Sunspot numbers seemed to be in a free-fall this week: The average daily sunspot numbers declined more than 29 points to 87, while the average daily solar flux fell 6.2 points to 126.2. Sunspot numbers for June 14-20 were 114, 113, 110, 96, 66, 64 and 46, with a mean of 87. The 10.7 cm flux was 148.6, 144.9, 134.5, 124, 118, 109.9 and 103.7, with a mean of 126.2. The estimated planetary A indic…
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Solar activity was lower this week, although for the past few days, both the sunspot numbers and solar flux were rising. The average daily sunspot numbers declined more than 14.3 points to 116.1, while the average daily solar flux was off by 14.5 points to 115.9. There were five new sunspot groups this week: two each on June 9-10, and one more on June 13. Sunspot numbers for June 7-13 were 98, …
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The average daily sunspot numbers increased about 60 percent during the past week (May 31-June 6), when compared to the previous seven days (May 24-30). The increase was 48.5 points, from 81.9 to 130.4. The average daily solar flux was also up: 18.6 points from 111.6 to 130.2. Sunspot numbers for May 31-June 6 were 76, 151, 113, 133, 155, 154 and 131, with a mean of 130.4. The 10.7 cm flux was …
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The average daily sunspot numbers sank more than 28 points this week (nearly 26 percent) to 81.9, while the average daily solar flux declined more than 16 points to 111.6. This is for the seven days of May 24-30, and is compared to the previous seven days, May 17-23. Sunspot numbers for May 24-30 were 96, 86, 70, 83, 87, 73 and 78, with a mean of 81.9. The 10.7 cm flux was 115.5, 117.2, 110, 11…
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The average daily sunspot numbers declined seven points over the past week to 110.3, while the average daily solar flux dropped 3.3 points to 131. Sunspot numbers for May 17-23 were 114, 118, 110, 124, 120, 95 and 91, with a mean of 110.3. The 10.7 cm flux was 136.3, 132.2, 130.9, 130.8, 125.1, 121.3 and 117.2, with a mean of 127.7. The estimated planetary A indices were 6, 8, 5, 13, 7, 16 and …
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The average daily sunspot numbers for the past week rose nearly 25 points, or about 27 percent, to 117.3. The big day was Monday, May 14 when the daily sunspot number jumped to 156. This was the day after four new sunspot groups, numbered 1481 through 1484 arrived. Sunspot numbers for May 10-16 were 93, 102, 85, 138, 156, 125 and 122, with a mean of 117.3. The 10.7 cm flux was 130.7, 136.4, 129…
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The average daily solar flux for the past week rose slightly, 116.2 to 119, but the average daily sunspot numbers declined more than 14 points (about 13 percent), to 92.6. Sunspot numbers for May 3-9 were 107, 101, 88, 104, 79, 90 and 79, with a mean of 92.6. The 10.7 cm flux was 114, 114, 116, 117.3, 121.7, 122.8 and 127.3, with a mean of 119. The estimated planetary A indices were 8, 4, 4, 5,…
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The average daily sunspot numbers declined 38 points to 106.7 this week, while the average daily solar flux declined nearly 18 points to 116.2. Sunspot numbers for April 26-May 2 were 117, 99, 118, 114, 104, 99 and 96, with a mean of 106.7. The 10.7 cm flux was 119.2, 117.9, 121.1, 116, 114.1, 109.9 and 115.5, with a mean of 116.2. The estimated planetary A indices were 17, 8, 5, 5, 3, 4 and 5,…
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Solar activity revived over the past week, with a big increase in sunspot numbers. On Friday, April 20, the daily sunspot number reached 162; four days later on April 24, the number reached 169. This level of activity has not been seen since last fall, when the daily sunspot number reached 173 on September 16, 184 on October 21 and 208 on November 9.
The average daily sunspot numbers more than d…
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As promised in the April 19th edition of The ARRL Letter, this week’s bulletin features a report on recent solar activity and solar cycle progression from Carl Luetzelschwab, K9LA.
Both the solar flux and sunspot numbers reached a short term low on April 8-11, but they are now rising again. For the past week — April 12-18 — the average daily sunspot numbers more than doubled, compared to the p…
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