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  ZENITH

 
Solar Terrestrial Activity Report    March 15 — March 22
  Solar Terrestrial Activity Report    March 22 — March 29
 
Solar Terrestrial Activity Report    March 29 — April 5
  Solar Terrestrial Activity Report    April 5 — April 12
 
Solar Terrestrial Activity Report    April 12— April 19
  Solar Terrestrial Activity Report    April 19 — April 26
       2004 calendar
 

Solar Terrestrial Activity Report    May 3 — May 10
May 3 : The geomagnetic field is quiet on May 3. Solar wind speed ranged between 339 and 374 km/sec. A low speed stream from coronal hole CH94 arrived at ACE at 00:30 UTC on May 4.
Solar flux measured at 20h UTC on 2.8 GHz was 91.3. The planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 8.3).
Three hour interval K indices: 21222222 (planetary), 12332222 (Boulder).
The background x-ray flux is at the class A7 level.
At midnight there were 4 spotted regions on the visible disk. The solar flare activity level was low. A total of 1 C class event was recorded during the day.
Region 10601 decayed quickly and was mostly quiet. Flare: C1.0 at 13:43 UTC.
Region 10603 decayed and had only two tiny spots left at midnight, the region is likely to become spotless today.
New region 10604 emerged near the southeast limb on May 2 and was numbered the next day by SEC. The region developed slowly on May 3.
Spotted regions not numbered by NOAA/SEC:
[S398] This region emerged on May 3 in the southeast quadrant at the southeastern edge of coronal hole CH94. Polarities are intermixed and the region could become interesting if development continues. Location at midnight: S12E13.
Coronal mass ejections (CMEs)
May 1-3: No fully or partly Earth directed CME observed.
Coronal holes
Coronal hole history (since late October 2002)
Compare today's report with the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A large trans equatorial coronal hole (CH94) - the recurrent eastern part of what was CH88 during the previous rotation - was in a geoeffective position on May 1 - May 4.

Propagation
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor to fair. Propagation along long distance north-south paths is fair. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant stations tonight: Radio Vibración (Venezuela) before 02:30 UTC, then CPN Radio (Perú) with an unusually strong signal. The two other usual Peruvians, Radio Santa Rosa on 1500 and La Peruanisima on 1590 kHz had about the best signals I've ever heard from them. Several North American stations had nice signals prior to 03h UTC, at which time these stations became weaker as the current coronal hole disturbance increased its influence. WWZN 1510, WBBR 1130, CJYQ 930 and CHNS 960 were the strongest stations].

 

Solar Terrestrial Activity Report    May 10— May 17
May 10 : the geomagnetic field is quiet to unsettled on May 10. Solar wind speed ranged between 361 and 426 km/sec. A weak flow from coronal hole CH95 is arriving late in the day and is causing the geomagnetic field to become unsettled.
May 11 : Solar flux measured at 20h UTC on 2.8 GHz was 93.0. The planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.8).
Three hour interval K indices: 12212233 (planetary), 22212213 (Boulder).
The background x-ray flux is at the class A6 level.
May 12 : At midnight there is 2 spotted regions on the visible disk. The solar flare activity level is very low. No C class events are recorded during the day.
Region 10606 was quiet and stable.
May 14 : Region 10608 developed early in the day, then decayed after noon.
Coronal mass ejections (CMEs)
May 15-16 : No fully or partly Earth directed CME observed.
May 17 : A slow partial halo CME is observed in LASCO C3 following a filament eruption in the southwest quadrant. This eruption began at 03:36 UTC is observed in EIT images. The CME could reach Earth on May 13 and cause unsettled to active conditions.
Coronal holes :
A large coronal hole in the northern hemisphere is probably located too far to the north to become geoeffective.
A small coronal hole (CH95) in the northern hemisphere near the equator is in a geoeffective position.

 

Solar Terrestrial Activity Report    May 17— May 24
The geomagnetic field is quiet on May 17 - 18.
Solar wind speed is ranging between 285 and 333 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz is 118.3. The planetary A index is 4 (STAR Ap - based on the mean of three hour interval ap indices: 5.8).
Three hour interval K indices: 22112112 (planetary), 22212222 (Boulder).
The background x-ray flux is at the class B2 level.
May 19 : at midnight there is 7 spotted regions on the visible disk. The solar flare activity level is very low. No C class events are recorded during the day.
May 20 : Region 10606 decayed in the leading penumbra, however, a couple of new spots emerged just east of that penumbra.
May 21 : Region 10609 decayed further and is currently a magnetically simply structured region with the positive and negative polarity spots are separated.
May 22 : Region 10612 developed further as a weak magnetic delta formed in the northwestern part of the trailing penumbra. C flares are possible.
May 23 : Region 10613 is quiet and stable.
New region 10614 emerged in the southwest quadrant on May 16 and was numbered the next day by SEC. The region is somewhat interesting as there are three small areas of positive polarity around and near the dominant negative polarity area. C flares are possible today before the region rotate around the southwest limb..
May 24 : New region 10615 is rotating into view at the northeast limb and is numbered the day after by SEC.
May 25 : New region 10616 is emerging near the northeast limb.
Coronal mass ejections (CMEs)
May 26 : No fully or partly Earth directed CME are observed.
Coronal holes : A small, recurrent coronal hole (CH96) in the southern hemisphere will likely rotate into a geoeffective position on May 22.

 

Solar Terrestrial Activity Report    May 24— May 31
May 24 : the geomagnetic field is quiet to unsettled on May 25. Solar wind speed is ranging between 443 and 505 km/sec under the influence of a high speed stream from coronal hole CH97.
Solar flux measured at 20h UTC on 2.8 GHz is 104.0. The planetary A index is 12 (STAR Ap - based on the mean of three hour interval ap indices: 12.4).
Three hour interval K indices: 33233233 (planetary), 33332433 (Boulder).
The background x-ray flux is at the class B2-B3 level.
May 26 : at midnight there is 5 spotted regions on the visible disk. The solar flare activity level is low. A total of 4 C class events is recorded during the day.
May 27 : Region 10613 decayed slowly and quietly.
Region 10615 decayed slowly and quietly.
Region 10618 developed quickly in the leading an trailing spot sections while slow decay is observed in the central section.
The large penumbra in the center split into two and no longer has a magnetic delta structure.
May 29 : A new magnetic delta structure is forming quickly in the leading spot section and could cause M class flares. Flares: C2.9 at 14:52, C2.0 at 17:42, C1.6 at 18:01 and C1.4 at 19:54 UTC.
New region 10619 is emerging in the southwest quadrant.
New region 10620 is emerging in the southeast quadrant to the southeast of region 10618.
Coronal mass ejections (CMEs)
May 30-31: No fully or partly Earth directed CME observed.
Propagations :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is good. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: none. At midnight UTC Rádio Papacasa (Brazil) was the best, however, there were at least two other stations from Brazil as well as Radio Cristal del Uruguay. The latter station had a poor signal but was the best between 00:30 and 02:30 UTC when finally Radio Vibración (Venezuela) began to dominate. On 1590.05 kHz an interesting station from Brazil was noted for a long time with mostly non stop (English) oldies. 1510 kHz had two stations from Brazil fighting for dominance, the poorest signal was from Rádio Planalto de Ibiapaba. The strongest station signed off at 01:02 UTC and only a few minutes later WWZN Boston surfaced and gradually got a fair signal. Several stations from Newfoundland (on 540, 590, 650, 740 and 930 kHz) were noted then as well, even WWBR New York on 1130 kHz was audible.

 

Solar Terrestrial Activity Report    May 31 — June 6
The geomagnetic field is quiet to unsettled on June 1. Solar wind speed ranged between 421 and 478 km/sec. Solar wind speed increased slowly after 17h UTC and another coronal hole flow is currently influencing the geomagnetic field. Active conditions are observed early on June 3.
June 4 :
Solar flux measured at 20h UTC on 2.8 GHz is 84.5. The planetary A index is 11 (STAR Ap - based on the mean of three hour interval ap indices: 11.5). Three hour interval K indices: 33133333 (planetary), 33122323 (Boulder).
The background x-ray flux is at the class A7 level. At midnight there were 3 spotted regions on the visible disk. The solar flare activity level is very low. No C class events are recorded during the day. Region 10621 decayed slowly and quietly.
New region 10626 emerged in the northeast quadrant on June 5 and is numbered the next day by SEC. The region decayed slowly on June 6 and could soon become spotless. New region 10627 emerged in the southeast quadrant and is numbered the next day by SEC. The region is mostly unchanged on June 6.
Coronal mass ejections (CMEs)
June 3-5: No fully or partly Earth directed CMEs observed. A large full halo CME is observed during the morning of June 4, its source is a few days behind the west limb.
Coronal holes :
 A recurrent trans equatorial coronal hole (CH99) is in a geoeffective position on May 31-June2. A small recurrent coronal hole (CH100) in the northern hemisphere is in a geoeffective position on June 4.
The darkest areas on the solar disk are likely coronal holes. The geomagnetic field is expected to be quiet to active on June 6-7 due to coronal hole effects and quiet to unsettled on June 8-9.
Propagations :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor to very poor. Propagation along long distance north-south paths is good to excellent. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay.  Radio Vibración (Venezuela) was noted occasionally. Good to excellent propagation towards Brazil was observed from well before local sunrise to nearly one hour after local sunrise. Rádio Inconfidência on 880 kHz had an unusually good signal with other strong stations noted on 740, 760, 840, 860, 930, 1010 kHz. Lots of frequencies had weaker signals from Brazil. Argentina was noted on a few frequencies with the Cordoba station on 700 kHz heard well. A few USA stations had weak signals on frequencies above 1600 kHz and WWZN Boston on 1510 kHz crossed the Atlantic with a fair signal.

 

Solar Terrestrial Activity Report    June 12 — June 19
Product: Geophysical Alert Message wwv.txt
Issued: 2004 Jun 11 1212 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Environment Center
# Geophysical Alert Message
#Solar-terrestrial indices for 10 June follow.
Solar flux 83 and mid-latitude A-index 9.
The mid-latitude K-index at 1200 UTC on 11 June was 3 (22nT).
No space weather storms were observed for the past 24 hours.
No space weather storms are expected for the next 24 hours.
The geomagnetic field is quiet to unsettled on June 12. Solar wind speed ranged between 392 and 528 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz is 82.5. The planetary A index is 11 (STAR Ap - based on the mean of three hour interval ap indices: 12.0).
Three hour interval K indices: 33223333 (planetary), 33212123 (Boulder).
The background x-ray flux is at the class A4 level.
June 13
At midnight there are 3 spotted regions on the visible disk. The solar flare activity level is very low. No C class events are recorded during the day.
June 14
Region 10622 is mostly unchanged and quiet.
Region 10631 developed slowly and quietly.
New region 10632 rotated into view on June 15 and is numbered the next day by SEC.
Coronal mass ejections (CMEs)
June 16 - 17: No fully or partly Earth directed CMEs observed.
A recurrent coronal hole (CH101) in the southern hemisphere will likely rotate into a geoeffective position.
Processed SOHO/EIT 284 image at 19:05 UTC on June 19. The darkest areas on the solar disk are likely coronal holes.
Forecast
The geomagnetic field is expected to be quiet to unsettled on June 18 - 19 and quiet to active on June 19 - 20 due to a high speed stream from coronal hole CH101.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation along long distance north-south paths is fair. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay and Radio Vibración (Venezuela). Propagation was best after local sunrise and then favoring signals from Uruguay, Argentina and Venezuela. The best stations were noted on 930, 950, 970, 1010, 1470 and 1590 kHz.

 

Solar Terrestrial Activity Report    June 20 — June 27
Recent activity
The geomagnetic field is quiet on June 22. Solar wind speed ranged between 310 and 348 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz is 116.7. The planetary A index is 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.8).
Three hour interval K indices: 11012221 (planetary), 11011021 (Boulder).
June 23 : the background x-ray flux is at the class B2 level.
At midnight there are 4 spotted regions on the visible disk. The solar flare activity level is low. A total of 1 C class event is recorded during the day.
June 24 : Region 10634 decayed further and has only a single large penumbra left.
Region 10635 decayed slightly in the leading spot section while some developed is observed to the west and northwest of the main trailing penumbra. There is still a chance of an M class flare. Flare: C1.7 at 22:11 UTC.
Spotted regions not numbered by NOAA/SEC:
[S420] This region was split off from region 10635 on June 23 as magnetograms suggested that this is a bipolar region by itself. June 25 : The region has many small spots. The region decayed slightly on June 20 and then developed slowly on June 21 and 22. Location at midnight: S15W21.
June 26 : [S423] A new region emerged in the southwest quadrant on June 22. Location at midnight: S14W47.
Coronal mass ejections (CMEs)
June 26-27: No LASCO images available after early on June 25. Other image sources do not indicate any significant activity during the interval.
Coronal holes :
A recurrent trans equatorial coronal hole (CH103) will rotate into a geoeffective position on June 26-27. The darkest areas on the solar disk are likely coronal holes.
Forecast
The geomagnetic field is expected to be mostly quiet on June 27-28.
Propagation : Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is good.

 

Solar Terrestrial Activity Report    June 27— July 4
The geomagnetic field is quiet to unsettled on June 28.
Solar wind speed ranged between 286 and 364 km/sec. Solar flux measured at 20h UTC on 2.8 GHz is 102.9. The planetary A index is 4 (STAR Ap - based on the mean of three hour interval ap indices: 5.3).
Three hour interval K indices: 00012231 (planetary), 11012121 (Boulder).
The background x-ray flux is at the class B2 level.
June 29
At midnight there are 3 spotted regions on the visible disk. The solar flare activity level is low. A total of 1 C class event is recorded during the day.
June 30
Region 10635 decayed further and will be rotating over the southwest limb today and tomorrow. There is still a magnetic delta structure in the main trailing penumbra. Flare: C2.5 at 11:32 UTC.
Region 10637 developed slowly and has quite a few small spots.
Spotted regions not numbered by NOAA/SEC:
[S424] A new region emerged in the northeast quadrant on July 1. Polarities are currently reversed. Location at midnight: N07E35.
Coronal mass ejections (CMEs)
June 29-July 2: Very few LASCO images available. A weak CME may have been associated with a C1 event in region 10635 on June 30.
Coronal holes :
A recurrent trans equatorial coronal hole (CH103) will rotate into a geoeffective position on June 26-27.
Processed SOHO/EIT 284 image at 13:05 UTC on July 2. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on July 3 and quiet to active on July 4 due to a high speed stream from coronal hole CH103.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is fair to good. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay and Radio Vibración (Venezuela). Many stations from Brazil were noted on other frequencies, particularly before 01:30 UTC. Fair to occasionally good signals could be heard on 1510, 1540, 1560 and 1570 kHz. The best trans Atlantic signal, without comparison, was from Rádio Sociedade (Bahia, Brazil) on 740 kHz. As usual 1510 WWZN Boston had the best signal from North America, only a few stations from Newfoundland were heard otherwise.

 
 

Solar Terrestrial Activity Report    July 6 — July 13
The geomagnetic field is quiet to unsettled on July 6. Solar wind speed ranged between 394 and 467 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz is 78.2 (the lowest solar flux since the end of the last solar minimum). The planetary A index is 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.9).
Three hour interval K indices: 21012233 (planetary), 12012222 (Boulder).
July 8 : The background x-ray flux is at the class A3 level.
At midnight there are 2 spotted regions on the visible disk. The solar flare activity level is very low. No C class events are recorded during the day.
Region 10639 decayed slowly and quietly. Region 10640 reemerged with spots. Coronal mass ejections (CMEs)
July 9 : No obviously earth directed CMEs are detected. An impressive full halo CME is observed late on July 10. Ejected material is first observed below the south pole in C3 images at 23:18 UTC and surrounded the entire disk shortly after midnight. This CME is likely to have had a backsided origin, about 7 days behind the southwest limb.
Coronal holes :
No significant coronal holes are currently approaching geoeffective positions.

Processed 284 image at 01:06 UTC on July 6. The darkest areas on the solar disk are likely coronal holes.
Forecast :
The geomagnetic field is expected to be quiet to unsettled on July 12.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is good. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. Radio Vibración was noted as well at times. Post sunrise propagation is interesting with stations from the Buenos Aires area peaking about half an hour after sunrise (Radio Chascomus on 1520 kHz was noted), then swung slightly northwards one hour after sunrise. At that time Radio Ñandutí (Asunción, Paraguay) had an amazingly good signal on 1020.1 kHz and there is another Paraguayan on 970 kHz. From North America WWZN on 1510 kHz is there again with a fair signal, otherwise Newfoundland is heard on 590 and 800 kHz.

 

Solar Terrestrial Activity Report    July 14 — July 19
The geomagnetic field is quiet to unsettled on July 14. Solar wind speed ranged between 394 and 467 km/sec.
- July 15 Solar flux measured at 20h UTC on 2.8 GHz is 78.2 (the lowest solar flux since the end of the last solar minimum).
- July 16 the planetary A index is 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.9).
Three hour interval K indices: 21012233 (planetary), 12012222 (Boulder).
The background x-ray flux is at the class A3 level.
- July 17 at midnight there are 2 spotted regions on the visible disk. The solar flare activity level is very low. No C class events are recorded during the day. Region 10639 decayed slowly and quietly. Region 10640 reemerged with spots.
Coronal mass ejections (CMEs) July 18-19 : No obviously earth directed CMEs are detected. An impressive full halo CME is observed late on July 19. Ejected material is first observed below the south pole in C3 images at 23:18 UTC and surrounded the entire disk shortly after midnight. This CME is likely to have had a backsided origin, about 7 days behind the southwest limb.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is good. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. Radio Vibración was noted as well at times. Post sunrise propagation is interesting with stations from the Buenos Aires area peaking about half an hour after sunrise (Radio Chascomus on 1520 kHz was noted), then swung slightly northwards one hour after sunrise. At that time Radio Ñandutí (Asunción, Paraguay) had an amazingly good signal on 1020.1 kHz and there is another Paraguayan on 970 kHz. From North America WWZN on 1510 kHz is there again with a fair signal, otherwise Newfoundland is heard on 590 and 800 kHz.

 

Solar Terrestrial Activity Report    July 19— July 26
The geomagnetic field is quiet to unsettled on July 19. Solar wind speed ranged between 350 and 464 km/sec.
- July 21 Solar flux measured at 19h UTC on 2.8 GHz is 84.6 (the lowest solar flux since the end of the last solar minimum).
- July 23 the planetary A index is 5 (STAR Ap - based on the mean of three hour interval ap indices: 7).
Three hour interval K indices: 21012236 (planetary), 12012228 (Boulder).
The background x-ray flux is at the class A3 level.
- July 25 at midnight there are 2 spotted regions on the visible disk. The solar flare activity level is very low. No C class events are recorded during the day. Region 10572 decayed slowly and quietly. Region 10663 reemerged with spots.
Coronal mass ejections (CMEs) July 23 : No obviously earth directed CMEs are detected. An impressive full halo CME is observed late on July 24. Ejected material is first observed below the south pole in C3 images at 23:01 UTC and surrounded the entire disk shortly after midnight. This CME is likely to have had a backsided origin, about 6 days behind the southwest limb.
Propagation :
Long distance low and medium frequency (below 2,4 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is good. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. Radio Vibración was noted as well at times. Post sunrise propagation is interesting with stations from the Buenos Aires area peaking about half an hour after sunrise (Radio Chascomus on 1520 kHz was noted), then swung slightly northwards one hour after sunrise. At that time Radio Ñandutí (Asunción, Paraguay) had an amazingly good signal on 1020.1 kHz and there is another Paraguayan on 970 kHz. From North America WWZN on 1510 kHz is there again with a fair signal, otherwise Newfoundland is heard on 590 and 800 kHz.
No significant coronal holes are currently approaching geoeffective positions.

 

Solar Terrestrial Activity Report    July 27 — August 3
Space Weather Message Code: ALTK08
Serial Number: 9
Issue Time: 2004 Jul 27 1118 UTC
Geomagnetic K-index of 8
Threshold Reached: 2004 Jul 27 1108 UTC
Synoptic Period: 0900-1200 UTC
Active Warning: Yes
The northern most extensions of a coronal hole (CH106) in the southern hemisphere could cause a weak disturbance on July 28.
The geomagnetic field is expected to be minor to very severe storm on July 27, unsettled to major storm on July 28 and quiet to active on July 29-30.
The geomagnetic field is quiet to major storm on July 31. Solar wind speed ranged between 551 and 931 km/sec. A very strong solar wind shock will be observed at 22:28 UTC, solar wind speed increased suddenly from 580 to 930 km/sec. This is the arrival of the large CME associated with the long duration M1 proton event observed between regions 10652 and 10653 on August 1. The transit time for the CME is only 31 hours. Early on August 2 solar wind speed is just above 1000 km/sec. The planetary A index for the 00-03h UTC interval is 184.
Solar flux measured at 20h UTC on 2.8 GHz is 128.0. The planetary A index is 31 (STAR Ap - based on the mean of three hour interval ap indices: 32.5).
Three hour interval K indices: 64333236 (planetary), 64332236 (Boulder).
The background x-ray flux is at the class B6 level.
At midnight there is 3 spotted regions on the visible disk. The solar flare activity level is moderate. A total of 7 C and 3 M class events are recorded during the day.
August 3 : Region 10652 decayed quickly losing penumbra and spots. There is still a chance of another major flare, however, the region is becoming significantly less complex over the last two days. Flares: C1.9 at 02:43, M1.3 at 05:52, C1.5 at 08:10, C2.9 at 09:05, C2.5 at 10:29, C4.7 at 16:59, M1.1/2N at 17:30, C1.0 at 22:07, C1.8 at 22:51, M1.2/1F at 00:00 UTC.
Region 10653 lost some penumbra around the main spot, however, a new penumbra emerged further south.
Region 10654 developed further and may produce C flares.
Coronal mass ejections (CMEs)
July 29 : No obvious Earth directed CMEs observed.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is useless. Propagation along long distance north-south paths is fair. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. On other frequencies a number of interesting stations from Brazil could be heard, i.e. an unidentified station on 1520 kHz with religious programming had a fair signal. No signs of any stations from North America.

 

Solar Terrestrial Activity Report    August 8 — August 15
The geomagnetic field is quiet to minor storm on August 8. Solar wind speed ranged between 323 and 510 km/sec under the influence of a low to medium high speed stream from coronal hole CH107.
August 9 : Solar flux measured at 20h UTC on 2.8 GHz is 94.6. The planetary A index is 20 (STAR Ap - based on the mean of three hour interval ap indices: 21.1).
Three hour interval K indices: 33544323 (planetary), 33544222 (Boulder).
The background x-ray flux is at the class B1 level.
August 10 : at midnight there are 4 spotted regions on the visible disk. The solar flare activity level is very low. No C class events are recorded during the day.
August 11 : Region 10655 decayed further with no trailing spots having penumbra, quite a few small spots disappeared.
August 12 :
Region 10656 developed slowly adding penumbra to a few trailing spots.
August 13 : Region 10657 is quiet and stable.
New region 10658 emerged early in the day to the northwest of region 10656. Penumbra is visible on a single spot, then the region decayed and only a single tiny spot is visible at the end of the day.
Coronal mass ejections (CMEs)
August 14 : No obviously Earth directed CMEs are detected
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is poor to fair. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant stations tonight: Radio Vibración (Venezuela) and Radio Cristal del Uruguay. Some stations from Brazil were noted before local sunrise with the most interesting signal from Floresta AM on 1590 kHz. Only a few stations from North America could be heard, WWZN Boston on 1510 kHz had a fair and stable signal for a long time.

 

Solar Terrestrial Activity Report    September 1 — September 8
The geomagnetic field is unsettled to major storm on September 1. Solar wind speed ranged between 363 and 548 km/sec under the influence of a high speed stream from coronal hole CH111.
September 2, Solar flux measured at 20h UTC on 2.8 GHz is 88.1. The planetary A index is 28 (STAR Ap - based on the mean of three hour interval ap indices: 28.5). Three hour interval K indices: 64543343 (planetary), 64443433 (Boulder).
September 4, The background x-ray flux is at the class B2 level.
At midnight the visible disk is spotless. The solar flare activity level is moderate. A total of 1 M class event is recorded during the day. Region 10663 rotated out of view at the northwest limb. Flares: M1.4 at 05:38 UTC. A weak type II radio sweep is associated with this event, as is a small CME off the central west limb.
Coronal mass ejections (CMEs)
August 29-31: No obviously Earth directed CMEs were observed.
Coronal holes :
A poorly defined coronal hole (CH111) in the northern hemisphere is in a geoeffective position on september 5-6.
Propagation, Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation along long distance north-south paths is poor to occasionally fair. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay with a very weak signal. Radio Vibración (Venezuela) and an unidentified station from Brazil were noted at times. On other frequencies some Brazilian stations are heard with Rádio Marajoara on 1130, Rádio Cristal on 1350 and Rádio Metropolitana on 930 kHz having the best signals. From the Caribbean both WDHP on 1620 and Harbour Light on 1400 kHz had weak signals. At local sunrise on september 7, several stations from Argentina and Paraguay had fair signals.
Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.

 

Solar Terrestrial Activity Report    September 10 — September 17
The geomagnetic field is quiet on September 10. Solar wind speed ranged between 345 and 358 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz is 131.0. The planetary A index is 4 (STAR Ap - based on the mean of three hour interval ap indices: 5.8).
September 12 : Three hour interval K indices: 11012122 (planetary), 12122122 (Boulder).
The background x-ray flux is at the class B5 level.
At midnight there are 4 spotted regions on the visible disk. The solar flare activity level is low. A total of 3 C class events is recorded during the day.
September 13
Region 10667 decayed very slowly and is quiet.
Region 10669 developed early in the day, then began to decay.
Region 10671 developed quickly during the first half of the day, since then some decay has been observed in the intermediate spots.
September 15 : There is currently a magnetic delta structure in the southern part of the large trailing penumbra. Flare: C2.6 at 06:29 UTC. New region 10672 rotated into view at the northeast limb. It is not yet clear if the southernmost penumbra should be split into a separate region, magnetograms currently indicate that the two parts of the region are not connected, neither in the positive nor in the negative polarity areas.
September 16 : The southern penumbra is the most active and the corona above it is hot. C class flaring with associated coronal mass ejections is likely. Flares: long duration C3.2 peaking at 06:01 and C1.0 at 22:16 UTC.
Coronal mass ejections (CMEs)
September 17 : No obviously Earth directed CMEs are observed. A full halo CME is observed after the C2 event behind the northeast limb on September 18. A CME is observed above the central east limb after the C3 event.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is good. Propagation along long distance north-south paths is very poor. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: WLAM Lewiston ME. Apart from a few stations from the Caribbean, a large number of North American stations dominated most of the other 10 kHz spaced frequencies in the MW band. WBBR 1130 had an impressive S9+20dB signal with several other stations topping S9. Greenland on 650 kHz had a strong signal as well.

 

Solar Terrestrial Activity Report    September 20 — September 27
The geomagnetic field is quiet to active on September 20. Solar wind speed ranged between 542 and 677 km/sec, first under the lingering effects of the CME observed on September 21-22, then under the influence of a high speed stream from coronal hole CH113. September 23 : Solar flux measured at 20h UTC on 2.8 GHz is 109.6. The planetary A index is 14 (STAR Ap - based on the mean of three hour interval ap indices: 15.3). Three hour interval K indices: 43233332 (planetary), 43122312 (Boulder). The background x-ray flux is at the class B3 level. September 24 : At midnight there are 3 spotted regions on the visible disk. The solar flare activity level is low. A total of 4 C class events is recorded during the day. A C1.3 long duration event peaking at 20:55 UTC had its origin behind the southwest limb. Region 10672 developed new spots to the immediate north and northeast of the leading penumbrae early in the day. Then the region began to decay and lost penumbra and spots, particularly in the trailing spot section. M class flares are possible. Flares: C2.7 at 07:49, C1.1 at 17:13, C1.1 at 17:51 UTC. September 25 : New region 10673 rotated fully into view at the southeast limb. The region doesn't appear to be complex spotwise, however, magnetograms hint at some complexity and the region is probably capable of C class flaring. Spotted regions not numbered by NOAA/SEC: [S453] This unipolar region emerged on September 15 in the northeast quadrant with a single, small spot. Coronal mass ejections (CMEs)
September 26-27: No obviously Earth directed CMEs are observed.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela). On other frequencies Puerto Rico was noted on 580, 1600 and 1660 kHz while the most usual stations from Newfoundland and Nova Scotia had fair signals as early as 23:30 UTC.

 

Solar Terrestrial Activity Report    September 28 — October 5
The geomagnetic field is quiet to slightly unsettled on September 28. Solar wind speed ranged between 357 and 385 km/sec. Solar flux measured at 20h UTC on 2.8 GHz is 89.5. The planetary A index is 5 (STAR Ap - based on the mean of three hour interval ap indices: 6.1). Three hour interval K indices: 01022322 (planetary), 10033211 (Boulder).
September 29 : The background x-ray flux is at the class A5 level. September 30 : at midnight there are 2 spotted regions on the visible disk. The solar flare activity level is very low. No C class events are recorded during the day
October 1 : region 10673 is quiet and stable. New region 10675 rotated into view at the southeast limb.
Coronal holes : No obvious coronal holes are currently approaching geoeffective positions. There is a large, mostly poorly defined coronal hole in the northern hemisphere, however, its southward extension does not appear to reach far enough south to become geoeffective.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair to poor at night and fair during local sunrise. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela). Several stations from the Canadian Atlantic provinces and the US northeast were observed throughout the MW band with poor to fair signals. The best signals were from CJYQ on 930 and VOCM on 590 kHz.

 

Solar Terrestrial Activity Report    October 9 — October 16
The geomagnetic field is quiet to unsettled on October 8 - 9. Solar wind speed ranged between 275 and 362 km/sec, slowly increasing early in the day due to a low speed stream from coronal hole CH117.
October 10 : Solar flux measured at 20h UTC on 2.8 GHz is 90.7. The planetary A index is 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.6). Three hour interval K indices: 13212213 (planetary), 02213322 (Boulder).
October 12 : The background x-ray flux is at the class B1 level.
At midnight there is 1 spotted region on the visible disk. The solar flare activity level is very low. No C class events is recorded during the day.
October 13 : New region 10680 is numbered as SEC did not consider the emerging flux areas part of region 10678. The region developed fairly quickly and has little or no separation between the opposite polarity fields. The region is rotating over the northwest limb.
Coronal mass ejections (CMEs)
October 14 - 15 : No obviously Earth directed CMEs observed. A trans equatorial coronal hole (CH117) is in a geoeffective position on October 3-4. A recurrent coronal hole (CH118) in the southern hemisphere is in a geoeffective position on October 14.
A southward (poorly defined) extension of the large northern polar coronal hole may would be in a geoeffective position on October 15. The geomagnetic field is expected to be quiet to unsettled on October 16 due to minor effects from coronal hole CH117. Quiet is likely on October 17 with unsettled to active conditions possible on October 18 - 19 due to a coronal flow from coronal hole CH118.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair to good. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant station tonight: WLAM Lewiston ME. On other frequencies propagation is best towards the northeastern part of the USA and the Canadian Atlantic provinces. Some stations from the Caribbean are noted as well.

 
 

Solar Terrestrial Activity Report    October 19 — October 26
The geomagnetic field is inactive to quiet on October 19. Solar wind speed ranged between 285 and 332 km/sec.
A low speed coronal hole (origin in coronal hole CH119) begin around noon and causes a significant increase in auroral activity while other geomagnetic effects are minor. Early on October 20 the stream appears to have peaked.
Solar flux measured at 20h UTC on 2.8 GHz is 96.2. The planetary A index is 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.6).
October 21 : Three hour interval K indices: 00011222 (planetary), 01012311 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight there are 6 spotted regions on the visible solar disk. The solar flare activity level is very low. No C class events are recorded during the day.
October 22 : Region 10682 decayed further losing spots and penumbral area.
Region 10683 decayed quickly and could become spotless within a couple of days if the current rate of decay persists.
Region 10684 developed small trailing spots while the leading penumbra is mostly unchanged.
October 23 : New region 10685 emerges in the southeast quadrant on October 17 and is numbered by SEC the following day. The region developed on October 18 adding penumbra to both polarities and several spots.
October 24 : New region 10686 rotates emerged near the southeast limb on October 16 and is noticed by SEC two days later. The region is decaying and could soon become spotless.
Spotted regions not numbered by NOAA/SEC.
October 25 : [S464] A new bipolar region emerges immediately to the west of region 10682 on October 18. Some interaction with region 10682 is possible if the region develops further. Location at midnight: S12W08.
Coronal holes :
A recurrent coronal hole (CH120) in the northern hemisphere will move into a geoeffective position on October 19-20.
Forecast :
The geomagnetic field is expected to be quiet on October 19 slightly influenced by a very weak coronal hole stream and inactive to quiet on October 20-22. A recurrent high speed coronal hole stream (from coronal hole CH120) will likely reach Earth on October 23 and cause unsettled to active conditions during the latter half of that day and on October 24-25.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant stations tonight: Radio Vibración (Venezuela) and WLAM Lewiston ME, both with fairly weak signals. On other frequencies propagation was best towards Colombia, the Canadian Atlantic provinces, Greenland (good signals on 570 and 650 kHz), the northeastern coastal parts of the USA. The Newfoundland stations on 740 and 930 kHz had S9 signals.

 

Solar Terrestrial Activity Report    October 27 — November 3
The geomagnetic field is quiet to active on October 27. Solar wind speed ranged between 418 and 509 km/sec under the influence of a high speed stream from coronal hole CH120. This coronal hole flow becomes less influential during the latter half of the day.
October 29 : Solar flux measured at 17h UTC on 2.8 GHz is 139.6. The planetary A index is 13 (STAR Ap - based on the mean of three hour interval ap indices: 12.6).
October 30 : Three hour interval K indices: 23343221 (planetary), 23343321 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there are 7 spotted regions on the visible solar disk. The solar flare activity level is low. A total of 9 C class events is recorded during the day.
November 1 : Region 10684 decayed further and lost nearly all trailing spots.
Region 10687 decayed significantly, particularly in the leading and central spot sections.
November 2 : A minor M class flare is possible. Flares: C2.4 at 07:16, C2.3 at 10:07, C6.8 at 10:31, C2.1 at 14:17, C4.4 at 14:42, C2.4 at 22.17 and C2.0 at 23:03 UTC.
Region 10689 was quiet and stable.
Region 10690 was quiet and stable.
Region 10691 decayed in the trailing spot section and lost its magnetic delta structure. Flare: C4.2 at 02:52 UTC.
Region 10692 decayed somewhat as the opposite polarity areas becomes better separated.
Spotted regions not numbered by NOAA/SEC:
[S466] This region emerged on October 25 in the northeast quadrant. Location at midnight: N16E62.
Coronal mass ejections (CMEs)
November 2-3 : No obviously Earth directed CMEs observed.

Coronal holes : A coronal hole (CH121) in the southern hemisphere is in a geoeffective position on October 28-29.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair to poor and improving. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela) and Radio Cristal del Uruguay at 01h UTC, later on WLAM Lewiston ME was noted as well. On other frequencies propagation was best towards the easternmost parts of the USA and Canada.
October 11 - 12 :
An extremely rare event has been produced, the sun did not has the least sunspot on surface (Wolf number = zero).
specialists in NASA, think that the descent of the cycle should much faster than be envisaged. It seems to them that the minimum would be at the end of 2006 and the next maximum in 2010.
Source: CDXC

  Solar Terrestrial Activity Report    November 4 - November 10
The geomagnetic field is inactive to quiet on November 4. Solar wind speed ranged between 332 and 358 km/sec. What is likely the early part of the low speed stream from coronal hole CH122 is observed at ACE at 18h UTC. The interplanetary magnetic field is mostly northwards afterwards and no significant effects on the geomagnetic field is observed.
November 5 : Solar flux measured at 20h UTC on 2.8 GHz is 133.1. The planetary A index is 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.5).
November 6 : Three hour interval K indices: 10021221 (planetary), 10122321 (Boulder). The background x-ray flux is at the class B6 level. At midnight there are 5 spotted regions on the visible solar disk. The solar flare activity level is low. A total of 8 C class events is recorded during the day. Region 10687 behind the northwest limb produces a C6.9 flare at 01:43 and a C2.5 long duration event peaking at 13:58 UTC. 
November 7 : Region 10690 decayed further and lost penumbra on the single spot. The region could become spotless today.
Region 10691 decayed early in the day, then developed slowly. Minor M class flares are possible. Flares: C9.8 at 09:47 and C1.2 at 19:18 UTC. (Both flares are reported by SEC as occurring in region 10689, video of the events has the location in the western part of region 10691.) An M2 flare is observed in this region early on November 8.
November 8 : Region 10693 decayed significantly in the intermediate and trailing spot sections. Flare: C1.8 at 01:21 UTC.
Region 10695 is quiet and stable. Region 10696 developed quickly and has minor M class flare potential. Flare: C1.2 at 19:18 UTC. This region is the source of a long duration M1.6 event peaking at 03:35 UTC on November 10.
Coronal mass ejections (CMEs)
November 4 : A faint full halo CME is observed in region 10691 early in the day. This CME could reach Earth on November 5, possibly late on November 6.
November 7 : No obviously Earth directed CMEs observed.
Coronal holes
A trans equatorial coronal hole (CH122) is in a geoeffective position on November 7 - 9. An extension (CH123) of the northern polar coronal hole is in a geoeffective position on November 10. A recurrent coronal hole (CH124) in the southern hemisphere will rotate to a geoeffective position on November 11.
AURORAL ALERT :
VALID BEGINNING AT: EFFECTIVE IMMEDIATELY VALID UNTIL: 23:00 UTC (6 pm EST) ON 10 NOVEMBER HIGH RISK PERIOD : 07-08, THEN 09 NOVEMBER (UTC DAYS) MODERATE RISK PERIOD: 07-10 NOVEMBER PREDICTED ACTIVITY INDICES: 30, 45, 60, 30 (07 NOVEMBER - 10 NOVEMBER) POTENTIAL MAGNITUDE OF MIDDLE LATITUDE AURORAL ACTIVITY:
MODERATE TO HIGH POTENTIAL DURATION OF THIS ACTIVITY: MAIN BELT = 12 HOURS MINOR BELT = 18 - 24 HOURS
ESTIMATED OPTIMUM OBSERVING CONDITIONS: NEAR LOCAL MIDNIGHT EXPECTED LUNAR INTERFERENCE:
LOW AFTER LOCAL MIDNIGHT OVERALL OPPORTUNITY FOR OBSERVATIONS FROM MIDDLE LATITUDES:
FAIR TO GOOD AURORAL ACTIVITY *MAY* BE OBSERVED APPROXIMATELY NORTH OF A LINE FROM...
(THIS LINE IS VALID *ONLY* IF FAVORABLE STORM CONDITIONS OCCUR) NORTHERN OREGON TO NORTHERN UTAH TO WYOMING TO NEBRASKA TO NORTHERN MISSOURI TO ILLINOIS TO KENTUCKY TO VIRGINIA. ACTIVITY *MAY* ALSO BE OBSERVED APPROXIMATELY NORTH OF A LINE FROM...
(THIS LINE IS VALID *ONLY* IF FAVORABLE STORM CONDITIONS OCCUR) NORTHERN FRANCE TO CENTRAL GERMANY TO CENTRAL POLAND TO BELARUS TO CENTRAL RUSSIA. NEW ZEALAND AND SOUTHERN REGIONS OF AUSTRALIA MAY ALSO OBSERVE PERIODS OF ACTIVITY.
  Solar Terrestrial Activity Report    November 14 - November 21
The geomagnetic field is quiet to active on November 14. Solar wind speed ranged between 450 and 538 km/sec. A high speed stream from coronal hole CH126 arrives late in the day and ss causing unsettled to active conditions early on November 15.
November 16 : Solar flux measured at 20h UTC on 2.8 GHz is 96.4. The planetary A index is 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.5). Three hour interval K indices: 22422211 (planetary), 45454323 (Boulder).The background x-ray flux is at the class B1 level. November 17 : At midnight there are 6 spotted regions on the visible solar disk. The solar flare activity level is very low. No C class events is recorded during the day. Region 10699 decayed slightly and could become spotless today. Region 10700 developed slowly. This region and region S454 are closely spaced bipolar regions. Region 10701 decayed and is about to lose the trailing spot.
Spotted regions not numbered by NOAA/SEC:
November 18 : [S474] This region emerged quickly just east northeast of region 10700 on November 12. Further growth could cause the two regions to merge. C flares are possible. Location at midnight: N06W25. November 19 : [S475] A new region emerged fairly quickly east northeast of region 10701 on November 13 and developed slowly on November 16. Location at midnight: S13E19. November 20 : [S476] A new region emerged in the northwest quadrant on November 17. Location at midnight: N08W68.
Coronal mass ejections (CMEs)
November 21 : No obviously Earth directed CMEs observed.
Coronal holes : Recurrent coronal hole CH127 in the northern hemisphere will likely rotate into a geoeffective position on November 16-17. The geomagnetic field is expected to be quiet to active on November 19 due to a high speed stream from coronal hole CH126 and quiet to unsettled on November 20-21.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is useless. Propagation along long distance north-south paths is very poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: none, nothing heard. The only identified trans Atlantic station is Rádio Sociedade on 740 kHz. A few other frequencies had stations with very weak signals.
 
 
Solar Terrestrial Activity Report    November 24 - December 1
The geomagnetic field is quiet to active on November 24. Solar wind speed ranged between 460 and 582 km/sec, slowly decreasing after 05h UTC. Solar flux measured at 20h UTC on 2.8 GHz is 106.3. The planetary A index is 10 (STAR Ap - based on the mean of three hour interval ap indices: 10.5). November 25 : Three hour interval K indices: 14431221 (planetary), 23432121 (Boulder).
The background x-ray flux is at the class B3 level.
November 26 : At midnight there are 3 spotted regions on the visible solar disk. The solar flare activity level is low. A single C class event is recorded during the day. This is a very long duration C1.1 event peaking at 07:57 and with an origin behind the southeast limb. November 27 : Region 10701 decayed slowly and quietly and will rotate out of view at the southwest limb today.
Region 10704 decayed slowly.
November 28 : [S477] This region is first observed on November 14, then lost its spots. A single spot is becoming visible on Nov. 28. Slow development is observed on November 29. Location at midnight: S04W52.
Coronal mass ejections : (CMEs)
November 27-28: No obviously Earth directed CMEs observed.
Coronal holes :
Recurrent coronal hole CH128 in the southern hemisphere is in a geoeffective position on November 30 -December 1.
Forecast :
The geomagnetic field is expected to be quiet to unsettled on November 26-27. A high speed stream from coronal hole CH128 is likely arrive on November 28 and cause unsettled to active conditions that day becoming quiet to active on November 29-30 Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation along long distance north-south paths is poor to fair. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. Radio Vibración (Venezuela) was heard weakly at times. On other frequencies propagation was best towards Brazil with a strong signal from Rádio Metropolitana on 930 and an unidentified station with religious programming on 580 kHz. The only North American station I could hear was WWZN Boston on 1510 kHz.
 
Solar Terrestrial Activity Report    December 1 - December 8
The geomagnetic field is quiet to active on December 1. Solar wind speed ranged between 511 and 729 km/sec under the influence of a high speed stream from coronal hole CH129.
Solar flux measured at 20h UTC on 2.8 GHz is 110.6. The planetary A index is 15 (STAR Ap - based on the mean of three hour interval ap indices: 14.9).
December 2 : Three hour interval K indices: 34323333 (planetary), 34323333 (Boulder).
The background x-ray flux is at the class B2 level.
December 3 : At midnight there are 3 spotted regions on the visible solar disk. The solar flare activity level is low. A total of 2 C class events is recorded during the day.
December 4 : Region 10706 is quiet and stable. Region 10707 developed slowly with a new penumbra forming to the west of the main penumbrae. The main penumbra split into two. Flare: C1.8 at 11:02 UTC.
December 5 : Region 10708 added a couple of small spots and is otherwise unchanged. Flare: C4.8 long duration event peaking at 06:58 UTC. A fairly small CME is observed over the northeast limb after this event.
Coronal mass ejections :
December 3 - 4 : No obviously Earth directed observed.
Coronal holes :
Large and well defined recurrent trans equatorial coronal hole CH129 is in a geoeffective position on December 2. A well defined coronal hole in the southeast quadrant is probably too far to the south to become geoeffective.
The geomagnetic field is expected to quiet to unsettled on December 7.
Propagation
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation along long distance north-south paths is poor to fair. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: unidentified station from Brazil. On other frequencies stations from Brazil had the best signals. The only North American station noted was WWZN Boston on 1510 kHz.
 
Solar Terrestrial Activity Report    December 10 - December 17
The geomagnetic field is mostly quiet on December 10, a single active interval is recorded at 09-12h UTC. Solar wind speed ranged between 372 and 433 km/sec under the influence of a coronal hole flow.
Solar flux measured at 20h UTC on 2.8 GHz is 87.4. The planetary A index is 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.9).
December 11 : Three hour interval K indices: 21142221 (planetary), 21143212 (Boulder).
The background x-ray flux is at the class A4 level.
December 12 : At midnight there are 3 spotted regions on the visible solar disk. The solar flare activity level is low. A total of 1 C class event is recorded during the day.
December 13 : Region 10709 lost all spots in the trailing negative polarity area while a single tiny spot emerged in the leading positive polarity area. Region 10710 decayed and could become spotless. Flare: C1.1 at 00:12 UTC.
Spotted regions not numbered by NOAA/SEC:
[S487] A new region emerged in the northwest quadrant near the central meridian on December 14. While the single small spot in this region is the largest on the visible disk, the region currently does not appear to have much potential for development.
Coronal mass ejections :
December 13 : A full halo (asymmetrical) CME is observed. This CME is likely to impact Earth on December 14.
December 15 - 16 : No obviously Earth directed CMEs observed.
Coronal holes :
Coronal hole CH132 in the southern hemisphere may have been in a geoeffective position on December 12 -13.
An extension (CH133) of the northern polar coronal hole could reach a geoeffective position on December 14.
Forecast :
The geomagnetic field is expected to be quiet to unsettled on December 16 and quiet to major storm on December 17.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is fair to poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. A few stations from North America are noted on other frequencies: 930 CJYQ, 1130 WBBR, 1510 WWZN and the Florida stations on 1660 and 1700 kHz.
  Solar Terrestrial Activity Report    December 22- December 29
The geomagnetic field is quiet to minor storm on December 22. Solar wind speed ranged between 350 and 473 km/sec. A high speed stream from coronal hole CH134 arrived after 05h UTC.
December 23 : Solar flux measured at 20h UTC on 2.8 GHz is 101.0. The planetary A index is 12 (STAR Ap - based on the mean of three hour interval ap indices: 12.3).
December 25 : Three hour interval K indices: 21352322 (planetary), 21342312 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there are 2 spotted regions on the visible solar disk. The solar flare activity level is very low. No C class events are recorded during the day.
December 26 : Region 10713 developed slowly and could produce C class flares.
Spotted regions not numbered by NOAA/SEC: [S490] A new region emerged in the southeast quadrant just northwest of region 10713 on December 27.
Coronal mass ejections (CMEs)
December 22-24 : No obviously Earth directed CMEs observed.
Coronal hole :
A recurrent coronal hole (CH134) in the southern hemisphere is in a geoeffective position on December 26. A recurrent coronal hole (CH135) in the northern hemisphere will be in a geoeffective position on December 27.
The geomagnetic field is expected to be quiet to minor storm on December 22 and quiet to unsettled on December 23 due to effects from coronal hole CH134. Mostly quiet conditions are likely on December 24-25. Another coronal hole flow could arrive on December 26 and cause unsettled to minor storm conditions that day and on December 27.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela). On other frequencies propagation was best towards the Caribbean and Newfoundland. Some of the 50 kW stations in New York and Boston were audible as well. Both WDHP on 1620 and Radio Juventus Don Bosco on 1640 kHz had fair signals.
 
     2005 calendar
  Solar Terrestrial Activity Report    December 30 - January 5
The geomagnetic field is quiet to unsettled on December 30. Solar wind speed ranged between 448 and 581 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz is 96.9. The planetary A index is 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.0).
January 1 : Three hour interval K indices: 11311132 (planetary), 12311232 (Boulder).
The background x-ray flux is at the class B3 level.
January 2 : At midnight there is 1 spotted region on the visible solar disk. The solar flare activity level is very low. No C class events are recorded during the day.
Region 10713 lost penumbral area, however, the region developed quickly during the latter half of the day as new magnetic flux emerged immediately to the south of the single penumbra. A magnetic delta structure could be forming in the new area. Minor M class flares are possible. This region is the source of an impulsive C7.2/1F flare at 00:10 UTC on January 4.
Coronal mass ejections :
January 3 - 4 : No obviously Earth directed CMEs observed.
Coronal holes :
No obvious coronal holes are currently in or near geoeffective positions.
Forecast :
The geomagnetic field is expected to be quiet to unsettled on January 5. Quiet conditions are likely on December 29-31.
Propagation :
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair, occasionally fair to good. Propagation along long distance north-south paths