Viewing archive of Tuesday, 21 December 2004
Solar activity report
Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 2004 Dec 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 356 Issued at 2200Z on 21 Dec 2004IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity has been very low. Region 713 (S08E22)
has produced several B-class flares and retains its beta-gamma
magnetic configuration.
IB. Solar Activity Forecast
Solar activity is expected to be very
low to low. There is a chance for an isolated C-class event from
Region 713.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to unsettled with an isolated period
of active to minor storm conditions observed at 21/1200 UTC. Solar
wind data indicated a possible co-rotating interaction region
signature during this period. Solar wind speed ranged from around
350 to 490 km/s with the IMF Bz fluctuating to -14 nT.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be predominately quiet to unsettled with isolated
periods of active conditions on 22-23 December due to coronal hole
effects. Quiet to unsettled conditions are expected for 24
December.
III. Event Probabilities 22 Dec to 24 Dec
| Class M | 20% | 20% | 20% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Dec 101 Predicted 22 Dec-24 Dec 100/105/105 90 Day Mean 21 Dec 104
V. Geomagnetic A Indices
Observed Afr/Ap 20 Dec 002/004 Estimated Afr/Ap 21 Dec 008/015 Predicted Afr/Ap 22 Dec-24 Dec 015/020-010/015-010/010
VI. Geomagnetic Activity Probabilities 22 Dec to 24 Dec
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 20% | 20% |
| Minor storm | 10% | 10% | 10% |
| Major-severe storm | 05% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 30% | 30% | 25% |
| Minor storm | 20% | 15% | 15% |
| Major-severe storm | 05% | 05% | 01% |
All times in UTC
Latest news
Monday, 1 December 2025
X1.9 solar flare, Coronal hole faces Earth
Friday, 14 November 2025
X4.0 solar flare
Tuesday, 11 November 2025
X5.1 solar flare, G4 geomagnetic storm watch
Latest forum messages
AR4299 M8.1 CME 2025/12/06 64AR4294 / 4296 / 4298 349Growth of Cycle 25 975Incoming & Unnumbered Active Regions 21Changelog/Featurelog 177
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Solar activity or if there is a chance to see the aurora, but with more traffic comes higher costs to keep the servers online. If you like SpaceWeatherLive and want to support the project you can choose a subscription for an ad-free site or consider a donation. With your help we can keep SpaceWeatherLive online!
Space weather facts
| Last X-flare | 2025/12/01 | X1.9 |
| Last M-flare | 2025/12/06 | M8.1 |
| Last geomagnetic storm | 2025/12/04 | Kp5 (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| November 2025 | 91.8 -22.8 |
| December 2025 | 167.7 +75.9 |
| Last 30 days | 107.1 +13.7 |