Viewing archive of Thursday, 31 December 2015
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 2015 Dec 31 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 365 Issued at 2200Z on 31 Dec 2015IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z
Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C4 event observed at
30/2245Z from Region 2473 (S21W60). There are currently 1 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is likely to be low with a
slight chance for an M-class flare on days one and two (01 Jan, 02 Jan)
and expected to be very low with a chance for a C-class flares on day
three (03 Jan).
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
The geomagnetic
field has been at quiet to major storm levels for the past 24 hours.
Solar wind speed, as measured by the ACE spacecraft, reached a peak
speed of 575 km/s at 31/0537Z. Total IMF reached 17 nT at 31/1909Z. The
maximum southward component of Bz reached -16 nT at 31/1915Z. Electrons
greater than 2 MeV at geosynchronous orbit reached a peak level of 883
pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at unsettled to major storm levels on day one (01 Jan) and
unsettled to active levels on days two and three (02 Jan, 03 Jan).
Protons greater than 10 Mev have a slight chance of crossing threshold
on days one and two (01 Jan, 02 Jan).
III. Event Probabilities 01 Jan to 03 Jan
| Class M | 20% | 20% | 05% |
| Class X | 01% | 01% | 01% |
| Proton | 10% | 10% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 31 Dec 096 Predicted 01 Jan-03 Jan 095/100/100 90 Day Mean 31 Dec 109
V. Geomagnetic A Indices
Observed Afr/Ap 30 Dec 002/002 Estimated Afr/Ap 31 Dec 026/041 Predicted Afr/Ap 01 Jan-03 Jan 021/030-015/018-015/018
VI. Geomagnetic Activity Probabilities 01 Jan to 03 Jan
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 35% | 30% | 30% |
| Minor storm | 35% | 15% | 15% |
| Major-severe storm | 20% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 05% | 15% | 15% |
| Minor storm | 20% | 30% | 30% |
| Major-severe storm | 75% | 45% | 45% |
All times in UTC
Latest news
Friday, 28 March 2025
X1.1 solar flare
Monday, 24 March 2025
Coronal hole faces Earth
Saturday, 22 March 2025
Strong G3 geomagnetic storm watch for 23 March
Latest forum messages
Unspecified geomagnetic activity 2169Similar AR 3664 vs AR 4048 ??? 5AR4048 54NOAA space weather enthusiasts darhboard 4AR4046 141
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!
Space weather facts
| Last X-flare | 2025/03/28 | X1.1 |
| Last M-flare | 2025/03/31 | M1.2 |
| Last geomagnetic storm | 2025/03/27 | Kp5 (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| February 2025 | 154.6 +17.6 |
| Last 30 days | 127.7 -23.5 |