Viewing archive of Sunday, 17 April 2016
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 2016 Apr 17 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 108 Issued at 2200Z on 17 Apr 2016IA. Analysis of Solar Active Regions and Activity from 16-2100Z to 17-2100Z
Solar activity has been at very low levels for the past 24
hours. There are currently 2 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be low with
a slight chance for an M-class flare on days one, two, and three (18
Apr, 19 Apr, 20 Apr).
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed reached a peak of 478 km/s at 16/2349Z. Total IMF reached 13
nT at 17/1937Z. The maximum southward component of Bz reached -5 nT at
17/0412Z. Electrons greater than 2 MeV at geosynchronous orbit reached a
peak level of 1036 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet to active levels on days one and two (18 Apr, 19 Apr) and
quiet levels on day three (20 Apr).
III. Event Probabilities 18 Apr to 20 Apr
| Class M | 15% | 15% | 15% |
| Class X | 01% | 01% | 01% |
| Proton | 05% | 05% | 05% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 17 Apr 102 Predicted 18 Apr-20 Apr 102/102/095 90 Day Mean 17 Apr 099
V. Geomagnetic A Indices
Observed Afr/Ap 16 Apr 008/012 Estimated Afr/Ap 17 Apr 015/018 Predicted Afr/Ap 18 Apr-20 Apr 012/012-010/012-007/008
VI. Geomagnetic Activity Probabilities 18 Apr to 20 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 35% | 35% | 20% |
| Minor storm | 10% | 10% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 15% |
| Minor storm | 30% | 30% | 25% |
| Major-severe storm | 45% | 45% | 25% |
All times in UTC
Latest news
Tuesday, 15 April 2025
CME arrival, G3 storm watch
Friday, 28 March 2025
X1.1 solar flare
Monday, 24 March 2025
Coronal hole faces Earth
Latest forum messages
Space Weather Memes 695Unspecified geomagnetic activity 2315AR4070 7Filaments and prominences 91Incoming & Unnumbered Active Regions 1803
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 | 2025/04/22 | M1.3 |
| Last geomagnetic storm | 2025/04/21 | Kp5+ (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| March 2025 | 134.2 -20.4 |
| April 2025 | 121 -13.2 |
| Last 30 days | 113 -27.2 |