Viewing archive of Sunday, 23 April 2017
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 2017 Apr 23 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 113 Issued at 2200Z on 23 Apr 2017IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z
Solar activity has been at very low levels for the past 24
hours. There are currently 3 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be very low
with a chance for a C-class flares on days one, two, and three (24 Apr,
25 Apr, 26 Apr).
IIA. Geophysical Activity Summary 22-2100Z to 23-2100Z
The geomagnetic
field has been at active to major storm levels for the past 24 hours.
Solar wind speed reached a peak of 813 km/s at 23/2023Z. Total IMF
reached 9 nT at 23/0406Z. The maximum southward component of Bz reached
-7 nT at 23/0351Z. Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 20544 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at active to minor storm levels on day one (24 Apr) and unsettled
to minor storm levels on days two and three (25 Apr, 26 Apr).
III. Event Probabilities 24 Apr to 26 Apr
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 23 Apr 083 Predicted 24 Apr-26 Apr 084/084/084 90 Day Mean 23 Apr 078
V. Geomagnetic A Indices
Observed Afr/Ap 22 Apr 037/061 Estimated Afr/Ap 23 Apr 030/044 Predicted Afr/Ap 24 Apr-26 Apr 023/030-015/020-015/020
VI. Geomagnetic Activity Probabilities 24 Apr to 26 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 45% | 40% | 40% |
| Minor storm | 25% | 25% | 25% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 10% |
| Minor storm | 25% | 25% | 25% |
| Major-severe storm | 65% | 60% | 60% |
All times in UTC
Current data suggests there is a slight possibility for aurora to appear at the following high latitude regions in the near future
Rovaniemi, Sodankylä, UtsjokiReykjavik
Kirkenes, Tromsø
Murmansk
Kiruna
Latest news
Monday, 24 March 2025
Coronal hole faces Earth
Saturday, 22 March 2025
Strong G3 geomagnetic storm watch for 23 March
Wednesday, 5 March 2025
Coronal hole faces Earth
Latest forum messages
Large Coronal Hole 25 169AR4043 21Incoming & Unnumbered Active Regions 1647Aurora photography hints for those of us with smartphones 45Photographing auroras 36
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!
Latest alerts
16:15 UTC - Geomagnetic activity
Minor G1 geomagnetic storm (Kp5) Threshold Reached: 16:05 UTC
15:15 UTC - Geomagnetic activity
Minor G1 geomagnetic storm (Kp5) Threshold Reached: 14:59 UTC
09:15 UTC - Geomagnetic activity
Minor G1 geomagnetic storm (Kp5) Threshold Reached: 08:59 UTC
06:27 UTC - Hemispheric Power Index
The OVATION model predicts the Hemispheric Power Index to reach 54GW at 07:01 UTC
06:00 UTC - Geomagnetic activity
Minor G1 geomagnetic storm (Kp5) Threshold Reached: 05:51 UTC
Space weather facts
| Last X-flare | 2025/02/23 | X2.0 |
| Last M-flare | 2025/03/27 | M2.0 |
| Last geomagnetic storm | 2025/03/26 | Kp6+ (G2) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| February 2025 | 154.6 +17.6 |
| March 2025 | 132.3 -22.3 |
| Last 30 days | 131.2 -21.8 |