Viewing archive of Friday, 17 December 1999
Geophysical 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.
Solar and Geophysical Activity Summary 1999 Dec 17 0245 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Solar and Geophysical Activity Summary
SGAS Number 351 Issued at 0245Z on 17 DEC 1999 This report is compiled from data received at SWO on 16 DECA. Energetic Events
Begin Max End Rgn Loc Xray Op 245MHz 10cm Sweep 0301 0302 0305 180 0308 0308 0308 190 0450 0452 0452 340 0651 0651 0653 260 0703 0703 0703 230 0736 0737 0745 2800 140 II 1048 1049 1049 270 1913 1914 1914 310 1952 1953 1953 330 2010 2015 2019 C3.5 3200 27
B. Proton Events
None.
C. Geomagnetic Activity Summary
THE GEOMAGNETIC FIELD WAS QUIET
THROUGHOUT THE PERIOD.
D. Stratwarm
None.
E. Daily Indices: (real-time preliminary/estimated values)
10 CM 194 SSN 146 AFR/AP 005/005 X-RAY BACKGROUND C1.0 DAILY PROTON FLUENCE (FLUX ACCUMULATION OVER 24 HRS) GT 1 MEV 4.9E+04 GT 10 MEV 1.2E+04 P/(CM2-STER-DAY) (GOES-8 SATELLITE SYNCHRONOUS ORBIT W75 DEGREES) DAILY ELECTRON FLUENCE GT 2 MEV 2.70E+05 E/(CM2-STER-DAY) (GOES-8 SATELLITE SYNCHRONOUS ORBIT W75 DEGREES) 3 HOUR K-INDICES: BOULDER 2 1 2 1 2 2 2 2 PLANETARY 1 1 2 1 1 2 2 2
F. Comments
None.
All times in UTC
Latest news
Monday, 19 January 2026
CME impact! S4 solar radiation storm
Sunday, 18 January 2026
X1.9 solar flare with earth-directed CME
Wednesday, 31 December 2025
Happy New Year! Celebrate with an M7.1 solar flare!
Latest forum messages
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 | 2026/01/18 | X1.9 |
| Last M-flare | 2026/01/21 | M3.4 |
| Last geomagnetic storm | 2026/01/22 | Kp5+ (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| December 2025 | 124 +32.2 |
| January 2026 | 119.1 -4.9 |
| Last 30 days | 122 +10.9 |