Viewing archive of Tuesday, 18 April 2000
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 2000 Apr 18 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 109 Issued at 2200Z on 18 APR 2000IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z SOLAR ACTIVITY WAS LOW. REGION 8963 (N16E09) RAPIDLY
EMERGED AS THE PRIMARY FLARE PRODUCING REGION ON THE VISIBLE DISK
AND WAS RESPONSIBLE FOR THE THREE LARGEST EVENTS OF THE PERIOD. THE
FIRST AND LARGEST EVENT WAS A C7/SF AT 18/0805UT, FOLLOWED BY A C4
FLARE WITH A TYPE II SWEEP AT 18/1153UT, AND FINALLY A C4/SF AT
18/1415UT. ALL EVENTS WERE ACCOMPANIED BY MINOR CENTIMETRIC BURSTS.
THIS REGION, THOUGH QUITE ACTIVE, IS A RELATIVELY SMALL DAO GROUP
WITH 80 MILLIONTHS OF WHITE LIGHT AREA. REGION 8955 (S22W19) HAS
STABILIZED, PRODUCING ONLY OCCASIONAL MINOR C-CLASS FLARES. NEW
REGION 8966 (S13E65) WAS NUMBERED TODAY. REMAINING REGIONS WERE
QUIET.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW.
REGIONS 8955 AND 8963 WILL LIKELY CONTINUE TO PRODUCE C-CLASS
ACTIVITY.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
THE GEOMAGNETIC FIELD WAS MOSTLY QUIET WITH OCCASIONAL UNSETTLED
PERIODS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO REMAIN AT QUIET TO UNSETTLED LEVELS.
III. Event Probabilities 19 APR to 21 APR
| Class M | 35% | 35% | 35% |
| Class X | 05% | 05% | 05% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 18 APR 160 Predicted 19 APR-21 APR 160/165/170 90 Day Mean 18 APR 183
V. Geomagnetic A Indices
OBSERVED AFR/AP 17 APR 011/014 ESTIMATED AFR/AP 18 APR 006/010 PREDICTED AFR/AP 19 APR-21 APR 008/012-010/015-005/008
VI. Geomagnetic Activity Probabilities 19 APR to 21 APR
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 25% | 20% |
| Minor storm | 10% | 10% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 30% | 35% | 25% |
| Minor storm | 20% | 25% | 15% |
| Major-severe storm | 05% | 05% | 01% |
All times in UTC
Latest news
Sunday, 1 February 2026
Complex sunspot region 4366
Monday, 19 January 2026
CME impact! S4 solar radiation storm
Sunday, 18 January 2026
X1.9 solar flare with earth-directed CME
Latest forum messages
AR4374 12AR4366 1014Feb 8-9 CMEs 25Space Weather Memes 793Do the high-resolution sunspot counts point to more complex sunspots? 59
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 | 2026/02/04 | X4.3 |
| Last M-flare | 2026/02/09 | M2.8 |
| Last geomagnetic storm | 2026/02/05 | Kp5+ (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| January 2026 | 112.6 -11.4 |
| February 2026 | 132.1 +19.5 |
| Last 30 days | 128.6 +27.4 |