Viewing archive of Wednesday, 19 September 2001
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 2001 Sep 19 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 262 Issued at 2200Z on 19 Sep 2001IA. Analysis of Solar Active Regions and Activity from 18-2100Z to 19-2100Z
Solar activity was low with numerous C-Class flares.
Region 9628 (S18E64) produced the largest flare of the day, a C7.5
at 19/1845 UTC. This region is the return of old Region 9591, which
produced a major flare during its last rotation. A long duration
C6.7 event occurred at 19/1607 UTC. LASCO/EIT imagery indicated a
partial halo CME originated from Region 9620 (N12E30) at 18/1531 UTC
with a plane of sky speed estimated at 332 km/s. Region 9629
(N26E38) was numbered today.
IB. Solar Activity Forecast
Solar forecast is expected to be low
to moderate. Region 9628 (S18E64), 9620 (N12E30) and 9616 (S13W24)
all have the potential to produce M-Class flares. Region 9628 also
has a slight possibility of producing a major flare.
IIA. Geophysical Activity Summary 18-2100Z to 19-2100Z
Geomagnetic activity was quiet to unsettled.
IIB. Geophysical Activity Forecast
Geomagnetic activity is
expected to be quiet to unsettled on the first day, increasing to
unsettled to active levels on the second and third day due to an
expected CME passage.
III. Event Probabilities 20 Sep to 22 Sep
| Class M | 80% | 80% | 80% |
| Class X | 10% | 10% | 10% |
| Proton | 05% | 05% | 05% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 19 Sep 199 Predicted 20 Sep-22 Sep 200/200/195 90 Day Mean 19 Sep 165
V. Geomagnetic A Indices
Observed Afr/Ap 18 Sep 007/008 Estimated Afr/Ap 19 Sep 008/008 Predicted Afr/Ap 20 Sep-22 Sep 012/010-015/015-010/012
VI. Geomagnetic Activity Probabilities 20 Sep to 22 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 35% | 25% |
| Minor storm | 10% | 20% | 15% |
| Major-severe storm | 01% | 05% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 45% | 30% |
| Minor storm | 15% | 30% | 20% |
| Major-severe storm | 01% | 10% | 04% |
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
AR4046 100Aurora photography hints for those of us with smartphones 48Large Coronal Hole 25 178Incoming & Unnumbered Active Regions 1655LASCO Data Not Updating 5
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 | 2025/03/28 | M1.7 |
| 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 |
| March 2025 | 128.3 -26.4 |
| Last 30 days | 128.3 -23.7 |