Viewing archive of Monday, 31 May 2004
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 2004 May 31 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 152 Issued at 2200Z on 31 May 2004IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z
Solar activity has been low. Region 618 (S10W83)
produced 5 C-class flares, including a C6.5/Sf at 31/0028 UTC. No
significant development was observed from any of the regions on the
visible disk, and no new regions were numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be very
low to low. Region 618 may still produce C-class flares before
disappearing tomorrow behind the west limb. Region 621 (S15E38) is
capable of C-class flares as well.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
The geomagnetic field has been quiet to active. Solar wind speed has
slowly increased over the past four days from 350 km/s to about 500
km/s, indicating the possible beginning effects of a coronal hole
high speed solar wind stream.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be unsettled to active for all three days (1-3 June),
with isolated minor storm conditions on 1 and 2 June from the
effects of the geoeffective coronal hole.
III. Event Probabilities 01 Jun to 03 Jun
| Class M | 20% | 10% | 10% |
| Class X | 05% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 31 May 095 Predicted 01 Jun-03 Jun 100/090/090 90 Day Mean 31 May 105
V. Geomagnetic A Indices
Observed Afr/Ap 30 May 011/013 Estimated Afr/Ap 31 May 015/015 Predicted Afr/Ap 01 Jun-03 Jun 015/015-015/015-012/018
VI. Geomagnetic Activity Probabilities 01 Jun to 03 Jun
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 35% | 35% | 20% |
| Minor storm | 20% | 20% | 10% |
| Major-severe storm | 05% | 05% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 40% | 40% | 40% |
| Minor storm | 30% | 25% | 20% |
| Major-severe storm | 15% | 15% | 10% |
All times in UTC
Latest news
Wednesday, 14 May 2025
Another X-flare! Potent sunspot region 4087!
Tuesday, 13 May 2025
X1.1 solar flare from sunspot region 4086
Tuesday, 15 April 2025
CME arrival, G3 storm watch
Latest forum messages
AR 14093 12Have you ever dreamed of the sun? 46Upper atmosphere phenomena Red sprites and Blue jets 24AR 14095 2Filaments and prominences 172
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 | 2025/05/14 | X2.7 |
| Last M-flare | 2025/05/21 | M1.2 |
| Last geomagnetic storm | 2025/05/17 | Kp6+ (G2) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| April 2025 | 140.6 +6.4 |
| May 2025 | 68.7 -72 |
| Last 30 days | 86.9 -26 |