Viewing archive of Sunday, 18 May 2025
Solar activity report
Report of Solar-Geophysical Activity 2025 May 18 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 138 Issued at 2200Z on 18 May 2025IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z Solar activity has been at low levels for the past 24 hours.
There are currently 4 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (19 May, 20 May,
21 May).
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
The geomagnetic
field has been at quiet to minor storm levels for the past 24 hours.
Solar wind speed reached a peak of 950 km/s at 18/0732Z. Total IMF
reached 12 nT at 18/0951Z. The maximum southward component of Bz reached
-8 nT at 18/1510Z. Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 1128 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (19 May) and quiet
to active levels on days two and three (20 May, 21 May).
III. Event Probabilities 19 May to 21 May
| Class M | 25% | 25% | 25% |
| Class X | 05% | 05% | 05% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 18 May 118 Predicted 19 May-21 May 120/118/118 90 Day Mean 18 May 161
V. Geomagnetic A Indices
Observed Afr/Ap 17 May 025/038 Estimated Afr/Ap 18 May 017/023 Predicted Afr/Ap 19 May-21 May 013/018-011/012-009/012
VI. Geomagnetic Activity Probabilities 19 May to 21 May
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 40% | 30% | 30% |
| Minor storm | 30% | 15% | 15% |
| Major-severe storm | 10% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 15% | 15% |
| Minor storm | 25% | 30% | 30% |
| Major-severe storm | 65% | 45% | 45% |
All times in UTC
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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 | |
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| Monthly mean Sunspot Number | |
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| Last 30 days | 128.6 +27.4 |