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Solar activity report
Report of Solar-Geophysical Activity 2024 Apr 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 112 Issued at 2200Z on 21 Apr 2024IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z
Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M2 event observed at
21/1514Z from Region 3638 (S18W35). There are currently 17 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be moderate
with a slight chance for an X-class flare on days one, two, and three
(22 Apr, 23 Apr, 24 Apr).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic
field has been at unsettled to active levels for the past 24 hours.
Solar wind speed reached a peak of 539 km/s at 21/2029Z. Total IMF
reached 7 nT at 21/1705Z. The maximum southward component of Bz reached
-6 nT at 21/1705Z. Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 754 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet to unsettled levels on days one and three (22 Apr, 24
Apr) and quiet to active levels on day two (23 Apr). Protons have a
slight chance of crossing threshold on days one, two, and three (22 Apr,
23 Apr, 24 Apr).
III. Event Probabilities 22 Apr to 24 Apr
| Class M | 75% | 75% | 75% |
| Class X | 20% | 20% | 20% |
| Proton | 20% | 20% | 20% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Apr 217 Predicted 22 Apr-24 Apr 215/215/200 90 Day Mean 21 Apr 161
V. Geomagnetic A Indices
Observed Afr/Ap 20 Apr 010/012 Estimated Afr/Ap 21 Apr 015/019 Predicted Afr/Ap 22 Apr-24 Apr 009/010-011/015-009/010
VI. Geomagnetic Activity Probabilities 22 Apr to 24 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 25% | 25% |
| Minor storm | 05% | 15% | 05% |
| Major-severe storm | 01% | 05% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 15% |
| Minor storm | 25% | 25% | 25% |
| Major-severe storm | 30% | 45% | 30% |
All times in UTC
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Space weather facts
| Last X-flare | 2025/05/14 | X2.7 |
| Last M-flare | 2025/05/19 | M3.1 |
| Last geomagnetic storm | 2025/05/17 | Kp6+ (G2) |
| Spotless days | |
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| Monthly mean Sunspot Number | |
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