Viewing archive of Friday, 20 April 2018
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 2018 Apr 20 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 110 Issued at 2200Z on 20 Apr 2018IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z Solar activity has been at very low levels for the past 24
hours. There are currently 1 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be very low
with a slight chance for a C-class flare on days one, two, and three (21
Apr, 22 Apr, 23 Apr).
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
The geomagnetic
field has been at quiet to major storm levels for the past 24 hours.
Solar wind speed reached a peak of 637 km/s at 20/1932Z. Total IMF
reached 23 nT at 20/0517Z. The maximum southward component of Bz reached
-19 nT at 20/0812Z. Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 2168 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (21 Apr), quiet to
unsettled levels on day two (22 Apr) and quiet levels on day three (23
Apr).
III. Event Probabilities 21 Apr to 23 Apr
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 20 Apr 073 Predicted 21 Apr-23 Apr 075/075/075 90 Day Mean 20 Apr 070
V. Geomagnetic A Indices
Observed Afr/Ap 19 Apr 002/002 Estimated Afr/Ap 20 Apr 029/048 Predicted Afr/Ap 21 Apr-23 Apr 019/025-010/010-005/005
VI. Geomagnetic Activity Probabilities 21 Apr to 23 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 35% | 30% | 10% |
| Minor storm | 25% | 10% | 01% |
| Major-severe storm | 10% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 20% | 20% |
| Minor storm | 25% | 30% | 20% |
| Major-severe storm | 55% | 35% | 10% |
All times in UTC
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