Viewing archive of Friday, 21 April 2017

Solar activity report

Report of Solar-Geophysical Activity 2017 Apr 21 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 111 Issued at 2200Z on 21 Apr 2017

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

Solar activity has been at very low levels for the past 24 hours. There are currently 3 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be very low with a chance for a C-class flares 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 quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 691 km/s at 21/2050Z. Total IMF reached 14 nT at 21/1613Z. The maximum southward component of Bz reached -12 nT at 21/1635Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2805 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to unsettled levels on day one (22 Apr), active to major storm levels on day two (23 Apr) and active to minor storm levels on day three (24 Apr).
III. Event Probabilities 22 Apr to 24 Apr
Class M05%05%05%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       21 Apr 082
  Predicted   22 Apr-24 Apr 082/082/082
  90 Day Mean        21 Apr 078

V. Geomagnetic A Indices
  Observed Afr/Ap 20 Apr  020/030
  Estimated     Afr/Ap 21 Apr  012/018
  Predicted    Afr/Ap 22 Apr-24 Apr  013/015-028/040-023/030

VI. Geomagnetic Activity Probabilities 22 Apr to 24 Apr
A. Middle Latitudes
Minor storm25%40%30%
Major-severe storm05%15%05%
B. High Latitudes
Minor storm25%20%20%
Major-severe storm60%75%65%

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