Report of Solar Geophysical Activity
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 113 Issued at 2200Z on 23 Apr 2015 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 23/1007Z from Region 2322 (just beyond west limb). There are currently 8 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on days one, two, and three (24 Apr, 25 Apr, 26 Apr). IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 555 km/s at 22/2319Z. Total IMF reached 6 nT at 22/2210Z. The maximum southward component of Bz reached -4 nT at 22/2138Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 955 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be predominantly quiet to unsettled for the next three days (24-26 Apr). III. Event probabilities 24 Apr-26 Apr Class M 20/20/20 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 23 Apr 141 Predicted 24 Apr-26 Apr 135/130/125 90 Day Mean 23 Apr 131 V. Geomagnetic A Indices Observed Afr/Ap 22 Apr 009/011 Estimated Afr/Ap 23 Apr 009/010 Predicted Afr/Ap 24 Apr-26 Apr 007/008-009/012-007/008 VI. Geomagnetic Activity Probabilities 24 Apr-26 Apr A. Middle Latitudes Active 15/25/15 Minor Storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/20/15 Minor Storm 25/30/25 Major-severe storm 20/30/20 Radio Events Observed 23 Apr 2015 A. 245 MHz Bursts Start End Peak Flux Time of Peak Duration 1722 1722 110 1722 0000 B. 245 MHz Noise Storms No 245 MHz Noise Storms Observed. www.swpc.noaa.gov/phenomena/solar-radiation-storm www.sec.noaa.gov/NOAAscales
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