Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 24 April 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast

SDF Number 114 Issued at 2200Z on 24 Apr 2017

IA.  Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: 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 slight chance for a C-class flare on days one, two, and three (25 Apr, 26 Apr, 27 Apr).

IIA.  Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 798 km/s at 23/2125Z. Total IMF reached 6 nT at 24/0615Z. The maximum southward component of Bz reached -5 nT at 24/0602Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 54298 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on days one and two (25 Apr, 26 Apr) and quiet to minor storm levels on day three (27 Apr).

III.  Event probabilities 25 Apr-27 Apr

Class M    01/01/01

Class X    01/01/01

Proton     01/01/01

PCAF       green

IV.  Penticton 10.7 cm Flux

Observed           24 Apr 080

Predicted   25 Apr-27 Apr 080/080/082

90 Day Mean        24 Apr 078

V.  Geomagnetic A Indices

Observed Afr/Ap 23 Apr  024/035

Estimated Afr/Ap 24 Apr  020/028

Predicted Afr/Ap 25 Apr-27 Apr  015/020-015/020-015/018

VI.  Geomagnetic Activity Probabilities 25 Apr-27 Apr

A.  Middle Latitudes

Active                40/40/40

Minor Storm           25/25/25

Major-severe storm    01/01/01

B.  High Latitudes

Active                10/10/10

Minor Storm           25/25/25

Major-severe storm    60/60/60