Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 26 April 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast

SDF Number 116 Issued at 2200Z on 26 Apr 2015

IA.  Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 26/1149Z from Region 2331 (S10W59). There are currently 4 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is likely to be low on days one, two, and three (27 Apr, 28 Apr, 29 Apr).

IIA.  Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 330 km/s at 25/2211Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1343 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (27 Apr, 28 Apr) and quiet to unsettled levels on day three (29 Apr).

III.  Event probabilities 27 Apr-29 Apr

Class M    05/05/05

Class X    01/01/01

Proton     01/01/01

PCAF       green

IV.  Penticton 10.7 cm Flux

Observed           26 Apr 119

Predicted   27 Apr-29 Apr 120/120/115

90 Day Mean        26 Apr 131

V.  Geomagnetic A Indices

Observed Afr/Ap 25 Apr  002/002

Estimated Afr/Ap 26 Apr  004/004

Predicted Afr/Ap 27 Apr-29 Apr  006/005-006/005-007/008

VI.  Geomagnetic Activity Probabilities 27 Apr-29 Apr

A.  Middle Latitudes

Active                10/10/15

Minor Storm           01/01/05

Major-severe storm    01/01/01

B.  High Latitudes

Active                20/20/15

Minor Storm           20/20/25

Major-severe storm    10/10/20