Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 22 April 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast

SDF Number 112 Issued at 2200Z on 22 Apr 2015

IA.  Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: 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 21/2145Z from Region 2322 (N11W87). There are currently 8 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on day one (23 Apr) and expected to be low with a slight chance for an M-class flare on days two and three (24 Apr, 25 Apr).

IIA.  Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 618 km/s at 21/2247Z. Total IMF reached 6 nT at 21/2223Z. The maximum southward component of Bz reached -3 nT at 22/1359Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 942 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and three (23 Apr, 25 Apr) and quiet levels on day two (24 Apr).

III.  Event probabilities 23 Apr-25 Apr

Class M    45/20/20

Class X    05/01/01

Proton     05/01/01

PCAF       green

IV.  Penticton 10.7 cm Flux

Observed           22 Apr 150

Predicted   23 Apr-25 Apr 150/145/145

90 Day Mean        22 Apr 131

V.  Geomagnetic A Indices

Observed Afr/Ap 21 Apr  018/020

Estimated Afr/Ap 22 Apr  013/018

Predicted Afr/Ap 23 Apr-25 Apr  015/015-007/008-009/012

VI.  Geomagnetic Activity Probabilities 23 Apr-25 Apr

A.  Middle Latitudes

Active                30/20/30

Minor Storm           05/05/05

Major-severe storm    01/01/01

B.  High Latitudes

Active                15/15/15

Minor Storm           30/25/30

Major-severe storm    35/25/35