Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 19 April 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast

SDF Number 109 Issued at 2200Z on 19 Apr 2015

IA.  Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity has been at low levels for the past 24 hours. There are currently 7 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (20 Apr, 21 Apr, 22 Apr).

IIA.  Geophysical Activity Summary 18/2100Z to 19/2100Z: 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 507 km/s at 18/2131Z. Total IMF reached 5 nT at 19/2025Z. The maximum southward component of Bz reached -5 nT at 19/2028Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 6550 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (20 Apr, 21 Apr) and unsettled to minor storm levels on day three (22 Apr).

III.  Event probabilities 20 Apr-22 Apr

Class M    15/15/15

Class X    01/01/01

Proton     01/01/01

PCAF       green

IV.  Penticton 10.7 cm Flux

Observed           19 Apr 152

Predicted   20 Apr-22 Apr 150/150/145

90 Day Mean        19 Apr 130

V.  Geomagnetic A Indices

Observed Afr/Ap 18 Apr  010/012

Estimated Afr/Ap 19 Apr  009/009

Predicted Afr/Ap 20 Apr-22 Apr  010/012-012/015-020/025

VI.  Geomagnetic Activity Probabilities 20 Apr-22 Apr

A.  Middle Latitudes

Active                30/35/45

Minor Storm           05/10/25

Major-severe storm    01/01/05

B.  High Latitudes

Active                15/15/05

Minor Storm           30/30/20

Major-severe storm    35/45/65