Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 19 April 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 109 Issued at 2200Z on 19 Apr 2013

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.
The largest solar event of the period was a C1 event observed at
19/1444Z. 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 and two (20 Apr, 21 Apr)
and expected to be very low with a chance for a C-class flares and a
slight chance for an M-class flare on day three (22 Apr).

IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: 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 325 km/s at
19/1948Z. Total IMF reached 5 nT at 19/2058Z. The maximum southward
component of Bz reached -2 nT at 19/1145Z. Electrons greater than 2 MeV
at geosynchronous orbit reached a peak level of 133 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one, two, and three (20 Apr, 21 Apr, 22
Apr).

III. Event probabilities 20 Apr-22 Apr
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 19 Apr 099
Predicted 20 Apr-22 Apr 100/100/095
90 Day Mean 19 Apr 111

V. Geomagnetic A Indices
Observed Afr/Ap 18 Apr 002/003
Estimated Afr/Ap 19 Apr 002/002
Predicted Afr/Ap 20 Apr-22 Apr 005/005-004/005-003/005

VI. Geomagnetic Activity Probabilities 20 Apr-22 Apr
A. Middle Latitudes
Active 10/10/10
Minor Storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 15/15/15
Major-severe storm 10/10/10