Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 March 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 76 Issued at 2200Z on 17 Mar 2013

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to
17/2100Z: 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
17/1253Z from Region 1698 (S19W72). There are currently 8 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with
a slight chance for an M-class flare on days one and two (18 Mar, 19
Mar) 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 (20 Mar).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet to major storm levels for the past 24 hours.
Solar wind speed, as measured by the ACE spacecraft, reached a peak
speed of 767 km/s at 17/1007Z. Total IMF reached 22 nT at 17/0744Z. The
maximum southward component of Bz reached -20 nT at 17/0752Z. Protons
greater than 10 MeV at geosynchronous orbit reached a peak level of 16
pfu at 17/0700Z. Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 149 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to minor storm levels on day one (18 Mar), quiet to
unsettled levels on day two (19 Mar) and quiet levels on day three (20
Mar).

III. Event probabilities 18 Mar-20 Mar
Class M 20/20/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Mar 126
Predicted 18 Mar-20 Mar 120/115/110
90 Day Mean 17 Mar 116

V. Geomagnetic A Indices
Observed Afr/Ap 16 Mar 008/010
Estimated Afr/Ap 17 Mar 029/046
Predicted Afr/Ap 18 Mar-20 Mar 018/025-008/008-006/005

VI. Geomagnetic Activity Probabilities 18 Mar-20 Mar
A. Middle Latitudes
Active 35/15/05
Minor Storm 20/05/01
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 30/20/10
Major-severe storm 50/20/05