Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 50 Issued at 2200Z on 19 Feb 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 C2 event observed at
19/1051Z from Region 1678 (N10W40). There are currently 7 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is likely to be moderate
with a slight chance for an X-class flare on days one, two, and three
(20 Feb, 21 Feb, 22 Feb).
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
402 km/s at 19/1610Z. Total IMF reached 8 nT at 19/0105Z. The maximum
southward component of Bz reached -6 nT at 19/1358Z.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (20 Feb), quiet to unsettled
levels on day two (21 Feb) and quiet levels on day three (22 Feb).
Protons have a slight chance of crossing threshold on days one, two, and
three (20 Feb, 21 Feb, 22 Feb).
III. Event probabilities 20 Feb-22 Feb
Class M 55/55/55
Class X 15/15/15
IV. Penticton 10.7 cm Flux
Observed 19 Feb 112
Predicted 20 Feb-22 Feb 120/120/115
90 Day Mean 19 Feb 115
V. Geomagnetic A Indices
Observed Afr/Ap 18 Feb 004/003
Estimated Afr/Ap 19 Feb 006/007
Predicted Afr/Ap 20 Feb-22 Feb 011/012-012/010-007/008
VI. Geomagnetic Activity Probabilities 20 Feb-22 Feb
A. Middle Latitudes
Minor Storm 10/10/05
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 20/30/25
Major-severe storm 15/40/20