Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 49 Issued at 2200Z on 18 Feb 2013
IA. Analysis of Solar Active Regions and Activity from 17/2100Z to
18/2100Z: 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
18/0241Z from Region 1675 (N13E04). There are currently 6 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be at low
levels on days one, two, and three (19 Feb, 20 Feb, 21 Feb) with a
chance for an M-class flare.
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: 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 373 km/s at
17/2215Z. Total IMF reached 7.7 nT at 18/1639Z. The maximum southward
component of Bz reached -6.8 nT at 18/2014Z.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels for the next three days (19 Feb, 20
Feb, 21 Feb) with a chance for active levels and a slight chance for
minor storm levels on days 2 - 3 (20 - 21 Feb).
III. Event probabilities 19 Feb-21 Feb
Class M 25/25/25
Class X 01/01/01
IV. Penticton 10.7 cm Flux
Observed 18 Feb 105
Predicted 19 Feb-21 Feb 105/100/100
90 Day Mean 18 Feb 116
V. Geomagnetic A Indices
Observed Afr/Ap 17 Feb 007/010
Estimated Afr/Ap 18 Feb 002/003
Predicted Afr/Ap 19 Feb-21 Feb 007/008-011/012-012/010
VI. Geomagnetic Activity Probabilities 19 Feb-21 Feb
A. Middle Latitudes
Minor Storm 05/10/10
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 25/20/30
Major-severe storm 30/15/40