Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 February 2013


Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 54 Issued at 2200Z on 23 Feb 2013

IA. Analysis of Solar Active Regions and Activity from 22/2100Z to
23/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C4 event observed at
23/1609Z from Region 1678 (N08W93). There are currently 4 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be very low
with a chance for a C-class flares on days one, two, and three (24 Feb,
25 Feb, 26 Feb).

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: 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
432 km/s at 23/1450Z. Total IMF reached 6 nT at 23/1449Z. The maximum
southward component of Bz reached -6 nT at 23/1449Z.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (24 Feb) and quiet levels
on days two and three (25 Feb, 26 Feb).

III. Event probabilities 24 Feb-26 Feb
Class M 05/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 23 Feb 100
Predicted 24 Feb-26 Feb 100/095/100
90 Day Mean 23 Feb 115

V. Geomagnetic A Indices
Observed Afr/Ap 22 Feb 009/008
Estimated Afr/Ap 23 Feb 006/009
Predicted Afr/Ap 24 Feb-26 Feb 007/008-005/005-004/005

VI. Geomagnetic Activity Probabilities 24 Feb-26 Feb
A. Middle Latitudes
Active 15/10/10
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/15/15
Major-severe storm 20/10/10

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