Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 31 Issued at 2200Z on 31 Jan 2013
IA. Analysis of Solar Active Regions and Activity from 30/2100Z to
31/2100Z: 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
31/0434Z from Region 1663 (S09W24). 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 C-class flares on days one, two, and three (01 Feb, 02
Feb, 03 Feb).
IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: 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 344 km/s at
31/2011Z. Total IMF reached 6.5 nT at 31/2045Z. The maximum southward
component of Bz reached -4.4 nT at 31/2023Z. Electrons greater than 2
MeV at geosynchronous orbit reached a peak level of 367 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (01 Feb) increasing to
unsettled to active levels on days two and three (02 Feb, 03 Feb) as a
coronal hole high speed stream becomes geoeffective and is, followed by
a glancing blow from an earth-directed CME.
III. Event probabilities 01 Feb-03 Feb
Class M 01/01/01
Class X 01/01/01
IV. Penticton 10.7 cm Flux
Observed 31 Jan 103
Predicted 01 Feb-03 Feb 100/105/105
90 Day Mean 31 Jan 119
V. Geomagnetic A Indices
Observed Afr/Ap 30 Jan 002/001
Estimated Afr/Ap 31 Jan 002/002
Predicted Afr/Ap 01 Feb-03 Feb 005/005-007/012-012/018
VI. Geomagnetic Activity Probabilities 01 Feb-03 Feb
A. Middle Latitudes
Minor Storm 01/01/10
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 15/20/25
Major-severe storm 10/10/35