:Product: 0411RSGA.txt
:Issued: 2010 Apr 11 2201 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 101 Issued at 2200Z on 11 Apr 2010
IA.  Analysis of Solar Active Regions and Activity from  10/2100Z
to 11/2100Z:  Solar activity was very low. No flares occurred during
the past 24 hours. The solar disk was generally void of spots,
although there was some evidence late in the period for emerging
flux and possible new spot formation near S18E07.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low for the next three days (12-14 April).
IIA.  Geophysical Activity Summary 10/2100Z to 11/2100Z:
The geomagnetic field was initially quiet but became unsettled at
mid-latitudes and active with some isolated storm periods at high
latitudes after a sudden impulse at 1305Z (5 nT in Boulder). The
sudden impulse followed observation of a weak shock at the ACE
spacecraft at 1215Z; velocity jumped from 380 km/s to about 450
km/s, and the total magnetic field increased from 4 nT to about 10
nT. The shock was followed by moderately enhanced southward field Bz
with values ranging between -3 nT to -8 nT. The shock was most
likely a result of the halo CME that was observed on 08 April. The
greater than 2 MeV electron flux at geosynchronous orbit reached
very high levels.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet with some unsettled periods for the first day
(12 April) as the current disturbance subsides. Activity is expected
to be quiet for the second and third days (13-14 April).
III.  Event Probabilities 12 Apr-14 Apr
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           11 Apr 075
Predicted   12 Apr-14 Apr  075/075/075
90 Day Mean        11 Apr 083
V.  Geomagnetic A Indices
Observed Afr/Ap 10 Apr  003/003
Estimated Afr/Ap 11 Apr  007/010
Predicted Afr/Ap 12 Apr-14 Apr  007/007-005/005-005/005
VI.  Geomagnetic Activity Probabilities 12 Apr-14 Apr
A.  Middle Latitudes
Active                20/10/10
Minor storm           05/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                25/20/20
Minor storm           15/10/10
Major-severe storm    05/01/01