:Product: 0412RSGA.txt
:Issued: 2010 Apr 12 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 102 Issued at 2200Z on 12 Apr 2010
IA.  Analysis of Solar Active Regions and Activity from  11/2100Z
to 12/2100Z:  Solar activity was very low. No flares occurred during
the past 24 hours. New Region 1062 (S18W05) was numbered today as a
small sunspot group but was beginning to decay at the end of the
period.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low for the next three days (13-15 April).
IIA.  Geophysical Activity Summary 11/2100Z to 12/2100Z:
The geomagnetic field ranged from quiet to severe storm levels during
the past 24 hours. Activity levels began the interval at unsettled
to active levels, but a strong substorm occurred between 0000-0300Z
with major to severe storm levels at many of the observatories.
Active to minor storm levels prevailed for 0300-0900Z and quiet to
unsettled levels for the remainder of the interval from 0900-2100Z.
Solar wind observations from the ACE spacecraft showed the
continuation of yesterdays disturbed flow associated with the 08
April CME. Of particular note was the northward turning of the Bz
component at 0142Z which was preceded by about 13 hours of
moderately southward Bz (-5 to -10 nT), evidently triggering the
substorm which started shortly after 0200Z. The greater than 2 MeV
electron flux at geosynchronous orbit reached high levels during the
past 24 hours.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet with periods of unsettled levels for the first
day (13 April). Quiet levels are expected to prevail for the second
and third days (14-15 April).
III.  Event Probabilities 13 Apr-15 Apr
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           12 Apr 075
Predicted   13 Apr-15 Apr  075/075/075
90 Day Mean        12 Apr 083
V.  Geomagnetic A Indices
Observed Afr/Ap 11 Apr  008/008
Estimated Afr/Ap 12 Apr  018/022
Predicted Afr/Ap 13 Apr-15 Apr  007/007-005/005-005/005
VI.  Geomagnetic Activity Probabilities 13 Apr-15 Apr
A.  Middle Latitudes
Active                20/15/15
Minor storm           10/05/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                25/20/10
Minor storm           15/10/05
Major-severe storm    05/01/01