:Product: 0421RSGA.txt
:Issued: 2006 Apr 21 2204 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Environment Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 111 Issued at 2200Z on 21 Apr 2006
IA.  Analysis of Solar Active Regions and Activity from  20/2100Z
to 21/2100Z:  Solar activity continued  very low. Region 874
(S01W25), the sole spotted region visible, was stable and quiet.
There are signs of new flux emerging in the southeast, where two
small groups are in the formative stage. The limbs were quiet.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low to low.
IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z:
The geomagnetic field was quiet to active. A period of enhanced solar
wind conditions began around midday, when Alfven waves caused Bz to
reach -10 nT for a brief period. Those fluctuations are still
occurring. The greater than 2 MeV electron flux at GOES was again at
high levels.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be predominantly quiet to unsettled for the next three
days. Solar wind wave activity may persist for the next few hours,
and there is a chance of another short-lived disturbance from
high-speed solar wind on April 23.
III.  Event Probabilities 22 Apr-24 Apr
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           21 Apr 079
Predicted   22 Apr-24 Apr  080/080/085
90 Day Mean        21 Apr 078
V.  Geomagnetic A Indices
Observed Afr/Ap 20 Apr  003/005
Estimated Afr/Ap 21 Apr  006/008
Predicted Afr/Ap 22 Apr-24 Apr  005/008-010/010-005/008
VI.  Geomagnetic Activity Probabilities 22 Apr-24 Apr
A.  Middle Latitudes
Active                15/20/15
Minor storm           01/05/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                20/20/20
Minor storm           05/10/05
Major-severe storm    01/01/01