Report of Solar-Geophysical Activity
Issued: 2009 Apr 20 2200 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 110 Issued at 2200Z on 20 Apr 2009


IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity was very low. No flares were observed.
The visible disk remains spotless.
IB. Solar Activity Forecast: Solar activity is expected to be very
low.
IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was quiet. Observations from the ACE
spacecraft indicated steady solar wind speeds throughout the period
averaging about 450 km/s.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels for 21 - 22 April due to
a recurrent enhancement in solar wind velocities. By 23 April,
mostly quiet conditions are expected.
III. Event Probabilities 21 Apr-23 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 20 Apr 070
Predicted 21 Apr-23 Apr 070/070/070
90 Day Mean 20 Apr 070
V. Geomagnetic A Indices
Observed Afr/Ap 19 Apr 004/004
Estimated Afr/Ap 20 Apr 005/005
Predicted Afr/Ap 21 Apr-23 Apr 007/008-007/007-005/005
VI. Geomagnetic Activity Probabilities 21 Apr-23 Apr
A. Middle Latitudes
Active 10/10/05
Minor storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/10/05
Minor storm 05/05/01
Major-severe storm 01/01/01
 

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