Joint USAF/NOAA Report of Solar and Geophysical Activity 22 Apr 2009

Product: Report of Solar-Geophysical Activity
Issued: 2009 Apr 22 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 112 Issued at 2200Z on 22 Apr 2009

IA. Analysis of Solar Active Regions and Activity from 21/2100Z
to 22/2100Z: Solar activity was very low. No flares were detected.
Region 1015 (N23W78) decayed to plage during the period.

IB. Solar Activity Forecast: Solar activity is expected to be very
low.

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z:
Geomagnetic field activity was at quiet levels. ACE solar wind
observations indicated a gradual velocity decrease from 427 to 378
km/sec during the period. IMF Bz was variable with a range of +4 to
-3 nT.

IIB. Geophysical Activity Forecast: Geomagnetic field activity is
expected to be at mostly quiet levels during the period (23 – 25
April).

III. Event Probabilities 23 Apr-25 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 22 Apr 071
Predicted 23 Apr-25 Apr 070/070/070
90 Day Mean 22 Apr 070

V. Geomagnetic A Indices
Observed Afr/Ap 21 Apr 003/005
Estimated Afr/Ap 22 Apr 003/005
Predicted Afr/Ap 23 Apr-25 Apr 005/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 23 Apr-25 Apr
A. Middle Latitudes
Active 05/05/05
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 10/10/10
Minor storm 01/01/01
Major-severe storm 01/01/01