Joint USAF/NOAA Report of Solar and Geophysical Activity 15 Apr 2009

Product: Report of Solar-Geophysical Activity
Issued: 2009 Apr 15 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 105 Issued at 2200Z on 15 Apr 2009
IA. Analysis of Solar Active Regions and Activity from 14/2100Z
to 15/2100Z: Solar activity was very low. The STEREO spacecraft
observed a CME which was possibly correlated with a small dimming on
the solar disk around sun center and just north of the equator as
observed by EIT imagery at 14/0148UT. No flares were observed
during the last 24 hours. The solar disk remains spotless.

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

IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z:
The geomagnetic field was at quiet levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet levels for 16 April. Predominately
unsettled conditions with isolated active periods are expected for
17 April due to a recurrent coronal hole high speed stream. Quiet
levels are expected to return for 18 April. Although the CME
discussed in Part IA may be observed at ACE, no significant increase
in geomagnetic activity is expected.

III. Event Probabilities 16 Apr-18 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green

IV. Penticton 10.7 cm Flux
Observed 15 Apr 069
Predicted 16 Apr-18 Apr 070/070/070
90 Day Mean 15 Apr 070

V. Geomagnetic A Indices
Observed Afr/Ap 14 Apr 001/002
Estimated Afr/Ap 15 Apr 002/003
Predicted Afr/Ap 16 Apr-18 Apr 005/005-008/010-005/005

VI. Geomagnetic Activity Probabilities 16 Apr-18 Apr
A. Middle Latitudes
Active 05/15/05
Minor storm 01/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 10/20/10
Minor storm 01/05/01
Major-severe storm 01/01/01