Joint USAF/NOAA Report of Solar and Geophysical Activity 16 Apr 2009

Product: Report of Solar-Geophysical Activity
Issued: 2009 Apr 16 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 106 Issued at 2200Z on 16 Apr 2009

IA. Analysis of Solar Active Regions and Activity from 15/2100Z
to 16/2100Z: Solar activity was very low. No flares were observed
the past 24 hours. The solar disk remains spotless.

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

IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z:
The geomagnetic field was at quiet to unsettled conditions.
Observations from the ACE spacecraft reflect the influence of the
recurrent coronal hole high speed stream. Solar wind velocities
have increased from around 300 km/s to 430 km/s through the 24 hour
period.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled with a chance of isolated active
conditions for 17 April. Predominantly quiet levels are expected
for 18-19 April.

III. Event Probabilities 17 Apr-19 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green

IV. Penticton 10.7 cm Flux
Observed 16 Apr 070
Predicted 17 Apr-19 Apr 070/070/070
90 Day Mean 16 Apr 070

V. Geomagnetic A Indices
Observed Afr/Ap 15 Apr 002/003
Estimated Afr/Ap 16 Apr 005/005
Predicted Afr/Ap 17 Apr-19 Apr 007/010-005/005-005/005

VI. Geomagnetic Activity Probabilities 17 Apr-19 Apr
A. Middle Latitudes
Active 10/05/05
Minor storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 20/10/10
Minor storm 05/01/01
Major-severe storm 01/01/01