Report of Solar and Geophysical Activity
SDF Number 231 Issued at 2200Z on 18 Aug 2008

IA. Analysis of Solar Active Regions and Activity from 17/2100Z
to 18/2100Z: Solar activity was very low. No flares were observed in
the past 24 hours and the solar disk continues to be spotless.
IB. Solar Activity Forecast: Solar activity is expected to be very
low.
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was initially quiet to unsettled until about
0600Z when conditions became disturbed due to the onset of a high
speed stream from a coronal hole. Activity levels were at active to
minor storm levels for the remainder of the period.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be mostly unsettled to active on day one (19 August),
due to the persistent effects from the high speed stream. Quiet to
unsettled levels are expected on day two (20 August), and quiet
levels on day three (21 August).
III. Event Probabilities 19 Aug-21 Aug
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 18 Aug 066
Predicted 19 Aug-21 Aug 066/066/066
90 Day Mean 18 Aug 066
V. Geomagnetic A Indices
Observed Afr/Ap 17 Aug 005/007
Estimated Afr/Ap 18 Aug 015/015
Predicted Afr/Ap 19 Aug-21 Aug 012/015-007/010-005/005
VI. Geomagnetic Activity Probabilities 19 Aug-21 Aug
A. Middle Latitudes
Active 35/10/05
Minor storm 10/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 50/15/05
Minor storm 15/05/01
Major-severe storm 01/01/01
 

NOAA Space Weather Scale descriptions can be found at www.sec.noaa.gov/NOAAscales