IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity was very low. 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 ranged from quiet to active levels due to a
coronal hole high speed stream. The solar wind velocity observed at
ACE reached a maximum of around 745 km/s at 20/1733Z. As of
forecast issue time, the solar wind remains elevated with values
around 670-700 km/s. The greater than 2 MeV electron flux remained
at high levels today.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be predominantly quiet to unsettled for the next three
days (21-23 December). Active conditions are possible on 21
December, with isolated minor storm period possible at high
latitudes, due to the continued influence of the high speed stream.
III. Event Probabilities 21 Dec-23 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 20 Dec 073
Predicted 21 Dec-23 Dec 072/071/070
90 Day Mean 20 Dec 071
V. Geomagnetic A Indices
Observed Afr/Ap 19 Dec 007/008
Estimated Afr/Ap 20 Dec 010/015
Predicted Afr/Ap 21 Dec-23 Dec 010/015-008/010-005/008
VI. Geomagnetic Activity Probabilities 21 Dec-23 Dec
A. Middle Latitudes
Active 30/25/15
Minor storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 35/30/20
Minor storm 15/10/05
Major-severe storm 05/05/05
 

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