Joint USAF/NOAA Report of Solar and Geophysical Activity 20 December 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Dec 20 2238 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
::::::::::CORRECTED COPY::::::::::
SDF Number 354 Issued at 2200Z on 20 Dec 2011
IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity has been at low levels for the past 24
hours. Region 1376 (N19W46) produced the largest event of the
period, a C2 event at 20/2036Z. Region 1376 also has shown the most
growth in areal coverage and magnetic complexity. A new region was
numbered today, Region 1384 (N12E61), as it rotated onto the east
limb. Several CME”s were observed in LASCO C2 and C3 imagery but
none appear to have any Earth directed components.
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels for the next three days (21 – 23 December).
IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field has been at predominantly quiet levels for the
past 24 hours.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to remain at mostly quiet levels for the next three days
(21 – 23 December).
III. Event Probabilities 21 Dec-23 Dec
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 20 Dec 137
Predicted 21 Dec-23 Dec 140/140/135
90 Day Mean 20 Dec 145
V. Geomagnetic A Indices
Observed Afr/Ap 19 Dec 006/006
Estimated Afr/Ap 20 Dec 003/003
Predicted Afr/Ap 21 Dec-23 Dec 004/005-004/005-004/005
VI. Geomagnetic Activity Probabilities 21 Dec-23 Dec
A. Middle Latitudes
Active 01/01/01
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 10/10/10
Major-severe storm 05/05/05