Joint USAF/NOAA Report of Solar and Geophysical Activity 27 December 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Dec 27 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 361 Issued at 2200Z on 27 Dec 2011
IA. Analysis of Solar Active Regions and Activity from 26/2100Z
to 27/2100Z: Solar activity has been at low levels for the past 24
hours. Regions 1386 (S18E22) and 1387 (S21W57) both have produced
multiple C-class events, with the largest being a C8/1f at 27/0422Z
from Region 1386. Associated with this event, was a non Earth
directed CME. Both Regions continue to grow and evolve as they
rotate across the disk. Region 1388 (S23E67) was numbered early in
the period as it rotated onto the east limb.
IB. Solar Activity Forecast: Solar activity is expected to be at
moderate levels for the next three days (28 – 30 December).
IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field has been at quiet levels for the past 24 hours.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to active levels with isolated periods of
minor storm levels on days one and two (28 – 29 December) with
multiple CME arrivals expected. A decrease in activity is expected
on day three (30 December) as CME effects wane.
III. Event Probabilities 28 Dec-30 Dec
Class M 70/70/70
Class X 01/01/01
Proton 10/10/10
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 27 Dec 140
Predicted 28 Dec-30 Dec 140/140/140
90 Day Mean 27 Dec 144
V. Geomagnetic A Indices
Observed Afr/Ap 26 Dec 002/000
Estimated Afr/Ap 27 Dec 000/000
Predicted Afr/Ap 28 Dec-30 Dec 012/018-014/022-011/010
VI. Geomagnetic Activity Probabilities 28 Dec-30 Dec
A. Middle Latitudes
Active 20/25/15
Minor storm 05/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 20/15/15
Minor storm 25/30/20
Major-severe storm 20/40/20