Joint USAF/NOAA Report of Solar and Geophysical Activity 19 December 2009

:Product: Report of Solar-Geophysical Activity
:Issued: 2009 Dec 19 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 353 Issued at 2200Z on 19 Dec 2009
IA. Analysis of Solar Active Regions and Activity from 18/2100Z
to 19/2100Z: Solar activity was low by virtue of a single C2.9/Sf at
10/0014Z from Region 1035 (N30W56). Since this event, only B-class
x-ray activity, with some weak, low frequency radio emissions have
been observed from this region. Over the past 24 hours, the region
decayed, both in areal coverage and spot number, but retained its
beta magnetic configuration. Two new regions were numbered this
period. Region 1036 (S29W19) emerged on the disk as a 3-spot beta
group, while Region 1037 (N18E54) rotated onto the disk as a 2-spot
beta group. Both regions have been quiet and stable.
IB. Solar Activity Forecast: Solar activity is expected to be low
for the next three days. There is a slight chance for an isolated
M-class event from Region 1035.
IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z:
The geomagnetic field has been quiet.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled with a chance for isolated active
periods on day one (20 December). This activity is in response to
the expected arrival of the CME observed on 16 December. Days two
and three (21 – 22 December) will see mostly quiet conditions.
III. Event Probabilities 20 Dec-22 Dec
Class M 10/10/05
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 19 Dec 082
Predicted 20 Dec-22 Dec 082/082/080
90 Day Mean 19 Dec 074
V. Geomagnetic A Indices
Observed Afr/Ap 18 Dec 002/002
Estimated Afr/Ap 19 Dec 002/005
Predicted Afr/Ap 20 Dec-22 Dec 015/015-007/008-005/005
VI. Geomagnetic Activity Probabilities 20 Dec-22 Dec
A. Middle Latitudes
Active 45/15/05
Minor storm 15/05/01
Major-severe storm 05/01/01
B. High Latitudes
Active 50/15/05
Minor storm 20/10/01
Major-severe storm 10/01/01