Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 December 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 352 Issued at 2200Z on 18 Dec 2013

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to
18/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C4 event observed at
17/2329Z. There are currently 7 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (19 Dec, 20 Dec,
21 Dec).

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed,
as measured by the ACE spacecraft, reached a peak speed of 390 km/s at
18/1444Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one, two, and three (19 Dec, 20 Dec, 21
Dec).

III. Event probabilities 19 Dec-21 Dec
Class M 30/30/30
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 Dec 156
Predicted 19 Dec-21 Dec 160/160/155
90 Day Mean 18 Dec 139

V. Geomagnetic A Indices
Observed Afr/Ap 17 Dec 003/001
Estimated Afr/Ap 18 Dec 004/004
Predicted Afr/Ap 19 Dec-21 Dec 005/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 19 Dec-21 Dec
A. Middle Latitudes
Active 05/05/05
Minor Storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 15/15/15
Major-severe storm 05/05/05