Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 December 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 357 Issued at 2200Z on 23 Dec 2013

IA. Analysis of Solar Active Regions and Activity from 22/2100Z to
23/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M1 event observed at
22/2208Z from Region 1928 (S16W74). There are currently 7 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be moderate
with a slight chance for an X-class flare on days one and two (24 Dec,
25 Dec) and expected to be low with a chance for M-class flares on day
three (26 Dec).

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: 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 345 km/s at
23/1148Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on day one (24 Dec), quiet to active levels on day
two (25 Dec) and quiet to unsettled levels on day three (26 Dec).
Protons greater than 10 Mev have a slight chance of crossing threshold
on days one and two (24 Dec, 25 Dec).

III. Event probabilities 24 Dec-26 Dec
Class M 60/60/40
Class X 10/10/05
Proton 10/10/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 23 Dec 136
Predicted 24 Dec-26 Dec 135/130/125
90 Day Mean 23 Dec 141

V. Geomagnetic A Indices
Observed Afr/Ap 22 Dec 002/001
Estimated Afr/Ap 23 Dec 003/003
Predicted Afr/Ap 24 Dec-26 Dec 005/005-007/010-008/008

VI. Geomagnetic Activity Probabilities 24 Dec-26 Dec
A. Middle Latitudes
Active 05/25/20
Minor Storm 01/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 15/25/25
Major-severe storm 05/35/25