Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 12 December 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 346 Issued at 2200Z on 12 Dec 2013

IA. Analysis of Solar Active Regions and Activity from 11/2100Z to
12/2100Z: 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
12/0336Z from Region 1912 (S21W66). There are currently 10 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 (13 Dec, 14 Dec,
15 Dec).

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: 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 336 km/s at
11/2114Z. Electrons greater than 2 MeV at geosynchronous orbit reached a
peak level of 104 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to minor storm levels on days one and two (13 Dec, 14
Dec) and quiet to active levels on day three (15 Dec).

III. Event probabilities 13 Dec-15 Dec
Class M 30/30/30
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 12 Dec 165
Predicted 13 Dec-15 Dec 165/160/160
90 Day Mean 12 Dec 135

V. Geomagnetic A Indices
Observed Afr/Ap 11 Dec 002/001
Estimated Afr/Ap 12 Dec 003/004
Predicted Afr/Ap 13 Dec-15 Dec 010/012-018/020-013/015

VI. Geomagnetic Activity Probabilities 13 Dec-15 Dec
A. Middle Latitudes
Active 35/40/30
Minor Storm 20/20/10
Major-severe storm 05/05/01
B. High Latitudes
Active 10/10/15
Minor Storm 25/25/30
Major-severe storm 50/60/40