Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 13 December 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 347 Issued at 2200Z on 13 Dec 2013

IA. Analysis of Solar Active Regions and Activity from 12/2100Z to
13/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C5 event observed at
12/2214Z from Region 1921 (N07E23). There are currently 9 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 (14 Dec, 15 Dec,
16 Dec).

IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: 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
13/1339Z. Total IMF reached 10 nT at 13/1838Z. The maximum southward
component of Bz reached -4 nT at 13/1314Z. Electrons greater than 2 MeV
at geosynchronous orbit reached a peak level of 1091 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to minor storm levels on day one (14 Dec), quiet to
active levels on day two (15 Dec) and quiet levels on day three (16
Dec).

III. Event probabilities 14 Dec-16 Dec
Class M 30/30/30
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 13 Dec 163
Predicted 14 Dec-16 Dec 160/160/155
90 Day Mean 13 Dec 136

V. Geomagnetic A Indices
Observed Afr/Ap 12 Dec 002/002
Estimated Afr/Ap 13 Dec 005/008
Predicted Afr/Ap 14 Dec-16 Dec 018/020-013/015-005/005

VI. Geomagnetic Activity Probabilities 14 Dec-16 Dec
A. Middle Latitudes
Active 40/30/05
Minor Storm 20/10/01
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 25/30/15
Major-severe storm 60/40/05