Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 27 December 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 361 Issued at 2200Z on 27 Dec 2013

IA. Analysis of Solar Active Regions and Activity from 26/2100Z to
27/2100Z: 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
27/1213Z from Region 1936 (S16E19). 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 (28 Dec, 29 Dec,
30 Dec).

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: 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 335 km/s at
27/1908Z. Total IMF reached 9 nT at 27/1701Z. The maximum southward
component of Bz reached -4 nT at 27/1858Z. Protons greater than 10 MeV
at geosynchronous orbit reached a peak level of 2 pfu at 27/0250Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one, two, and three (28 Dec, 29 Dec, 30
Dec).

III. Event probabilities 28 Dec-30 Dec
Class M 25/25/25
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 27 Dec 131
Predicted 28 Dec-30 Dec 135/135/135
90 Day Mean 27 Dec 142

V. Geomagnetic A Indices
Observed Afr/Ap 26 Dec 002/002
Estimated Afr/Ap 27 Dec 003/005
Predicted Afr/Ap 28 Dec-30 Dec 005/005-006/005-006/005

VI. Geomagnetic Activity Probabilities 28 Dec-30 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