Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 September 2014

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 263 Issued at 2200Z on 20 Sep 2014

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to
20/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C1 event observed at
20/1254Z from Region 2171 (S10E53). There are currently 6 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low with a
slight chance for an M-class flare on days one, two, and three (21 Sep,
22 Sep, 23 Sep).

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: 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 586 km/s at
20/1642Z. Total IMF reached 10 nT at 19/2359Z. The maximum southward
component of Bz reached -7 nT at 20/0015Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and three (21 Sep, 23
Sep) and quiet levels on day two (22 Sep).

III. Event probabilities 21 Sep-23 Sep
Class M 20/20/20
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 20 Sep 119
Predicted 21 Sep-23 Sep 125/125/125
90 Day Mean 20 Sep 131

V. Geomagnetic A Indices
Observed Afr/Ap 19 Sep 023/022
Estimated Afr/Ap 20 Sep 005/006
Predicted Afr/Ap 21 Sep-23 Sep 008/008-006/005-007/008

VI. Geomagnetic Activity Probabilities 21 Sep-23 Sep
A. Middle Latitudes
Active 20/10/20
Minor Storm 05/01/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/20/25
Major-severe storm 30/10/30