Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 September 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 261 Issued at 2200Z on 18 Sep 2013

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to
18/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3 event observed at
18/0315Z from Region 1846 (S17E62). There are currently 5 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low
with a chance for a C-class flares on days one, two, and three (19 Sep,
20 Sep, 21 Sep).

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: 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 570 km/s at
18/2019Z. Total IMF reached 10 nT at 18/1335Z. The maximum southward
component of Bz reached -5 nT at 18/1531Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (19 Sep, 20 Sep)
and quiet levels on day three (21 Sep).

III. Event probabilities 19 Sep-21 Sep
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 Sep 104
Predicted 19 Sep-21 Sep 105/105/110
90 Day Mean 18 Sep 112

V. Geomagnetic A Indices
Observed Afr/Ap 17 Sep 008/009
Estimated Afr/Ap 18 Sep 007/008
Predicted Afr/Ap 19 Sep-21 Sep 007/008-007/008-005/005

VI. Geomagnetic Activity Probabilities 19 Sep-21 Sep
A. Middle Latitudes
Active 10/10/05
Minor Storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/25/15
Major-severe storm 10/10/05