Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 October 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 293 Issued at 2200Z on 20 Oct 2013

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 C2 event observed at
20/0840Z from Region 1868 (N23W44). There are currently 6 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 (21 Oct, 22 Oct,
23 Oct).

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 330 km/s at
20/1236Z. Electrons greater than 2 MeV at geosynchronous orbit reached a
peak level of 2723 pfu.

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

III. Event probabilities 21 Oct-23 Oct
Class M 25/25/25
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 20 Oct 133
Predicted 21 Oct-23 Oct 130/125/120
90 Day Mean 20 Oct 112

V. Geomagnetic A Indices
Observed Afr/Ap 19 Oct 003/002
Estimated Afr/Ap 20 Oct 004/004
Predicted Afr/Ap 21 Oct-23 Oct 009/010-008/008-006/005

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