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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 291 Issued at 2200Z on 18 Oct 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 C8 event observed at
18/1526Z from Region 1861 (S07W79). There are currently 10 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 day one (19 Oct) and likely to be low
with a slight chance for an M-class flare on days two and three (20 Oct,
21 Oct).

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 421 km/s at
17/2105Z. Electrons greater than 2 MeV at geosynchronous orbit reached a
peak level of 3594 pfu.

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

III. Event probabilities 19 Oct-21 Oct
Class M 30/15/15
Class X 05/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 Oct 140
Predicted 19 Oct-21 Oct 140/130/125
90 Day Mean 18 Oct 111

V. Geomagnetic A Indices
Observed Afr/Ap 17 Oct 010/011
Estimated Afr/Ap 18 Oct 003/004
Predicted Afr/Ap 19 Oct-21 Oct 006/005-006/005-010/012

VI. Geomagnetic Activity Probabilities 19 Oct-21 Oct
A. Middle Latitudes
Active 05/05/25
Minor Storm 01/01/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 15/15/20
Major-severe storm 05/05/20