Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 April 2014

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 111 Issued at 2200Z on 21 Apr 2014

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to
21/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C5 event observed at
21/2002Z from Region 2038 (S10W20). There are currently 8 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares and a slight chance for an X-class flare on
day one (22 Apr) and expected to be low with a chance for M-class flares
on days two and three (23 Apr, 24 Apr).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed, as measured by the ACE spacecraft, reached a peak speed of
711 km/s at 20/2206Z. Total IMF reached 12 nT at 20/2126Z. The maximum
southward component of Bz reached -7 nT at 21/0030Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (22 Apr) and quiet to
unsettled levels on days two and three (23 Apr, 24 Apr). Protons greater
than 10 Mev have a slight chance of crossing threshold on day one (22
Apr).

III. Event probabilities 22 Apr-24 Apr
Class M 50/40/30
Class X 10/05/01
Proton 10/05/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 Apr 159
Predicted 22 Apr-24 Apr 160/150/150
90 Day Mean 21 Apr 156

V. Geomagnetic A Indices
Observed Afr/Ap 20 Apr 020/021
Estimated Afr/Ap 21 Apr 014/017
Predicted Afr/Ap 22 Apr-24 Apr 014/015-007/008-007/008

VI. Geomagnetic Activity Probabilities 22 Apr-24 Apr
A. Middle Latitudes
Active 30/20/20
Minor Storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/30/30
Major-severe storm 35/25/25