Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 22 May 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 142 Issued at 2200Z on 22 May 2013

IA. Analysis of Solar Active Regions and Activity from 21/2100Z to
22/2100Z: Solar activity has been at high levels for the past 24 hours.
The largest solar event of the period was a M5 event observed at
22/1332Z from Region 1745 (N13W80). There are currently 7 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
days one, two, and three (23 May, 24 May, 25 May).

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: 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
500 km/s at 22/0442Z. Total IMF reached 6 nT at 22/2005Z. The maximum
southward component of Bz reached -5 nT at 21/2357Z. Protons greater
than 10 MeV at geosynchronous orbit reached a peak level of 279 pfu at
22/2035Z. Protons greater than 100 MeV at geosynchronous orbit reached a
peak level of 3 pfu at 22/1830Z. Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 722 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to active levels on day one (23 May), quiet to
unsettled levels on day two (24 May) and quiet to active levels on day
three (25 May). Protons are expected to cross threshold on days one and
two (23 May, 24 May) and are likely to cross threshold on day three (25
May).

III. Event probabilities 23 May-25 May
Class M 50/50/50
Class X 20/20/20
Proton 99/99/70
PCAF RED

IV. Penticton 10.7 cm Flux
Observed 22 May 133
Predicted 23 May-25 May 125/125/130
90 Day Mean 22 May 122

V. Geomagnetic A Indices
Observed Afr/Ap 21 May 008/008
Estimated Afr/Ap 22 May 009/012
Predicted Afr/Ap 23 May-25 May 012/012-007/015-012/008

VI. Geomagnetic Activity Probabilities 23 May-25 May
A. Middle Latitudes
Active 30/15/30
Minor Storm 10/05/15
Major-severe storm 01/01/05
B. High Latitudes
Active 15/15/15
Minor Storm 30/25/25
Major-severe storm 40/25/45